JPH0280851A - Shift control device for automatic transmission - Google Patents

Abstract

PURPOSE:To carry out shift-downs each at the optimum speed by operating a cut-off valve and an accumulator control valve in accordance with 4-3 kick down, manual down and coast down. CONSTITUTION:In the accumulator 67 of an over-drive direct clutch C-O, back pressure is controlled by a solenoid modulator valve 73 via a cut-off valve 75 and an accumulator control valve 72, on the back pressure side of the piston 83 thereof. The cut-off valve 75 discharges the oil on the back pressure side of the accumulator 67 in an accelerator-on condition, to delay the engagement of the clutch C-O at the time of carrying out 4-3 shift down. As the oil via the valve 72 is fed to the back pressure side of the accumulator 67 in an accelerator-off condition, i.e., at the time of carrying out 4-3 manual down, the engagement of the clutch C-O is accelerated. On the other hand, at the time of 4-3 coast down, oil pressure is fed from the valve 73 to the accumulator valve 72, which forcedly discharges the back pressure side oil of the accumulator 67, to delay the engagement of the clutch, reducing an engaging shock.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a shift control device for an automatic transmission, and particularly to a shift control device for improving the characteristics when downshifting from 4th gear to 3rd gear.

(Prior Art) Conventionally, automatic transmissions for automobiles have been equipped with multi-disc clutches or brakes to engage and disengage various shafts, gears, etc. when switching gear stages of the automatic transmission. For example, a forward clutch is used to connect the input shaft and front ring gear, a direct clutch is used to connect the input shaft and rear sun gear, and a second coast brake is used to connect the front and rear sun gear (hereinafter referred to as front ring gear). & rear sun gear), the second brake is used to lock the left rotation of the front & rear sun gear, and the first & reversal brake beam is used to lock the abrasive carrier.

Further, an overdrive direct clutch is provided to connect the sun gear and the planetary carrier, and an overdrive brake is provided to lock the sun gear and the case.

In other words, if you are driving in D range and are shifting from 3rd to 4th gear.
When shifting up from 4th gear to 3rd gear, the overdrive direct clutch is disengaged and the overdrive brake is locked, and when shifting down from 4th gear to 3rd gear, the overdrive direct clutch is disengaged and the overdrive brake is locked.
- The overdrive brake is released as the clutch is engaged.

(Intelligence MA to be Solved by the Invention) However, in the above conventional shift control device, when downshifting from 4th gear to 3rd gear, the 3-4 shift valve is operated and the overdrive direct clutch engagement oil passage is activated. If the overdrive brake engagement oil path is switched, a uniform downshift will be performed under all driving conditions, i.e., when shifting from 4th to 3rd gear by manual downshifting, such as when applying engine braking. However, when slowing down while coasting, when shifting from 4th gear to 3rd gear by coasting down, or when it is necessary to accelerate suddenly, kick When shifting from 4th speed to 3rd speed by downshifting, it is desirable to downshift relatively slowly, but downshifting is always performed at a constant speed.

In other words, if the structure is such that the 3-4 shift valve is simply actuated to switch between the overdrive direct clutch engagement oil passage and the overdrive brake engagement oil passage, almost at the same time as the switching, the overdrive direct clutch Due to the various driving conditions mentioned above, the engagement and disengagement cannot be accelerated or delayed, and there may be a shock or poor response when downshifting, resulting in a poor driving feeling for the driver. I couldn't give it.

The present invention solves the above problems, and when performing special 4-3 manual down which applies engine brake,
Special feature 4 that reduces speed while traveling at high speed or by inertia
- To provide a shift control device for an automatic transmission that can perform a late shift down when performing a 3-coast down and a special 4-3 kickdown that requires rapid acceleration. do.

