JPH02304254A - Gear change control device for sub-transmission - Google Patents

Abstract

PURPOSE:To eliminate a start delay immediately after the startup of an engine by decreasing the fluid pressure rise rate of a low-speed select friction element in an automatic shift range for normal drive, and increasing the rate in a backward travel range for reverse rotation output. CONSTITUTION:In shifting a sub-transmission via the coupling of a low-speed select friction element RD/B so provided as to be in parallel to a one-way clutch, the rise rate of the coupling pressure is made small in a normal drive range (automatic shift range) with the operation of an accumulator 68. Furthermore, RD/B is coupled after releasing a high-speed select friction element DC and then the engagement of the one-way clutch, thereby restraining a gear change shock. On the other hand, the rise rate of the coupling pressure is increased at the time of the reverse rotation output (backward travel), thereby quickly coupling RD/B. According to the aforesaid construction, a start delay immediately after an engine startup and the coupling shock of the low-speed select friction element RD/B due to engine racing related to the start delay can be properly prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a shift control device for an auxiliary transmission used in a multi-stage automatic transmission. .

(Prior Art) A multi-stage automatic transmission is constructed by coupling a main transmission and a sub-transmission in tandem, and is known, for example, as described in Japanese Patent Application Laid-Open No. 113351/1983.

In this type of multi-speed automatic transmission, the sub-transmission is generally equipped with a direct clutch (frictional element for high-speed selection) and a induction brake (frictional element for low-speed selection), which are selectively hydraulically actuated to achieve high and low speeds. Configure so that switching is possible.

In addition, the auxiliary transmission is equipped with a one-way clutch that can function as a reduction brake during forward drive (during transmission from the input side to the output side), and when switching between high and low speeds, the reduction brake is released and the direct clutch is engaged. When doing so, the rotating members to be connected by the direct clutch are prevented from rotating in opposite directions to accelerate wear of the direct clutch and to prevent engagement shock of the direct clutch from occurring. Therefore, even if the reduction brake is not engaged during upper pressure drive, the transmission function will not be affected, but unless it is engaged during reverse rotation output (backward driving), power transmission will not be possible.

However, if the reduction brake is not engaged during forward drive, the direct clutch is also not engaged at this time.
There are three modes: this mode, a mode in which only the direct clutch is engaged for high speed selection, and a mode in which only the reduction brake is engaged for low speed selection and intermediate rotational output,
Switching between these modes requires a plurality of valves for switching between high and low speeds of the auxiliary transmission. Therefore, as described in the above-mentioned literature, when selecting a low speed, it is common sense to engage the reduction brake not only during reverse rotation output but also during forward drive.

Conventionally, switching between high and low speeds of the auxiliary transmission is achieved by a circuit as described in the above-mentioned document and schematically shown in FIG. 4 attached to this specification. That is, the shift valve SF■ is set to the low speed selection pressure PL3.
exists, the reduction brake RD/B is engaged by the line pressure P, and the direct clutch D/C is engaged.
By draining and opening the sub-transmission, the sub-transmission is placed in a low-speed selection state.

When the high speed selection pressure P0 is present, the shift valve SFV engages the direct clutch D/C with the line pressure PL and drains and releases the reduction brake RD/B, thereby placing the auxiliary transmission in the high speed selection state. When switching between high and low speeds, the rise of the reduction brake engagement pressure and the direct clutch engagement pressure are transiently controlled by the respective accumulators ACCI and ACC2, contributing to alleviation of shift shock.

(Problem to be Solved by the Invention) However, as described above, the one-way clutch is provided in parallel with the one-way clutch or the duction brake RD/B does not need to be engaged because the one-way clutch functions during normal drive. Even if the reduction brake is engaged, this engagement must be done after the direct clutch D/C has been released and the one-way clutch has started functioning, otherwise the direct clutch D/C will interlock the auxiliary transmission while the direct clutch D/C is not released and will not cause a shock. will occur. On the other hand, due to the reverse rotation output, R immediately after starting the engine in N or P range.
When switching to range, the auxiliary transmission is initially in a neutral state due to a delay in pressure generation immediately after the engine starts, and after switching to R range, it is switched from this state to a deceleration state by engaging the reduction brake RD/B. . However, if there is a delay in engaging the reduction brake RD/B during this switching, the reduction one-way clutch RD/OWC
However, since this R range cannot perform the substitute function as described above, the neutral time of the auxiliary transmission becomes longer by the engagement delay described above, and when switching from the N or P range to the R range immediately after the engine starts, the multi-stage automatic shift There is a large time delay for the machine to go from a neutral state to a state where reverse rotation output is possible. This not only causes a delay in starting from the rear, but also causes the engine to race during this period, causing a large R range selection shock. Furthermore, the above-mentioned tendency becomes even more pronounced when the manual valve is switched from the N or P range to the R range immediately after the engine is cold started because the viscosity of the transmission hydraulic fluid is high.

However, in the past, as seen in the accumulator ACCI, the rise characteristic of the reduction brake pressure was uniquely determined by the accumulator's built-in spring, and was the same during forward drive and reverse rotation output. For this reason, if the above characteristics are determined to meet the requirements for forward drive, a delay in rear start or a large shock will occur when the reverse rotation output occurs, and if the above characteristics are determined to meet the requirements for reverse drive, then during forward drive It was inevitable that a large shift shock would occur due to the interlock of the sub-transmission.

It is an object of the present invention to solve the above-mentioned problems by making the above-mentioned characteristics different between forward drive and reverse rotation output.

(Means for Solving the Problems) For this purpose, the speed change control device for an auxiliary transmission according to the present invention is capable of high-low speed switching by selective hydraulic actuation of a high-speed selection friction element or a low-speed selection friction element, and has a In a multi-speed automatic transmission in which an auxiliary transmission equipped with a one-way clutch that can function as a substitute for a low-speed selection friction element during driving is coupled in tandem with a main transmission, the working pressure increase rate of the low-speed selection friction element is determined. , a means is provided for decreasing the output in the automatic transmission range intended for forward drive and increasing it in the reverse travel range intended for reverse rotation output.

(Function) The auxiliary transmission enters the low speed selection state by the hydraulic actuation of the low speed selection friction element, and the high speed selection state by the hydraulic actuation of the high speed selection friction element, and the combination of these states and the selected gear of the main transmission A multi-speed automatic transmission can obtain a large number of gears. The auxiliary transmission is equipped with a one-way clutch that can serve as a substitute for the friction element for selecting medium and low speeds in forward drive.
Even when the friction element for low speed selection is released when switching between high and low speeds, it is possible to prevent the rotating members that should be connected by the friction element for high speed selection from rotating in the opposite direction, thereby avoiding early wear of the friction element for high speed selection and shock from engagement. can do.

On the other hand, the above method gradually increases the hydraulic pressure of the friction element for low speed selection, which is to be activated when switching from the high speed selection state to the low speed selection state, in the automatic shift range intended for forward drive, and reverse rotation output is increased. Immediately raise the vehicle in the desired reverse driving range. Therefore, during forward drive, after the one-way clutch starts functioning by releasing the high-speed selection friction element, the low-speed selection friction element is engaged to prevent the occurrence of shock.
During reverse rotation output, by rapidly engaging the friction element for low speed selection, it is possible to prevent a delay in starting from the rear and a large shock in the engagement of the friction element for low speed selection due to the engine racing due to this delay, thereby preventing forward drive. It is possible to make the operating oil pressure increase characteristics of the friction element for low speed selection as required both when outputting rotation and when outputting reverse rotation.

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows a shift control hydraulic circuit for a multi-stage automatic transmission according to an embodiment of the present invention, and FIG. 2 shows a gear transmission mechanism to be controlled by this system.

First, to explain the gear transmission mechanism shown in FIG. 2, 1 indicates an input shaft, and 2 indicates an output shaft. These input and output shafts 1.2 are arranged in a coaxial butting relation, and a main planetary gear transmission mechanism 3 is concentrically arranged on the input shaft 1, and an evolving gear transmission mechanism 4 is concentrically arranged on the output shaft 2.
Place them respectively.

The main planetary gear transmission mechanism 3 is based on the "Automatic Transmission System REdRO" published by the applicant in 1987.
IA type maintenance manual J (A261CO7) Middle tube 1-53
It is the same as the transmission mechanism described on page 2, and has two first and second
A planetary gear set 5.6 is provided in tandem, each of which has a first
and second sun gear 53, 6. , first and second ring gears 5R16R1, pinions 5P16F meshing with these sun gears and ring gears, and first and second carriers 5c and 6c that rotatably support these pinions.

Sun gear 5. In addition to being able to be fixed by band brake B/B, it can also be coupled to input shaft 1 by reverse clutch R/C. Career 5. can be connected to the input shaft 1 by a high clutch H/C, can be prevented from rotating in the opposite direction to the input shaft 1 by a row one-way clutch L10WC, and can be fixed by a low reverse brake LR/B.

Career 5. Furthermore, by forward clutch F/C,
It can be coupled to the outer race of the forward one-way clutch F10WC arranged in the same direction as the row one-way clutch L10WC, and the inner race of the forward one-way clutch is coupled to the ring gear 6R. Also, ring gear 6R is connected to carrier 5 by overrun clutch OR/C. The sun gear 6 is coupled to the input shaft 1.

The planetary gear transmission mechanism 4 includes a third planetary gear set 7, which is comprised of a third sun gear 75, a third ring gear 7R%, a pinion 7P% that meshes with these gears, and a third carrier 7C that rotatably supports the pinion 7P. A simple planetary gear set. a carrier 6 which is an output element of the main planetary gear transmission mechanism 3;
Connect the ring gear 7 and I to the carrier 7c, and connect the carrier 7c to the output shaft 2.
join to. The ring gear 7R can further be coupled to the sun gear 73 as appropriate by a direct clutch D/C, and the sun gear 7R and the beam reduction one-way clutch RDloWC are connected to each other.
In addition to preventing rotation in the opposite direction to the input shaft 1, it can also be appropriately fixed by the reduction brake RD/B.

