JPH02304255A - Speed-change device of auxiliary transmission - Google Patents

Abstract

PURPOSE:To prevent interlock by holding a shift valve in the hydraulically operated state of its low-speed selecting frictional element by the outputted reverse selection pressure, in the reverse traveling range (reverse rotation output) position of the manual valve of a multiple stage automatic transmission. CONSTITUTION:When a manual valve is operated to R range, a reverse selection pressure PR is led into the chamber 48d of a third shift valve 46 through a one-way orifice and shuttle valve to move a spool 46b upward, thus disengaging the connection of a frictional element D/C for high-speed selection and applying a line pressure PL to a friction element RD/B for low-speed selection to connect it. With this constitution, even if an auxiliary transmission is mis-operation by a computer, the friction element D/C will not be operated. Accordingly, such a danger as the friction element D/C is driven in reverse traveling range (in reverse rotating output) and the auxiliary transmission is interlocked with the D/C and a one-way clutch in parallel with the friction element RD/B can be prevented securely.

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 auxiliary transmission generally includes a direct clutch (friction element for high speed selection) and a duction brake (friction element for low speed selection), which are selectively hydraulically operated via a shift valve. The configuration is such that high-low speed 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 coupled by the direct clutch are prevented from rotating in opposite directions, which will accelerate the wear of the direct clutch and prevent the direct clutch from becoming locked. Therefore, when setting the main transmission to the reverse gear selection state so that the multi-stage automatic transmission outputs reverse rotation (to make the vehicle run backwards), the sub-transmission is set to the high-speed selection state where the direct clutch is engaged. If this happens, there is a risk that the sub-transmission will be damaged due to interlock between the direct clutch and the one-way clutch. Therefore, in the reverse travel range where the multi-stage automatic transmission is intended to output reverse rotation, the sub-transmission must be placed in a low-speed selection state in which the reduction brake is engaged.

Therefore, switching between high and low speeds of the auxiliary transmission is conventionally achieved by a circuit as described in the above-mentioned document and schematically shown in FIG. 4 attached to this specification. That is, when selecting a forward low speed gear and when selecting a reverse gear of a multi-stage automatic transmission, the solenoid pressure P3L is drained, and the shift valve SFV is set to the forward low speed selection pressure pts and the spring S.
P (when selecting a low forward gear) or spring SP (when selecting a reverse gear) to the downshift position, engage the reduction brake RD/B with line pressure PL, and drain and release the direct clutch D/C. By doing so, the auxiliary transmission is placed in the low speed selection state. Also, when a forward high speed gear of a multi-stage automatic transmission is selected, a shift solenoid pressure PSL is generated, which moves the shift valve SFV to the upshift position against the spring SP, and engages the direct clutch D/C by the line pressure PL. reduction brake R
By draining and opening the D/B, the auxiliary transmission is placed 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 is caused by the rise of the reduction brake engagement pressure and the direct clutch engagement pressure of the respective accumulators ACCI and ACC.
2 provides transient control and contributes to alleviating shift shock.

(Problem to be Solved by the Invention) However, in such a conventional shift control device for an auxiliary transmission, since the auxiliary transmission is placed in a low speed selection state only by electronic control of the solenoid pressure PsL during reverse, the electronic control system There is a risk that the solenoid pressure PSL will be generated when the vehicle is in reverse due to malfunction of the vehicle, causing the sub-transmission to enter the high-speed selection state. In this case, the sub-transmission is interlocked and damaged as described above.

For this reason, the electronic control system generates or drains the forward solenoid pressure PST depending on the gear position, but the reverse solenoid pressure P! It was necessary to establish a logic to ensure that L was drained, and the central processing unit (CPU) capacity of the computer had to be increased, which was disadvantageous in terms of cost.

The present invention forcibly holds the shift valve in the downshift position by the reverse selection pressure output from the manual valve operated by the driver in the reverse travel range,
This aims to solve the above-mentioned problem.

(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 controlling high and low speeds by selectively hydraulically operating a high speed selection friction element or a low speed selection friction element via a foot valve. It is possible to switch
In a multi-speed automatic transmission that is tandemly coupled with a main transmission and an auxiliary transmission equipped with a one-way clutch that can function as a substitute for a friction element for selecting low speed during forward drive, the reverse rotation output of the multi-speed automatic transmission is When the manual valve is in the reverse travel range position, the shift valve is maintained in a state in which the low speed selection friction element is hydraulically operated by the reverse selection pressure output from the manual valve.

(Function) Depending on the state of the shift valve, the sub-transmission is hydraulically actuated to select a low-speed selection friction element or a high-speed selection friction element, resulting in a low-speed selection state or a high-speed selection state, which prevents the worn out state and the retraction of the main transmission. The multi-speed automatic transmission can obtain a large number of speeds in combination with the selected speeds including the variable speeds.

