JPS6231746A - Cut-back pressure control device in multistage automatic speed change gear - Google Patents

Abstract

PURPOSE:To satisfy shock tuning upon up-shift operation, by communicating a high speed frictionally engaging component in an auxiliary speed change unit and frictionally engaging components for speed stages above the second speed stage in a main speed change unit, with an oil chamber on the side resisting the urging force of a cut-back valve. CONSTITUTION:A cut-back control valve 43 comprises a spool 81 urged downward by a spring 82 and a lower oil chamber G. Further, the lower oil chamber G is communicated with a brake B0 in an over-drive planetary gear unit and a brake B2 which is cooperated with an one-way clutch to inhibit a sun-gear in a main speed change unit from rotating in one direction, through an interchanging valve 83 which allows the supply of either one of hydraulic pressures. As a result, a cut-back pressure is effected even if two speed stage operation is established by the overall speed change gear.

Description

Detailed Description of the Invention (a) Field of Industrial Application The present invention relates to an automatic transmission installed in an automobile, and more specifically to cutback pressure control in a multi-stage automatic transmission consisting of a main transmission unit and a sub-transmission unit. Regarding equipment.

(b) In conventional technology-a, an automatic transmission is equipped with a torque converter and a planetary speed change gear mechanism, and the speed change gear mechanism includes an overdrive (0/D) planetary gear unit, a front planetary gear unit, and a rear planetary gear unit. Become. The transmission gear mechanism achieves four forward speeds and one reverse speed through two solenoid valves and three shift valves.

In addition, conventionally, a cutback valve is provided to apply cutback pressure to the throttle valve, and the cutback valve is used for the 2nd gear to which hydraulic pressure is supplied in 2nd gear or higher.
Hydraulic pressure is applied to the brake B2, cutback pressure is cut off in first gear and reverse gear, and cutback pressure is supplied in second gear.

On the other hand, as shown in Japanese Unexamined Patent Publication No. 57-37140, three solenoid valves and three shift 1 valves are installed, and an overdrive planetary gear unit is used as a sub-transmission unit, and a front and rear planetary gear unit is installed. ! The present applicant has devised a speed change control device that is used in combination with a main speed change unit consisting of the following to obtain six forward speeds.

←→ Problems that the invention attempts to solve-i By the way, the multi-stage automatic transmission consisting of a sub-transmission and a main transmission unit has a sub-transmission unit with overdrive and two direct gears, and a main transmission with 1st, 2nd and 2nd speeds. Combining the three 3rd speed gears yields 6 gears, but if the supply pressure to the 2nd brake B2 is used as the signal pressure, as with the conventional cutback valve, the main gear 2nd gear is in the 1st gear state. When the auxiliary transmission unit upshifts from direct connection to 0/D, that is, when the entire transmission becomes 2nd speed, the conventional cutback valve does not supply cutback pressure, and therefore throttle pressure and even line pressure is set to a higher pressure than necessary, which impairs the shaft tuning during the upshift and causes unnecessary power loss due to the hydraulic pump.

Therefore, an object of the present invention is to provide a cutback pressure control device for a multi-stage automatic transmission that solves the above-mentioned 1gJ problem by applying cutback pressure even when the entire transmission shifts to 2nd speed. It is something to do.

(b) Means for Solving the Problem The present invention has been made in view of the above-mentioned circumstances, and includes disposing a spool in a cutback valve so as to be biased in one direction, and to oppose the biasing direction. a predetermined frictional engagement element that forms an oil chamber on the side thereof, and further includes a predetermined frictional engagement element to which hydraulic pressure is supplied when the sub-transmission unit is at high speed through a mutual switching valve that allows hydraulic pressure to be supplied from either one of the oil chambers; It is characterized in that it communicates with a predetermined frictional engagement element to which hydraulic pressure is supplied at second or higher speeds of the main transmission unit.

Specifically, as shown in FIG. 1, the cutback valve 43 has a spool 81 and a lower reservoir G which are urged downward by a spring 82.

The lower pond chamber G controls one rotation of the brake B of the overdrive planetary gear unit and the sun gear 30 (see FIG. 8) of the main transmission unit through a mutual switching valve 83 that allows oil pressure to be supplied from either side. It communicates with the brake B2 which cooperates with the one clutch F1 to prevent the brake.