The gear transmission device of the above embodiment can be used for driving (D, III, II) which is manually selected by the driver according to the desired driving mode.
.

R) For each range, operate the clutches and brakes in the combinations shown in the table below (indicated by O mark) to achieve the first forward movement.
It is possible to obtain gear stages from 5th to 5th and reverse. However, if you do not wish to drive in neutral (N) range or park (P)
In the range, all friction elements (clutches and brakes) of the main planetary gear transmission mechanism are deactivated, thereby disabling power transmission to the creating planetary gear transmission mechanism.

First, to explain the action of the main planetary gear transmission mechanism 3, when the forward clutch F/C is activated, the ring gear 6R rotates in the opposite direction to the input shaft 1 via the forward one-way clutch F10WC and the row one-way clutch L10WC. be prevented. Therefore, the rotation from the input shaft 1 to the sun gear 6s is caused by the pinion 6, the ring gear 6,
The first speed state is achieved in which the carrier 6c is decelerated in the same direction as the input shaft 1 and rotated in the normal direction. At this time, the gear ratio of sun gear 6 and ring gear 6R is α2α2, and when the carrier 6c is reversely driven at high speed in the same direction as the human power shaft 1, the one-way clutch F10WC is used.

Due to the opening of LloWC, no reverse driving force is transmitted to the input shaft 1, and engine braking cannot be obtained. When engine braking is desired, it is necessary to operate the overrun clutch OR/C and the low reverse brake LR/B to prevent the one-way clutches F10WC and LloWC from being released, as indicated by the Δ mark in the table above.

When forward clutch F/C and band brake B/B are operated, sun gear 5 is activated by band brake B/B.
．． is fixed and serves as a reaction force receiver, forward clutch F/C and forward one-way clutch F10WC
In conjunction with the operation of , the power from the human axle load to the sun gear 6 causes the carrier 6° to rotate forward at a higher speed than the first speed state, and the second speed state is obtained. The gear ratio at this time is sun gear 5. Assuming that the gear ratio of the forward one-way clutch F10WC and the ring gear 5R is α, the force does not reach the input shaft 1 due to the release of the forward one-way clutch F10WC, and engine braking cannot be obtained. When engine braking is desired, it is necessary to operate the overrun clutch OR/C to release the forward one-way clutch F10WC as indicated by the symbol Δ in the table above.

When the forward clutch F/C and high clutch H/C are activated, the ring gear 6R rotates together with the input shaft 1, and the integral rotation of the sun gear 6 and the ring gear 6°, which are connected to the input shaft 1, causes the rotation of the ring gear 6R. Career 6. A third speed (directly coupled) selection state is obtained in which the input shaft rotates in the same manner as the input shaft 1.

Even in this state, the forward one-way clutch F10WC
is released during reverse drive, making it impossible to obtain engine braking. Therefore, when engine braking is required, it is necessary to operate overrun clutch OR/C to release forward one-way clutches F and/OW C.

When the high clutch H/C and band brake B/B are activated, the carrier 5c rotates together with the input shaft 1 due to the activation of the high clutch H/C, and the sun gear 5c is fixed due to the activation of the band brake B/H. Through the transfer of the pinion 5F on the sun gear 53, the ring gear 53, and therefore the rear hand 6c, can obtain an increased speed selection state. Furthermore, this 4
In the speed selection state, forward one-way clutch F10
Since there is a WC, there is no support even if the forward clutch F/C is kept in operation, and this forward clutch is kept in the operated state for convenience of shifting.

Reverse clutch R/C and low reverse brake LR
/B is activated, the sun gear 5s rotates together with the input shaft 1 by the activation of the reverse clutch R/C, and the carrier 5s is rotated by the activation of the low reverse brake LR/B. is fixed, the ring gear 5R1 and therefore the carrier 6 are reversed in the opposite direction to the input shaft 1, and it is possible to obtain a reverse selection state with a gear ratio of 1□.

Next, to explain the operation of the planetary gear transmission mechanism 4, when the reduction brake RD/B is operated, the sun gear 7
, are fixed, and the rotational power from the carrier 6C to the ring gear 7R is transmitted to the carrier 76, and therefore to the output shaft 2, while rotating the pinion 7F around the sun gear 7s under deceleration, thereby obtaining a deceleration state. Therefore, reduction brake R
The D/B functions as a low speed selection wear element for the auxiliary transmission.

At this time, the gear ratio is 1+α3, where α3 is the gear ratio of the sun gear 7 and ring gear 7R.

When direct clutch D/C is activated, sun gear 7
, are connected to the ring gear 7R, so that a direct connection state can be obtained in which the rotational power of the carrier 6c is directly transmitted to the carrier 7 and the output shaft 2.

Therefore, the direct clutch D/C functions as a high-speed selection friction element of the auxiliary transmission.

・When switching the reduction brake RD/B from the operating state to the non-operating state, the direct clutch D/C
If the sun gear 7 rotates in the opposite direction to the carrier 6 and ring gear 7R before the operation of the direct clutch D/
This not only accelerates the wear of C, but also increases the shock when it is activated, causing shift shock. However, one-way clutch RD10WC has ring gear 7,
It is useful to prevent the above-mentioned rotation of I and solve the above-mentioned problem.

In addition, there may be cases where it is not necessary to operate the one-way clutch RD10WC and the reduction brake RD/B, but the high-low speed switching circuit can be simplified by making the planetary gear transmission mechanism only in two states: the direct clutch or the reduction brake. Therefore, we decided to operate the reduction brake even when it is not needed.

As for the transmission system as a whole, as is clear from the table above, it is possible to obtain the first speed of the main transmission 3 and the deceleration state α2 (very low gear) of the auxiliary transmission 4, and the auxiliary transmission 4 is maintained as it is. By setting the main transmission 3 to the second speed and third speed (directly connected) states, the transmission ratios can be respectively set to the second speed and the third speed. Then, by keeping the main transmission 3 in the 3rd speed (directly connected) state and bringing the sub-transmission 4 into the directly connected state, the 4th speed (directly connected gear) with a gear ratio of 1 can be obtained. By keeping the auxiliary transmission 4 in the directly connected state and putting the main transmission 3 in the 4th speed (speed increase) state, the gear ratio is also changed, and the reverse gear is changed to the main transmission while the auxiliary transmission 4 is in the deceleration state. What can be obtained by putting the transmission 3 in the reverse state is α
．． α is 0.4 within the range of 0, 4 to 0.6, which is considered preferable in terms of strength and durability of the planetary gear sets 5 to 7, respectively.
41.0.560.0.384, but as is clear from this example of a gear ratio, an appropriate gear ratio can be obtained, and the lowest gear (1st gear) 5 of the gear transmission in such a manner that the gear ratio width between the highest speed stage (fifth speed) and the highest speed stage (fifth speed) is widened. speed ratio can be achieved.

Next, the hydraulic circuit shown in FIG. 1 that controls the speed change of the transmission train will be explained. This hydraulic circuit includes an engine-driven oil pump O/P, a pressure regulator valve 20, a pilot valve 22, a duty solenoid 24, a pressure modifier valve 26, a modifier accumulator 28,
Accumulator control valve 30, torque converter relief valve 32, lock-up control valve 34, lock-up solenoid 36, manual valve 38, first shift solenoid A, second shift solenoid B, third shift solenoid 01 overrun clutch solenoid 40
, first shift valve 42, second shift valve 44, third shift valve 46.5-2 relay valve 48.5-2 sequence valve 50
, ■-2 accumulator valve 52, N-D accumulator 54
．． 3.4-speed servo release/reverse clutch accumulator 56, accumulator switching valve 58.5-speed servo apply accumulator 60, overrun clutch control valve 62, overrun clutch pressure reducing valve 64, reduction timing valve 66, reduction brake accumulator 68 , a direct clutch accumulator 70, and a range pressure reducing valve 72 as main components,
These are the torque converter T/C1 inserted between the input shaft 1 in FIG. 2 and the engine (not shown), the forward clutch F/C, the high clutch H/C, the band brake B/B, and the reverse clutch R. /C, low reverse brake LR/B, overrun clutch OR/C.

Direct clutch D/C and reduction brake R
It is configured by connecting to the D/B as shown in the figure.

The torque converter T/C is a lock-up type that allows direct connection between input and output elements as appropriate, and when supplying hydraulic oil to the release chamber REL and discharging hydraulic oil from the apply chamber APL, the converter is in the above-mentioned disconnected state. The well-known method transmits the engine power to the input shaft 1 in Fig. 2 in a lock-up state in which the input and output elements are directly connected when the engine power is transmitted to the input shaft 1 in Fig. 2 and the hydraulic oil flows in the opposite direction. shall be taken as a thing.

In addition, the band brake B/B shall be appropriately fastened by a well-known servo according to Japanese Patent Application Laid-Open No. 62-159839, and 2
It is tightened when pressure is supplied only to the speed servo apply chamber 2S/A, and released when pressure is supplied to the 3rd and 4th speed servo release chambers 3.43/R, and in addition, the 5th speed servo apply chamber 5S is closed. /A is also re-fastened when pressure is supplied.

The pressure regulator valve 20 has springs 20a and 20j.
Basically, the oil pump O/P is equipped with a spool 20b elastically supported at the position shown in the figure and a plug 20c disposed opposite to the lower end surface of the spool in the figure. The pressure is regulated to a pressure determined by the spring force, and when the spring force of the spring 20j is increased by the plug 20c, the above pressure is increased by that amount to reach a predetermined line pressure. For this purpose, the pressure regulator valve 20 is configured to receive the pressure in the circuit 81 via the damping orifice 82 onto the pressure receiving surface 20d of the spool 20b, thereby biasing the spool 20b downward, so that the stroke position of the spool 20b is Ports 20e to 20h are provided which are opened and closed according to the conditions. Port 20e is connected to circuit 81 and is arranged to communicate with ports 20h and 20f as spool 20b is lowered from the position shown. As the spool 20b descends from the illustrated position, the communication between the port 20f and the port 20g, which is used as a drain port, decreases, and at the point when the communication with the port 20f is cut off, it becomes the port 20e.
Place it so that it begins to communicate with the Then, the port 2Of is connected to the capacity control actuator 85 of the oil pump O/P via a circuit 84 with a bleed 83 in the middle, and pulsation thereon is suppressed by a feedback accumulator 86. The oil pump O/P is a variable capacity vane pump driven by an engine, and the eccentricity is reduced when the pressure toward the actuator 85 exceeds a value, so that the capacity becomes smaller. The plug 20c of the pressure regulator valve 20 receives the modifier pressure from the circuit 87 on its lower end face in the figure, and receives the backward selection pressure from the circuit 88 on the pressure receiving surface 20i, and generates an upward force in the figure in response to these pressures. It is assumed that the spring 20j is added to increase the spring force.