By the way, when the driver desires a reverse gear, the driver sets the manual valve to the reverse range. At this time, the manual valve outputs a reverse selection pressure to place the main transmission in a reverse gear selection state, and this reverse selection pressure simultaneously maintains the shift valve in a state in which the low speed selection friction element is hydraulically operated. Therefore, the reverse sub-transmission is never erroneously set to the high speed selection state and damaged due to the interlock. In addition, there is no need for the electronic control system to have complicated logic for this purpose, and the control system only needs to consider the forward movement.
It is possible to reduce the cost by reducing the capacity of the PU.

(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 a sub-planetary 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 RE41?" published by the applicant in 1987.
OIA type maintenance manual J (A261CO7) Middle East 1-5
It is the same as the transmission mechanism described on page 3, and includes two first and second planetary gear sets 5.6 in tandem, which are first and second sun gears 5s=6s, first and second ring gears, respectively. 5m+6. I. When meshed with these sun gear and ring gear, a simple planetary gear set is formed, which is made up of ions 5P, 6P, and first and second carriers 5C16c 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.

The carrier 5c is further controlled by the forward clutch F/C.
The row one-way clutch L10WC can be coupled to the outer race of the forward one-way clutch F10WC arranged in any direction, 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 sub-planetary gear transmission mechanism 4 includes a third planetary gear set 7, a third sun gear 78, a third ring gear 7R1, a pinion 7F that meshes with these, and a third carrier 7 that rotatably supports the pinion 7F. A simple planetary gear set. a carrier 6 which is an output element of the main planetary gear transmission mechanism 3;
Connect ring gear 7R- to output shaft 2, and connect carrier 7c to output shaft 2.
join to. Ring gear 7R can further be coupled to sun gear 7 as appropriate by direct clutch D/C, and sun gear 7s is connected to reduction one-way clutch RDloWC.
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 is capable of driving (D, III, n) 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 ○ marks) 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 auxiliary planetary gear transmission mechanism.

First, to explain the action of the main free gear transmission mechanism 3, when the forward clutch F/C is activated, the ring gear 6R is moved in the opposite direction to the input shaft 1 via the forward one-way clutch F10WC and the row one-way clutch L10WC. rotation is prevented. Therefore, the rotation from the input shaft I to the sun gear 6° is the pinion 6, the ring gear 6,
1, the carrier 6C is decelerated in the same direction as the input shaft 1 and rotates normally, resulting in a first speed state. The gear ratio at this time is □, where the gear ratio of the sun gear 6 and ring gear 6 is α21+α2. However, when the carrier 6c is reversely driven at high speed in the same direction as the input shaft 1 in the first gear α2 state, the one-way clutch F10WC is activated.

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 release the one-way clutches F10WC and LloWC, as indicated by Δ 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
Together with the operation of , the power from the input shaft 1 to the sun gear 6 causes the carrier 6c 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 5s and ring gear 5s. If the gear ratio with I 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 carrier is rotated by the integral rotation of the sun gear 6 coupled to the input shaft 1 and the ring gear 6R. A third speed (directly coupled) selection state in which the shaft 6c rotates in the same manner as the human power shaft 1 is obtained.

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

When high clutch H/C and band brake B/B are activated, carrier 5. rotates together with the human power shaft 1, and the sun gear 5. rotates with the operation of the band brake B/B. is fixed, so sun gear 5. Pinion on top 5. Through the rolling of the ring gear 5R1, the carrier 6 can obtain a speed increase 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 L
When R/B is activated, reverse clutch R/C is activated and sun gear 5. rotates together with input shaft 1, and carrier 5. rotates together with input shaft 1, and carrier 5. is fixed, so ring gear 5. I, therefore carrier 6, is input shaft 1
The gear ratio is reversed in the opposite direction, and the reverse selection state with a gear ratio of 1□ can be obtained α1.

Next, to explain the operation of the sub-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 6° to the ring gear 7, I is transmitted to the carrier 7cs while rolling the pinion 7 around the sun gear 7, and is therefore transmitted to the output shaft 2 under deceleration, and a deceleration state is obtained. It will be done. Therefore, the reduction brake RD/B functions as a wear element for low speed selection of 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 from the carrier 7c to the output shaft 2.

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

In addition, when switching the reduction brake RD/B from the operating state to the non-operating state, the sun gear 7s is connected to the carrier 6c and the ring gear 7R before the direct clutch D/C is activated.
If the direct clutch D/C rotates in the opposite direction, it will not only accelerate the wear of the direct clutch D/C, but also increase the shock when it is activated, causing shift shock. However,
The one-way clutch RD10WC is useful for preventing the above-mentioned rotation of the ring gear 7R and solving the above-mentioned problem.