(E) Operation Based on the above configuration, when the transmission 1 is in the first gear as a whole,
That is, the sub-transmission unit 16 is the 0/D direct clutch C.
0 is engaged and the brake B0 is released, and the main transmission unit 21 is in the 1st speed state with the forward clutch C1 engaged and the brake B2 released (see FIG. 6). Hydraulic pressure does not act on the lower reservoir chamber G of the cutback valve 43. Therefore, in this state, the cutback valve 43 is biased by the spring 82 and is in the left half position in FIG. . Furthermore, in reverse (see Figure 12), N range and P range, 0/D brake B0 and (2n
d) Since no hydraulic pressure is supplied to the brake B2, the cantback valve 43 operates in the same manner as described above.

When the entire transmission shifts from 1st speed to 2nd speed, the main transmission unit 21 maintains the 1st speed state with the forward clutch C engaged and the brake B2 released,
In addition, the sub-transmission unit 16 is changed from direct connection to O/D when brake B0 is engaged and O/D direct clutch C0 is released.
/D (Figure 7). Then, along with the supply of hydraulic pressure to the 0/D brake B0, the cunny back valve 43 supplies hydraulic pressure to the upper oil chamber G via the mutual switching valve 83, and the spool 81 of the valve 43 is connected to the spring 82. It moves upward against the resistance (to the left half position in Figure 1), and the holes h x and p are brought into communication. As a result, the throttle valve 41 is supplied with cut bank pressure from the boat plFp2, pushes the spool 79 back against the spring 76, and sets the throttle pressure low.

Furthermore, when the entire transmission shifts from 2nd speed to 3rd speed, the main transmission unit 2) engages the brake B outside the forward clutch C2 and enters the 2nd speed state, and the auxiliary transmission unit 2)
16 is open. When the key B0 is released, the clutch C0 is engaged and the O/D is directly connected. (8th
(see figure). Then, the mutual switching valve 83 switches so that the boat G1 is closed and the boat G2 is opened, and the cant back valve 43 is switched under fF! Hydraulic pressure from the brake B2 is supplied to the J chamber G via the oil path G4, and the spool 81 is held in the upper position (left half position), and the bows 1-x and p
remains connected. Similarly, when the entire transmission shifts to 4th, 5th, and 6th speeds, the main transmission unit 2
1, the brake B remains engaged, and the sub-transmission unit 16 switches its brake B0 between engagement and release, but the cutback valve 43 maintains the mutual switching valve 83 at the switching position. Maintain the condition and open the upper oil chamber G.
Based on the fact that the hydraulic pressure from the brake B2 continues to be supplied to the brake B2, the cutback pressure supply position W (left half position) is maintained.

(f) Example Embodiments of the present invention will be described below along with the drawings.

As shown in FIG. 2, the multi-stage automatic transmission 1 includes a torque converter 2, a planetary transmission gear mechanism 3, and a hydraulic control 81.
A converter housing 6 and a converter housing 6 are respectively provided.
+- Transmission case 7, extension housing 9, valve body 10, and oil pan 1
It is stored in 1. The torque converter 2 is equipped with a lock-up clutch 12, and the rotation of the input member 13 is directly transmitted to the input shaft 15 of the transmission gear mechanism 3 via the oil flow of the torque converter 2 or by the lock-up clutch 12. The transmission gear mechanism 3 consists of an auxiliary transmission unit 16 consisting of an overdrive (0/DJ planetary gear unit 17), and a main transmission unit 21 consisting of a front planetary gear unit 19 and a rear planetary gear unit 20.The 0/D planetary gear unit 17 is an input shaft. 1
5, a sun gear 23 fitted on the input shaft 15, and a ring gear 25 connected to the input shaft 26 of the main shift unit 21. O/D direct clutch C8 and one-way clutch F. is present between the sun gear 23 and the case 7.
A D brake B0 is provided. The front planetary gear unit 19 also includes a planetary gear 29 that is directly connected to the output shaft 27, a sun gear 30a1 that is fitted onto the output shaft 27 and is integrally formed with the sun gear 30b of the planetary gear unit 20, and a forward transmission to the input shaft 26. It consists of a ring gear 31 connected via a clutch C1, and a direct clutch C is interposed between the input shaft 26 and the sun gear 30, and a coast brake B1 is interposed between the sun gear 30 and the case 7. Further, a one-way clutch F and a brake B2 for locking the outer race of the clutch F are disposed between the sun gear 30 and the case 7. In addition, the rear planetary gear unit 20 includes a planetary gear 31 and a sun gear 3.
0b and a ring gear 32 directly connected to the output shaft 27, and between the planetary gear 31 and the case 7, a brake B3 and a one-way flange F2 are arranged in parallel. In addition, 35 in FIG. 2 is an oil pump.

The case 7 of the 0/D planetary gear unit 17 is equipped with a rotation sensor A1 made of a photoelectric sensor or magnetic sensor.
Notches or holes are formed at equal intervals in the flange piece 23a that is installed or connected to the sun gear 23. Therefore, the rotation sensor A detects the rotational speed of the sun gear 23, that is, the shift operation state of the sub-transmission unit 16.