The pressure regulator valve 20 is normally in the state shown in the figure, and when oil is discharged from the oil pump O/P, this oil flows into the circuit 81.

At the illustrated position of the spool 20b, no oil in the circuit 81 is drained, and the pressure increases. This pressure is at orifice 82
The pressure acting on the pressure receiving surface 20d pushes down the spool 20b against the springs 20a and 20j, and connects the port 20e to the port 20h. This causes the above pressure to be reduced to port 20.
A portion of the water is drained from h and lowered, and the spool 20b is pushed back by the springs 20a and 20j. By repeating this action, the pressure regulator valve 20 basically reduces the pressure (line pressure) in the circuit 81 to the spring 20a.

The value corresponds to the spring force of 20j. Incidentally, an upward force due to the modifier pressure from the circuit 87 is acting on the plug 20c, and the plug 20c increases the spring force of the spring 20j according to the modifier pressure, and the modifier pressure increases as described below. Since this occurs when the reverse is not selected and increases in proportion to the engine load (engine output torque), the above-mentioned line pressure increases as the engine load increases except when the reverse is selected.

At the time of reverse selection, an upward force is applied to the plug 20c by the reverse selection pressure (same value as the line pressure) from the circuit 88 instead of the modifier pressure, and this is applied to the spool 20b, so that the line pressure remains constant as desired in the reverse selection frame. value. When the rotational speed of the oil pump O/P reaches or exceeds the rotational speed of the engine (or higher than the rotational speed of the engine), the oil discharge amount that increases accordingly becomes excessive, and the pressure in the circuit 81 exceeds the pressure regulation value.

This pressure lowers the spool 20b further from the pressure regulating position, connects the boat 20f to the boat 20e, and connects the drain boat 20f to the drain boat 20e.
Cut off from 0g. As a result, some of the oil in the boat 20e is removed from the boat 20f and the bleed 83, but
A feedback pressure is generated within circuit 84. This feedback pressure increases as the rotational speed of the oil pump O/P increases, and reduces the eccentricity (capacity) of the oil pump O/P via the actuator 85. In this way, the capacity of the oil pump O/P is controlled so that the discharge amount remains constant while the rotational speed exceeds a certain value, thereby preventing an increase in power loss of the engine due to discharge of more than necessary oil.

As mentioned above, the line pressure generated in the circuit 81 is transferred to the pilot valve 22, manual valve 38, third shift valve 46 and 3,
It is supplied to a 4-speed servo release/reverse clutch accumulator 56.

The pilot valve 22 includes a spool 22b elastically supported in the illustrated position by a spring 22a, with the end face of the spool 22b farthest from the spring 22a facing the chamber 22c. Pilot valve 2
2 is further provided with a drain boat 22d, a pilot pressure circuit 90 having a filter 89 is connected between this and the line pressure circuit 81, and this circuit 90 is connected to the chamber 22c via an orifice 91.

Pilot valve 22 is normally in the state shown, where line pressure from circuit 81 is supplied to pilot pressure circuit 90 to create a pilot pressure in this circuit.

Then, the pilot pressure passes through the orifice 91 to the chamber 22c.
is fed back to push the spool 22b back against the spring 22a. When the pilot pressure reaches a value corresponding to the spring force of the spring 22a, the circuit 90 is switched and connected to the drain boat 22d, and the pilot pressure in the circuit 90 maintains a constant value corresponding to the spring force of the spring 22a. This pilot pressure is in circuit 9
0 causes shift solenoids A and B.

In addition to leading to C and overrun clutch solenoid 40,
Pressure modifier valve 26, orifice 92, 9
3. It is supplied to the lock-up control valve 34 and the lock-up solenoid 36, and also to the third shift valve 46.

The duty solenoid 24 normally closes the drain port of the drain circuit 94 connected to the orifice 92, and
This drain boat shall be opened at 8 o'clock.

However, the lever solenoid 24 is controlled by a computer together with other solenoids described later, and is turned on and off at a certain level.
As the ratio of ON time to the cycle (duty ratio) increases, the control pressure in the drain circuit 94 is lowered, and when the duty is 0%, this control pressure is set to the same value as the pilot pressure, which is the source pressure, and when the duty is 100%, the control pressure is Set to 0. The duty ratio is made smaller as the engine load (for example, engine throttle opening) increases except when the reverse range is selected, and thereby the above-mentioned control pressure is made higher as the engine load increases. Further, when the reverse range is selected, the duty ratio is set to 100% and the above control pressure is set to 0.

The pressure modifier valve 26 includes a spool 26b biased downward in the figure by a spring 26a and control pressure from the circuit 94, and the pressure modifier valve 26 further includes an output port 26c connected to the circuit 87, and a pilot pressure An input port 26d and a port 26g to which the circuit 90 is connected are provided, as well as a drain boat 26e. Orane2
An orifice 26h is formed in the spool 26b to feed back the modifier pressure in the circuit 87 to a chamber 26f facing the end face of the spool 26b far from the spool 26b. The spring force of the spring 26a is set to a value greater than the force due to the pilot pressure from the port 26g, and the modifier pressure becomes a value obtained by amplifying the control pressure from the circuit 94 during the pressure regulating operation below by the difference between the two forces. do it like this.

The spool 26b of the pressure modifier valve 26 directs the force of the spring 26a and the control pressure from the circuit 94 downward in the figure, and directs the force of the modifier pressure fed back to the chamber 26f and the force of the pilot chamber from the port 26g. The spool 26b receives the force upward in the figure, and is stroked to a position where these forces are balanced. If the modifier pressure is insufficient to meet the above downward force, the modifier pressure is increased by replenishing the pilot pressure by connecting the spool 26b and the beak output boat 26c to the input port 26d, and conversely, the modifier pressure is excessive. , spool 26b connects output port 26c to drain boat 26e to reduce modifier pressure. By repeating this action, the pressure modifier valve 26 adjusts the modifier pressure in the circuit 87 to correspond to the difference between the force due to the spring 26a and the force due to the pilot pressure from the port 26g, and the force due to the control pressure from the circuit 94. Pressure regulator valve 2 adjusts the modifier pressure to the specified value.
0 plug 20c.

By the way, as mentioned above, the control pressure increases as the engine load increases except when reverse is selected, and since it is 0 when reverse is selected, the modifier pressure that amplifies this control pressure by the above difference also increases when the reverse is selected. It increases as the engine load increases, and becomes 0 when reverse is selected, allowing the pressure regulator valve 20 to control the line pressure described above. Note that the modifier pressure in the circuit 87 is suppressed from pulsating by the modifier accumulator 28 during the pressure regulating action.

Torque converter relief valve 32 includes a spool 32b resiliently supported in the position shown by a spring 32a, which communicates output port 32C with input port 32d in the position shown, decreasing this communication as it moves upward in the figure. It is assumed that the output port 32C is switched and connected to the drain port 32e. In order to control the stroke of the spool 32b, an orifice 32g is formed in the spool 32b to feed back the output pressure of the spring 32c to a chamber 32f facing the spool end face far from the spring 32a. The output port 32c is connected to the front lubricating section F R/L via the relief valve 95.
UB and is connected to lockup control valve 34 by circuit 96. Input port 32d
is connected to the port 20h of the pressure regulator valve 20 by a circuit 97, and leads leakage oil from the pressure regulator valve 20 to the input port 32d as hydraulic oil for the torque converter T/C.

The torque converter relief valve 32 is normally in the state shown in the figure, and the pressure regulator valve 20 is injected.
2d is supplied via circuit 96 to lockup control valve 34 and thus to torque converter T/C. When the torque converter supply pressure is generated here, this pressure is fed back from the orifice 32g to the chamber 32f, causing the spool 32b to rise in the figure against the spring 32a. When the torque converter supply pressure exceeds a set value corresponding to the spring force of the spring 32a, the spool 32b connects the output port 32c to the drain port 32e to reduce the torque converter supply pressure and transfer this pressure to the spring force of the spring 32a. Keep it below the corresponding setting value. Note that even with this relief function, if the torque converter supply pressure exceeds the above set value, the relief valve 95 opens to release the excess pressure to the front lubricating part FR/LUB, thereby preventing deformation of the torque converter T/C.

The lock-up control valve 34 includes a spool 34a, a stepped plug 34b and a plug 34c coaxially abutted against each other at both ends of the spool 34a, and a spring 34d inserted between the spool 34a and the plug 34c. When the spool 34a is in the limit position opposite to the illustrated position, a circuit 96 is connected to a circuit 98 communicating with the release chamber REL of the torque converter T/C, and a circuit 99 communicating with the torque converter apply chamber APL is connected to the drain circuit 100. Connect to. At this time circuit 96
The torque converter operating oil flows through the torque converter T/C from the release chamber REL to the apply chamber APL to put the torque converter in the converter state. After flowing, the hydraulic oil is transferred from the drain circuit 100 to the oil cooler C00.
L, and after being cooled here, the rear lubricating section RR/L
Head to UB. When spool 34a is in the illustrated limit position, circuit 96 is connected to circuit 99 and circuit 98 is connected to drain boat 34e. At this time, the torque converter hydraulic oil in the circuit 96 is transferred from the apply chamber APL to the relief chamber RE.
Flow through the torque converter T/C to L to put the torque converter in a lock-up state. Note that in this lock-up state, the hydraulic oil that has passed through the torque converter is removed from the drain port 34e, so it does not pass through the oil cooler C00L;
02 bypasses the torque converter and guides the hydraulic oil to the oil cooler C00L, which cools it and cools it as well as the rear lubricating section RR.
/Compensate for LUB lubrication.