In addition, there may be cases where it is not necessary to operate the one-way clutch RD10WC and the ducting brake RD/B, but the high-low speed switching circuit can be configured by setting the sub-planetary gear transmission mechanism to only the two states of operating the direct clutch or re-duction brake. For simplicity, 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. Furthermore, examples of the gear ratios shown in the table above include the gear ratio α, which can be obtained by putting the transmission 3 in the reverse position.

α2. α is 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.
．． 441.0.560.0.384, but as is clear from the example of this gear ratio, an appropriate gear ratio can be obtained, and the lowest gear (1st gear) It is possible to achieve a five-speed gear transmission in such a manner that the gear ratio range between the highest speed stage (fifth speed) and the highest speed stage (fifth speed) is increased.

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 A1 second shift solenoid B2 third shift solenoid C, 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
．． 1-2 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. C, low reverse brake LR/B, t-bar/) latch OR/C, direct clutch D/C and reduction brake RD/
It is configured by connecting to 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 engine power to the input shaft 1 shown in Fig. 2 in a lock-up state in which the input and output elements are directly connected when the hydraulic oil is passed 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 3.4S/H, 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, and the oil pump O/P discharges oil to the line pressure circuit 81 by springs 20a and 20j. When the spring force of the spring 20j is increased by the plug 20c, the pressure is increased to 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 Boats 20e to 20h are provided which are opened and closed depending on the time. Boat 20e is connected to circuit 81 and is arranged so that as spool 20b descends from the position shown, it communicates with boats 20h and 20f. As the spool 20b descends from the illustrated position, the communication with the boat 20g, which is used as a drain boat, decreases, and at the point when the communication with the boat 20f is cut off, the boat 20e
Place it so that it begins to communicate with the The boat 20f is then connected to the capacity control actuator 85 of the oil pump O/P via a circuit 84 in which a bleed 83 is present, and pulsations thereon are 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 0/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 boat 20e to the boat 20h. As a result, the above pressure is equal to the boat 20
A portion of the water is drained from h and lowered, and the spool 20b is pushed back by the springs 20a and 2Qj. By repeating this action, the pressure regulator valve 2o 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 it 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.

When reversing is selected, an upward force is applied to the plug 20c by the retracting 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 at the desired constant level when reversing is selected. value. When the rotational speed of the oil pump 0/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 2Of to the boat 20e, and connects the drain boat 2Of to the boat 20e.
Cut off from 0g. As a result, some of the oil in the boat 20e is removed from the port 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 oil pump ◯/P controls the capacity so that the discharge amount remains constant while the rotational speed exceeds a certain value, and prevents the power loss of the engine from becoming large 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 9o is connected to the chamber 22c via an orifice 91.

Pilot valve 22 is normally in the state shown, in which line pressure from circuit 81 is supplied to pilot pressure circuit 9o 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 9o is switched and connected to the drain boat 22d, and the pilot pressure in the circuit 9o 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 4o,
Pressing 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 the
This drain boat shall be opened at N time.

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 O. 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 O.

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 boat 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 boat 26g, and the modifier pressure becomes a value obtained by amplifying the control pressure from the circuit 94 during the pressure regulation 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 boat 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 compensate for the above downward force, the spool 26b is replaced with a capo 26c.
1-26d to increase the modifier pressure by replenishing the pilot pressure, and conversely, if the modifier pressure is excessive, the spool 26b connects the output port 26c to the drain boat 26e to decrease the modifier pressure. By repeating this action, the pressure modifier valve 2
6 is the modifier pressure of the circuit 87, the difference between the force due to the spring 26a and the force due to the pilot pressure from the boat 26g,
The control pressure from the circuit 94 is adjusted to a value corresponding to the force, and the modifier pressure is applied to the plug 20c of the pressure regulator valve 20.

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.

The torque converter relief valve 32 includes a spool 32b elastically supported in the position shown by a spring 32a, and the spool 32c is connected to the input port 32d in the position shown.
This communication is decreased as it goes up in the figure, and the output port 32c is switched to be connected to the drain boat 32e. A chamber 32f facing the spool end face far from the spring 32a 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 spool 32c. The output port 32c is connected to the front lubricating section FR/L via the relief valve 95.
UB and is connected to lockup control valve 34 by circuit 96. The input port 32d is connected to the boat 2 of the pressure regulator valve 20 by the circuit 97.
0h, 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 closed to the input port 32.
The leaked oil to d is supplied to the lock-up control valve 34 and, therefore, the torque converter T/C via the circuit 96. 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 spring 32a, spool 32b
2c to drain boat 32e to reduce the torque converter supply pressure and keep this pressure below a set value corresponding to the spring force of spring 32a. 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 hydraulic 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 C00L.
is guided to the rear lubricating section RR/LU after being cooled here.
Head to B. 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 flows from the apply chamber APL to the release chamber REL.
Flow through the torque converter T/C to lock up the torque converter. In this lock-up state, the hydraulic oil that has passed through the torque converter is removed from the drain boat 34e, so it does not pass through the oil cooler C○OL.
2 bypasses the torque converter and guides the hydraulic oil to the oil cooler C00L, which cools it and supplies the rear lubrication section RR/
Ensures lubrication of L U B.