(Means for Solving the Problems) In order to solve the above problem, the present invention selectively controls the overdrive direct clutch and the overdrive brake in the transmission gear mechanism of an automatic transmission using a 3-4 shift valve. In a shift control B device for an automatic transmission that shifts between 3rd and 4th speed by engaging the overdrive direct clutch, an accumulator is connected to the engagement oil passage of the overdrive direct clutch, and the overdrive direct clutch is connected to the overdrive direct clutch. on the back pressure side of the piston of the accumulator for
A solenoid modulator valve is connected via a cutoff valve and an accumulator control valve.

The cut-off valve receives hydraulic pressure, for example, throttle pressure, in accordance with the acceleration/deceleration state of the vehicle on one end surface.
The accumulator control valve is configured to assume at least two positions in response to hydraulic pressure from a linear solenoid valve.

The positions of both of the above valves are changed depending on the type of 4-3 shift down, and during the 4-3 kickdown, the above-mentioned force is applied to the hull valve of the 7-off valve by receiving hydraulic pressure depending on the acceleration/deceleration state of the vehicle, such as throttle pressure. 1 is activated to supply the hydraulic pressure regulated by the solenoid modulator valve as back pressure to the accumulator, and 4-
3. During manual down, the back pressure is removed by operating a cut-off valve in response to the hydraulic pressure depending on the acceleration/deceleration state of the vehicle, such as throttle pressure, and furthermore, during 4-3 coast down, the hydraulic pressure from the linear solenoid valve is applied. This actuates the accumulator control valve to remove the back pressure.

(Operation and Effects of the Invention) According to the present invention, as described above, an accumulator is connected to the engagement oil passage of the overdrive direct clutch, and a cutoff valve and an accumulator control valve are connected to the back pressure side of the piston of the accumulator. A solenoid modulator valve is connected through to control the back pressure.

The cant-off valve has one end face that receives oil pressure corresponding to the acceleration/deceleration state of the vehicle, such as oil pressure from a throttle valve, and assumes two positions. Oil on the pressure side is drained.

When the oil on the back pressure side is discharged in this way, the operating resistance of the accumulator disappears and the oil storage capacity increases.
-3 When downshifting, the engagement of the overdrive direct clutch is delayed.

That is, if a 4-3 downshift is performed with the accelerator turned on during kickdown, the overdrive direct clutch will be engaged later and the shock caused by the downshift will be reduced.

Further, the cut-off valve is configured such that oil sent through the accumulator control valve when the accelerator is off is supplied to the back pressure side of the accumulator. When oil is supplied to the back pressure side in this way, the operating resistance of the accumulator increases and the oil storage capacity decreases, so when a 4-3 downshift is performed, the overdrive direct clutch engages more quickly. That is, when performing 4-3 manual down with the accelerator off, the overdrive direct clutch engages quickly and the downshift response improves.

On the other hand, the accumulator control valve takes at least two positions in response to hydraulic pressure from the linear solenoid valve. This linear solenoid valve operates during 4-3 coastdown to supply hydraulic pressure from the solenoid modulator valve to the accumulator control valve, and forcibly discharges oil on the back pressure side of the accumulator. Therefore, as in the case of kickdown, the operating resistance of the accumulator is eliminated and the oil storage capacity is increased, so that when a 4-3 downshift is performed, engagement of the overdrive direct clutch is delayed. In other words, the engagement shock during 4-3 coast down is reduced.

(Example) Hereinafter, an example of a shift control device for an automatic transmission of the present invention will be described in detail with reference to the drawings.

The automatic transmission 1, as shown in FIGS. 2 and 3,
It includes a torque converter 2, a planetary gear transmission gear mechanism 3, and a hydraulic control device 5, which are housed in a convergence housing 6, a case 7, an extension housing 9, a valve body 10, and an oil pan 11, respectively.

The torque converter 2 is equipped with a lock amplifier clutch 12 for improving power transmission efficiency, and the rotational power of the input member 13 is transmitted indirectly through the oil flow within the torque converter 2 or through the lock amplifier clutch 12. Through engagement, the signal is directly transmitted to the input shaft 15 of the transmission gear mechanism 3.

Further, the speed change gear mechanism 3 has an overdrive planetary gear unit 17 and a main speed change unit 21 consisting of a front planetary gear unit 19 and a rear planetary gear unit 20.