In order to control the stroke of the spool 34a, a drain circuit 103 is connected to the chamber 34f between the spool 34a and the plug 34c, and this circuit is connected to the orifice 93 of the pilot pressure circuit 90, and is normally connected to the drain boat of the circuit 103. A lock-up solenoid 36 that closes is provided oppositely. Then, the pressure in the torque converter release chamber circuit 98 is applied to the stepped plug 34b through the orifice 104, and the pressure in the pilot pressure circuit 90 is applied to the stepped plug 34b through the orifice 105 in a downward direction in the figure.

The ON/OFF state of the lock-up solenoid 36 is controlled by a computer (not shown), and this computer determines whether the driving condition is such that the torque converter T/C should be locked up. If lock-up is not to occur, the lock-up solenoid 36 is turned OFF and closed to generate a pressure in the drain circuit 103 having the same value as the pilot pressure, which is the source pressure. This pressure reaches the chamber 34f and the spring 34
d to move the spool 34a into the orifice 104.d.
105 and acting on the stepped plug 34b, the torque converter T/C is brought into the converter state as requested. If lock-up is to be performed, the lock-up solenoid 36 is turned on and opened, and the drain circuit 103 is brought into a non-pressure state. At this time, the pilot pressure input from the orifice 105 lowers the stepped plug 34b along with the spool 34a against the spring 34d, thereby bringing the torque converter T/C into the lock-up state as required.

In this example, in order to prohibit lock-up when selecting the first forward speed and when selecting the reverse range, the chamber 34g facing the end face of the plug 34c far from the spool 34a is connected to the output port of the shuttle valve 107 by the circuit 106. Reverse selection pressure circuits 88 are connected to the two input ports of the shuttle valve, respectively.
and the first speed selection pressure circuit 108 are connected. These circuits 88
Or, when selecting reverse or when selecting first speed in which pressure is generated at 108, the corresponding selection pressure reaches the chamber 34g from the shuttle valve 107, causing the spool 34a to rise as shown in the figure via the plug 34c, thereby switching the torque converter T/C to the converter. state.

Note that the pilot pressure from the orifice 105 always urges the stepped plug 34b downward to prevent the stepped plug, spool 34a, and plug 34c from vibrating.

The manual valve 38 can be set to the parking (P) range, reverse (R) range, or neutral (N) range by the driver's manual selection operation.
) range, forward automatic transmission (D) range, third forward speed engine brake (III) range, and second forward speed engine brake (II) range (also used as first speed engine brake range). According to the selected range of the spool, the line pressure circuit 81 is connected to ports 380°, 381[1, 38m, 38R] as shown in the following table. Note that in this table, O marks indicate boats that communicate with the line pressure circuit 81, and no marks indicate boats that are being drained.

The boat 38D is connected to the accumulator control valve 30, the forward clutch F/C, and the D range pressure circuit 110.
Accumulator switching valve 58, first shift valve 42, second shift valve 44, and overrun clutch control valve 6
Connect to 2. Also, boat 38■ is ■range pressure circuit 11
1 connects to the corresponding input of the shuttle valve 112, and the boat 38 is connected to the range pressure reducing valve 7 by the range pressure circuit 113.
2, and the boat 38R is connected to the aforementioned reverse selection pressure circuit 8.
Connect 8. As described above, the circuit 88 is connected to the pressure regulator valve 20 and the shuttle valve 107 so that the pressure regulator valve 20 performs the line pressure adjustment function when the reverse is selected, and the lock-up control valve 34 performs the lock-up inhibiting function when the reverse is selected. as well as one-way orifice 114 and shuttle valve 1
Low reverse brake LR via 15 corresponding input ports
/B, and also connects to reverse clutch R/C via one-way orifice 117.

The accumulator control valve 30 is a stepped spool 30
a, and the chamber 30b facing the large diameter end is connected to the circuit 94.
The chamber 30c facing the small diameter end is opened to the atmosphere.

Therefore, the spool 30a is raised in the figure by the pressure in the circuit 94 adjusted as described above by the duty solenoid 24, and the output port 30d is raised as shown in the figure by the pressure in the circuit 94 adjusted as described above.
When the boat 30d is cut off from the D-range pressure circuit 110 and connected to the D range pressure circuit 110, the accumulator back pressure is output from the boat 30d. This pressure acts on the difference in pressure-receiving area between lands at both ends of the spool 30a, and urges the spool 30a downward in the figure, opposing the pressure within the chamber 30b. Then, the spool 30a strokes so that both are balanced, and the accumulator back pressure from the boat 30d changes depending on the pressure inside the chamber 30b. Therefore, the pressure inside the chamber 30b is reduced to the duty solenoid 24.
As mentioned above, it is adjusted to increase as the engine load increases outside the reverse range, and the source pressure D
The pressure of the range pressure circuit 110 is forward traveling (D, I[1
, II) Since it occurs only in the range, the accumulator back pressure occurs only when the forward travel range is selected, and increases as the engine load increases, so that the capacity of the corresponding accumulator is adjusted to match the engine load. I can do it. Note that the accumulator back pressure is supplied to the 1-2 accumulator valve 52 and the N-D accumulator 5 by the circuit 116.
It is supplied to a 4.5-speed servo apply accumulator 60, a direct clutch accumulator 70, and an overrun clutch pressure reducing valve 64.

A one-way orifice 120 is inserted into the D range pressure circuit 1100 immediately before the forward clutch F/C, and this one-way orifice and forward clutch F
The N-D accumulator 54 and the accumulator switching valve 58 are sequentially connected between the N-D accumulator 54 and the accumulator switching valve 58 through a one-way cup 121 that can be replaced with one having a different inner diameter.

The first shift valve 42 includes a spool 42b elastically supported in the illustrated position by a spring 42a, and this spool is in the illustrated position when the first shift solenoid A is turned ON (closed) to supply pilot pressure from the circuit 90 to the chamber 42c. shall be raised from D range pressure circuit 1 at the illustrated position of spool 42b
10 to the second speed pressure circuit 122, the first speed pressure circuit 108 to the drain port 42d, the range pressure circuit 124 to the drain port 42f, and between the circuits 125 and 126,
Also, when the spool 42b is in the raised position, the circuit 108 is connected to the circuit 127.
, circuit 122 to circuit 128 , circuit 124 to circuit 129 , and circuit 126 to circuit 128 .

The circuit 122 passes through the check valve 130 to the band brake B.
/B is connected to 2-speed servo apply chamber 2S/A, and circuit 1
24 to the corresponding input of shuttle valve 115 and circuit 12
5 to the 5-2 relay valve 48, and the circuit 126 to the 5-2 relay valve 48.
The circuit 127 is connected to the relay valve 48 and the overrun clutch control valve 62, and the circuit 127 is connected to the 5-2 sequence valve 50 on the one hand and the second shift valve 44 on the other hand.
8 is a one-way orifice with mutually opposite directions 131.13
2 to the High Clara 1,000 H/C and to the second shift valve 44, and the circuit 129 is connected to the second shift valve 44.

A bypass circuit 133 connected in parallel with a check valve 130 is provided in the second speed pressure circuit 122, and a 1-2 accumulator valve 52 is inserted into this bypass circuit. This 1-
The 2-accumulator valve includes a spool 52a, and springs 52b are attached to the large diameter end surface and the small diameter end surface of the spool 52a, respectively.

52c. The back pressure of the accumulator in the circuit 116 is applied downward in the figure to the stepped portion 52d of the spool 52a, and due to this and the difference in spring force between the springs 52b and 52c, the spool 52a is lowered further from the normal pressure regulating position shown in the figure. It shall be in the position shown. At this spool position, the spool 52a is output (output) 52e is input to the boat 52
f, from the boat 52e to the 2nd speed servo apply chamber 2S
Outputs 2nd speed servo apply pressure to /A. This pressure is fed back to the chamber 52g via the orifice 134,
Push back the spool 52a.

When the second speed servo apply pressure from the output port 52e exceeds the spring force difference and the value corresponding to the accumulator back pressure acting on the stepped portion 52d, the spool 52a connects the output port 52e to the drain port 52h and outputs the pressure. The second speed servo apply pressure from port 52e is reduced by the excess amount, and this pressure is regulated to the above value.

By the way, the second speed servo apply pressure is blocked by the check cup 135, passes through the orifice 136, acts on the piston cup 52i of the spring 52c, and strokes this to gradually increase the spring force of the spring 52c. The pressure also increases with a predetermined time gradient. Also, step part 5
Since the accumulator back pressure acting on 2d is regulated by the duty solenoid 24 and the accumulator control valve 30 so as to increase as the engine load increases as described above, the The level (usually referred to as engine power) can be increased as the engine load increases.

The second shift valve 44 includes a spool 44b elastically supported in the illustrated position by a spring 44a, and this spool is in the illustrated position when the second shift solenoid B is turned ON (closed) to supply pilot pressure from the circuit 90 to the chamber 44c. shall be raised from The circuit 127 is connected to the drain boat 44d at the illustrated position of the spool 44b, and the circuit 127 is connected between the circuits 110 and 128.
The circuit 129 is connected to the drain boat 44e, and the spool 4
4b in the raised position between circuits 110 and 127;
28 to the drain boat 44e, and the circuit 129 to the circuit 1.
Leads to 40. The circuit 140 is 1. II range pressure reducing valve 72
Connect to.

5-2 Relay valve 48 comprises a spool 48b elastically supported in the illustrated position by a spring 48a, and the spool 48b is connected to circuit 1.
When pressure is present in 26, this pressure shall force it into the raised position. Circuit 12 in the illustrated position of spool 48b
5 to the drain boat 48c and the circuit 125 in the raised position.
to circuit 141, which is connected to 5-2 sequence valve 50.