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 device i90, 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 closed at 0FFL 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 3
4d to move the spool 34a to the orifice 104.
．． 105 and acting on the stepped plug 34b, the torque converter T/C1 is raised as shown in the figure against the release pressure and pilot pressure acting on the stepped plug 34b. 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 circuit 88 described above for each of the two shuttle valves.
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, forward third speed engine brake (I[[) range, forward second speed engine brake (n) range (also used as first speed engine brake range) spool 38a The boat 38D is equipped with a line pressure circuit 81 according to the selected range of the spool as shown in the following table.

38111, 3811.38R. Note that in this table, ○ marks indicate boats that communicate with the line pressure circuit 81, and no marks indicate boats that are being drained.

The boat 38D in Table 2 has an accumulator control valve 30, a forward clutch F/C, and a D range pressure circuit 110.
Accumulator switching valve 58, first shift valve 42, second shift valve 44, and overrun clutch control valve 6
2. Connect to. Also, boat 38■ is ■range pressure circuit 1
11 to the corresponding input of the shuttle valve 112, the boat 38R is connected to the range pressure reducing valve 72 by the range pressure circuit 113, and the reverse selection pressure circuit 88 is connected to the boat 38R. 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. In addition, the low reverse brake L is connected via the one-way orifice 114 and the corresponding input port of the shuttle valve 115.
In addition to connecting to R/B, one-way orifice 117
Connects to reverse clutch R/C via .

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.
A chamber 30. is connected to the chamber 30. and the small diameter end faces the chamber 30. c is open to atmosphere. Therefore, the spool 30a is connected to the duty solenoid 24.
Due to the pressure in the circuit 94 adjusted as described above, the pressure in the circuit 94 is increased in the figure, and the output port 30d is connected to the drain boat 30.
When the boat 30d is cut off from the boat 30d 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 2.
4, as mentioned above, the pressure in the D range pressure circuit 110, which is the source pressure, is adjusted to increase as the engine load increases outside the reverse range (D, II).
I, II) Since it occurs only in the range, accumulator back pressure occurs only when the forward drive range is selected, and increases as the engine load increases, making the capacity of the corresponding accumulator corresponding to the engine load. be able to. Note that the accumulator back pressure is connected to circuit 116.
This supplies the 1-2 accumulator valve 52, the N-D accumulator 54.5 speed servo apply accumulator 60, the direct clutch accumulator 70, and the overrun clutch pressure reducing valve 64.

A one-way orifice 120 is inserted into the part of the D range pressure circuit 110 immediately before the forward clutch F/C, and this one-way orifice and the forward clutch F
/C, the N-D accumulator 54 and the accumulator switching valve 58 are sequentially connected via a one-way fitting 121 which 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 Spoo 7? 42b, the D range pressure circuit 110 is connected to the 2nd speed valve circuit 122, and the 1st speed pressure circuit 10 is connected to the 1st speed pressure circuit 10.
8 to the drain boat 42d, ■ Range pressure circuit 124
is connected to the drain boat 42f, between circuits 125 and 126, and in the raised position of the spool 42b, the circuit 108 is connected to the circuit 127, the circuit 122 is connected to the circuit 128, and the circuit 1
24 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 clutch 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 connected to the output port (52e) to the manual port 52.
f, and connects to the 2nd speed servo apply chamber 2S from the port 52e.
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 boat 52e exceeds a value corresponding to the sum of the spring force difference and the accumulator back pressure acting on the stepped portion 52d, the spool 52a passes the output boat 52e to the drain boat 52h and outputs the output. The second speed servo apply pressure from the boat 52e is reduced by the excess amount, and this pressure is regulated to the above value.

By the way, the 2nd speed servo apply pressure is blocked by the check cup 135, acts on the piston cup 52i of the spring 52c through the orifice 136, and strokes it to gradually increase the spring force of the spring 52c. The pressure also increases with a predetermined time gradient. Also, the stepped portion 52
Since the accumulator back pressure acting on d is regulated by the duty solenoid 24 and the accumulator control valve 30 to increase as the engine load increases, the The level (commonly referred to as the seed valve) 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 the I and 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 3.4-speed servo release chamber 3.4S/R of the band brake B/B and the high clutch 870, and the one-way orifice 145 and the circuit 142 are connected in the middle of the circuit 142. It is connected to the accumulator switching valve 58 through a circuit 147 into which two one-way cups 146, which can be replaced with ones with different inner diameters, are inserted. This valve is further connected to a 3rd and 4th speed servo release/reverse clutch accumulator 56 via a circuit 148, and to a reverse clutch R/C via a circuit 149.

