JPS6280339A - Back-up pressure controller for automatic transmission - Google Patents

Abstract

PURPOSE:To prevent the speed change shock when an accelerator is put ON, and selection is performed from the manual range to the automatic speed change range by taking-in the drive-torque generation state as the condition for releasing the back-up pressure. CONSTITUTION:A back-up pressure controller 200 is equipped with a throttle opening-degree detecting means 201, car-speed detecting means 202, range- position detecting means 203, and a drive-torque detecting means 4 which uses an idle switch or negative pressure switch, and a gear-position detecting means 205. Each detection signal of these detecting means 201-205 is input into a micro-computer 206. Therefore, the generation of a drive torque in the case when an accelerator is put ON is detected by the drive-torque detecting means 204, and the generation of back-up pressure is released by the back-up pressure control means. Therefore, when selection is performed from the manual range to the automatic speed change range, no high pressure is supplied onto a frictional element fastened in the automatic speed change range.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the control of an automatic transmission installed in a vehicle, and the present invention is directed to the control of an automatic transmission mounted on a vehicle, and to prevent the friction element from slipping when the friction element is engaged during engine braking. The present invention relates to a backup pressure control device for an automatic transmission in which backup pressure is supplied to the automatic transmission.

Conventional technology This type of backup pressure control device is described in the 1984 maintenance manual "Automatic Transaxle JRN4FO2A Model, RL" published by Nissan Motor Co., Ltd.
There is something like the one shown in 4FO2A type (published in February 1982). That is, the backup pressure control device used in this automatic transmission is equipped with a backup valve and is used to control the 4th gear (D4) or 3rd gear of the automatic transmission range (D range).
When the manual range (■ range or I range) is selected from speed (D3) and the soft down is performed to 2nd speed, the backup valve is activated and the line pressure supplied at the manual range position of the manual valve is directly transferred. It is designed to supply the pressure modifier valve. Then, the signal pressure supplied from the breather modifier valve to the pressure regulator valve is set high, and the line pressure regulated by the regulator valve is set even higher, and this high line pressure is used as a backup pressure to It is supplied to friction elements (clutches, band brakes, etc.) that are engaged in the manual range.

That is, when the gear is shifted down from the D range high speed gear (D, D3) to the manual range, engine braking is applied, and during this engine braking, torque from the wheel direction acts on the friction element, but the friction element has a high torque. By supplying fastening pressure (backup pressure), the friction elements are prevented from slipping, thereby fully exerting the engine braking function, and also preventing the friction elements from burning out. In addition, when the manual range is shifted down from 2nd gear to 1st gear, the backup valve is switched again and the line pressure supply to the lub is stopped, which occurs in the manual range 2nd gear. The backup pressure is released.This is because the engine brake in 2nd gear reduces the vehicle speed to a predetermined speed and then shifts down to 1st gear, so the friction element that is engaged in 1st gear has no pressure from the wheel side. This is because excessive torque does not act.

Figure 9 shows the hydraulic pressure (
In the idling state when engine braking is applied, the backup pressure shown by the broken line is set to be significantly higher than the other line pressure characteristics shown by the solid line.

Problems to be Solved by the Invention However, in such conventional backup pressure control devices, the backup pressure generated in the manual range is reduced when the manual range is selected to the automatic shift range and when the manual range shifts from 2nd gear to 1st gear. When the pressure is turned down, the pressure is released by stopping the line pressure supplied from the backup valve to the pressure modifier valve.

Therefore, if you select the manual range once and then try to accelerate again, turn on the accelerator and generate drive torque, and if you select the automatic shift range from the manual range, the backup pressure that was generated in 2nd gear of the manual range will be reduced. Since the friction elements of the automatic shift range are engaged in a state in which the line pressure remains high, a significantly large shift shock occurs.

In addition, when manual Lenz l speed is activated, A/' is ON (
Similarly, when shifting up to 2nd gear in the same range by generating drive torque, the friction elements in 2nd gear are engaged by the backup pressure generated in 2nd gear, resulting in a significantly large shift yoke. There was a problem.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a backup pressure control device for an automatic transmission that can significantly reduce shift jam by incorporating a drive torque generation state as a condition for releasing the backup pressure.

Means for Solving the Problems In order to achieve the above object, the backup pressure control device for an automatic transmission of the present invention is designed to engage when the automatic transmission range is selected from the manual range, as shown in FIG. In an automatic transmission configured to supply backup pressure to a friction element (a), the automatic transmission includes a means (b) for detecting the generation of drive torque, and a torque generation signal based on the torque generation signal from the drive torque detection means (b). This is constructed by providing a control means (C) for canceling the generation of backup pressure.

Effects With the above configuration, in the present invention, the drive torque detection means (b) detects the drive torque generation when the accelerator is turned on, and the backup pressure control means (C
) to release the backup pressure generation. Therefore, when selecting from the manual range to the automatic shift range using the accelerator ONL, the backup pressure is already released when the accelerator is turned on, so high pressure is not supplied to the friction elements engaged in the automatic shift range. Also, when shifting up from 1st gear to 2nd gear in the manual range, the backup pressure is released when the accelerator is turned on, so
High pressure is also not supplied to the friction elements that are engaged in second gear.

Example Embodiments of the present invention will be described in detail below with reference to the drawings.

That is, FIG. 2 shows an overall circuit showing an embodiment of a hydraulic pressure control device using one back-up pressure narrow bag of the present invention,
An example of a power transmission train of an automatic transmission controlled by this hydraulic pressure control device is shown in the schematic diagram of FIG. 3, for example. That is, this power transmission train includes a torque converter 3 that transmits rotation from an engine output shaft I to an input shaft 2.
, a first planetary gear set 4, a second planetary gear set 5, an output shaft 6, and various friction elements described below.

The torque converter 3 is driven by the engine output shaft l, and includes a pump impeller 3P that is also used to drive the oil pump O/P, and a turbine that is fluidly driven by the pump impeller via internal working fluid and transmits power to the input shaft 2. The stator 3S is placed on a fixed shaft via the runner 3T1 and the one-way clutch 7, and increases the torque to the turbine launch 3T.
This is a normal lock-up torque converter with L added. The torque converter 3 is supplied with working fluid from the release chamber 3R, and while the working fluid is removed from the apply chamber 3A, the lock-up clutch 3L is released and the engine power is transferred through the pump impeller 3P and turbine runner 3T. (in the converter state) torque is transmitted to the input shaft 2 while increasing, and conversely, working fluid is supplied from the apply chamber 3A, and while the working fluid is removed from the release chamber 3R, the lock-up clutch 3L is engaged and the engine power is increased. is transmitted as is to the input shaft 2 via this lock-up clutch (in the lock-up state). In the latter lock-up state, the slip of the lock-up torque converter 3 (relative rotation of the pump impeller 3P and the turbine launch 3T) can be arbitrarily controlled (slip control) by reducing the working fluid displacement pressure from the release chamber 3R. can do.

The first planetary gear set 4 is a normal simple planetary gear set consisting of a sun gear 4S, a ring gear 4R1, a pinion 4P that meshes with these gears, and a carrier 4C that rotatably supports the pinion 4P, and the second planetary gear set 5 also includes a sun gear 5S, a ring gear. 5R, pinion 5P, and carrier 5C.

Next, the various friction elements mentioned above will be explained. The carrier 4C can be appropriately connected to the input shaft 2 via a high clutch H/C, and the sun gear 4S can be appropriately fixed by a band brake B/B, and the input shaft 2 can be connected by a reverse clutch R/C.
It can be combined as appropriate. Further, the carrier 4C can be appropriately fixed by a multi-plate low reverse brake LR/B, and is prevented from being reversed (rotation in the opposite direction to the engine) via a row one-way clutch LO/C. ring gear 4
R is integrally coupled to the carrier 5C and drivingly coupled to the output shaft 6, and the sun gear 5S is coupled to the input shaft 2. Ring gear 5R
can be appropriately coupled to the carrier 4C via the overrun clutch OR/C, and is also correlated to the carrier 4C via the forward one-way clutch FO/C and the forward clutch F/C. It is assumed that the forward one-way clutch FO/C connects the ring gear 5R to the carrier 4C in the reverse direction (direction opposite to the engine rotation) when the forward clutch F/C is engaged.

High clutch H/C, reverse clutch R/C, low reverse brake LR/B, overrun clutch OR
/C and forward clutch F/C are each operated by hydraulic pressure supply to perform the above-mentioned appropriate coupling and fixing, or band brake B/B is connected to 2nd speed servo apply chamber 2S/A and 3rd speed servo release. When the chamber 3S/R and the 4th speed servo apply chamber 4S/A are set and the 2nd speed selection pressure P is supplied to the 2nd speed servo apply chamber 2S/A, the band brake B/B is activated and in this state. When the 3rd speed selection pressure P3 is also supplied to the 3rd speed servo release chamber 3S/R, the band brake B/B becomes inactive, and then the 4th speed selection pressure P4 is also supplied to the 4th speed servo apply chamber 4S/A. Then, the band brake B/B is activated.