The 5-2 sequence valve 50 includes a spool 50b resiliently supported in the position shown by a spring 50a, which spool is forced into the lowered position when pressure is present in the circuit 142. In the illustrated position of the spool 50b, the circuit 141 is connected to the drain boat 50c, and in the lowered position, the circuit 141 is connected to the drain boat 50c.
41 to the circuit 127.

The circuit 142 is connected to a circuit 144 with a one-way orifice 143 that connects the 3.4S/R of the band brake B/B's 3.4-speed servo release chamber and the high-crunch H7C. One-way cup 14 that can be replaced with one with a different inner diameter
6 is connected to the accumulator switching valve 58 through a circuit 147 into which the accumulator switching valve 58 is inserted. This valve is further connected via circuit 148 to
The 4-speed servo release/reverse clutch accumulator 56 is connected, and the reverse clutch R/C is connected via the circuit 149.

It is assumed that the accumulator switching valve 58 includes a spool 58b that is supported in the illustrated position by a spring 58a, and that this spool moves to the left in the figure when pressure is present in the D range pressure circuit 110. Circuit 14 in the illustrated position of spool 58b
8 is connected to the circuit 149, the accumulator 56 is used for pressure increase control of the reverse clutch R/C, and the spool 58b is connected to the circuit 149.
At the left-hand position, the circuit 148 is connected to the circuit 147, and the accumulator 56 is used to control the pressure increase in the 3rd and 4th speed servo release chambers 3 and 4S/R.

Band brake B/B 5-speed servo apply chamber 5S/A
The circuit 150 to the 5-speed servo apply accumulator 6
0 and one-way orifice 151, and is connected to overrun clutch control valve 62. It is assumed that the overrun clutch control valve 62 includes a spool 62b elastically supported in the illustrated position by a spring 62a, and this spool is raised in the figure by supplying pressure to the chamber 62c. room 6
2c is the overrun clutch solenoid 40 ON (
When the solenoid 40 is closed), pilot pressure is supplied from the circuit 90, and the pressure inside the chamber 6Zc is exhausted when the solenoid 40 is OFF. The overrun clutch pressure reducing valve 64 is in the illustrated position of the spool 62b.
The circuit 152 from the spool 62b is connected to the drain port 62d, and the circuit 152 is connected to the drain port 62d in the raised position of the spool 62b.
to circuit 126.

The third shift valve 46 includes a spool 46b elastically supported in the illustrated position by a spring 46a, and a chamber 46c facing both end surfaces of the spool.
46d, pilot pressure of circuit 90 and circuit 153, respectively.
supply pressure. The circuit 153 connects to the output boat of the shuttle valve 154, and each of the two ports of the shuttle valve has a third
The pressure generated when the shift solenoid C is turned ON (closed) (the same value as the pilot pressure of the circuit 90) and the backward range pressure (described later) are selectively supplied to the circuit 155. When one of these pressures occurs, it passes through shuttle valve 154 and circuit 153 to chamber 46d, and in cooperation with spring 46a forces spool 46b into the position shown against the pilot pressure into chamber 46c, causing chamber 46d to move into chamber 46d. While no pressure is supplied to chamber 46d, spool 46b is lowered in the figure against spring 46a by pilot pressure to chamber 46c. The circuit 156 is connected to the drain boat 46e at the position shown on the spool 46b, and the circuit 1
57 is connected to the line pressure circuit 81, and in the lowered position of the spool 46b, the circuit 156 is connected to the line pressure circuit 81, and the circuit 1
57 to drain boat 46f.

A one-way orifice 158 is inserted into the circuit 156 and connected to the direct clutch D/C, and a direct clutch accumulator 70 is provided in the circuit 156 by connecting it through a one-way orifice 159. Further, the circuit 157 connects the reduction brake RD/
B, and a reduction brake accumulator 68 is connected between the one-way orifice 160 and the reduction brake RD/B.

This accumulator 68 connects the circuit 161 from the back pressure chamber to the output port of the shuttle valve 112 and connects one input of the shuttle valve 112 to the
Connect the range pressure circuit 111 and supply range pressure.

A circuit 155 is connected to the other input of the shuttle valve 112, and this circuit is connected to the reverse selection pressure circuit 88 to supply the other input of the shuttle valve 112 with a reverse selection pressure.

The pressure of the circuit 161 is also supplied to the chamber 66a of the reduction timing valve 66 to control the reduction timing valve 66, which is constituted by a spool 66b elastically supported in the illustrated position by a spring 66c. Spool 66b is chamber 6
When there is no pressure in the chamber 6a, it is in the illustrated position, and when there is pressure in the chamber 66a, it is raised against the spring 66c. Bypass circuit 163 with orifice 162 in the illustrated position of spool 66b is connected to circuit 157.
circuit 163 in the raised position of spool 66a.
．． It runs between 157. The bypass circuit 163 bypasses the one-way orifice 160, and connects the end farthest from the reduction timing valve 66 to the reduction brake RD/B.

Overrun clutch pressure reducing valve 64 reduces the pressure in circuit 152 and supplies it to overrun clutch OR/C, and includes a spool 64b that is brought to the illustrated position by spring 64a and accumulator back pressure from circuit 116. At this spool position, the overrun clutch O is connected from this boat by connecting the output capo 64c to the circuit 152.
Outputs R/C operating pressure.

For this reason, boat 64c and overrun clutch OR/C
A circuit 165 in which an orifice 164 is inserted connects the two. Overrun clutch operating pressure is spool 6
It is fed back to the chamber 64e through an orifice 64d provided in 4b. Therefore, as the overrun clutch operating pressure increases, the spool 64b is lowered in the figure, and this pressure increases the accumulator back pressure from the circuit 116 and the spring 64.
When the spring force of a exceeds the value corresponding to Japanese sulphur, spool 6
4b connects the output port 4c to the drain boat 64f to release excess pressure.

As a result, the overrun clutch working pressure is reduced to a value corresponding to the above-mentioned Japanese sulfur, but since the accumulator back pressure from circuit 116 increases as the engine load increases, the overrun clutch working pressure also increases as the engine load increases. The engagement capacity of the overrun clutch OR/C can be controlled to be appropriate for preventing engine brake shock, which will be described later. In addition, a one-way valve 166 is connected between the circuit 152 and the overrun clutch OR/C.
The one-way valve 166 and orifice 164 constitute a one-way orifice.

The range pressure reducing valve 72 reduces the range pressure from the circuit 113 and outputs it to the circuit 140, and includes a spool 72b elastically supported at the illustrated position by a spring 72a. At this spool position, the circuit 140 is connected to the circuit 113 to generate pressure, and this pressure is applied to the orifice provided in the spool 72b. 2c feeds back to the right end surface of the spool to move the spool 72b to the left in the figure.

When the output pressure of circuit 140 exceeds a value corresponding to the spring force of spring 72a, spool 72b drains circuit 140)? 2a to release excess pressure and transfer the output pressure to spring 72.
The pressure is reduced to a constant value corresponding to the spring force of a.

The speed change operation by the hydraulic circuit shown in FIG. 1 will be explained next. Prior to this explanation, the following table shows the ON/OFF combinations of shift solenoids A, B, and C to obtain the first to fifth forward speeds.

Table 3 If the driver does not wish to drive but wishes to park or stop and sets the manual valve 38 to the P or N range, manual valve ports 38D, 38III, 3811 and 38
All R are drain ports as shown in Table 2 above, and line pressure is never output from these ports, so the forward clutch F/C and high clutch H/ C, band brake B/B, reverse clutch R/C, low reverse brake LR/B, and overrun clutch OR/C are all kept inactive, and the main transmission 3 in the power transmission train shown in FIG.
can be kept in a neutral state where power cannot be transmitted.

Therefore, regardless of the state of the sub-transmission 4, the multi-stage automatic transmission maintains a neutral state in which power cannot be transmitted; however, for the above-mentioned reasons, the sub-transmission 4 is set to a deceleration state as shown in Table 1 as described below. put. That is, by turning on and closing the third shift solenoid C, pilot pressure is supplied to the chamber 46d of the third shift valve 46 via the shuttle valve 154 and the circuit 153.

Therefore, the third shift valve 46 is in the state shown, and the circuit 15
6 to the drain port 46e to connect the direct clutch D.
/C and connect the circuit 157 to the line pressure circuit 81.
Reduction brake RD/B by line pressure
is engaged, and the sub-transmission 4 is brought into a deceleration state.

In a state in which the manual valve 38 is set to the D range with the desire for forward automatic shift driving in the D range, automatic shifts are performed between all gears: 1st speed to 5th speed as follows.

(1st speed) That is, in the D range, the manual valve 38 outputs the line pressure of the circuit 81 as the D range pressure from only the port 38D as shown in Table 2 above, and this D range pressure is supplied to the circuit 110 to be applied to each part. reach The D range pressure heading towards the forward clutch F/C passes through the one-way orifice 120.
In conjunction with the function of the N-D accumulator 54, the forward clutch F/C is gradually engaged to alleviate the engagement shock.

On the other hand, when the vehicle is stopped in the D range, the computer keeps the third shift solenoid C ON and both the first shift solenoid A and the second shift solenoid B to 0IJL.
, the spool 4 of the first shift valve 42 and the second shift valve 44
2b and 44b to the raised position. Therefore, the circuit 128 of the high clutch H/C is drained through the second shift valve boat 44e, releasing the high clutch H/C, and the circuit 14
The 3rd and 4th speed servo release chambers 3.43/R of the band brake B/B connected to the high clutch circuit 128 via 4 are also drained.

Also, band brake B/B 2nd speed servo apply chamber 23
/A is also rendered pressureless because its circuit 122 is connected to the drained circuit 128 described above by the first shift valve 42. Furthermore, the circuit 150 of the 5-speed servo apply chamber 5S/A of the band brake B/B is drained as follows. That is, unless the driver performs an operation to request engine braking, which will be described later, the computer turns on the overrun clutch solenoid 40 and raises the spool 62b of the overrun clutch control valve 62 in the figure. This valve thus connects circuit 152 to drain port 62d to release overrun clutch OR/C while simultaneously connecting circuit 150 to circuit 126. Since this circuit 126 is connected to the circuit 128 by the first shift valve 42 and the circuit 12B is connected to the drain port 44e of the second shift valve as described above, the fifth speed servo apply chamber 5S/A is drained. The reverse clutch R/C and low reverse brake LR/B are released because their circuits 88 are drained from the corresponding valve 38R of the manual valve 38.