A rotation sensor A2 is also installed in the case 7 of the front planetary gear unit 19, and the clutch connecting piece 30a extending from the sun gear 30 is also formed with notches or holes at equal intervals. Therefore, the rotation sensor A2 detects the rotation speed of the sun gear 30, that is, the shift operation state of the main transmission unit 21.

On the other hand, the hydraulic transmission controller HIt5 has a large number of valves, accumulators and orifices 36, as shown in FIG.
It consists of a strainer 37 and the like, and the valve will be described below. The manual valve 40 can be set to P or R using the shift lever.
, N, D, S, and L ranges, and each oil passage "l bPCI dt e" is switched as shown in Fig. 1. Line pressure is supplied to oil passage l. The throttle valve 41 is connected to the downshift plug 42.
The cam rotates according to the depression of the accelerator pedal, and the throttle level corresponding to the engine output is
Get pressure. The cutback valve 43 generates cutback pressure, which will be described later, and acts on the throttle valve 41. The primary regulator valve 45 is regulated by the throttle pressure and generates line pressure corresponding to the load. That is, when the load is high, the line pressure is increased to ensure the working pressure of the clutches C, brakes B, etc., and when the load is light, the line pressure is regulated to a lower level. The secondary regulator valve 46 is the primary regulator valve 45.
The pressure is regulated by the oil pressure from the converter 2 and each lubricating part 47.
Controls the converter hydraulic pressure and lubricating hydraulic pressure supplied to the The lock-up ν pre-relay valve 49 is controlled by a solenoid valve SL, and switches the oil flow to the lock-up clutch 12 and the oil cooler 50. That is, by turning on the solenoid valve SL, line pressure is applied to the upper end oil chamber e',
This locks up the converter hydraulic oil path f from the primary regulator valve 45 and locks up the clutch off oil #g.
At the same time, the converter hydraulic pressure is drained. The first shift valve 51 switches the main transmission unit 21 between 1st speed and 2nd speed (1st speed and 3rd speed for the transmission 1 as a whole), and is operated by a solenoid valve Sl. That is, when the solenoid valve S1 is turned off, line pressure is applied to the oil chamber 1, and the line pressure oil passage a+ is blocked in the D range, S range, and L range of the manual valve 40, and when the solenoid valve S is turned on, the oil Route a to oil route G6
and supplies line pressure to brake B2 and B2 accumulator B2A. The second shift valve 52 is connected to the 2nd and 3rd gears of the main transmission unit 21 (3rd and 5th gears for the entire transmission).
It is operated by a solenoid valve S. That is, when solenoid valve S2 is turned off, line pressure is applied to oil chamber k, line pressure oil passage l is communicated with oil passage m to supply line pressure to direct clutch C2 and C2 accumulator C2A, and solenoid valve S2 is turned off.
It is occluded by turning on. The third lift valve 53 switches the sub-transmission unit 16, and is operated by the solenoid valve S3.

That is, by turning on the solenoid valve S3, line pressure is applied to the oil chamber n, the line pressure oil passage 4 is communicated with oil passage 0, and the line pressure is applied to the 0/D brake via the B0 release control valve 65, which will be explained later. B. and B0 Achinimulator B. A, and by turning off the solenoid valve S3, the line pressure oil passage e is connected to the oil passage q, and the line pressure is reduced to 0.
/D direct clutch C0 and C0 accumulator C
Connects to 6A.

The first coast modulator valve 55 regulates the line pressure of oil Ms/ supplied via the second shift valve 52 to a coast modulator pressure in the L range of the manual valve 40, and further The modulator pressure is supplied to eight brakes via the first shift valve 51 and the second lift valve 52. In the S range of the manual valve 40, the second coast modulator valve 56 is connected to the oil line l supplied via the first L-foot valve 51.
The line pressure is adjusted to the coast modulator pressure, and the coast modulator pressure is further supplied to the brake B1. The first accumulator control valve 57 is slotted).
By supplying the line pressure l to the oil chamber r, the line pressure l supplied via the second accumulator control valve 70, which will be described later, is regulated to the accumulator control pressure.
The control pressure is B0 accumulation rake B. It is supplied to each back pressure chamber 59°60.61 of A, C2 accumulator C2A and B2 accumulator B2A.

Furthermore, in addition to the above-mentioned hydraulic equipment, this hydraulic shift control mechanism 5
The S0 modulator valve 65. A B0 release control valve 66, a B0 sequence valve 67, a lock-up control valve 69, and a second accumulator control valve 70 are provided.