Such a power transmission train includes friction elements B/B, H/C, F/
C.

By operating OR/C, LR/B, and R/C in various combinations as shown in the table below, the friction elements FO/C, L
Together with the appropriate differential of the O/C, the rotational state of the elements constituting the planetary gear set 4.5 can be changed, thereby changing the rotational speed of the output side 6 relative to the rotational speed of the input shaft 2,
As shown in the table below? This provides four forward speeds and one reverse speed. Note that in the following table, the O mark indicates operation (hydraulic inflow), and the double mark indicates a friction element that should be activated when engine braking is required.

]: While the overrun clutch OR/C is operated, the forward one-way clutch FO/C placed parallel to it is inactive, and while the low reverse brake L/B is operated, Of course, the row one-way clutch LO/C arranged in parallel becomes inoperative.

By the way, the hydraulic pressure side control device shown in FIG. 2 includes a pressure regulator valve 20. Pressure modifier valve 22, duty solenoid 24, pilot valve 2
6. Torque converter regulator valve 28, lock-up control valve 301, shuttle valve 32, duty solenoid 34, manual valve 36, first lift valve 38
, second shift valve 40, first shift solenoid 42, second
Shift solenoid 44, forward clutch control valve 46.3-2 timing valve 48.4-2 relay valve 5
0.4-2 sequence valve 52, ■range pressure reducing valve 54,
Shuttle valve 56, oatmeal run clutch control valve 58, third shift solenoid 60, overrun clutch pressure reducing valve 63. 2nd speed servo apply pressure accumulator 64. 3rd speed servo release pressure accumulator 66, forming the main parts of the shock reduction device of the present invention. The main components are a 4-speed servo apply pressure accumulator 68 and an accumulator control valve 70, which are connected to the torque converter 3, forward clutch F/C, high clutch H/C, band brake B/B, and reverse clutch R/C. It is connected to the C low reverse brake LR/B, overrun clutch OR/C, and oil pump O/P as shown in the figure.

The pressure regulator valve 20 includes a spool 20b supported by a spring 20a in the left half position in the figure, and a plug 20c abutting against the lower end surface of the spool in the figure. Basically, the oil pump O/P is connected to the circuit 71. The oil discharged to the line is regulated to a pressure determined by the spring force of the spring 2Qa, but when the plug 2Qc applies an upward force to the spool 20b in the figure, the above pressure is increased by that amount to reach the predetermined line pressure. It is something. For this purpose, the pre-tunya regulator valve 20 is connected to the circuit 7 via a damping orifice 72.
1 is received by the pressure receiving surface 20d of the spool 20b, and the spool 20b is biased downward by this,
Boats 20e to 20h are provided which are opened and closed according to the stroke position of the spool 20b. The boat 20e is connected to the circuit 71 and arranged so that as the spool 20b descends from the left half position in the figure, it communicates with the boats 20h and 20f.

As the spool 20b descends from the left half position in the figure, the communication between the boat 2Of and the drain boat 20g is reduced, and at the point when the communication with the boat 20g is cut off, the boat 2Of
Place it so that it starts communicating with Qe. and boat 20
f is connected to the capacity control actuator 75 of the oil pump 0/P via a circuit 74 with a bleed 73 in the middle. The oil pump O/P is a variable capacity vane pump driven by the engine as described above, and the eccentricity is reduced when the pressure toward the actuator 75 exceeds a certain value, so that the capacity becomes smaller.

The plug 20c of the pre-tunya regulator valve 20 receives modifier pressure from the circuit 76 on its lower end face in the figure, and receives backward selection pressure from the circuit 77 on its pressure receiving surface 20i, and generates an upward force in the figure in response to these pressures. The spool 20b
shall be added to.

The pressure regulator valve 20 is normally in the left half state in the figure, and when oil is discharged from the oil pump O/P, this oil flows into the circuit 71. Spool 2
At the left half position of 0b, the oil in the circuit 71 is not drained in small pieces and the pressure increases. This pressure acts on the pressure receiving surface 20d through the orifice 72, pushes down the spool 20b against the spring 20a, and connects the boat 20e to the boat 20h. As a result, the above pressure is partially drained from the boat 20h and lowered, and the spool 2Qb is pushed back by the spring 20a. By repeating this action, the pressure regulator valve 20 basically sets the pressure within the circuit 71 (hereinafter referred to as line pressure) to a value corresponding to the spring force of the spring 20a. Incidentally, an upward force due to the modifier pressure from the circuit 76 acts on the plug 20c, causing the plug 20c to come into contact with the spool 2Qb as shown in the right half of the figure, and this upward force causes the spool 20b to assist the spring 20a. And, as will be explained later, modifier pressure occurs when the reverse is selected, and increases in proportion to the engine load (engine output torque), so the above line pressure increases when the engine load does not increase when the reverse is selected. The price will increase accordingly.

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 77 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 O/P reaches or exceeds the rotational speed of the engine (or higher than the rotational speed of the engine), the oil discharge amount that increases accordingly becomes excessive, and the pressure in the circuit 71 exceeds the pressure regulation value.

This pressure lowers the spool 20b further from the pressure regulating position in the right half of the figure, communicates the port 2Of with the port 20e, and blocks it from the drain port 20g. This will cause port 20
A portion of the oil e is removed from port 2Of and bleed 73, but a feedback pressure is generated within circuit 74.

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 75. In this way, the capacity of the oil pump O/P is controlled so that the discharge amount remains constant while the rotational speed exceeds a certain value, thereby preventing an increase in power loss of the engine due to discharge of more than necessary oil.

The line pressure generated in the circuit 71 as described above is supplied to the pilot valve 26, the manual valve 36, the accumulator control valve 70, and the 3-speed servo release pressure accumulator 66 through the line pressure circuit 78.

The pilot valve 26 includes a spool 26b elastically supported in the upper half position in the figure by a spring 28a, with the end face of the spool 26b far from the spring 26a facing the chamber 26c, and the pilot valve 26 is further provided with a drain port 26d. , a pilot pressure circuit 79 with strainer S/T is maintained. A communication hole 26e is provided in the spool 26b to guide the pressure of the pilot pressure circuit 79 to the chamber 26c.
It shall be switched and connected to d.

The pilot valve 26 is normally in the upper half state in the figure, and when it is supplied with line pressure from the circuit 78, it increases the pressure in the circuit 79. The pressure in the circuit 79 reaches the chamber 26c through the communication hole 26e, causing the spool 26b to move to the right in the figure, and when the spool 26b exceeds the pressure regulating position shown in the lower half of the figure,
The circuit 79 is cut off from the circuit 78 and at the same time communicates with the drain port 26d. At this time, the pressure in the circuit 79 is reduced, and when the spool 26b is pushed back by the spring 26a due to this pressure reduction, the pressure in the circuit 79 is increased again. In this way, the pilot valve 26 can reduce the line pressure from the circuit 78 to a constant value determined by the spring force of the spring 26a, and output it to the circuit 79 as pilot pressure.

This pilot pressure is transmitted through a circuit 79 to the pressure modifier valve 22, the duty node 24, 34, the lockup control valve 30, the forward clutch control valve 46, the shuttle valve 32, the first . 9th “IfQ:
No 1L'11. I/I'4I'IJIQ^nee J-e
Supplied to L+1 valve 56.

The duty solenoid 24 includes a coil 24a, a spring 24d, and a plunger 24b, and has an orifice 80.
The circuit 81 connected to the pilot pressure circuit 79 via
It is assumed that when the coil 24a is turned on, it communicates with the drain port 24c. This duty cycle node 24 has a coil 24a turned ON, OFF, and FF at a constant cycle by a computer (not shown), and also turns on the coil 24a at a constant cycle.
The time ratio (duty ratio) is controlled to generate a control pressure in the circuit 81 according to the duty ratio. The duty ratio is made smaller as the engine load (for example, engine throttle opening) increases except when the reverse is selected, and thereby the above-mentioned control pressure is made higher as the engine load increases. Further, the duty ratio at the time of reverse selection is set to 100%, and the above-mentioned control pressure is set to 0.

The pressure modifier valve 22 includes a spool 22b that is biased downward in the figure by a spring 22a and a control pressure from the circuit 81. 22c, an input port 22d to which the pilot pressure circuit 79 is connected, and a drain boat 22e are provided, and the circuit 76 is connected to the chamber 22f facing the end face of the spool 22b far from the spring 22a.