Therefore, when the auxiliary transmission is decelerating due to the operation of the reduction brake RD/B, the main transmission is operated by the forward clutch F.
/C will be operated, and together with the operation of the forward one-way clutch F10WC as shown in Table 1 above, each gear automatic transmission will be in the first gear selection state. However, at this time, the first shift valve 42 and the second shift valve 44 are
08 to the circuit 127 and the D range pressure circuit 110 in sequence, and the D range pressure from the circuit 110 is connected to the circuits 127 and 108.
It is supplied to the lock-up control valve 34 via the shuttle valve 107 and the circuit 106, and in order to put the torque converter T/C in the converter state regardless of the operating state of the lock-up solenoid 36, the engine is also stalled in the first gear selection state. It is possible to maintain a stop by operating the brakes without having to worry. In addition, when the forward clutch F/C is operated, its operating hydraulic pressure is throttled by the one-way orifice 120, and the N-D accumulator 54 is stroked from the right half position to the left half position as it rises. is performed slowly, and the forward clutch F
/C fastening shock, that is, the N-D select shift when switching from N or P range to D range can be alleviated.

When the engine output is increased by depressing the accelerator pedal in the first speed selection state, the vehicle is started.

(Second speed) When the vehicle speed increases after the vehicle starts and the driving state becomes such that the second speed should be selected, the computer turns off the first shift solenoid A and switches the first shift valve 42 to the state shown in the figure, as shown in Table 3 above. . As a result, the first shift valve 42 switches and connects the circuit 126 to the circuit 125, but this circuit 125 is connected to the circuit 5-2.
Because the illustrated position of the relay valve 48 communicates with the drain boat 48c, the circuit 126, and therefore the 5-speed servo apply chamber 5S/A, continues to be drained. The first shift valve 42 also connects the lock-up control valve 34 to the lock-up solenoid 36 by connecting the circuit 108 to the drain boat 42d.
The torque converter T/C can be locked up as appropriate under the computer control. The first shift valve 42 also connects the circuit 122 to the D range pressure circuit 110, and outputs the D range pressure from this to the circuit 122 as the second speed servo apply pressure. This pressure is passed through circuit 133 to 1-2
The pressure is regulated by the action of the accumulator valve 52 and is supplied to the second speed servo apply chamber 2S/A, and the band brake B/B is engaged. By the way, due to the pressure regulating action of the 1-2 accumulator valve 52, the engagement of the band brake B/B is 1.
- 2-speed shifting is performed in a manner that does not cause a shock, forward clutch F/C, forward one-way clutch F1
In conjunction with maintaining the operation of OWC and reduction brake RD/B, it is possible to shift the multi-stage automatic transmission from the first gear to the second gear in a hair-shift manner, as is clear from Table 1 above.

(3rd speed) After that, when the operating state becomes such that 3rd speed should be selected, the computer turns off the second shift solenoid B as shown in Table 3 above.
F and switch the second shift valve 44 to the illustrated state. As a result, the circuit 128 is cut off from the drain boat 44e and communicated with the D range pressure circuit 110, and the D range pressure from this circuit reaches the high clutch H/C via the circuit 128 and the one-way orifice 132, and is engaged. On the other hand, the pressure applied to engage the high clutch H/C reaches the 3rd and 4th speed servo release chambers 3.43/R via a circuit 144 branching from the high clutch circuit 128, and reaches the band brake B/C.
Release B. The pressure to the servo release chamber 3.43/R is now controlled by the accumulator switching valve 58 from the circuit 110.
It is moved to the left in the figure by range pressure and passes between circuits 147 and 148, so after passing through the one-way orifice 145, it reaches the accumulator 56 via the one-way cup 146 and circuits 147 and 148. Therefore, the pressure in the servo release chambers 3, 4S/R gradually increases while the accumulator 56 is stroked from the right half position shown in the figure to the left half position shown in the figure. Therefore, the band brake B/B is released in a timely manner relative to the engagement of the high clutch H/C.

As a result of the above, the high clutch H/C is engaged and the band brake B/B is switched to disengaged, and together with the operation maintenance of the forward clutch F/C, forward one-way clutch F10WC, and reduction brake RD/B, the first As is clear from the table, the multi-speed automatic transmission is capable of upshifting from second speed to third speed. Note that during this upshift, 1. Accumulator 5
6 can suppress shift shock by the above-mentioned action.

(4th speed) After that, when the operating state is reached in which 4th speed should be selected, the computer selects the first and second shift solenoids A as shown in Table 3 above.
, B remain OFF, that is, the main transmission remains unchanged, and the third shift solenoid C is turned OFF to lower the spool 46b of the third shift valve 46 in the figure. This results in
A circuit 157 connects to the drain boat 46f to release the reduction brake RD/B, and a circuit 156 connects to the line pressure circuit 81 to engage the direct clutch D/C by the line pressure. Therefore, the sub-transmission is switched from the deceleration state to the direct connection state, and the multi-stage automatic transmission can be shifted from the 3rd speed to the 4th speed by a hair-shift, as is clear from Table 1 above.

During this upshift, the direct clutch D/
The working pressure of C is throttled by the one-way orifice 158 and increases while stroking the direct clutch accumulator 70 from the right half shown position to the left half shown position, so this rise is gradual and direct clutch D
/C engagement shock, that is, 3-4 gear shift shock can be alleviated.

(Fifth speed) After that, when the operating state becomes such that the fifth speed should be selected, the computer activates the first shift solenoid A to control the spool 42b of the first shift valve 42, as is clear from Table 3 above.
is raised again in the figure. As a result, the second shift valve 44
The high clutch and servo release circuit 128, which was connected to the D range pressure circuit 110, is connected to the circuit 126 at the first shift valve 42, and the D range pressure is supplied to this circuit 126. This pressure is supplied from circuit 126 to 5-speed servo apply chamber 5S/A via overrun clutch control valve 62 and circuit 150, and engages band brake B/B. On the other hand, the circuit 122 is cut off from the D range pressure circuit 110 by the switching of the first shift valve 42, but is switched to the circuit 128, so pressure continues to be supplied to the 2nd speed servo apply chamber 2S/A. . Therefore, band brake B/B is engaged, and together with forward clutch F/C, high clutch H/C, and direct clutch D/C to maintain operation, it is clear from Table 1 above that the multi-stage automatic transmission is activated. It is possible to perform an upshift from 4th speed to 5th speed (overdrive OD).

For this upshift, the 5th gear servo apply chamber 5
Since the pressure to S/A is throttled by the one-way orifice 151 and gradually increases while the accumulator 60 is stroked from the right half shown position to the left half shown position, the band brake B/B must be engaged accordingly. This can be done without shock, and the 4-5 gear shift shock can be alleviated.

Furthermore, the above switching of the first shift valve 42 causes the circuit 108 to be cut off from the drain boat 42d and connected to the circuit 127, but this circuit is not connected to the drain boat 44d when the second shift valve 44 is in the illustrated state. Therefore, the lock amplifier control valve 34 is in the chamber 34g in the fifth speed selected state.
Torque converter T/
The lock-up control of C can continue to be left to electronic control by the solenoid 36.

(OD Prohibition) If the driver does not wish to shift to 5th gear (OD) and has turned on an OD prohibition switch (not shown), the computer will shift to 5th gear as shown in Table 3 above. Do not select the ON/OFF combination of solenoids A, B, and C. Therefore, the multi-speed automatic transmission automatically changes gears between 1st and 4th speeds, but at this time, the computer activates the overrun crank solenoid 40 when the engine throttle opening is below a predetermined value (for example, 1/16 opening). Kano F. This switches the overrun clutch control valve 62 to the state shown, and connects the circuit 152 to the D range pressure circuit 110. The D range pressure from this circuit is output to the circuit 152, and after being reduced as described above by the overrun clutch pressure reducing valve 64, it passes through the orifice 164 to the overrun clutch OR/C, where it is engaged. By engaging the overrun clutch OR/C, the multi-stage automatic transmission enables engine braking in the second to fourth speeds, as is clear from Table 1 above. At this time, since the operating pressure of the overrun clutch is reduced by the valve 62 as described above,
It is possible to alleviate the shock when the overrun clutch OR/C is engaged.

The above switching of the overrun clutch control valve 62 is performed by connecting the circuit 150 to the drain port 1-62d.
The speed servo apply chamber 5S/A is drained to compensate for the release of the band brake B/B. As a result, when the overrun clutch OR/C is engaged, the band brake B/
B is reliably released, and it is possible to prevent both from being engaged at the same time and interlocking the gear transmission train.

(4-3 Shift) The shift for switching the sub-transmission from the direct connection state to the deceleration state in the D range will be described below with respect to the 4-3 down shift shift.

During this shift, the computer shifts the main transmission (shift solenoids A and B) to the fourth
While selecting the speed, the third shift solenoid C is turned on from OFF to switch the third shift valve 46 to the state shown in the figure.

As a result, the pressure in the circuit 156 is exhausted through the drain boat 46e, and the direct clutch D/C is released.
The line pressure is introduced through the circuit 157 to the line pressure circuit 81, thereby engaging the reduction brake RD/B as follows, and shifting the multi-speed automatic transmission from 4th speed to 3rd speed as is clear from Table 1 above. You can downshift to.

When the reduction brake RD/B is engaged, pressure is not supplied to the circuit 161 leading to the chamber 66a of the reduction timing valve 66 and the accumulator back pressure chamber of the reduction brake accumulator 68 in the D range. The reason is that manual valve port 38■ is circuit 1.
This is to bring the manual valve 11 into a no-pressure state and the manual valve 38R to bring the circuit 155 into a no-pressure state via the circuit 88.