As shown in detail in FIG. 4, the S modulator valve 65 is supplied with line pressure from the line pressure port 1-1 via the oil strainer 37, and is further supplied to the upper end oil chamber S via the oil passage S. The feedback pressure that is communicated and acts on the nuclear oil chamber S1 and the spring 71 are balanced and a predetermined pressure (
For example, the pressure is regulated to 4 kg/c/), and the regulated solenoid module pressure is further supplied to the oil passage. Furthermore, the oil passage t is connected to the plug 72 and the oil passage 1. The solenoid valve S is connected to the solenoid valve S0 through the solenoid valve S0, and also to the Bo series control valve 66.

Control pressure by on/off control or duty control is supplied to the oil chamber t2, and the control valve 66 is controlled. In addition, solenoid valve S. is rotation sensor A,
Although it is controlled by a signal from the control unit E based on A2,
When the valves S, . Furthermore, the boat y of the B0 release control valve 66 is connected to the O/D brake B0 and the B0 accumulator B via an oil passage y. A, and also communicates with the lower end oil chamber y2 via the orifice 36 as feedback pressure. Further, the oil passage y1 communicates with the boat y3 of the sequence valve 67 via a bypass passage y5 at its tip end, and furthermore, the oil passage y1 communicates with the boat y3 of the sequence valve 67 through a bypass passage y5.
It communicates with the lower end oil chamber y4 of No. 7 as feedback pressure. The feedback pressure in the oil chamber y4 is balanced with the spring 80 at the upper end, but the spring 80 is set to the initial piston operating pressure at which the brake plates of the O/D brake B start contacting each other. The sequence valve 67 is in the left half position until the initial operating pressure, and hydraulic pressure is supplied to the O/D brake B0 through boats Z2 and y2, and when the initial operating pressure is exceeded, it is switched to the left half position. Boats z2 and y3 are blocked. In addition, the boat 2 of the control valve 66 communicates with the third shift valve 53 via the oil passage z1 and the orifice 36, and the B0 sequence valve from the boat 0 via the bypass passage z5. 67, and an oil passage y6 branched from the oil passage y1 communicates with the oil passage 2° via a check valve 72. On the other hand, the third
The shift valve 53 has an upper chamber n communicating with eight solenoid valves, a boat l communicating with line pressure, and a boat q communicating with the O/D direct clutch via an oil passage q and an orifice 36. C8 and C. It communicates with accumulator CoA. Note that a check valve 75 that allows discharge from the clutch C6 is interposed in parallel with the orifice 36 of the oil passage q1. Further, d in the figure is a drain boat.

In addition to the conventional lock-up control valve 69, which enables lock-up when the main transmission unit 21 is in 2nd gear or higher, the auxiliary transmission unit 16 also controls the O/D shift even when the main transmission unit 21 is in 1st gear. In this state, that is, when the transmission as a whole is in second gear or higher, control is performed so that lockup is possible. Furthermore, when the sub-transmission unit 16 is in the O/D state and the main transmission unit 21 upshifts, the second accumulator control valve 70 is operated in a manner that the main Accumulator B because the variable speed brake capacity is excessive. A, C2A, B2A back pressure chambers 59, 60
．． 61 to optimize the brake capacity.

As shown in FIG. 1, the cut valve 43 has a spool 81 that is urged downward by a spring 82, and an upper oil chamber G is disposed at the lower end of the spool 81. . In addition, the upper oil chamber G has a port G or G
2, and one port G of the switching valve 83.

is the port G of the first shift valve 51 via the oil passage G.
Furthermore, the port G5 communicates with the brake B2 and the B2 accumulator B2A via the oil passage G6, and the other port G2 of the switching valve 83 communicates with the oil passage G.
3, it communicates with an oil passage Z1 extending from port 0 of the third shift valve 53.

Throttle pressure is supplied from the throttle valve 41 to the port x of the cutback valve 43, and the pressure is transmitted as cutback pressure via bow +-p, which is communicated or shut off by switching the valve 41. Port p1 of throttle valve 41. Supplied to p2. The throttle valve 41 has a downshift plug 42 operated by a throttle cam 44 that is linked to an accelerator pedal, and a downshift plug 42 that is disposed via a spring 76 and biased upward by a lower spring 77. As the spool 79 moves downward via the spring 76 based on the rotation of the throttle cam 44, pressure corresponding to the throttle opening is applied from the line boat l to the throttle port 1.
・Supplied to x3.