Here, the above-mentioned overdrive planetary gear unit 1
7 is connected to the input shaft 15 and consists of a carrier 24 that supports the planetary pinion 22, a sun gear 23 that surrounds the human power shaft 15, and a ring gear 25 that is directly connected to the input shaft 26 of the main transmission unit 21. .

Further, an overdrive direct clutch C0 and a one-way clutch F are interposed between the carrier 24 and the sun gear 23, and an overdrive brake B is disposed between the sun gear 23 and the case 7. There is.

Next, the front planetary gear unit 19
7 and supports the planetary pinion 28; a sun gear 30a that surrounds the output shaft 27 and is integrated with the sun gear 30b of the rear planetary gear unit 20; and a forward clutch connected to the input shaft 26. Ring gear 31 connected via C1
It consists of In addition, the input shaft 26 and the sun gear 30a
A direct clutch C8 is interposed between the sun gear 30a and the case 7, and a second coast brake B+ consisting of a band brake is interposed between the sun gear 30a and the case 7. sungear 30
Furthermore, a one-way clutch F is provided between a and case 7.
, a second brake B2 consisting of multiple plates is provided.

The rear planetary gear unit 20 includes a carrier 33 that supports the brake pinion 32, and a sun gear 30b.
, and a ring gear 35 directly connected to the output shaft 27, and between the carrier 33 and the case 7 there is a 1st &
Rev brake B, and one-way clutch F! are arranged in parallel. In addition, in FIG. 2, 36 is a hydraulic pump.

Here, as shown in No. 21, in the overdrive planetary gear UniSoto 17, the boss portion 23a of the sun gear 23 extends in the axial direction, and the boss portion 23a and the carrier 24
A one-way clutch F is interposed between the sleeve 24a and the sleeve 24a fixed to the sleeve 24a.

Further, a flange portion 40 constituting a cylinder extends from the boss portion 23a, and a piston 41 is fitted into the flange portion 40 to form an overdrive direct clutch C.
0 hydraulic actuator. An overdrive brake B0 is disposed between the inner circumferential surface of the flange portion 40 and the case 7.
An annular flange 42 extending in the outer radial direction is fixed to the outer periphery of the 0.

A large number of holes or notches are formed in the flange portion 42, and a non-contact type sensor 45 such as a light or magnetic sensor is provided in the case 7 opposite to the holes or notches. The sensor 45 detects the rotational speed of the flange 42 that is integral with the input shaft 15 when the overdrive direct clutch C0 is connected, that is, during first, second, and third speeds.

On the other hand, a vehicle speed sensor 46 that detects the rotation of the output shaft 27 is installed inside the extensilan case 9, and signals from the vehicle speed sensor 46 and the sensor 45 are sent to the control section along with signals from other sensors. , hydraulic control l described later
Each solenoid valve SI+S of device 5 (see Figure 4)
t, Ss, and S4.

Next, the hydraulic control unit device 5 will be explained based on FIG. 4.

In the figure, Co, C+, and Ct are hydraulic servos for each of the clutches, and Bo, B+, Bz, and f3s are hydraulic servos for each of the brakes. 2 is a torque converter,
36 is a hydraulic pump, and 37 is a strainer.

Reference numeral 51 denotes a manual valve that is operated by the driver when shifting gears, and is connected to the shift lever in the driver's seat via a push cable, and is set to each position P or R according to the movement of the shift lever.

Switched to N, D, 2nd, L, line pressure boat p
However, as shown in Fig. 5 by circles, each port a, b
, c, and d.

Further, 52 is a primary regulator valve that regulates line pressure by throttle modulator pressure and line pressure during reverse, and supplies the oil pressure-regulated here to a lock-up relay valve 57 and a secondary regulator valve 55, which will be described later.

Reference numeral 53 denotes a throttle valve, which compresses two upper and lower springs in response to the degree of depression of the accelerator pedal, and generates a throttle pressure corresponding to the engine output by compressing two springs, upper and lower, in response to the amount of depression of the accelerator pedal, and by applying a cant-back valve 59 to be described later. It is intended to obtain.