Therefore, the reduction timing valve 66 is in the illustrated state, cutting off the circuits 157 and 163, and cannot supply the pressure of the circuit 157 to the reduction brake RD/B through the one-way orifice 160. Further, the back pressure of the reduction accumulator 68 is set to O, and the accumulator characteristics are determined only by the built-in spring 68a.

Therefore, the reduction brake engagement pressure is the solid line P in Figure 3.
As shown by o, first the piston 68 of the accumulator 68
The spring force equivalent value P of the spring 68a which brings the piston b to the right half position shown in the figure rises, and then the one-way orifice 16 is moved while the piston 68b is stroked to the left half position shown.
The piston 68 rises at a time gradient determined by the inner diameter of the piston 68.
At the instant t when b finishes its stroke, it further rises by the return spring force of the reduction brake RD/B,
Reduction brake RD/B loss stroke instant t
2, it becomes the same as the line pressure PL which is the source pressure.

By the way, the pressure value required to engage the reduction brake RD/B is P2, and the pressure value required to engage the reduction brake RD/B is P2.
/B is only concluded at the instant t2. However, the D range does not require engine braking and is intended for positive drive from the input shaft side to the output shaft side, and when the direct clutch D/C is released, the reduction one-way clutch RD10WC (see Figure 2) is the power source. The transmission can be taken over, and the delay in engagement of the reduction brake RD/B will not affect the speed change. By delaying the engagement of the reduction brake, it is possible to prevent simultaneous engagement with the direct clutch D/C, and it is possible to reliably prevent shift shock caused by interlocking of the sub-transmission.

■When a range driver desires engine braking driving in 3rd gear or lower, the manual valve 38 is set to ■range.

At this time, the computer shifts solenoids A and B.

The ON/OFF combination of C is determined so that the first, second, or third speed shown in Table 3 is selected depending on the driving condition, and the engine throttle opening is set to a predetermined value (for example, 1/16 By turning off the overrun clutch solenoid 40 and engaging the overrun clutch OR/C when the engine is opened (opening degree) or less, it is possible to run with engine braking in 2nd or 3rd gear, as is clear from Table 1 above. .

By the way, if the manual valve 38 is set to the ■ range while driving in the 5th or 4th gear set to the ■ range, as is clear from Table 1 above, the auxiliary transmission will shift as described above for the 4-3 downshift. Similarly, the direct connection state is switched to the deceleration state. However, in this lever range, the manual valve 38 also outputs the line pressure from the circuit 81 to the port 38I, and this pressure passes through the shuttle valve 112 and the circuit 161 to the chamber 6 of the reduction timing valve 66.
6a and the back pressure chamber of the accumulator 68. Therefore, the reduction timing valve 66 is connected to the spool 66b.
is raised between circuits 157 and 163, and the circuit 157
The pressure is supplied to the reduction brake RD/B not only through the one-way orifice 160 but also through the orifice 162. Further, the accumulation characteristics of the accumulator 68 are determined not only by the spring 68a but also by the line pressure from the circuit 161.

Therefore, the reduction brake engagement pressure first produces a reduction brake stroke shelf, as shown by the two-dot chain line P in FIG. - corresponds to the sum of - rises to a higher value, then rises at a steep slope determined by the sum of the inner diameter of one-way orifice 160 and orifice 162, and reaches line pressure PL after the end of the stroke of accumulator piston 68b. Therefore, the reduction brake engagement pressure is instantaneously increased by the inner diameter of the orifice 162 and the back compression bone of the accumulator 68. becomes the set value P2, and the reduction brake RD/B can be engaged at an early stage.

By the way, this range ■ requests engine braking and operates the manual valve 38 by the driver, and is designed to reverse drive from the output shaft side to the input shaft side, and is timed to release the direct clutch D/C. If the reduction brake RD/B is not engaged quickly, there will be a delay in the effectiveness of the engine brake, and the requested engine brake will not be obtained. However, the early engagement of the reduction brake can eliminate this problem. On the other hand, t in Figure 3
. Since the moment when the reduction brake engagement starts as shown by is during the stroke shelf time of the accumulator 68, the rate of change in the reduction brake engagement pressure is not such as to cause a reduction brake engagement shock (shift shock), but rather a shift shock at the time of the shift. can be alleviated.

■When a range driver desires engine braking driving in second gear or lower, the manual valve 38 is set to ■range.

At this time, the computer shifts solenoids A and B.

The ON/OFF combination of C is determined depending on the driving condition so that the first speed or the second speed shown in Table 3 is selected, and the engine throttle opening is set to a predetermined value (for example, 1/16
Opening degree) or less, turn overrun clutch solenoid 40 to O.
FF and engage overrun clutch OR/C.

On the other hand, the manual valve 38 also outputs the line pressure of the circuit 81 from the port 38n, and the line pressure from the port 38n to the circuit 113 is reduced by the valve 72 and supplied to the circuit 140 as low reverse brake pressure.

At the first speed, the first and second shift valves 42 and 44 have their spools raised as shown in the figure, and the pressure in the circuit 140 is lower than that in the circuit 1.
29. The low reverse brake LR/B is reached through 124 and the shuttle valve 115, and is engaged. Therefore, the multi-speed automatic transmission enables engine braking driving in the first gear. Note that if the capacity of the low reverse brake LR/B is set to be large so that it is engaged even when reversing is selected, which will be described later, the engagement pressure of the awl is also reduced by the valve 72.
It is possible to prevent the engagement shock of the low reverse brake LR/B from increasing.

At the second speed, the first shift solenoid 42 is in the state shown, and the circuit 124 is connected to the low reverse brake engagement pressure circuit 129.
The low reverse brake LR/B is released to connect to the drain boat 42f, and with the 2nd gear selected and the overrun clutch OR/C engaged, the multi-speed automatic transmission runs with engine braking in 2nd gear. enable.

By the way, if the driver requests emergency engine braking and switches the manual valve 38 to ■ range while driving in 5th gear with D range, the jump from 5th gear to 2nd gear will occur due to the following action. and compensate for shifting.

Furthermore, as is clear from Table 1 above, this jump shifting is as follows:
This is accomplished not only by the main transmission changing gears, but also by switching the sub-transmission from the direct-coupled state to the deceleration state, but the state switching of the sub-transmission is done in the same way as described for the effect when switching from the D range to the ■ range. Since this is done, we will focus on the first. Second
Only the shift on the main transmission side by switching the shift solenoids A and B and the overrun clutch solenoid 40 will be described.

In 5th gear, the first shift solenoid A is ON as mentioned above.
to bring the first shift valve 42 into the spool up state and shift the second shift valve 42 to the spool up state.
When the shift solenoid B is OFF, the second shift valve 44 is placed in the state shown in the figure, and when the overrun clutch solenoid 40 is turned on, the overrun clutch control valve 62 is placed in the spool raised state, and the forward clutch F/C,
High clutch H/C 12-speed servo apply chamber 23/A,
The 5th speed selection state of the multi-stage automatic transmission is obtained in which pressure is supplied to the 3.4-speed servo release chamber 3.43/R and the 5th-speed servo apply chamber 5S/A. In this state, the 3.degree. 4-speed servo release pressure reaches the 5-2 sequence valve 5o from the circuit 144 through the circuit 142, and maintains this valve in the state in which the spool 50b is lowered in the figure. In addition, the 5th speed servo apply pressure is applied to the overrun clutch control valve 6 from the circuit 150.
2. The circuit 126 leads to the 5-2 relay valve 48, which is maintained in the state in which the spool 48b is raised in the figure.

When the driver switches the manual valve 38 to the ■ range at 22, the computer switches the first shift solenoid A to OFF, switches the first shift valve 42 to the state shown in the figure, switches the second shift solenoid B to ON, and switches the first shift solenoid A to the state shown in the figure. The 2 shift valve 44 is switched to the spool up state, but the overrun clutch solenoid 4o is kept ON until the 5-2 jump shift is completed, and the overrun clutch control valve 62 is kept in the spool up state. Due to the above switching of the second shift valve 44, the pressure in the 3.4-speed servo release chamber 3, 4S/R is about to be drained together with the pressure in the high clutch H/C, but these pressures are drained through the one-way orifice 131°143.
are narrowed down and not immediately eliminated. Therefore, during this time 3
．． The pressure in the 4-speed servo release chamber 3, 4S/R keeps the 5-2 sequence valve 5o in the spool downward state, and the circuit 12
7.141 is connected. Further, the above switching of the second shift valve 44 causes the circuit 127 to communicate with the D range pressure circuit 110, and the D range pressure is transmitted from the circuit 167 to the 5-2 sequence valve 50. Circuit 141.5-2 relay one valve 4 days,
circuit 125, first shift valve 4 switched as described above;
2, times 1126, overrun clutch control valve 62, circuit 150 and 5th speed servo apply chamber 5S/
A and backs up the 5th speed servo apply pressure in this chamber regardless of the ON/OFF combination of shift solenoids A and B for 2nd speed selection. This backup is
The 5th speed servo apply pressure acts on the lower end chamber of the 5-2 relay valve 48 to maintain the valve in the spool raised state, thereby self-maintaining.

After that, when the pressure in the 3rd and 4th speed Sanibore apply chamber 3.43/H is released, the spool 50b of the 5-2 sequence valve 5o, which had been stroked, is returned to the raised position by the spring 50a, so that the circuit 141 is moved to the drain boat 5Q.
Leads to c. Therefore, the 5th speed servo apply pressure backed up as described above is removed from the drain boat 50c, and due to this removal, the 5-2 relay valve 48 is also returned to the illustrated state. As a result of the above, 3rd and 4th speed servo apply chambers 3 and 4
After the pressure in S/R is released, the 5th speed servo apply chamber 5S/
A will be released, and the band brake B/B will not be disengaged, and the pressure will continue to be supplied to the second speed servo apply chamber 2S/A, so that the band brake B/B will remain in the engaged state. Therefore, when the pressure of the high clutch H/C released together with the pressure of 3°4S/R in the 3.4-speed servo release chamber releases this high clutch, the multi-stage automatic transmission will move to the 5th gear as is clear from Table 1 above. It is possible to shift from the second speed to the second speed without passing through an intermediate gear.