Then, at the left half position of the spool 22b in the figure, it is exactly port 2.
These ports are arranged so that port 2c is isolated from ports 22d and 22e.

The pressure modifier valve 22 receives the wooden swords downward in the figure on the spool 22b by the spring force of the spring 22a and the control pressure from the circuit 81, and applies the force due to the output pressure from the port 22C that has reached the chamber 22f to the spool 22b. The spool 2 is placed in a position where these forces are balanced, facing upward in the figure.
2b is stroked. If the output pressure from the port 22c is insufficient to match the downward force, the spool 22b descends beyond the pressure regulating position shown in the left half.

At this time, the boat 22c communicates with the port 22d and receives pilot pressure from the circuit 79 to increase its output pressure.

Conversely, if this output pressure is too high to match the downward force, the spool 22b will rise toward the right half position in the figure.

At this time, the boat 22C communicates with the drain port 22e, and the output pressure is reduced. By repeating this action, the pretsunoya modifier valve 22 regulates the output pressure from the port 22c to a value corresponding to the phase of the force due to the spring force of the spring 22a and the control pressure from the circuit 81, and adjusts this to the modifier pressure. It is supplied from the circuit 76 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 the reverse is selected, and since it is 0 when the reverse is selected, the modifier pressure is a value obtained by amplifying this control pressure by the spring force of the spring 22a. increases as the engine load increases except when reverse is selected, becomes 0 when reverse is selected, and pressure regulator valve 2
0 to enable the line pressure control described above.

A torque converter regulator valve 28 includes a spool 28b elastically supported in the right half position in the figure by a spring 28a,
While the spool strokes between the right half position in the figure and the left half position in the figure, the boat 28c is communicated with the port 28d, and as the spool 28b rises from the left half position in the figure, the port 28c is connected to the port 28d. The degree of communication is decreased with respect to the port 28e, and the degree of communication is increased with respect to the port 28e. Spring 28 is used to control the stroke of spool 28b.
The chamber 28f facing the spool end face far from a is the spool 28
It communicates with the port 28c through the communication hole 28g provided in b. The port 28c is connected to a predetermined lubricating part via a relief valve 82 and connected to the lock-up control valve 30 via a circuit 83, and the port 28d is connected via a circuit 84 to port 2 of the pressure regulator valve 20.
0h, and port 28e is connected to lockup control valve 30 by circuit 85. The circuit 85 has an orifice 86 on the way, and the orifice and boat 28c
is connected to a circuit 83 through an orifice 87, and an oil cooler 89 and a predetermined lubricating part 9o are connected by a circuit 88.
Make it understandable.

The torque converter regulator valve 28 is normally in the right half state in the figure, and when oil is supplied from the port 20h of the pressure regulator valve 20 via the circuit 84, this oil is transferred from the circuit 83 to the torque converter as described later. Head to 3. When supply pressure to the torque converter is generated, this torque converter supply pressure reaches the chamber 28f through the communication hole 28g, causing the spool 28b to rise in the figure against the spring 28a. When the spool 28b rises from the left half position in the figure due to an increase in the torque converter supply pressure, the port 28e opens and a portion of the torque converter supply pressure is removed through the port 28e7A and the circuit 88, thereby increasing the torque converter supply pressure. The pressure is adjusted to a value determined by the spring force of the spring 28a. The oil removed from the circuit 88 is cooled by an oil cooler 89 and then directed to a lubricating section 90. Note that if the torque converter supply pressure exceeds the above value due to the pressure regulating action of the torque converter regulator valve 28, the relief valve 82 opens and releases the excess pressure to the corresponding lubricating part to prevent deformation of the torque converter 3. do.

The lock-up control valve 30 is constructed by coaxially abutting a spool 30a and a plug 30b.
When the spool 30a is at the limit position shown in the right half of the figure, the circuit 83 is connected to the circuit 91 from the torque converter release chamber 3R, and when the spool 30a is lowered to the left half position in the figure, the circuit 83 is connected to the circuit 8.
5, and when the spool 30a further descends, the circuit 9
1 shall be connected to the drain boat 30c. In order to control the stroke of the spool 30a, the end face of the spool 30a far from the plug 30a faces the chamber 30d, and the pressure of the circuit 91 is guided through the orifice 92 to the chamber 30e facing the end face of the plug 30b far from the spool 30a. Make it. In addition, torque converter apply chamber 3
Circuit 93 from A connects to circuit 85 at a point closer to lockup control valve 30 than orifice 86. In addition, the pilot pressure from the circuit 79 is applied to the plug 30b through the orifice 94, thereby continuing to apply a downward force in the figure to the spool 30.
Prevent pulsation of a.

The lock-up control valve 30 controls the stroke of the spool 30a by the pressure supplied to the chamber 30d, and as long as this pressure is sufficiently high, the spool 30a maintains the right half position in the figure. At this time, the oil from the circuit 83 flows through the circuit 91, the release chamber 3R, the apply chamber 3A, the circuit 93, and the circuit 85 under pressure regulation by the torque converter regulator valve 28.
It is excluded from circuit 88. Thus, the torque converter 3 transmits power in the converter state. As the pressure within chamber 30d decreases, spool 30a passes through orifice 92.
; The pressure from the circuit 83 is lowered in the figure via the plug 30b by the pressure from the circuit 83, and when it has further descended from the left half position in the figure, the pressure regulating oil from the circuit 83 is applied to the circuit 85, 93, the apply chamber 3A, the release chamber 3R, and the circuit. 91, drain boat 30c
The torque converter 3 starts to flow to the chamber 30d.
Power is transmitted under a slip control state in which the slip decreases as the internal pressure decreases. When the pressure in the chamber 30d is further lowered from this state, the circuit 91 is completely communicated with the drain boat 3 and OC by further lowering of the spool 30a, and the pressure in the release chamber 3R is set to O, and the torque converter 3 is in a lock-up state. power transmission.

The shuttle valve 32 controls the stroke of the lock-up control valve 30 together with a forward clutch control valve 46 (to be described later), and includes a spool 32b elastically supported in the lower half position in the figure by a spring 32a. Switch to the upper half position in the figure as appropriate depending on the pressure. In the shuttle valve 32, the spool 32b connects the circuit 95 at the timing 30d in the lower half position to the pilot pressure circuit 7.
9, and a circuit 96 extending from the chamber 46a of the forward clutch control valve 46 is connected to a circuit 97 from the duty solenoid 34.
When 2b is in the upper half position in the figure, the circuit 95 is connected to the circuit 97, and the circuit 96 is connected to the circuit 79.

The duty solenoid 34 includes a coil 34a and a spring 34.
It consists of a plunger 34b elastically supported in the closed position at d.
A circuit 97 connected to a pilot pressure circuit 79 via an orifice 98 is connected to the drain boat 34c when the coil 34a is turned on (energized). The duty solenoid 34 is connected to the coil 3 by a computer (not shown).
4a is controlled to turn on and off at a constant cycle, and the ratio of the ON time to the constant cycle (duty ratio) is controlled to generate a control pressure in the circuit 97 according to the duty ratio. When the shuttle valve 32 is in the upper half state in the figure, the control pressure of the circuit 97 is locked up 1'' I-+-? -11 no t, 2n/7+I 7 kr+ -2 raw 1st addition L=
(fh -k h Originally, the duty ratio was set to 0%, which caused the circuit 97
The control pressure of the circuit 79 is made the same as the pilot pressure of the circuit 79 which is the source pressure. At this time, the control pressure is applied to the spool 30a in the chamber 30d.
is held in the right half position in the figure, and the torque converter 3 is kept in the converter state to meet the above requirements. As the requirements for both of the above-mentioned functions of the torque converter 3 become lower, the duty ratio is increased and the control pressure is lowered.
The torque converter 3 is operated in a slip control state that matches the requirements, and under low engine load and high rotation speeds where the above functions of the torque converter 3 are not required, the duty ratio is set to 100%, thereby setting the control pressure to 0 and locking up. The torque converter 3 is maintained in the lock-up condition as required via the control valve 3o.

Note that when the control pressure of the circuit 97 is used to control the stroke of the forward clutch control valve 46 when the Nyuttle valve 32 is in the lower half state in the figure, the duty ratio of the solenoid 34 is set to reduce the N→D select shock as described later. Or,
determined to prevent creep.

The manual valve 36 can be set in the parking (P) range, reverse (R) range, neutral (N) range, or
Forward automatic gear shift (D) range, forward 2nd gear engine brake (II) range, forward 1st gear engine brake (1)
A spool 36a that is stroked in a range is provided, and a line circuit 78 is connected to ports 36D, 362, 361, and 36R according to the selected range of the spool as shown in the following table. Note that in this table, O marks indicate ports that communicate with the line pressure circuit 78, and no marks indicate ports that are drained.