A secondary regulator valve 55 adjusts the oil pressure of the primary regulator valve 52 to provide lubricating oil pressure, and supplies it to the quasi-relay valve 57.

56 is the lock amplifier control valve, and the oil pressure that leaks at the valve tip of the lock-up relay valve 57 is U.
Section f4. Further, the lock-up relay valve 57 is operated by signal hydraulic pressure from the linear solenoid valve S and the solenoid relay valve 58 to engage and disengage the lock-up clutch 12 of the torque converter 2.

Reference numeral 59 denotes a cutback valve, which applies cutback pressure to the throttle valve 53 to regulate the throttle pressure. When the cutback valve 59 is in the L range or the R range, the second coast brake B and the second brake B! It is operated by hydraulic pressure supplied to the

60 is a 1-2 shift valve that switches between 1st speed and 2nd speed, and the hydraulic pressure of solenoid valve S2 is supplied to the tip of the valve.

takes the left half position when in ① speed, and takes the left half position when in 2nd, 3rd, and 4th speeds. In other words, in 1st gear, the second coast brake B, second coast brake B
The hydraulic pressure supply to the 1sL & Rev brake B is always stopped, and the hydraulic pressure supply to the 1sL & Rev brake B is performed only when in the L range. When the second speed is reached, the valve is in the left half position, and the hydraulic pressure from the manual valve 51 is supplied to the second brake B. Further, in the 2nd and L ranges, the hydraulic pressure is received from a 2-3 shift valve, which will be described later, and is supplied to the second coast brake B via the second coast modulator valve 66.

Further, 61 is a 2-3 shift valve that switches between 2nd and 3rd speeds, and the hydraulic pressure of a solenoid valve S is supplied to the tip of the valve 61, and the valve 61 is half occupied in 1st and 2nd speeds. position, and assumes the left half position at 3.4 speed. That is, the supply of hydraulic pressure to the direct clutch C2, which was stopped at the 1st and 2nd speeds, is started when the valve is in the left half position at the 3rd speed.

62 is a 3-4 shift valve that switches between 3rd speed and 4th speed, and the hydraulic pressure of solenoid valve S2 is supplied to the tip of the valve 62;
2. It takes the half-way position when in third gear, and takes the left-half position when in fourth gear. In other words, the oil pressure that was supplied to the overdrive direct clutch C0 during the 1st, 2nd, and 3rd gears is no longer supplied because the valve is in the left half position in the 4th gear. Hydraulic pressure is now supplied to the overdrive brake B, which had been stopped at the time.

63 is the solenoid valve S when the vehicle speed is, for example, 9h/h or more. This is a reverse inhibit valve that is activated when the direct clutch C8 is opened and stops the hydraulic pressure to the direct clutch C8.

Further, 65 is a low coast modulator valve, and 66 is a second coast modulator valve, which are operated when applying engine braking.

Each of the above clutches Co, C+, Cz and brake B,
l Bt is each provided with an accumulator. That is, 67 is an accumulator for C0, 68 is an accumulator for C1, 69 is an accumulator for B, and 70 is an accumulator for C.
71 is an accumulator for B. Each back pressure chamber 69 of the B0 accumulator 69, C1 accumulator 70, and B2 accumulator 71
An accumulator control valve 72 is provided to regulate the hydraulic pressure communicated with a, 70a, and 71a, as well as the low coast modulator valve 65 and the second coast modulator valve 66.

As described above, S and B2 are solenoid valves for switching and controlling the 12 shift valves 60, 2-3 shift valves 61, and 3-4 shift valves 62;
, and B4 are the near solenoid valves, to which hydraulic pressure regulated by the solenoid modulator valve 73 is supplied.

Further, 74 is an orifice control valve, and 75 is a cut-off valve.

Here, each solenoid valve S of this automatic transmission l,
, S□l 33 + 34, clutch Co, CCHI
Brake Be, B! , Bs and one-way clutch F, , F, , F, are at each position P.