After this jump shift, the computer switches the overrun clutch solenoid 40 to OFF, switches the overrun clutch control valve 62 to the state shown in the figure, connects the 5th gear supply bore ply pressure circuit 150 to the drain port 62d, and connects the overrun clutch pressure circuit to the drain port 62d. 152 to the D range pressure circuit 110, and the overrun clutch OR/C is engaged with the upcoming D range pressure. By engaging this overrun clutch OR/C, the multi-speed automatic transmission enables engine braking in 2nd gear, but when switching from D range to ■ range while requesting a large engine brake while 5th gear is selected. The above-mentioned action ensures a jump shift from 5th gear to 2nd gear, so that required engine braking can be ensured.

Note that the action of the 5-2 sequence valve 50 is that pressure exists in the 5-speed servo apply chamber 5S/A, and this 5-speed servo apply pressure causes the 5-2 relay valve 48 to be in the spool up state. The existence of the 5-2 relay valve 48 can prevent malfunctions in which the backup of the 5th speed servo apply pressure is performed only during selection and is performed at other speeds.

When the ■ range driver requests engine braking driving in the first speed, he turns on the I range switch (not shown) with the manual valve 38 set to the ■ range.

At this time, the computer shifts solenoids A and B.

C are all ONL for 1st speed selection as shown in Table 3 above, respectively.
Turns off the overrun clutch solenoid 40 when the engine throttle opening is below a predetermined value (for example, 1/16 opening)
do. As a result, the multi-stage automatic transmission enters a state similar to that described above for the first speed in the (1) range, and maintains this state to enable first speed engine braking.

When the R range driver desires to drive in reverse and sets the manual valve 38 to the R range, the manual valve is connected to port 3 as shown in Table 2 above.
The line pressure of the circuit 81 is output only to 8R, and all other ports are used as drain ports. The line pressure output to the port 38R is supplied to the circuit 88 as a backward selection pressure, while passing through the shuttle valve 107 and the circuit 106 to reach the chamber 34g of the lock amplifier control valve 34. As a result, the valve 34 is stroked upward in the figure, and the torque converter T/
C is maintained in the converter state as when the first speed is selected.

The retraction selection pressure of circuit 88 is applied to one-way orifice 1 on the other hand.
14 to circuit 155, and then shuttle valve 154
and the chamber 46, d of the third shift valve 46 via the circuit 153.
When the valve reaches the state shown in the figure, the direct clutch D
/C is released and reduction brake RD/B is engaged to bring the auxiliary transmission into a decelerating state. By the way, at this time, the reverse selection pressure passing through the circuit 155 passes through the shuttle valve 112 and the circuit 161 and is transferred to the chamber 66a of the reduction timing valve 66.
It also reaches the back pressure chamber of the reduction brake accumulator 68, causing these valves and accumulators to function in the same manner as described in the case of range (1). As a result, the reduction brake RD/B is quickly engaged, and when the reverse rotation is selected, the reduction one-way clutch R is set to output the reverse rotation and is in the same transmission state as the reverse drive (engine brake).
Even if D10WC (see FIG. 2) cannot function, the auxiliary transmission can be quickly brought into a deceleration state.

Note that when the manual valve 38 is in the N or P range, the auxiliary transmission is in the deceleration state as shown in Table 1 above, so when the manual valve 38 is in the N range, the auxiliary transmission is also in the deceleration state when the manual valve 38 is switched from the P range to the R range. There is no change in the state, and the early engagement of the reduction brake RD/B by the above-mentioned functions of the reduction timing valve 66 and the reduction accumulator 68 appears to be meaningless. However, when switching to the R range immediately after starting the engine in the N or P range, the auxiliary transmission is initially in a neutral state due to the delay in pressure generation immediately after the engine starts, and after switching to the R range, the sub-transmission is in a neutral state. The vehicle is switched to a deceleration state by engaging the reduction brake RD/B. By the way, if there is a delay in engagement of the reduction brake RD/B during this switching, the reduction one-way clutch RD10WC cannot perform the substitute function as described above in this R range, so the neutral time of the auxiliary transmission will be longer by the above engagement delay. Therefore, when switching from the N or P range to the R range immediately after starting the engine, there is a large time delay for the multi-stage automatic transmission to change from a neutral state to a state in which reverse rotation output is possible. This not only causes a delay in starting from the rear, but also causes the engine to race during this period, causing a large R range selection shock. The above tendency is due to the high viscosity of the transmission hydraulic fluid when switching the manual valve 38 from the N or P range to the R range immediately after a cold start of the engine.
It becomes even more noticeable. However, in this R range, as described above, the reduction timing valve 66 and the reduction brake accumulator 68 quickly engage the reduction brake RD/B by the reverse selection pressure from the circuit 161, resulting in a delay in starting from the rear and a large R range selection shock. can be prevented.

The retraction selection pressure in circuit 88 also applies to one-way orifice 11.
4 and the low reverse brake L via the shuttle valve 115
It reaches the R/B and engages it, and also reaches the reverse clutch R/C via the one-way orifice 117 and engages it. Other friction elements related to the main transmission, forward clutch F/C, high clutch H/C, band brake B/B, and overrun clutch OR/C, are all operated by pressure from manual valve boats 38D, 38■, and 3811. All boats have been drained, so they will not be tied up. Therefore, by engaging the low reverse brake LR/B, the reverse clutch R/C, and the reduction brake RD/B, the multi-stage automatic transmission can select reverse as is clear from Table 1 above. For this reverse selection, shift solenoids A, B, C and overrun clutch solenoid 40 are turned on and off.
However, if these are turned off, the hydraulic oil will continue to be drained and the oil pump O/P will continue to be drained.
During this period, the computer programs solenoids A, B, C, and 40 to remain ON because driving energy is lost.

Note that when the reverse is selected, the accumulator switching valve 58 is in the state shown in the figure because it does not receive pressure from the D range pressure circuit 110, and by connecting the circuit 148 to the circuit 149, the accumulator 56 functions as a reverse clutch accumulator as follows. let

In other words, as mentioned above, the pressure reaching the reverse clutch R/C is throttled by the one-way orifice 117, and then the pressure reaching the reverse clutch R/C is
9. It is also led to the accumulator 56 via the accumulator switching valve 58 and the circuit 148, and gradually rises while stroking this accumulator. Thereby, it is possible to reduce the engagement shock of the reverse clutch R/C, that is, the selection shock when the manual valve 38 is switched from the P or N range to the R range.

(Effects of the Invention) Thus, the speed change control device for the auxiliary transmission of the present invention has the following features as described above.
Since a one-way clutch (in the illustrated example, the beam one-way clutch RD10WC) exists in parallel, the friction element for low speed selection (° in the illustrated example is the reduction brake R).
When shifting the auxiliary transmission by engaging D/B), the engagement pressure is increased with different characteristics during forward drive and reverse rotation output, and the rate of increase in this engagement pressure is made smaller during forward drive, Since the configuration is such that the output is increased during reverse rotation, during forward drive, the low speed selection friction element is engaged after the high speed selection friction element (direct clutch D/C in the illustrated example) is released and the one-way clutch is engaged. This makes it possible to reliably prevent gear change shock caused by the simultaneous engagement of both elements, and to quickly engage the friction element for low speed selection when the reverse rotation is output, thereby reducing the delay in starting from the rear immediately after starting the engine, and It is possible to reliably prevent a shock from engaging the low-speed selection friction element due to the accompanying engine revving.

[Brief explanation of the drawing]

Fig. 1 is a shift control hydraulic circuit diagram of a multi-stage automatic transmission showing an embodiment of the device of the present invention, Fig. 2 is a schematic diagram showing the power transmission train of the automatic transmission, and Part 3 is a reduction diagram using the device of the present invention. A time chart illustrating changes in brake engagement pressure over time, and FIG. 4 is a conventional shift control hydraulic circuit diagram for an auxiliary transmission. 1... Input shaft 2... Output shaft 3... Main transmission 4... Sub-transmission D/C... Direct clutch (friction element for high speed selection) RD/B... Reduction brake ( Friction element for low speed selection) RDloWC...Reduction one-way clutch (
One-way clutch) 0/P...Oil pump 20...Pressure regulator valve 22...Pilot valve 24...Duty solenoid 26...Pressure modifier valve 28...Modifier accumulator 30... Accumulator control valve T/C...torque converter 32...torque converter relief valve 34...lock-up control valve 36...lock-up solenoid 38...manual valve A...first shift solenoid B... ...Second shift solenoid C...Third shift solenoid 40...Overrun clutch solenoid 42...
First shift valve 44...Second shift valve 46...
Third shift valve 48...5-2 relay valve 50...
・5-2 sequence valve 52...1-2 accumulation valve 54...N-D accumulator 56...3rd and 4th speed servo release and reverse clutch accumulator 58...Accumulator switching valve 60... 5-speed servo apply accumulator 62...
・Overrun clutch control valve 64...Overrun clutch pressure reducing valve 66...Reduction timing valve 68...Reduction brake accumulator 70・
...Direct clutch accumulator 72...■ Range pressure reducing valve (Fig. 3)

Claims (1)

[Claims] 1. Equipped with a one-way clutch that can switch between high and low speeds by selectively hydraulically operating a friction element for high speed selection or a friction element for low speed selection, and can function as a substitute for the friction element for low speed selection during normal drive. In a multi-stage automatic transmission in which an auxiliary transmission and a main transmission are coupled in tandem, the increase rate of the working oil pressure of the low speed selection friction element is made small in the automatic transmission range intended for forward drive, and reverse rotation is performed. A speed change control device for an auxiliary transmission, characterized in that it is provided with means for increasing output in a reverse travel range. 2. A shift control device for an auxiliary transmission according to claim 1, wherein the means comprises an accumulator, and the back pressure of the accumulator is changed between an automatic shift range and a reverse travel range.