Further, the throttle pressure acts on the bow I-x4, and the cutback pressure acts on the port p, and these pressures act on the spool 79 based on the difference in land diameter of the spool 79.
9 against the spring 76, and both springs 7
6.77 is balanced, the line port 1 is closed, and the throttle pressure becomes a hydraulic pressure corresponding to the throttle opening and vehicle speed. Note that the downshift plug 42 is configured so that the hydraulic pressure from the port x2 is applied to the land 4 of the downshift plug 42.
2a, 42b (42a>42 b), Bo)
Lands 42b, 4 due to cutback pressure acting on p2
2c (42, b>42 c), the pressing of the springs 76, 77 against the throttle cam 44 reduces the force.

Note that port a of the cutback valve 43 communicates with port a of the manual valve 40;
The bow 1-u switched by the valve 43 is in communication with a lock-up control valve 69. Furthermore,
The ports 1-H of the valve 51 are connected to the first coast modulator valve 55, the port ■ is connected to the brake B3, the port J is connected to the second coast modulator valve 56, and the port is connected to the second shift valve 52. are doing.

Next, the operation of this embodiment will be explained.

Each solenoid valve S of the present multi-stage automatic transmission 1.

s2. s,,sL,s. , each clutch C8, C1, c2
, brake B0. B, , B3, and each one-way clutch F0. F,, F2, each position P, R,
N.D.

The S and L gears are controlled as shown in the operation table shown in FIG. 5, respectively.

That is, at 1st speed in D range or S range, as shown in FIG. 6, 0/D direct clutch C0, one-way clutch F0. F2 and forward clutch C8
are engaged, and the others are in a released state.

Therefore, the sub-transmission unit 16 includes the clutch c1 and the one-way clutch F. Planetary Gyauni through!・
17 are integrated and directly connected, and the input shaft 15
The rotation is directly transmitted to the input shaft 26 of the main transmission unit 21. In addition, in the main transmission unit 21, the input shaft 26
The rotation of A leftward revolution force is applied to the planetary gear 31, but the revolution is prevented by the one-way clutch F, and the power is transmitted to the ring gear 32 that is integrated with the output shaft 27.・
21 is in the 1st speed state, and together with the direct connection of the sub-transmission unit) and 16, the entire transmission is in the 1st speed state.

At this time, the main transmission unit 21 is branched into two systems, from the front planetary gear unit 19 to the output shaft 27 and from the rear planetary gear unit 20 to the output shaft 27, thereby distributing the load received by the gears. .

In the first speed state, the solenoid valve S3 is in the off state and the third shift valve 53 is in the right half position,
The line pressure of line port 2 is connected to 0/D clutch C0 and C0 accumulator C0A via port q and oil passage q1.
, the B0 release control valve 66 is turned on and therefore in the left half position.
The hydraulic pressure of the 0/D brake B0 is released through ports y and 2 of the 0/D brake B0. On the other hand, the solenoid valve S1 is also in the off state, and the first shift valve 51 is in the right half position.
In the manual valve 40, the line pressure supplied from the line boat l through the port a is supplied to the forward clutch C, but the boat a2 is blocked at the second valve 51, and no hydraulic pressure is applied to the (2nd) brake B2. do not. This state, that is, O/D brake B0 and (2n
d) When no hydraulic pressure is applied to both of the brakes B2, no hydraulic pressure is applied to the upper oil chamber G of the cutback valve 43, and therefore the cutback valve 43 is operated by the spring 82 so that the spool 81 is in the lower position ( In the right half position), ports 1-x and p are cut off, and no cutback pressure is supplied to the throttle valve 41.

Also, when in 2nd gear in D range or S range, 0/D brake B is applied, as shown in FIG. , one-way clutch F2 and forward clutch C1 are engaged, and the others are in a released state. Therefore, in the sub-transmission unit 16, the sun gear 23 is locked by the brake B0, the planetary gear 22 rotates and transmits power to the ring gear 25, and the input shaft 26 of the main transmission unit 21 is rotated at an increased speed (
0/Transmit DJ. Furthermore, the main transmission unit 21 is in the same state as the first speed, so the first speed of the main transmission unit 21 and the speed increase of the sub-transmission unit 16 combine to bring the entire transmission into the second speed state.

This ta, as shown in Fig. 4, solenoid valve S3
is turned on, line pressure is supplied to the oil chamber n of the third shift valve 53, and the third shift valve 53 is switched to the state shown in the left half diagram. Then, clutches C0 and C. Pressure oil in accumulator CA is discharged from port q to drain boat d, clutch C0 is released, and line pressure port 1 communicates with port O.