The accumulator switching valve 58 includes a spool 58b elastically supported in the position shown by a spring 58a, and this spool is D
It is assumed that when pressure exists in the range pressure circuit 110, it moves to the left in the diagram. Circuit 148 in the illustrated position of spool 58b
is connected to the circuit 149, and the accumulator 56 is used to control the pressure increase of the reverse clutch R/C. At the leftward position of the spool 58b, the circuit 148 is connected to the circuit 147, and the accumulator 56 is connected to the 3rd and 4th speed servo release chambers 3 and 4S/ Used for pressure rise control of 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, 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. Circuit 153 is connected to the output port of shuttle valve 154, and each of the two valves has a third
When shift solenoid C is turned on (closed), spontaneous pressure (same value as the pilot pressure of circuit 90) and backward range pressure (described later) are selectively supplied to 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
■Connect range pressure circuit 111 to one input of 2 to 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. By connecting the output port 4c to the circuit 152 at this spool position, the overrun clutch OR
Outputs working pressure of /C.

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 fed back to the right end surface of the spool through an orifice 72c provided in the spool 72b, causing the spool 72b to move to the left in the figure. When the output pressure of the circuit 140 exceeds the value corresponding to the spring force of the spring 72a, the spool 7
2b connects the circuit 140 to the drain port 72d to release excess pressure and reduce the output pressure to a constant value corresponding to the spring force of the spring 72a.

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, all of the manual valve boats 38D, 3811[, 38■, and 38R are shown in Table 2 above. Since these boats are drain boats and there is no line pressure output from these boats, the forward clutch F/C, high clutch H/C, band brake B/B, which are operated using the line pressure from these boats as source pressure, The 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. 2 is kept in a neutral state where power cannot be transmitted. is over.

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 boat 46e and 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.

When the manual valve 38 is set to the D range with the desire to perform forward automatic shift driving in the D range, automatic shifts are performed between all gears and the first to fifth gears as follows.

(1st speed) That is, in the D range, the manual valve 38 outputs the line pressure of the circuit 81 only from the boat 38D as the D range pressure 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 0PJL.
, 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 and 4S/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 2S
/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 sets the overrun clutch solenoid 40 to 0IJL 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. This circuit 126 is then changed to a circuit 128 by the first shift valve 42.
Since the circuit 12B is connected to the drain port 44e of the second shift valve as described above, the fifth speed servo apply chamber 53/A is drained. Reverse clutch R/C
The low reverse brake LR/B is released because its circuit 88 is drained from the corresponding port 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 is activated, and in combination with the operation of the forward one-way clutch F10WC as shown in Table 1 above, each gear automatic transmission is placed in the first speed 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 circuit i27.108.
The torque is supplied to the lock-up control valve 34 via the shuttle valve 107 and the circuit 106, and the torque converter T/C is set to the converter state regardless of the operating state of the lock-up solenoid 36, so that the engine is stalled even when the first speed is selected. You can keep the vehicle stopped by operating the brakes without any trouble. In addition, when the forward club clutch F/C is operated, its working oil pressure is throttled by the one-way orifice 120, and the N-D accumulator 54 is raised while being stroked from the right half position shown in the figure to the left half position shown in the figure. The rise is done slowly, and the forward clutch F
/C fastening shock, that is, N-D select shock 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, it continues to drain the circuit 126 and therefore the 5th speed servo apply chamber 53/A. The first shift valve 42 further connects the lockup control valve 34 to the lockup 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 23/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 port 44e and communicates with the D range pressure circuit 110, and the D range pressure from this circuit passes through the circuit 128 and the one-way orifice 132, reaches the high clutch H/C, and engages the high clutch H/C. On the other hand, the pressure applied to engage the Mihai clutch H/C reaches the 3rd and 4th speed servo release chambers 3.43/H 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 chambers 3 and 4S/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 chamber 3, 43/R increases gradually 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 the forward clutch F/C, forward one-way clutch F10WC, and reduction brake RD/B are maintained in operation, and the above-mentioned 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, the accumulator 56
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 upshifted from the third speed to the fourth speed, 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 is reached in which the fifth speed should be selected, the computer turns on the first shift solenoid A and switches the spool 42b of the first shift valve 42 again as shown in Table 3 above. raise. As a result, the high clutch and servo release circuit 128, which was connected to the D range pressure circuit 110 through the second shift valve 44, is connected to the circuit 1 through the first shift valve 42.
26, and this circuit 126 is supplied with D range pressure. 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, due to the above switching of the first shift valve 42, the circuit 1
22 is disconnected from the D range pressure circuit 110, but the circuit 1
28, so the 2nd speed servo apply chamber 2
Pressure continues to be supplied to S/A. Therefore,
As is clear from Table 1 above, the band brake B/B is engaged, and the forward clutch F/C, high clutch H/C, and direct clutch D/C are maintained in operation, and the multi-stage automatic transmission is activated. Upshifting from 4th speed to 5th speed (overdrive ○D) can be performed.