The first lift valve 38 is provided with a spool 38b elastically supported in the left half position in the figure by a spring 38a, and this spool is connected to the chamber 3.
It is assumed that when pressure is supplied to 8c, it is switched to the right half position in the figure. The first shift valve 38 changes the boat 38d to the drain boat 38e when the spool 38b is in the left half position.
Port 38f is connected to port 38g, port 38h is connected to port 38i, and when spool 38b is in the right half position in the figure, port 38d is connected to port 38j, port 38r is connected to port 38kl, port 38h is connected to port 381N,
-Let them communicate with each other.

The second shift valve 40 includes a spool 40b elastically supported in the left half position in the figure by a spring 40a.
When pressure is supplied to 0c, it is assumed to be in the right half position in the figure.

When the spool 40b is in the left half position in the figure, the second shift valve 40 allows the boat 40d to communicate with the drain port 40e, the port 40f with the port 40g, and the port 40h with the orifice-equipped drain port 40i, so that the spool 40b
When is in the right half position in the figure, port 40d to port 40,
It is assumed that the port 40f is connected to the drain boat 40e, and the port 40h is connected to the port 40k.

The spool positions of the first and second shift valves 38 and 40 are the first shift solenoid 42 and the second shift solenoid 4, respectively.
These shift solenoids are controlled by coils 42a, 44a and plungers 42b, 4, respectively.
4b, and springs 42d and 44d. The first lift solenoid 42 is connected to a pilot pressure circuit 79 via an orifice 99, and a circuit 100 leading to the chamber 38c.
When the coil 42a is ON (energized), the drain port 42c
The control pressure in the circuit 100 is set to the same value as the pilot pressure which is the source pressure, thereby switching the first shift valve 38 to the right half state in the figure. Further, the second shift solenoid 44 is connected to the pilot pressure circuit 79 via the orifice 101, and connects the circuit 102 leading to the chamber 40c to the coil AA2 (T+ n NI to M fR) n''=V
It is assumed that the control pressure in the circuit 102 is set to the same value as the pilot pressure of the source pressure by cutting off from the h-i J'-port 44c, thereby switching the second lift valve 40 to the right half state in the figure.

The first to fourth forward speeds can be obtained by combinations of the ON and OFF states of these shift solenoids 42 and 44, and therefore the states of the soft valves 38 and 40, which are summarized in the table below.

In Table 3, the O mark in this table indicates the right half of the shift valve in the figure (ascending), the X mark indicates the left half of the shift valve in the figure (descending), and the shift solenoid 42 and 44. ON.

OFF is determined by a computer (not shown) that determines a suitable gear position based on the vehicle speed and engine load based on a predetermined gear change pattern, and determines the appropriate gear position.

Forward clutch computer valve 46 is connected to spool 46
b, and the pilot pressure from the circuit 79 guided through the orifice 103 is applied downward in the figure to prevent pulsation of the spool, and the spool is further provided with a pilot pressure in the circuit 105 through the orifice 104. The operating pressure of the forward clutch F/C is fed back and applied downward in the figure. The spool 46b is stroked to a position where the downward force in the figure due to these pressures and the force due to the pressure inside the chamber 46a are balanced. Spool 46
b is the drain port 46 when the circuit 105 is in the right half position in the figure.
c, and the circuit 105 is connected to the circuit 106 at the left half position in the figure.
The circuit 105 is provided with a one-way orifice 107 that exerts a throttling effect only on the hydraulic pressure toward the forward clutch F/C, and the circuit 106 is connected to the boat 36D of the manual valve 36.

3-2 The timing valve 48 includes a spool 48b elastically supported at the left half position in the figure by a spring 48a.
8a, the pressure inside the chamber 48e is high, and the spool 4
When 8b is in the right half position in the figure, ports 48c and 48a
The gap shall be cut off.

4-2 The relay valve 50 includes a spool 50b elastically supported at the left half position in the figure by a spring 50a, and at this spool position, the boat 50c is connected to the drain port 50d with an orifice, and pressure is supplied into the chamber 50e. When spool 50 [1 is in the right half position in the figure, port 5Qc is bowed] 50f
This shall lead to the following.

4-2 The sequence valve 52 includes a spool 52b that is elastically supported at the right half position in the figure by a spring 52a, and at this spool position, the boat 52c is connected to the drain boat 52 with an orifice.
d, and when the pressure in the chamber 52e is high and the spool 52b is at the left hand position in the figure, the port 52c is connected to the boat 52f.

■The range pressure reducing valve 54 includes a spool 54b which is biased toward the right half position in the figure by a spring 54a, and boats 54c and 54d are provided that communicate with each other at this spool position, and the spool 54b is located at the left half position in the figure. A drain boat 54e is provided which begins to communicate with port 54c when raised to position and finishes closing boat 54d. Spool 5 far from spring 54a
The chamber 54f facing the end face of the tube 4b is connected to the boat 54c via an orifice 108. Thus, the range pressure reducing valve 54 is normally in the right half state in the figure, and when pressure is supplied to the boat 54d, pressure is output from the boat 54c.

This output pressure acts on the lower end surface of the spool 54b in the figure through the orifice 108, and as the output pressure increases, the spool 54b
4b is raised as shown in the figure. When the spool 54b rises above the left half position in the figure, the boat 54c
e, the output pressure from boat 54c is reduced.

When the spool 54b descends beyond the left half position in the figure due to this output pressure drop, the boat 54c communicates with the boat 54d.
The output pressure from boat 54c is increased. By repeating this action, the output pressure from the boat 54c is reduced to a constant value determined by the spring force of the spring 54a.

The shuttle valve 56 includes a spool 56b elastically supported in the left half position in the figure by a spring 56a, and this spool is connected to the chamber 56.
It is held in this position when there is a pressure supply to g, but chamber 5
While no pressure is supplied to 6g, when the upward force in the figure due to the pressure from the boat 56c exceeds the value, it is stroked to the right half position in the figure. At the left half position in the figure, the boat 56d is connected to the circuit 109 from the third shift solenoid 60, and at the same time, the boat 56e is connected to the train port 56f, and at the right half position in the figure, the boat 56d is connected to the pilot pressure circuit 79. 56e is connected to the circuit 109.

The third shift solenoid 60 includes a coil 60a, a plunger 60b, and a spring 60d.
circuit 109 connected to pilot pressure circuit 79 via 0
When the coil 60a is ON (energized), the drain boat 60c
It is assumed that the control pressure in the circuit 109 becomes the same value as the pilot pressure which is the source pressure. Note that ON/OFF of the third lift solenoid 6G is determined by a computer (not shown).

Overrun clutch computer valve 58 spring 58a
It is assumed that a spool 513b is elastically supported in the left half position in the figure, and this spool is switched to the right half position in the figure when pressure is supplied to the chamber 58c. Further, the Subur 58b connects the port 58d to the drain port 58e and the port 58f to the port 58g at the left half position in the figure, and connects the port 58d to the port 58h and the port 58r to the drain port 58e at the right half position in the figure. It is assumed that the

The overrun clutch pressure reducing valve 62 includes a spool 62b elastically supported at the left half position in the figure by a spring 62a, and when there is pressure from a port 62c on this spool, this applies a downward force in the figure. Hold the spool 62b in this position. When pressure is supplied to port 62d while there is no pressure inflow from port 62c, this pressure increases the output pressure from port 62e. This output pressure is in the chamber 62f
When the value corresponding to the spring force of the spring 62a is reached, the spool 62'D is moved to the right half position in the figure to cut off the connection between ports 62d and i2e, and the overrun clutch pressure reducing valve 62 outputs the output from port 62e. Pressure spring 6
It is assumed that the pressure is reduced to a constant value determined by the spring force of 2a.

The 2-speed servo apply pressure accumulator 64 is configured by elastically supporting a stepped piston 64a at the left half position in the figure by a spring 64b, and a chamber 6 defined between both ends of the stepped piston 64a.
4c is opened to the atmosphere, and the small diameter end face and large diameter end face of the stepped piston are made to face the closed chambers 64d and 64e, respectively.

The 3-speed servo release pressure accumulator 66 includes a stepped piston 66a elastically supported in the left half position in the figure by a spring 66b, and a chamber 66c defined between both ends of the stepped piston is connected to the line pressure circuit 78. The small-diameter end face and large-diameter end face of the stepped piston are respectively connected to a sealed chamber 66d.

66e.

4th speed servo apply pressure apply pressure 68 is applied to stepped piston 6
8a is elastically supported at the left half position in the figure by a spring 68b, and a sealed chamber 68c is defined between both ends of the stepped piston, and a small diameter end face and a large diameter end face of the service piston are respectively connected to a sealed chamber 68d, 68e.