Then, the line pressure from port O is maintained at port z2p''/of the sequence valve 67 until the initial operating pressure of the B0 piston is reached.
3 and oil passage y5, and when the initial working pressure of the B0 piston is exceeded, the valve 67 is switched to the right half position based on the feedback pressure of the oil chamber y4, and then from the boat O. The line pressure is supplied to port z of the B release control valve 66 via the orifice 36 and the oil passage 2□. Furthermore, in this state, the control valve 66 is in the left half position, and the port Z
and y are in communication, and the line pressure is applied to brakes B0 and 2/B 07 cumulator B via oil path y□. A is supplied to brake B. engage.

In the second speed state, based on the oil pressure supplied to the 0/D brake B0, oil pressure is supplied to the upper oil chamber G of the cutback valve 43 via the oil passage G3 and the port G1 of the mutual switching valve 83, Therefore, the cutback valve 43 is moved upward on the spool 81 against the spring 82 to the left half position in FIG. 1, and the ports 1-x and p are communicated with each other. As a result, the throttle pressure from port 1-x is transferred to port p1pp of the throttle valve 41 via port p.
2, the spool 79 is pushed back against the spring 76, the throttle pressure is set lower by a predetermined amount, and the pressing force of the downshift plug 42 against the throttle cam 44 is reduced.

In addition, at the third speed in the D range, as shown in Fig. 8, the 0/D clutch C0, one-way clutch F0, forward clutch C1, one-way clutch F, and brake B2 are engaged, and the others are in the released state. . Therefore, the sub-transmission unit 16 is in the above-mentioned directly connected state, and the input shaft 1
5 is directly transmitted to the input shaft 26 of the main transmission unit 21.

Further, in the main transmission unit 21, the rotation of the input shaft 26 is transmitted to the ring gear 31 of the front gear unit 31 via the clutch C1, and applies a leftward rotational force to the sun gear 30 via the planetary gear 29. is prevented from rotating in that direction by the one-way clutch F when the brake B2 is engaged, and therefore the planetary gear 29 revolves while rotating on its own axis, and the second speed rotation is transmitted to the output shaft 27 via only the front gear unit 29. be done. As a result, the direct connection state of the sub-transmission unit 16 and the main transmission unit 2
1 and the second speed state, the transmission 1 as a whole obtains the third speed.

At this time, the solenoid valve S1 is turned on and the first shift valve 51 is switched to the left half position in FIG.
and is supplied to accumulator B2A. The resulting shift state of the main transmission unit 21, that is, the change in rotation of the sun gear 30, is detected by the rotation sensor A2, and the solenoid valve S is activated by an electric signal from the control section E. is under duty control or on-control to reduce the modulator pressure in the oil passage t. That is, the So modulator valve 65 regulates the line pressure of the line port 1 using the spring 71 and the feedback pressure of the stage room S1 and supplies it to the oil passage t. The pressure in the stage chamber t2 of the B0 release control valve 66 communicating with the oil passage t is also reduced. Therefore, the control/roll valve 66 is in the left half position in FIG. 4 while receiving feedback pressure from the brake B0 in the oil chamber y2, and the brake B0 and accumulator B are in the left half position in FIG. Hydraulic pressure from A is discharged to drain boat d via oil path y1 and port y. At this time, the rotation sensor A2 detects the completion of the shift of the main transmission unit 21, that is, the rotation of the sun gear 30 has stopped, and the fourth resolenoid valve S3 is turned off by an electric signal from the control section E, and the third shift valve 53 is turned off. 1st
Switch to the left half position in the figure. Then, line pressure port l communicates with port q, and clutches C0 and C are connected via oil passage q.
0 line pressure is sent to the accumulator C0A, the clutch C0 is engaged, and the port o is connected to the drain port d.
, and the oil pressure of the 0/D brake B0 is connected to the oil path y6. The fluid is immediately completely drained from the drain port d via the check valve 72, the oil passage z3, and the port 0, and the shifting of the sub-transmission unit 16 is completed. This results in 0/
The releasing operation of the D brake B0 corresponds to the engaging operation of the brake B2.

In the third speed state, the mutual switching valve 83 is switched by the drain of the O/D brake B0 and the supply of hydraulic pressure to the brake B2, and the port G1 is closed and the port G
2 opens. Then, the cutback valve 43 opens the oil passage G4 and the switching valve 8 based on the supply of hydraulic pressure to the brake B2.
Hydraulic pressure acts on the upper oil chamber G through the port G2 of No. 3, and the spool 81 is held at the upper left half position in FIG. 1. In this state, cutback pressure is supplied to the throttle valve 41 as in the second speed.