At the gears R, R (V≧9), N, D, 2nd, and L, control B is performed as shown in the operation table shown in Fig. 6, respectively.
be done.

That is, in 1st speed in the D range or 2nd range, the solenoid valve S1 is in the on state, and as a result, the overdrive direct clutch Co, one-way clutches Fe, Fx, and forward clutch CI are engaged, and the others are in the released state. It has become. Therefore, the overdrive planetary gear unit 17 is integrated and directly connected via the overdrive direct clutch C0 and the one-way clutch F, and the rotation of the input shaft 15 is directly connected to the input shaft 26 of the main transmission unit 21. Reportedly. In the main transmission unit 21, the rotation of the input shaft 26 is transmitted to the ring gear 31 of the front planetary gear unit 19 via the forward clutch C1, and further to the carrier 29 and the output shaft 27 integrated with the carrier 29.
At the same time, a leftward rotational force is applied to the carrier 33 of the rear planetary gear unit 20 via the sun gear 30, but since this rotation is prevented by the one-way clutch F, the planetary binion 32 is rotated. The power is transmitted to the ring gear 35 which is integrated with the output shaft 27.

Also, when in 2nd speed in D range, solenoid valve S
In addition to turning on 1, solenoid valve S! turns on. As a result, overdrive direct clutch C0, one-way clutch Fe, forward clutch C
1. One-way clutch F1 and second brake B!
are engaged, and the others are in a released state. Therefore, the overdrive planetary gear unit 17 is in the directly connected state described above, and the rotation of the input shaft 15 is directly transmitted to the input shaft 26 of the main transmission unit 21. Further, the cough main transmission unit 21 is configured so that the rotation of the input shaft 26 is controlled by the forward clutch C9.
is transmitted to the ring gear 31 of the front planetary gear unit 19 via the planetary gear unit 19, and imparts a leftward rotational force to the sun gear 30 via the planetary pinion 28, but the sun gear 30 is applied to the one-way clutch F1 when the second brake B8 is engaged. Rotation in that direction is prevented at . Therefore, the planetary pinion 28 rotates while the carrier 29
rotates, and second speed rotation is transmitted to the output shaft 27 via only the front planetary gear unit 19.

Also, in 3rd gear in D range and 2nd range,
Solenoid S is turned off, overdrive direct clutch C0, one-way clutch F0, forward clutch CI, direct clutch C, and second brake Bt are engaged, and the others are in a released state. therefore,
The overdrive planetary gear unit 17 is in the above-mentioned direct connection state, and the main transmission unit 21 is integrated with the front planetary gear unit I9 through the engagement of the forward clutch C3 and the direct clutch C8, so that the input shaft 26 rotates. is transmitted to the output shaft 27 as is.

And in the 4th gear, that is, the highest gear in the D range,
Solenoid valve S is also turned off, forward clutch C1% direct clutch Cχ and second brake B
are in an engaged state, and the main transmission unit 21 is in a directly connected state as in the case of 3rd gear, but the overdrive planetary gear unit 7 7 is connected to the overdrive direct clutch C0.
is released, and the overdrive brake B0 is switched to be engaged. Therefore, sun gear 23
is longitudinally driven by the overdrive brake B0, and while the carrier 24 rotates, the planetary pinion 22 rotates and transmits power to the ring gear 25, and the rotation of the overdrive is transmitted to the input shaft 26 of the main transmission unit 21 which is directly connected. communicated.

On the other hand, during downshifting, in the case of 4-3, the overdrive direct clutch C0 is engaged and the overdrive brake B is released, and in the case of 3-2, the overdrive direct clutch C1 is released and the overdrive direct clutch C1 is released, and in the case of 3-2.
In the case of 1, the second brake B2 is released.

Furthermore, when the manual valve 51 is operated to the 2nd range, the speed is the same as that for the D range. In the case of the second speed state, in addition to the forward clutch CI, the overdrive direct clutch C0, and the second brake B8, the second coast brake B1 is engaged, and the sun gear 30 of the main transmission unit 21 is engaged.
lock and apply engine braking.