The accumulator control valve 70 includes a spool 7Qb elastically supported in the left half position in the drawing by a spring 70a, and a chamber 70c facing the end face of the spool 70b far from the spring 70a.
The control pressure of the circuit 81 is guided to. The spool 70b connects the output port door 0d to the drain boat 70e at the left half position in the figure, and when the control pressure to the chamber 70c becomes high and the spool 70b rises above the right half position in the figure, the boat 70d is connected to the line pressure circuit. 78 shall be switched and connected. Then, the output port door 0d is connected to the accumulator 164d by the circuit tti.
A chamber 10 connected to the spring 68c and housing the spring 70a.
Also connect to f.

Thus, the accumulator control valve 70 raises the spool 70b above the right half position in the figure by the control pressure applied to the chamber 70c except when the reverse movement is selected. As a result, the line pressure from the circuit 78 is output to the circuit 111, and when the pressure in the circuit 111 reaches a value corresponding to the control pressure, the spool 70111 is elastically supported at the right half position in the figure. Therefore, the pressure in the circuit 111 is regulated to a value corresponding to the control pressure.
As the engine output torque (engine output torque) increases, the output torque from the circuit 111 to the chamber 64d of the accumulator 64.
The pressure supplied to 68c as accumulator back pressure also increases as the engine output torque increases. Note that since the control pressure is 0 when the reverse is selected, no pressure is output to the circuit lit.

Next, to provide a supplementary explanation of the hydraulic circuit network, the circuit 106 extending from the port 3BD of the manual valve 36 is connected to the port 38g of the first shift valve 38 and the port 40g of the second shift valve 40, and the circuit 106 extends from the port 3BD of the manual valve 36. It is also connected to port 56c of shuttle valve 56 and port 58g of overrun clutch control valve 58 via a more branched circuit 112. The port 38f of the first shift valve 38 is connected to the circuit 11
3 is connected to the port 50f of the 4-2 relay valve 50, and is also connected to the accumulator chamber 64e and the 2-speed servo apply chamber 2S/A via the one-way orifice 114, and the port 5 is connected to the chamber of the shuttle valve 32 by the circuit 115. Also connect to 32c. Further, the port 38h of the first shift valve 38 is connected to the chamber 50 of the 4-2 relay valve 50 by the circuit 116.
e and the port 58h of the overrun clutch control valve 58, and the port 50c of the 4-2 relay valve 50.
is connected to port 40k of second shift valve 40 by circuit 117. 38C to the port 38 of the first shift valve 38
is connected to the H/C together with the port 40f of the second shift valve 40 by a circuit 118, and in the middle there is a pair of one-way orifices arranged in opposite directions,
Insert 12Q. A circuit 12 branched from the circuit 118 between these orifices and the high clutch H/C
1 is a circuit 12 that is connected to the 3-speed servo release chamber 3S/R and the accumulator chamber 66e via the one-way orifice 122, and bypasses the one-way orifice 122.
The boats 48c and 48d are connected to the circuit 123, and the 3-2 timing valve 48 is inserted into this circuit 123. A circuit 124 branched from the circuit 121 between the one-way orifice 122 and the 3-speed servo release chamber 3S/R is connected to the chamber 52e of the 4-2 sequence valve 52, and the boats 52c and 52f of the 4-2 sequence valve 52 are connected to the Boat 38i of the first shift valve 38 and boat 4 of the second shift valve 40
Connect to 0h.

The boat 38j of the first shift valve 38 is connected to the boat 40d of the second soft valve 40 by the circuit 125, and the boat 38d is connected to the boat 40d of the second soft valve 40.
A Q circuit 126 connects the shuttle ball 127 to one inlet boat. The other inlet port of the shuttle ball 127 is connected by a circuit 128 to the boat 36R of the manual valve 36 together with said circuit 77 on the one hand, and to the reverse clutch R/R via a one-way orifice 129 on the other hand.
C and the accumulator chamber 68d, and the exit boat of the shuttle ball 127 is connected to the low reverse brake LR/B by a circuit 130. The boat 40j of the second shift valve 40 is connected to the boat 54c and chamber 54f of the I range pressure reducing valve 54 through a circuit 131, and the boat 54d of the range pressure reducing valve 54 is connected to the boat 38f of the manual valve 36 through a circuit 132.

The boat 56e of the shuttle valve 56 is connected to the 3-
2 connected to the chamber 48e of the timing valve 48, and the boat 56d
is connected to chamber 58c of overrun clutch control valve 58 by circuit 134. The boat 58d of the overrun clutch control valve 58 is connected to the accumulator chamber 66d by a circuit 135, and is also connected to the accumulator chamber 611te and the 4-speed servo apply chamber 4S/A via a one-way orifice 136. and boat 51B of overrun clutch control valve 58
is connected to the boat 62d of the overrun clutch pressure reducing valve 62 by a circuit 137, the boat 62e of the pressure reducing valve 62 is connected to the overrun clutch OR/C by a circuit 138, and a check valve 139 is provided between the circuits 137 and 138. Boat 62c of overrun clutch pressure reducing valve 62
is connected to the boat 361 of the manual valve 36 and the chamber 56g of the shuttle valve 56 by a circuit 140.

The operation of the hydraulic circuit in the forward travel range will now be described.

Pressure regulator valve 20. The pressure modifier valve 22 and the duty solenoid 24 use the above-described functions to regulate the oil from the oil pump O/P to a line pressure that increases in proportion to the engine output torque, except when the reverse is selected, and when the reverse is selected, the oil pump (1) The oil from /P is kept at a constant value and output to the circuit 78.This line pressure is controlled by the pilot valve 26, the manual valve 36, the accumulator control valve 70, and the accumulator 66.
, and the accumulator 66 is in the right half state in the figure. The accumulator control valve 70 applies accumulator back pressure proportional to the engine output torque to the accumulator 64.
68 chambers 64d and 68c, and these accumulators are respectively in the right half state in the figure. Incidentally, when the backward movement is selected, the accumulator control valve 70 sets the accumulator back pressure to O as described above, and places the accumulators 64 and 68 in the left half state in the figure. Further, the pilot valve 26 always outputs a constant pilot pressure to the circuit 79 due to the above operation.

If the P or N range driver does not wish to drive and sets the manual valve 36 to the P or N range, the manual valve boat 36D, 3
61. All of 36I and 36H are drain boats as shown in Table 2 above, and line pressure is not output from these boats, so the forward clutch F/C is operated using the line pressure from these boats as source pressure. , high clutch H/C, band brake B/B, reverse clutch R/C, low reverse brake LR/B, and overrun clutch OR/C are all kept inactive, and the power transmission train shown in Fig. 2 is used to transmit power. It can be left in an impossible neutral state.

In a state where the manual valve 36 is set to the D range with the desire for forward travel in the D range, automatic gear shifting is performed as follows.

(First speed) That is, in the D range, the manual valve 36 outputs the line pressure from the circuit 78 to the boat 36D as shown in Table 2 above. The line pressure from the boat 36D is transferred to the boat 38g of the first shift valve 38 and the second shift valve 38 by the circuit 106 as the D range pressure.
It is supplied to the boat 40g of the shift valve 40 and the forward clutch control valve 46, and is also supplied by the circuit 112 to the boat 56c of the shuttle valve 56 and the boat 58g of the overrun clutch control valve 58.

On the other hand, when the vehicle is stopped in the D range, the computer automatically switches between the first shift solenoid 42 and the second shift solenoid 44.
Both ONL, the first shift valve 38 and the second shift valve 4
0 is in the right half state in the figure. Therefore, the high clutch H/C is connected from the circuit 118 to the drain boat 4Qe via the boat 40f and becomes inoperative. Also, the 2nd speed servo apply chamber 2S/A is connected to the boats 38f and 38 from the circuit 113,
Circuit 118. 40e (via boat 40f)
21.
118. It communicates with the drain boat 40e via the boat 40f, and since the 4-speed servo apply chamber 4S/A communicates with the same drain boat 40e as described below, the band brake B/B also becomes inactive. That is, while the engine output torque is above a certain level, the D range pressure (line pressure) from the boat 56c, which is proportionally high, causes the shuttle valve 56 to be in the right half state in the figure, and the overrun clutch control valve 5 is output from the circuit 134.
8 is supplied with the pilot pressure of the circuit 79, and this valve is placed in the right half state in the figure. In addition, even if the engine output torque is below a certain level and the shuttle valve 56 is in the left half state in the figure, if there is no engine brake request operation, which will be described later, then the overrun clutch control valve 5 is transferred from the circuit 109 to the circuit 34.
8, the computer turns on the third shift solenoid 60 to make the control pressure the same as the pilot pressure, and puts the overrun clutch control valve 58 in the right half state in the figure. Therefore, at this time, the 4th speed servo apply pressure 4S/
A is the circuit 135. Boats 58d, 58h, circuit 116
°baud) 38h, 38Q, circuit 118. boat 40f
As mentioned above, it leads to the drain boat 40e.