Further, at the fourth speed in the D range, as shown in FIG. 9, the 0/D brake B0, forward clutch C2, brake B2, and one-way clutch F1 are engaged, and the others are in a released state. Therefore, the sub-transmission unit 16 is in the speed increasing (0/D) state mentioned above, and the main transmission unit 21
is in the 2nd speed state, and thus the transmission 1 as a whole obtains 4th speed.

In the fourth speed state, the cutback valve 43 is
As oil pressure is supplied to the O/D brake B0, oil pressure also acts on port GK of the mutual switching valve 83, but based on the fact that the first shift valve 51 is held in the left half position in FIG. Since the line pressure from a continues to be supplied to port G2, the switching valve 83 is not switched, and therefore the state in which hydraulic pressure is supplied to the upper oil chamber G through G2 is maintained, and the line pressure from port and p are in communication with each other at a cutback pressure supply position.

In addition, at 5th speed in the D range, as shown in Fig. 10, the 0/D clutch C0, one-way clutch F0, forward clutch C4, direct clutch C2, and brake B2 are engaged, and the others are in the M released state. . Therefore, the sub-transmission unit 16 is in the above-mentioned direct connection state, and the main transmission unit 21 is connected to the front gear gear unit 19 by the engagement of the gears 7, C, C2, and the input The rotation of the shaft 26 is directly transmitted to the output shaft 27. As a result, the direct connection of the sub-transmission unit 16 and the third speed of the main transmission unit 21 combine to provide a fifth speed in which the input shaft 15 and the output shaft 27 rotate integrally in the transmission 1 as a whole.

Even in the 5th speed state, the solenoid S1 is in the on state, the first shift valve 51 is still in the left half position, and the cutback valve 43 passes through the port G2 of the mutual switching valve 83 and the oil chamber G Hydraulic pressure continues to be supplied to the cut bank pressure supply position, which is the left half position.

Further, at the 6th speed in the D range, as shown in FIG. 11, the 0/D brake B0, forward flange C1, direct clutch C2, and brake B2 are engaged, and the others are in a released state. Therefore, the auxiliary transmission unit 16 is in the above-mentioned direct connection state, and the main transmission unit 21 is also in the above-mentioned 3rd speed state, and both of these speed change units 1-16.
1 together, the transmission 1 as a whole obtains 6 speeds.

Even in the 6th speed state, the first shift valve 51 is in the left half position, and the cutback valve 43 is in the lower position.
It is held in the cutback pressure supply position by the hydraulic pressure applied to the cutback pressure supply position.

Also, at R129, as shown in Figure 12, 0./D
Clutch C0, one-way franchise F0, Guilef)・
Clutch C2 and brake B3 are engaged, and the others are in a released state. Therefore, the auxiliary transmission unit 16 is in a directly connected state, and in the main transmission unit 21, the rotation of the input shaft 26 is directly transmitted to the sun gear 30 by the clutch C2, and the revolution of the rear planetary gear 31 is locked by the brake B3. The rotation of the sun gear 30 is transmitted as reverse rotation to the link gear 32 via the rotation of the planetary gear 31, causing the output shaft 27 to rotate in the opposite direction.

In the reverse state, line pressure is no longer supplied to port 8 by switching the manual valve 40 to the R range, and therefore the hydraulic pressure of brake B is drained.
Further, the third solenoid valve is in the off state, and the third shift valve 53 is in the left half position, and the 0/D brake B is applied.

The hydraulic pressure has also been drained. Therefore, in the cutback valve 43, as in the first speed state, no oil pressure acts on the upper oil chamber G, and the spool 81 is moved downward by the biasing force of the spring 82 and is in the left half position in FIG. 1- Throttle pressure at x is cut off and port pp p□.

The cutback pressure of p2 is drained.

In addition, in the P range and the N range, line pressure is not supplied to port a by switching the manual valve 40 (therefore, the cutback valve 43 is also held at the cutback pressure cutoff position as in the R range). .

In addition, during the 3rd and 4th speeds in the S range or L range, the coast brake B1 is engaged in the 3rd and 4th speeds of the D range mentioned above (see Figures 8 and 9). Therefore, rotation of the sun gear 30 is prevented in both directions.
Engine braking is possible. At this time, when shifting from 2nd speed to 3rd speed, solenoid valve S is activated as in the D range. is controlled so that the auxiliary transmission unit 1-16 and the main transmission unit 21 are shifted simultaneously.

In addition, in the 1st and 2nd speeds in the L range (see Figures 6 and 7), the brake B is engaged, and therefore the rear planetary gear 31 revolves. is blocked in both directions, allowing engine braking.

Note that the cut bank valve 43 at the 3rd speed, 4th speed, 1st speed, and 2nd speed in the above-mentioned N range and L range is the same as in each shift in the D range.