The 2nd speed in the L range is the same as the 2nd speed in the 2nd range described above, but in the 1st speed, the forward clutch CI, overdrive direct clutch C0
In addition, 1st & Rev brake B is engaged,
Lock the carrier 33 of the rear planetary gear unit 20 and apply the engine brake.

Next, in the R range, overdrive direct clutch C0, one-way clutch F0, direct clutch C1, and brake B are engaged, and the others are in a released state.

Therefore, overdrive planetary gear unit 1
7 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 direct clutch C2, and the rotation of the rear carrier 33 is locked by the brake B. 3o
The rotation is transmitted as reverse rotation to the ring gear 35 through the rotation of the planetary pinion 32, causing the output shaft 27 to rotate in the opposite direction. In addition, even if the manual valve 51 is operated in the R range, if the vehicle speed is higher than a predetermined speed, for example, 9 km/h, eight solenoid valves are on and the direct clutch C3 is in a released state, so the reverse rotation state occurs. It won't be.

As mentioned above, when downshifting 4-3,
Overdrive direct clutch C0 is engaged and overdrive brake B is applied.

is now being released. Here, the overdrive direct clutch C0 is arranged in parallel with the one-way clutch F, and the one-way clutch F,
This is to assist in power transmission through engagement.

In the shift control device for an automatic transmission of the present invention, 4-
3. Depending on the conditions of the 3-shift, the engagement of the overdrive direct clutch C0 is delayed to reduce the shock during downshifting, and while the engagement is complete, only the one-way clutch F is engaged. Power transmission is performed by

Next, FIG. 1 shows a main part of a hydraulic circuit applied to a shift control device for an automatic transmission according to the present invention.

In the figure, overdrive direct clutch C0 receives oil supply from boat a of 3-4 shift valve 62, and overdrive brake B receives oil supply from boat b of 3-4 shift valve 62. It has become. The 3-4 shift valve 62 assumes two positions by turning on and off the solenoid valve S8, and receives the oil pressure regulated by the primary regulator valve 52 at the bow 1-c, so that the boat a and the boat selectively supplied to b. In other words, when in 1st, 2nd, and 3rd gear,
The solenoid valve St is in an on state, and is drained to remove the oil pressure of the boat d, and the 3-4 shift valve 62 is placed in the right-hand position. Therefore, the oil pressure from the primary regulator valve 52 is sent to the overdrive direct clutch c6. Then, when the 4th gear is reached, the solenoid valve S is turned off.
Oil pressure is supplied to the boat d, the 3-4 shift valve 62 is placed in the left half position, and the oil pressure from the primary regulator valve 52 is sent to the overdrive brake B0.

Conversely, during a 4-3 shift down, the hydraulic pressure from the primary regulator valve 52 that was being sent to the overdrive brake B is now supplied to the overdrive direct clutch C0 by switching the 3-4 shift valve 62. Become.

In addition, a throttle 81 and a throttle with a check valve 82 are arranged in the oil passage for engaging the overdrive direct clutch C0 extending from the boat a, and the overdrive direct clutch C6 side from these is provided with an overdrive direct clutch C6. The C0 accumulator 67 is branch-connected. The accumulator 67 for the cough overdrive direct clutch C0 is the overdrive direct clutch C9.
The oil enters the upper chamber of the accumulator 67 for the overdrive direct clutch C0 via the boat e, and the oil enters the upper chamber of the overdrive direct clutch C0 accumulator 67.
is pushed down against the spring 84. Then, the overdrive direct clutch C0 is only engaged when a constant pressure is obtained.

On the other hand, an overdrive brake B extending from boat b,
A throttle 85 and a throttle 86 with a check valve are arranged in the engagement oil passage of the overdrive brake B,
An overdrive brake B0 achievator 69 is branch-connected to the side. The overdrive brake ro.