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.

Further, the above switching of the first shift valve 42 causes the circuit 108 to be cut off from the drain port 42d, and is connected to the circuit 127, but this circuit is not connected to the drain port 44d when the second shift valve 44 is in the illustrated state. Therefore, in the fifth gear selection state, the lock-up control valve 34 is in the chamber 34g.
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-stage automatic transmission is automatically shifted between the first speed and the fourth speed, but at this time, the computer turns off the overrun clutch solenoid 40 when the engine throttle opening is below a predetermined value (for example, 1/16 opening). . 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, the shock when the overrun clutch OR/C is engaged can be alleviated.

Note that the above switching of the overrun clutch control valve 62 drains the fifth speed servo apply chamber 5S/A through the circuit 150 to the drain port 62d, thereby compensating for the release of the band brake B/B. As a result, when overrun clutch OR/C is engaged, 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 port 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 chamber 66a of the reduction timing valve 66 and the circuit 161 leading to the accumulator back pressure chamber of the reduction brake accumulator rake 68 in the D range. The reason is that the manual valve boat 38I [1 puts the circuit 111 in a no-pressure state and the manual valve port] 38R
This is to bring the circuit 155 into a no-pressure state through 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 reduccidin accumulator 68 is set to 0, and the accumulator characteristics are determined only by the built-in spring 68a.

Therefore, the reduction brake engagement pressure first rises to a value equivalent to the spring force of the spring 68a that moves the piston 68b of the accumulator 6 to the right half position shown, and then moves the one-way orifice 160 while stroking the piston 68b to the left half position shown. It rises at a time gradient determined by the inner diameter, and at the moment the piston 68b finishes its stroke, it further rises by the return spring force of the reduction brake RD/B, and instantly becomes equal to the line pressure, which is the source pressure, at the loss stroke of the reduction brake RD/B. become.

By the way, as mentioned above, since the characteristics of the accumulator 68 are such that the tank pressure is set to a low value determined only by the spring force of the spring 68a, the reduction brake RD/B is not engaged during the initial stroke and is not engaged thereafter. It will be concluded for the first time. However, the D range does not require engine braking, but rather direct drive from the input shaft side to the output shaft side.

When the left clutch D/C is released, the reduction one-way clutch RD10WC (see FIG. 2) can take over the power transmission, and the delay in engagement of the reduction brake RD/B does 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 is shifting 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, the manual valve 38 was set to the ■ range while the vehicle was running in the 5th or 4th gear set to the D range.

In this case, as is clear from Table 1 above, the auxiliary transmission switches from the direct connection state to the deceleration state in the same manner as described above for the 4-3 downshift. However, in the lever ■ range,
The manual valve 38 now outputs the line pressure from the circuit 81 to the boat 3811, and this pressure is supplied to the chamber 66a of the reduction timing valve 66 and the back pressure chamber of the accumulator 68 via the shuttle valve 112 and the circuit 161. Ru. Therefore, the reduction timing valve 66 is lifted up the spool 66b and passes between the circuits 157 and 163, and supplies the pressure of the circuit 157 not only through the one-way orifice 160 but also through the orifice 162 to the reduction brake RD/B. Also, the accumulator 68 is a spring 68.
The accumulation characteristics are determined not only by the line pressure from the circuit 161, but also by the line pressure from the circuit 161, and the tank pressure is increased.

Therefore, the reduction brake engagement pressure first produces a reduction brake stroke shelf, then rises to a higher value corresponding to the sum of the spring force and the line pressure from circuit 161, which places the accumulator piston 68b in the right half position, and then one-way It rises at a steep slope determined by the sum of the inner diameter of orifice 160 and the inner diameter of orifice 162, and reaches the same value as the line pressure, which is the original pressure, after the stroke of accumulator piston 68b is completed. Therefore, the reduction brake engagement pressure can instantly engage the reduction brake RD/B earlier by the inner diameter of the orifice 162 and the back pressure of the accumulator 68.

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, since the engagement of the reduction brake is started during the mechanical stroke 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 so that the first speed or second 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
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 is also connected to the circuit 81 from the boat 3811.
The line pressure of this boat 38I [
The line pressure from 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 via 124 and the intermediate torque valve 115, and is engaged.

Therefore, the multi-speed automatic transmission enables engine braking driving in the first gear. In addition, low reverse brake LR/
It would be difficult if the capacity is set to be large because B is engaged even when the reverse mode is selected as described later, but since the engagement pressure is reduced by the valve 72, the engagement shock of the low reverse brake LR/B is prevented from increasing. be able to.