Furthermore, the reverse clutch R/C is drained from the boat 36R via the circuit 128 and is in an inoperative state, and the low reverse brake LR/B is also drained as follows and is in an inactive state. That is, one inlet circuit 128 leading to the shuttle ball 127 associated with the circuit 130 to the low reverse brake LR/B is drained as described above, and the other circuit 126 is also connected to the boats 38d, 38j.

Circuit 125. The I range pressure reducing valve 54 connected to the boats 40d and 40f through the circuit 131 is connected to the manual valve boat 36.
Since it is not receiving pressure supply from I, it is in the right half state in the figure and is drained from the boat 36I, so the low reverse brake LR/B is in an inoperative state as described above. Next, the overrun clutch OR/C is operated by the check valve 139 from the circuit 138 because the overrun clutch control valve 58 is in the right half state in the figure as described above.
It communicates with the drain boat 58e via the boat 58f, and is in an inactive state.

As mentioned above, since there is no pressure in the circuit 113 heading towards the 2nd speed servo apply chamber 2S/A, the circuit 1
The shuttle valve 32 connected to the chamber 32c through the valve 15 is shown in the lower half of the figure. Therefore, this shuttle valve 32 is connected to the circuit 9
5 supplies pilot pressure from the circuit 79 to the chamber 30d, keeps the lock-up control valve 30 in the right half state in the figure, and puts the torque converter 3 into the converter state. The shuttle valve 32 further supplies the control pressure from the circuit 97 to the upstream chamber 46a of the circuit 96, and controls the forward clutch control valve 46 as follows by adjusting the control pressure to an appropriate value by controlling the duty of the solenoid 34. I can do it.

That is, when the D range and the axle are not performing a starting operation (releasing the brake and depressing the accelerator pedal at vehicle speed O), the duty ratio of the solenoid 34 is set to 100% and the control pressure to the chamber 46a is applied. Let it be O.

As a result, the forward clutch control valve 46 is in the right half state in the figure, and even though the D range pressure is output to the circuit IQ6 as described above, this is the forward clutch F/
C is not reached and it is kept inactive.

And high clutch H/C, band brake B/B
.

Reverse clutch R/C, low reverse brake LR/
B.

Since the overrun clutch OR/C is also inactive as mentioned above, the automatic transmission will remain in a neutral state in which power cannot be transmitted unless a starting operation is performed even in the D range, resulting in a creep phenomenon or a shift from the N range to the D range. Select shock (ND select shock) at the time of switching can be prevented.

When the driver performs a start operation, the computer gradually decreases the duty ratio of the solenoid 34 until it finally reaches 0%.

As a result, the control pressure to the chamber 46a gradually increases, and finally reaches the same value as the pilot pressure of the circuit 79, which is the source pressure. During this time, the forward clutch control valve 46 is gradually switched from the right half state in the figure to the left half state in the figure, and the circuit 105
Gradually increase the pressure towards the forward clutch P/C from
Ultimately, it becomes the same value as the D range pressure (line pressure) from the circuit 106.

Therefore, the forward clutch F/C is gradually operated,
As shown in Table 1 above, forward one-way clutch PO/
In conjunction with the operation of C and row one-way clutch LO/C, the automatic transmission enters the first speed selection state, and the vehicle can be started. Furthermore, at this time of starting, in order to gradually increase the working oil pressure of the forward clutch F/C as described above,
In addition, in conjunction with the throttling effect of the one-way orifice 107, the forward clutch F/C operates at a predetermined speed, making it possible to prevent start shock.

(Second speed) After that, when the vehicle speed increases and the driving state becomes such that the second speed should be selected, the computer switches the first shift solenoid 42 to OFF as shown in Table 3 above, and the first shift valve 3
8 to the left half state in the figure.

This causes the first shift valve 38 to connect the circuit 126 to the drain boat 38e for continued draining, and to connect the circuit 116 to the boats 38h, 38i and 4-2 sequence valve 52 (
Since no pressure is currently supplied to the third-speed servo release chamber 3S/H, this valve continues to drain water by communicating with the drain port 52d via the boat 52c in the right half of the figure. However, the first shift valve 38 shifts the circuit 113 to the circuit 1
06, the D range pressure is also supplied to the second speed servo apply chamber 23/A via the circuit 113, actuating the band brake B/B and forward clutch F/C.
operation maintenance and forward one-way clutch FO/C
Coupled with this operation, the automatic transmission enters the second speed selection state, as is clear from Table 1 above.

During this upshift from 1st speed to 2nd speed, the hydraulic pressure to the 2nd speed servo apply chamber 2S/A is throttled by the one-way orifice 114, pushing the accumulator piston 64a located at the right half position in the figure as described above. Since the band brake B/B gradually rises while moving, the operation of the band brake B/B proceeds gradually, and the shock at the time of the gear change can be alleviated. Then, the chamber 6 surrounding the accumulator piston 64a
Since the back pressure within 4d is proportional to the engine output torque as described above, the above-mentioned gear shift and yoke reduction effects can be reliably achieved.

Note that, as is clear from Table 1 above, not only the second speed but also the third and fourth speeds are selected, the second speed servo apply chamber 23
Since the D range pressure is supplied to /A, the shuttle valve 32, which supplies this pressure to the chamber 32c by the circuit 115, maintains the state in the upper half of the diagram during selection of the second to fourth speeds. This causes the forward clutch control valve 46 to open in the chamber 46.
A is supplied with pilot pressure from circuit 79 to maintain the state on the left side in the figure, and the forward clutch F/C is kept in a fully activated state without performing the pressure regulating action, thereby shifting from 2nd to 4th speeds. or not prevent it from being selected. On the other hand, the control pressure of the circuit 97 is supplied to the chamber 30d of the lock-up control valve 30, and by determining this control pressure as described above by the computer via the duty solenoid 34, the lock-up control valve 30 is The torque converter 3 can be put into a converter state, a slip control state or a lock-up state to match the operating conditions.

(Third speed) After that, when the operating state is reached in which the third speed should be selected, the computer also turns off the second shift solenoid 44 and puts the second shift valve 40 in the left half state in the figure, as shown in Table 3 above. .

As a result, the D range pressure that had reached port 40g passes through port 40f and circuit 118 to one-way orifice 1.
20, and then is throttled by the one-way orifice 119 and supplied to the high clutch l(/C, which activates it.On the other hand, this pressure passes through the one-way orifice 122 via the circuit 121 branched from the circuit 118, and It also reaches the speed servo release chamber 3S/R and deactivates the band brake B/B. 3rd speed servo release chamber 3
The pressure to S/R is from chamber 52e of 4-2 sequence valve 52.
On the other hand, although this valve is placed in the left half state in the figure to allow the boat 52c to communicate with the boat 52f, the second shift valve 40 communicates the boat 52f with the drain boat 4Qi, so the circuit l[6 continues to be drained. . Therefore, high clutch!
(Activation of /C.

Band brake B/B will be switched to non-operation,
As is clear from Table 1 above, the automatic transmission can select the third speed in conjunction with the operation of the forward one-way clutch FO/C.

Note that during this upshift from 2nd speed to 3rd speed, the high clutch 11/C and 3rd speed servo release chamber 3
The pressure to the S/R is throttled by the one-way orifice 119 and increases while pushing away the accumulator piston 66a, which is in the right half state in the figure, against the line pressure in the chamber 66c, so that the shock at the time of the gear shift occurs. can be prevented.

(4th speed) After that, when the operating state becomes such that 4th speed should be selected, the computer turns the first shift solenoid 42 to O as shown in Table 3 above.
N, and the first shift valve 38 is switched to the right half state in the figure. As a result, the first shift valve 38 cuts off the circuit 113 to the 2nd speed servo apply chamber 23/A from the D range pressure circuit 106, but it connects to the circuit 118 in the boat 38k and continues to the D range pressure circuit 113 to the 2nd speed servo apply chamber 2S/A. While supplying range pressure, the circuit 126 is cut off from the drain boat 38e, but it is connected to the circuit 125 at the boat 38j,
By passing through this and leading to the drain boat 40e, circuit 1
Continue to drain 26.

The first shift valve 38 further connects the circuit 116 to the circuit 118 via boats 38h, 38Q, and connects the circuit 118.116.
Boat 58h.

58d1 circuit 135. By supplying D range pressure to the 4th speed servo apply chamber 43/A via the one-way orifice 136, the band brake B/B is switched to the operating state,
In combination with maintaining the operation of the forward clutch F/C and high clutch H/C, the automatic transmission can be placed in the fourth speed selection state as shown in Table 1 above.