The accumulator 69 for overdrive brake B,
This oil enters the lower chamber of the overdrive brake low accumulator 69 through the boat f, and pushes the piston 87 up against the spring 88. The overdrive brake B0 is not engaged until a certain pressure is obtained.

Here, each of the accumulators 67, 69 is provided with ports g, h on the back pressure side of the piston 83, 87. The port g is connected to the boat i of the cutoff valve 75, and hydraulic pressure is supplied or stopped depending on the position of the cutoff valve 75. Also, port h
is the port j of the accumulator control valve 72
The hydraulic pressure is supplied or stopped depending on the position of the accumulator control valve 72. The hydraulic pressure supplied to these ports g and h provides back pressure to the accumulators 67 and 69, thereby acting as resistance to the operation of the accumulators 67 and 69, thereby increasing the overdrive direct clutch C0 and the overdrive brake B. , which acts to speed up the engagement and disengagement.

The back pressure is controlled as follows.

The hydraulic pressure regulated by the solenoid modulator valve 73 is supplied to the boat k of the accumulator control valve 72, and since the accumulator control valve 72 is normally in the left half position, the overdrive brake is applied via the port j. It is supplied to the back pressure side port h of the accumulator 69, and is also supplied to the boat l of the hot-off valve 75 via the boat j.

By the way, the cut-off valve 75 is configured to take two positions depending on the oil pressure supplied from the throttle valve 53, for example, depending on the acceleration/deceleration state of the vehicle. That is, when the accelerator is turned on, the throttle valve 5
3 port m to port n of the cut-off valve 75
+P is supplied with hydraulic pressure, and the cut-off valve 75 assumes the right-hand position. At this time, boat l and port i are cut off, so the back pressure applied to port g of accumulator 67 for overdrive direct clutch C0 disappears, and overdrive direct clutch C
6 is delayed. That is, in the case of a 4-3 downshift, for example a 4-3 kickdown, with the accelerator on, the overdrive direct clutch C6 is engaged late, reducing the shock during downshifting.

Further, when the accelerator is turned off, the supply of hydraulic pressure from the boat m of the throttle valve 53 to the boats n, p is stopped from the cut-off valve 75 to the boats n, p.
of oil is discharged. Therefore, the cut-off valve 7
5 assumes the left half position, and the boat l and port j are communicated with each other, so that back pressure is applied to the port g of the accumulator 67 for the overdrive direct clutch C0, and as a result, the overdrive direct clutch C0 is engaged. becomes faster. That is, in the case of a 43-shift down with the accelerator off, for example a 4-3 manual down, the overdrive direct clutch C0 is engaged quickly, resulting in a good response during downshift.

As described above, the cutoff valve 75 is switched by turning on and off the accelerator, and accordingly, the accumulator 6 for the overdrive direct clutch C0 is switched.
The supply of back pressure applied to gear No. 7 is controlled to perform soft down control in accordance with driving condition A1, but the 4-3 coast down control, which naturally reduces speed and downshifts from 4th gear to 3rd gear, is performed. At this time, it is desirable to reduce the shock of downshifting in the same way as during kickdown.Therefore, during the 4-3 coast down, the back pressure of the accumulator 67 for the overdrive direct clutch C0 is removed. .

For this purpose, a near solenoid valve S, which is activated during 4-3 coast down, is used to control the accumulator control valve 720. That is, port q of the accumulator control valve 72
Port r of linear solenoid valve S is connected to , and when linear solenoid valve S4 is activated and hydraulic pressure is supplied to port q, it moves to the right hand position, and the distance between bow) k and port j is will be cut off. As a result, the back pressure formed on the boat j side can be forcibly removed.

Note that the cut-off valve 75 is provided with a bow) n and a port p branching from one oil passage, and this is for giving a snap action to the cough force/7-off valve 75. In order to form the snap action, the pressure receiving area of the land 89 of the spool valve is made larger than the pressure receiving area of the land 90. Therefore, when the accelerator is turned on, oil is initially supplied from boat tn and boat P.