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 the multi-speed automatic transmission applies engine braking in the 2nd gear due to the 2nd gear selection state and the engagement of the overrun clutch OR/C. enable running.

By the way, while driving in 5th gear in D range, an emergency engine brake was requested and the driver's manual valve 38 was activated.
When switching to range, the jump shift from 5th gear to 2nd gear is compensated for by the following action.

Furthermore, as is clear from Table 1 above, this jump shifting is as follows:
This is achieved not only by the main transmission changing gears but also by switching the auxiliary transmission from the direct-coupled state to the deceleration state, but the state switching of the auxiliary 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 turned OFF, the second shift valve 44 is brought into the state shown in the figure, and when the overrun clutch solenoid 40 is turned ON, the overrun clutch control valve 62 is brought into the spool raised state, and the forward clutch F/C,
High clutch H/C 12-speed servo apply chamber 2S/A,
3. The 5th speed selection state of the multi-stage automatic transmission is obtained in which pressure is supplied to the 4-speed servo release chambers 3, 4S/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 50 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.

Here, when the driver switches the manual valve 38 to the ■ range, the computer switches the first shift solenoid A to OFF, switches the first shift valve 42 to the state shown in the figure, and switches the second shift solenoid B to ON. The second shift valve 44 is switched to the spool up state, but the overrun clutch solenoid 40 is kept ON until the end of the 5-2 jump shift, and the overrun clutch control valve 62 is kept in the spool up state. By 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 from the one-way orifice 131, 14.
3, it is narrowed down and not immediately eliminated.

Therefore, during this time, the pressure in the 3rd and 4th speed servo release chambers 3 and 4S/R keeps the 5-2 sequence valve 50 in the spool downward state, and communicates between the circuits 127 and 141.

Further, the circuit 127 is switched to D by the above switching of the second shift valve 44.
It communicates with the range pressure circuit 110, and the future D range pressure is transmitted from the circuit 167 to the 5-2 sequence valve 50 and the circuit 141.
．． 5-2 relay valve 48, circuit 125, first shift valve 42 switched as described above, circuit 126, overrun clutch control valve 62, circuit 150, and is supplied to the 5-speed servo apply chamber 5S/A. The 5th speed servo apply pressure in the chamber is backed up regardless of the ON/OFF combination of shift solenoids A and B for 2nd speed selection.

This backup is self-maintained by the 5th speed servo apply pressure acting on the lower end chamber of the 5-2 relay valve 48 to keep this valve in the spool raised state.

After that, when the pressure in the 3rd and 4th speed servo apply chambers 3 and 4S/R is released, the spool 50b of the 5-2 sequence valve 50, which had been stroked, is returned to the raised position by the spring 50a, and the circuit 141 is moved to the drain boat. 50
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, 3.4-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 released at all and the pressure will continue to be supplied to the 2nd speed servo apply chamber 2S/A, thereby maintaining the engaged state. Therefore, when the pressure of the high clutch H/C released together with the pressure of the 3rd and 4th speed servo release chambers 3°4 S/R releases this high clutch, the multi-stage automatic transmission is activated as shown in Table 1 above. From 5th gear to 2nd gear without going through any intermediate gears.
You can shift gears quickly.

After this jump gear 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 boat 62d, and connects the overrun clutch pressure circuit to the drain boat 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 5-21J 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 turns on the shift solenoids A, B, and C for selecting the first gear as shown in Table 3 above, and turns the overrun clutch solenoid 40 on when the engine throttle opening is below a predetermined value (for example, 1/16 opening). Turn off. As a result, the multi-stage automatic transmission enters the same state as described above for the first range gear, and maintains this state to shift to the first gear.
Enables fast engine braking driving.

When the R range driver desires to drive in reverse and sets the manual valve 38 to the R range, the manual valve is set as per report 3 in Table 2 above.
The line pressure of circuit 81 is output only to 8R, and all other boats are used as drain ports. The line pressure output to the port 38R is supplied to the circuit 88 as a backward selection pressure, and on the other hand, reaches the chamber 34g of the lock-up control valve 34 via the shuttle valve 107 and the circuit 106. As a result, the valve 34 is stroked upward in the figure, and the torque converter T/
C' is kept in the converter state as in the first speed selection.

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 reaches the chamber 46d of the third shift valve 46 via the circuit 153 to bring this valve into the state shown, and direct clutch D/
By releasing C and engaging reduction brake RD/B, the auxiliary transmission is brought into a decelerating state. By the way, at this time, the reverse selection pressure passing through the circuit 155 is applied to the shuttle valve 112 and the circuit 1.
61, it also reaches the chamber 66a of the reduction timing valve 66 and the back pressure chamber of the reduction brake accumulator 68, and causes these valves and accumulators to function in the same manner as described in the case of the range (2). As a result, the reduction brake RD/B is quickly engaged, and even if the reduction one-way clutch RD10WC (see Figure 2) cannot function because the transmission state is the same as the reverse drive (engine brake) when the reverse drive is selected, the secondary The transmission can be quickly brought into a deceleration state.