In this upshift from 3rd speed to 4th speed, the 4th speed selection pressure (highest speed selection pressure) to the 4th speed servo apply chamber 4S/A is throttled by the one-way orifice 136, as described above. Since the accumulator piston 68a in the right half state in the figure gradually rises while being pushed away against the back pressure in the chamber 68c, it is possible to prevent shock during the shift. Since the back pressure in the chamber 68c applied to the accumulator piston 68a is proportional to the engine output torque as described above, the above-mentioned shift shock reducing effect can be reliably achieved.

In addition, the pressure supplied to the 4-speed servo apply chamber 4S/A (
4th speed selection pressure) reaches the chamber 66d of the accumulator 66. Thus, the capacity of the accumulator 66 during the upshift from the second speed to the fourth speed is made different from the capacity of the accumulator 66 during the upshift from the second speed to the third speed to meet the requirements. It is possible,
Thereby, the shift shock reducing effect can be appropriately performed even in the jump shift.

r4 → q shift pib no S no ykt15: e) During selection of 4th speed When the operating state in which 3rd speed should be selected occurs, the computer turns off the first shift solenoid 42, as is clear from Table 3 above. to switch the first shift valve 38 to the left half state in the figure. As a result, the same state as when the 3rd speed was selected is reached, and the pressure in the 4th speed servo apply chamber 4S/A passes through the one-way orifice 136 and is immediately removed from the drain boat 40i, causing a downshift to 3rd speed. can be done.

(4→2 downshift) During the selection of the 4th speed, when the operating state becomes such that the 2nd speed should be selected, the computer turns off the first shift solenoid 42 and the first shift valve 38, as is clear from Table 3 above. is switched to the left half state in the figure, and the second shift solenoid 44 is switched to the left half state in the figure.
is turned on to switch the second shift valve 40 to the right half state in the figure. By switching the first shift valve 38, the circuit 113 to the second speed servo apply chamber 23/A is changed from the circuit 118 to the circuit 10.
The connection to B has been changed and the 2nd speed servo apply chamber 2 continues.
Supply pressure to S/A. Furthermore, by switching the second shift valve 40, the circuit 118 is cut off from the D range pressure circuit 106 and communicated with the drain boat 40e. Therefore, the operating pressure of the high clutch H/C passes through the one-way orifice 119, is throttled by the one-way orifice 120, and is removed from the drain boat 40e through the circuit 118.
The pressure in the quick servo release chamber 3S/R is also throttled by the one-way orifice 122 and then removed through the same route.

By the way, the pressure of 3rd speed servo release chamber 3S/R is connected to circuit 1.
The 4-2 sequence valve 52 guided by and responsive to the drain boat 52 remains in the left half state in the figure until the pressure is released, and drains the boat 52c connected to the circuit 116 via the boats 38i and 38h from the drain boat 52d. Cut off boat 5
Continue to lead to 2f. This causes the 4 connected to circuit 116 to
The pressure in the speed servo apply chamber 4S is not removed, and the pressure in the third speed servo release chamber 38/R is maintained until removal is completed. During this time, the pressure in the 4-speed servo apply chamber 4S/A is supplied to the 4-2 relay valve 5o via the circuit 116, and this valve is maintained in the right half state in the figure. Therefore, the pressure in the circuit tta to the 2nd speed servo apply chamber 2S/A is 50
f, 50c, circuit 117. Poe) to 40, 4Qh,
52f.

52c, 38i, 38h and circuit 116. boat 5
8h, 58d, the pressure inside the 4-speed servo apply chamber 4S is maintained via the circuit 135.

When the pressure in 3rd speed servo release chamber 3S/R is released, 4
-2 sequence valve 52 is in the right half state in the figure to communicate boat 52c to drain boat 52d, and removes the pressure in 4-speed servo apply chamber 4S/A that communicates with circuit 116 from drain boat 52d. As a result of this removal, the 4-2 relay valve 50 enters the left half state in the figure, and removes the pressure in the circuit 117 from the drain boat 50d. Thus, during the shift, the pressure in the 4th gear servo apply chamber 4s is removed after the pressure in the 3rd gear servo release chamber 3S/R and high clutch H/C is released, and the pressure in the former is removed. This prevents the pressure from being released before the latter pressure and shifting from 4 to 3 to 2, making it possible to reliably shift from 4 to 2.

(3→2 downshift shift) When the operating state becomes such that the second speed should be selected in the third speed selection state, the computer turns the second shift solenoid 44 (IN) to the second The shift valve 40 is switched to the right half state in the figure.

Due to this switching, even if the boat 40h is connected from the drain boat 401 to the port 40, the circuit 11
6 (4-speed servo apply chamber 4S/A) is 4-
Since the 2 relay valve 50 is in the left half state in the figure and the circuit 117 is connected to the drain boat 5Qd, the boat 52f becomes the drain boat, and the 4-2 sequence valve 52 is connected to the 4-speed servo apply regardless of the state. Keep chamber 4S/A in an unpressurized state.

On the other hand, the above switching of the second shift valve 40 connects the circuit 118 to the drain boat 40e, and the high clutch H/C
and 3-speed servo reli, -pressure in chamber 3S/R to 4-2.
When changing gears, it is removed through the route described above.

Therefore, a downshift from 3rd speed to 2nd speed is obtained, but at this time, the pressure in the 3rd speed servo release chamber 3S/H is removed at a predetermined timing according to the engine operating condition as shown below. Smooth gear shifting is possible.

In other words, if the engine output torque is below a certain level, the internal pressure)
puts the shuttle valve 56 in the left half state in the figure, and the chamber 48e of the 3-2 timing valve 48 is connected to the circuit 133 and the boat 56e.
Since the 3-2 timing valve 48 is connected to the drain boat 56F through the drain boat 56F, the 3-2 timing valve 48 is in the left half state in the figure. Therefore, under this low engine output torque, the 3rd speed servo release chamber 3S
The pressure of /H is discharged not only through the one-way orifice 122 but also through the orifice 48f, and the discharge speed is fast.

When the engine output torque is above a certain level, the D range pressure (line pressure) from the high boat 56c corresponding to this puts the shuttle valve 56 in the right half state in the figure, and the 3-2 timing valve 4
8 is changed in state by control pressure from circuit 109. The computer turns on the third shift solenoid 60 when the engine output torque and vehicle speed are higher than a predetermined value, and sets the control pressure to the same value as the pilot pressure, which is the original pressure. Therefore 3
-2 timing valve 48 is in the right half state in the figure, and is in 3rd gear position.

The pressure in the borehole chamber 38/H is released at a low speed using only the one-way orifice 122.

(2-1 Downshift gear change) Fue 94 Junkon Juno l-Matsuhfkan 1: When the J91 is in the 1st shift state, the computer turns on the first shift solenoid 42 as is clear from Table 3 above. and the first shift valve 3
8 to the right half state in the figure. As a result, the circuit 113 to the 2nd speed servo apply chamber 2S/A is connected to the D range pressure circuit 1.
Cut off from 06, boat 38f.

38k to circuit 118. By the way, circuit 118
is connected to the drain port 40e by the second shift valve 40, the pressure in the second speed servo apply chamber 2S/A passes through the one-way orifice 114 and is quickly removed, resulting in a downshift from second speed to first speed. You can get variable speed.

■If the range driver desires engine braking in 2nd gear, etc., and sets the manual valve 36 to the manual range. It also outputs the line pressure of the circuit 78. Pressure is supplied from the boat 36D following the same route as in the case of the D range described above,
Computer is 1st and 2nd shift solenoid 42.44
The automatic transmission can be shifted between the first speed and the second speed by turning ON and OFF so as to obtain the first speed or the second speed according to Table 3 above.

The pressure (■ range pressure) from the manual valve boat 361 reaches the boat 62c of the overrun clutch pressure reducing valve 62 via the circuit 140, and places this valve in the left half state in the figure.

The range pressure from the circuit 140 further reaches the chamber 56g of the shuttle valve 56, locking this valve in the left half state in the figure.

In this state of the shuttle valve 56, the control pressure of the circuit 110 is supplied to the chamber 58c of the overrun clutch control valve 58, and the computer uses this control pressure via the OFF' of the third shift solenoid 60 during second speed selection. 0
The overrun clutch control valve 58 is in the left half state in the figure. Thus, D from circuit 112
Range pressure is in circuit 137. Overrun clutch pressure reducing valve 6
2 and circuit 138 to the overrun clutch OR/C as a friction element, which is activated to enable engine braking in second gear.

For example, this engine brake is activated when selecting from D range 4th gear to ■ range, or from D range 3rd gear to ■ range.
Works when selected in the range.