Further, in the above embodiment, the sub-transmission unit 16 is located in the front stage and the main transmission unit 1-21 is located in the rear stage, which is a longitudinally mounted automatic transmission for rear wheel drive. Of course, the present invention can also be similarly applied to a front-wheel drive horizontal automatic transmission in which the auxiliary transmission unit is located at the rear stage.

(1.) Effects of the Invention As explained above, according to the present invention, by combining each gear stage of the sub-transmission unit 16 and the main transmission unit 21, multi-stage shifting can be performed. Since the cutback pressure acts on the throttle valve 41 in the second gear or higher in the entire transmission 1, the throttle pressure and line pressure are not set to a higher pressure than necessary, and power loss due to the hydraulic pump 35 can be reduced. At the same time, it is possible to prevent shift tuning from deteriorating during upshifting. Furthermore, in the cutback valve 43, there is an oil chamber G to which hydraulic pressure is supplied in the second gear or higher of the main transmission unit 21.
By simply installing a mutual switching valve 83 so that hydraulic pressure can be supplied even when the sub-transmission unit 16 is running at low speeds, it is possible to achieve appropriate cutback pressure with a slight change in the oil passage without major design changes. can be supplied.

Further, an overdrive planetary unit 17 is used as the sub-transmission unit 16, a front planetary gear unit 19 and a rear planetary gear unit 20 are used as the main transmission unit 21, and an overdrive planetary gear 17 is used in the oil chamber G of the cutback valve 43. When connected to brake B and brake B2 that prevents unidirectional rotation of sun gear 30 of front and rear planetary gear units 19°20, conventional automatic transmission gear mechanism with overdrive can be used almost as is, and manufacturing equipment has been significantly changed. The multi-stage automatic transmission 1 can be provided at low cost without having to do so.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a cutback pressure control device according to the present invention, Fig. 2 is an overall sectional view showing an automatic transmission to which the invention can be applied, and Fig. 3 is an overall view showing its hydraulic control mechanism. 4
The figure shows the main parts of the hydraulic control mechanism, and FIG. 5 shows the operating states of each device at each position. FIGS. 6 to 12 are diagrams showing the operation of the automatic transmission in different states. 1. Multi-stage automatic transmission, 2. Torque converter
, 3... (planetary) transmission gear mechanism, 5. Hydraulic control mechanism, 16... Sub-transmission unit, 17.
Overdrive planetary gear unit, 19...Front planetary gear unit, 20...Rear planetary gear unit, 21...Main transmission unit, 41
...Throttle valve, 43...Cutback valve, 51゜52.53...Shift valve, 81...-Stool, 82...Spring, 83...Mutual switching valve, Bo, B2. B,
... Frictional engagement element (brake), Bo... Predetermined frictional engagement element (0/D brake), B2... Predetermined frictional engagement element (2°nd-jLy-1, C0, C1, C2 -Friction engagement element [clutch], Sl, B2. S...
SL, So... Solenoid valve, So... Solenoid valve, G... (lower) oil chamber, G1. G2...
·port. Applicant: Aisin Warner Co., Ltd. Toyota Motor Corporation

Claims (2)

[Claims] (1) A transmission gear mechanism that has a sub-transmission unit and a main transmission unit, and obtains multi-stage transmission by a combination of these transmission units based on controlling a frictional engagement element that switches the transmission line of each of these transmission units. and a hydraulic control mechanism having a shift valve, a solenoid valve, a manual valve and a throttle valve that control each frictional engagement element of the transmission gear mechanism, and a cutback valve that applies cutback pressure to the throttle valve. In the multi-stage automatic transmission, the cutback valve is disposed with a spool biased toward one direction, and an oil chamber is formed on the side opposite to the bias direction, and the oil chamber is further provided with either one of the spools biased in one direction. A predetermined frictional engagement element to which hydraulic pressure is supplied when the auxiliary transmission unit is at high speed and a predetermined friction engagement element to which hydraulic pressure is supplied when the main transmission unit is in second or higher speed through a mutual switching valve that allows hydraulic pressure to be supplied from one side. A cutback pressure control device in a multi-stage automatic transmission that communicates frictional engagement elements. (2) The auxiliary transmission unit is an overdrive planetary gear unit, the main transmission unit includes a front planetary gear unit and a rear planetary gear unit, and the predetermined friction engagement element of the auxiliary transmission unit is a brake of the overdrive planetary gear unit. The multi-stage automatic according to claim 1, wherein the predetermined friction engagement element of the main transmission unit is a brake that locks an outer race of a one-way clutch that prevents rotation of a sun gear in one direction in the front and rear planetary gear units. Cutback pressure control device in transmission.