The retract selection pressure in circuit 88 also applies to one-way orifice 114.
and the lower hearth brake LR via the shuttle valve 115.
/B and engages it, and also reaches reverse clutch R/C via 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 all use the pressure from manual valve boats 38D, 381[r, and 38II as operating pressure, and since these boats are all drained, they will not be engaged. . Therefore, low reverse brake LR/B, reverse clutch R/C
By engaging the reduction brake RD/B, the multi-stage automatic transmission can select reverse as is clear from Table 1 above. Shift solenoids A and B are used for this reverse selection.
, C and overrun clutch solenoid 40 are turned on,
Turning these off has no effect, but if these are turned off, the hydraulic oil will continue to drain and drive energy for the oil pump ○/P will be lost. Program to keep it ON.

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.

By the way, in this R range, as described above, the reverse selection pressure of the circuit 88 reaches the third shift valve 46 via the circuits 155 and 153, and this valve is held in the state shown to bring the sub-transmission into the deceleration state. Therefore, this condition is compensated even when the third shift solenoid is turned off.

Therefore, in the R range where reverse rotation output is intended, it is possible to reliably prevent the sub-transmission from engaging the direct clutch D/C and entering the interlock state. Therefore,
There is no need for a logic that always turns on the third shift solenoid C in the R range, and the CPU capacity of the computer can be reduced to reduce costs.

Note that, instead of the above-described example, the third shift valve 46 may be configured as shown in FIG. 3 to achieve the same purpose. That is, in the above example, the solenoid pressure PSL that generates the ONN light of the third shift solenoid C is supplied to the chamber 46c that was guiding the pilot pressure, and this solenoid pressure is not supplied to the chamber 46d, and the solenoid pressure PSL is supplied to the chamber 46c.
Only the reverse selection pressure PR generated in the R range is supplied. Therefore, in this example, the shuttle valve 154 shown in FIG. 1 is not necessary, and it is sufficient to simply connect the third shift solenoid C to the chamber 46c and the circuit 155 to the chamber 46d.

In this example, the solenoid pressure P is
By generating or draining the SL, the shift valve spool 46b is lowered in the figure or raised to the position shown in the figure, and the auxiliary transmission is brought into a direct connection state or a deceleration state. In the R range, the spool 46b is held in the illustrated position by the reverse selection pressure PR to keep the sub-transmission in a decelerating state. Even if solenoid pressure PSL is generated in this R range, this pressure is based on the pilot pressure lower than the reverse selection pressure PR (same value as the line pressure), or because the spring 46a is present, The transmission can be maintained in a deceleration state and the same objective as the previous embodiment can be achieved.

(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 the shift valve 46 is held in a state in which the low speed selection friction element (reduction brake RD/B) is activated by the reverse selection pressure output from the manual valve 38 in the reverse travel range, the auxiliary transmission is controlled by the computer. The high-speed selection friction element will never be activated even if it malfunctions, and the high-speed selection friction element will be activated in the reverse travel range, and the one-way clutch (reduction one-way clutch RD10WC) will operate the auxiliary transmission. The danger of interlocking can be eliminated.

Furthermore, it is no longer necessary to determine the logic of the electronic control system in consideration of avoiding this risk, and the CPU capacity of the computer can be reduced accordingly, resulting in lower costs.

[Brief explanation of the drawing]

Fig. 1 is a shift control hydraulic circuit diagram of a multi-stage automatic transmission showing one embodiment of the present invention, Fig. 2 is a schematic diagram showing a power transmission train of the same automatic transmission, and Fig. 3 is a diagram of another embodiment of the present invention. A main part hydraulic circuit diagram showing an example, 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) 07P...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 patent applicant Nissan Motor Co., Ltd. Representative Patent Attorney Akio Sugimura, Patent Attorney Oki Sugimura, Patent Attorney
Yasuyasu Patent Attorney Tomi 1)
Jitsukai Patent Attorney Masa Umemoto Human Patent Attorney Hitoshi Takashi 3rd
figure

Claims (1)

[Claims] 1. High-low speed switching is possible by selective hydraulic actuation of the high-speed selection friction element or the low-speed selection friction element via a shift valve, and functions as a substitute for the low-speed selection friction element during normal drive. In a multi-stage automatic transmission in which an auxiliary transmission equipped with a one-way clutch and a main transmission are coupled in tandem, when the manual valve is in the reverse travel range position to output reverse rotation of the multi-stage automatic transmission, the manual valve A speed change control device for an auxiliary transmission, characterized in that the shift valve is maintained in a state in which a low speed selection friction element is hydraulically operated by a reverse selection pressure output from the auxiliary transmission.