At that time, oil supplied from port n pushes land 89 downward, but oil supplied from port n pushes land 89 and 9
Since the spool valve is pressurized and the spool valve is urged upward from the difference in the pressure receiving area, the speed at which the spool valve descends is low, and if the oil supply from Bow 4P is cut off during the descent, the spool valve The force that urges the valve upward is eliminated, and the oil supplied from port n exclusively pushes the land 89 downward, so that the downward speed becomes faster.

Conversely, when the spool valve rises, a similar snap action is applied, and the speed increases in the latter half of the rise.

In this way, reliable switching operation can be obtained when descending and ascending, so the above-mentioned overdrive direct clutch C
Supply and stop of back pressure to the 0 accumulator 67 becomes quick.

In Fig. 7, the horizontal axis shows time, and the vertical axis shows torque To, the rotation speed of overdrive direct clutch C0, and the accumulator for overdrive direct clutch C0. Take the back pressure of and show the respective time series changes, and the control of the present invention? ■The solid line indicates the operation when the back pressure is controlled by the device, and the broken line indicates the conventional operation.

Note that the present invention is not limited to the above embodiments,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[Brief explanation of the drawing]

FIG. 1 shows a shift control device in an automatic transmission of the present invention,
Fig. 2 is an overall sectional view of an automatic transmission to which the present invention is applied, Fig. 3 is a schematic configuration diagram thereof, Fig. 4 is a circuit diagram showing its hydraulic control device, and Fig. 5 is an operation of manual valves in each range. 6 is a diagram showing the operating states of the solenoid valve, clutch, brake, and one-way clutch in each range, and FIG. 7 is an operational diagram of the shift control device in the automatic transmission of the present invention. 1... automatic transmission, 2... torque converter, 3...
...Speed gear mechanism, 5...Hydraulic control device, 12...
Lock-up clutch, 17... Overdrive planetary gear unit, 19... Front planetary gear unit, 20... Rear planetary gear unit,
21... Main transmission unit, 51... Manual valve, 52... Primary regulator valve, 53...
...Throttle valve, 55...Secondary regulator valve, 56...Lock-up control valve, 57...Lock-up relay valve, 58...
Solenoid relay valve, 60...1-2 shift valve, 61...2-3 shift valve, 62...3-4
Shift valve, 65...Low coast modulator valve, 66...Second coast modulator valve, 67...Accumulator for overdrive direct clutch C0, 69...Overdrive brake B
, accumulator, 72... accumulator control valve, 73... solenoid modulator valve, 74... orifice control valve, 7
5... Cutoff valve, 83.87... Piston, 84, 88... Spring, Bo... Overdrive brake, C0... Overdrive direct clutch, S! ...Solenoid valve, S4...Linear solenoid valve. Patent applicant: Aisin ADA Co., Ltd.
Name) Agent: Patent Attorney Mamoru Shimizu (1 other person)

Claims (2)

[Claims] (1) Overdrive direct clutch and overdrive brake in the transmission gear mechanism of an automatic transmission,
3-4 shift valve selectively engages 3rd and 4th gears
In a shift control device for an automatic transmission that shifts between speeds, an accumulator is connected to the engaging oil passage of the overdrive direct clutch, and one end surface is connected to the back pressure side of the piston of the overdrive direct clutch accumulator. A solenoid modulator valve is connected to the solenoid modulator valve through a cut-off valve that receives oil pressure according to the acceleration/deceleration state of the vehicle and assumes two positions, and an accumulator control valve that receives oil pressure from the linear solenoid valve and takes at least two positions. , 4-3 At the time of kickdown, the valve of the cut-off valve is moved to supply the hydraulic pressure regulated by the solenoid modulator valve as back pressure to the accumulator, and
During 4-3 manual down, operate the cut-off valve to remove the above back pressure, and further during 4-3 coast down, operate the accumulator control valve using hydraulic pressure from the linear solenoid valve to remove the above back pressure. A shift control device for an automatic transmission featuring: (2) The shift control device for an automatic transmission according to claim 1, wherein the oil pressure corresponding to the acceleration/deceleration state of the vehicle is a throttle pressure.