Note that at this time, the overrun clutch pressure reducing valve 62 does not perform a pressure reducing action because it is in the locked state as described above, and the D range pressure, that is, the line pressure is supplied to the overrun clutch OR/C, and the line pressure is used as backup pressure. It is now possible to

■The range driver wishes to run with engine braking in 1st gear,
When the manual valve 36 is set to I range, this manual valve is boat 36D as shown in Table 2 above.

The line pressure of the circuit 78 is output to 36II and 36I. Pressure is supplied from the boat 36D through the same route as in the case of the D range described above, and the computer is supplied with pressure from the first. Turn on the second shift solenoids 42 and 44 to obtain either 1st or 2nd speed according to Table 3 above.

By turning off, the automatic transmission can be shifted between the first and second speeds. Here, the reason why 2nd gear may be selected despite being in the ■range is that when the engine is reversely driven from the wheels while driving in the ■range, the engine may overspeed in the high vehicle speed range. In order to prevent this, the second gear is set once under such conditions, and then the first gear is set at a vehicle speed that does not cause overspeeding of the engine.

The pressure from the manual valve boat 36I is applied by keeping the shuttle valve 56 and the overrun clutch pressure reducing valve 62 in the left half state in the figure, as in the case of the above-mentioned range (1), and the overrun clutch control valve 58 from the circuit 109. The state is changed by control pressure.

By the way, the computer sets this control pressure to 0 by turning off the third shift solenoid 60 in the I range, holds the overrun clutch control valve 58 in the left half state in the figure, and operates the overrun clutch OR/C. continue.

The pressure from the manual valve boat 36I passes through the circuit 132 and reaches the I range pressure reducing valve 54, which reduces the pressure from the circuit 132 to a constant value by the above action and outputs it to the circuit 131. By the way, the second shift valve 40 is in the right half state in the figure as shown in Table 3, regardless of whether it is in the first speed or the second speed, and outputs the pressure of the circuit 131 to the circuit 125. On the other hand, the first shift valve 38 is in the left half state in the figure as shown in Table 3 at the second speed, cutting off the pressure in the circuit 125 and communicating the circuit 126 to the drain port 38e. Thus, the circuit 130 to the low reverse brake LR/B passes through the shuttle ball 125 and the circuit 125 to the drain port 38e.
, and the low reverse brake LR/B is inactive. Therefore, operation of the overrun clutch OR/C enables engine braking running in the second speed.

As mentioned above, when the vehicle speed reaches a point where the engine does not overspeed even in 1st gear, it becomes 1st gear.
The shift valve 38 is in the right half state in the figure, and the circuit 125 is connected to the circuit 126, and the pressure that reaches the circuit 125 is transferred to the circuit 1.
26. The shuttle ball 1271 is supplied to the low reverse brake LR/H via the circuit 130 to operate it.

In this way, together with the fact that the overrun clutch OR/C is activated as described above, it is possible to run with engine braking in the first gear.

In addition, No. 1! During engine braking in 2nd speed and 2nd speed, the overrun clutch pressure reducing valve 62 is locked in the left half state in the figure as described above, so it does not perform a pressure reducing action and the operating pressure of the overrun clutch OR/C is reduced. (backup pressure) is the line pressure. Also, during running with engine braking in the first gear, the pressure toward the low reverse brake LR/B is reduced to a predetermined value by the pressure reducing action of the I range pressure reducing valve 54, so the capacity of the low reverse brake is adjusted to meet the demand. As a result, engine brake shock can be prevented from occurring.

FIG. 4 shows a backup pressure control device 200 of the present invention, which includes a throttle opening detection means 201, a vehicle speed detection means 202, and a range position detection means using an inhibitor switch (not shown) or the like. 203
, a drive torque detecting means 204 using an idle switch or a negative pressure switch, and a gear position detecting means 205 in the D range immediately before selecting the ■ range or the ■ range.
Detection signals from 202, 203, 204, and 205 are input to a microcomputer 208. The microcomputer 206 includes means 207 for determining the current driving range based on the signal from the range position detecting means 203 and the drive torque detecting means 2.
Means 20 for determining whether the accelerator is ON or OFF, that is, whether the current coasting state is present, based on the signal from 04.
8, means 209 for determining whether backup pressure is generated in the hydraulic pressure control device, that is, whether engagement pressure for overrun clutch OR/C or low and reverse brake LR/B is generated; means 210 for calculating backup pressure according to the state; and driving means 211 for duty-controlling the duty solenoid 24.
It is equipped with

FIG. 5 shows a flowchart for executing a program processed by the microcomputer 206, and this flowchart includes the steps shown in FIG. 6(A).

Subroutines shown in (B), (C), and (D) are provided. Here, before explaining the flowchart of FIG. 5, the subroutine of FIG. 6 will be explained first. In addition, here, FIG. 5A will be temporarily referred to as a first subroutine, FIG. 2B as a second subroutine, FIG. 1C as a third subroutine, and FIG. In the first subroutine, a throttle value is read in step 1100, and based on this throttle value, step 1101 is performed.
The line positive value is calculated in step 1102, and duty data for controlling the duty solenoid 24 is set.

In the second subroutine, in step 1200, the vehicle speed Vsp
is read, the line pressure is calculated in step 12o1 from this vehicle speed Vsp and the backup data shown in FIG. 7, and the duty is set to overnight in step 1202.

The backup data shown in FIG. 7 has two characteristics (D, select backup data (a) and D3 select backup data (b)) depending on the gear position immediately before shifting to the manual range. In subroutine 2, the line positive value is determined based on the D4 select backup data (a) which indicates a relatively high line positive value. Next, in the third subroutine, step 1300
The vehicle speed Vsp is read in, the line pressure is calculated in step 1301 based on the D3 select backup data (b) showing a relatively low line positive value shown in FIG. 7, and duty data is set in step 13G2. In the fourth subroutine, in step 1400, the duty data is simply set to O, that is, the duty ratio (100%) is set so that the control pressure by the duty solenoid 24 is zero.

Next, the main routine shown in FIG. 5 will be explained.

First, in step 1000, the driving range (D, n) is selected.

(2) If the answer is YES, the process proceeds to step 1001, where it is determined whether the D range is selected.

If the result in step 1001 is No, that is, in the ■ range or in the I range, it is determined in step 1002 whether or not the coasting state is present. If it is in the coasting state (YES), it is determined in step 1003 whether or not backup pressure is being output, and in step 1003, it is determined that backup pressure is not being output (NO).
), the process proceeds to step 1004, where it is determined whether the gear position is D4 before shifting to the manual range, and if it is not D4 (No), the process proceeds to step 1004.
5, it is determined whether the gear position before shifting is D3. If it is determined in step 1005 that the pre-shift gear position is not D3 (NO), that is, if the pre-shift gear position is up or down, step 1
006, the first subroutine is executed in step 1006 to obtain duty data based on the throttle value, and duty is output to the duty solenoid 24 in step 1007 based on this duty data. On the other hand, in step 1001, the D range is set (
If it is determined that the coasting state is not present (NO) in step 1002, the process proceeds to step 1008, where the backup flag is cleared to confirm that there is no need to output backup pressure, and the process proceeds to step 1008. The process advances to 1006 and similar processing is performed.

Next, if it is determined in step 1004 that the pre-shift gear position is D4 (YES), that is, if the vehicle speed is significantly high, the process proceeds to step 1010, where the D4 backup flag is set, and the process proceeds to step 1011. In step 1011, the second subroutine is executed to set duty data based on the D4 select backup data shown in FIG. 7 and the vehicle speed, and in step 1007, duty is output. on the other hand,
If it is determined in step 1005 that the gear position before shifting is D3 (YES), that is, if the vehicle speed is slightly lower than the D4 state, the process proceeds to step 1020, sets a backup flag, and returns to step 102.
Go to 1. In this step 1021, the third subroutine is executed to set duty data based on the D3 select backup data shown in FIG. 7 and the vehicle speed, and in step 10o7, duty is output.

On the other hand, if it is determined in step 1003 that the backup pressure is being output (YES), the process proceeds to step 1030, where it is determined whether or not the first speed is in the ■range and ■range. In the case of low reverse brake LR/B+, if the backup pressure at the 1st speed is supplied, the backup pressure at the 1st speed is controlled by the pressure reducing action of the range pressure reducing valve 54, so the line pressure itself The process proceeds to step 1008 and the same processing is performed thereafter without requiring any control.

Also, if it is determined in step 1030 that the gear is not in 1st gear (NO), that is, if it is determined that it is in 2nd gear in the ■range or ■range, the process proceeds to step 1031, and the backup when the engine brake is applied from D4th gear. Determine whether pressure control is required. And the step 1
If D4 backup is required (YES) in step 031, the process advances to step 1010 and the same processing is performed thereafter. On the other hand, if it is determined in step 1031 that it is not a D4 backup (No), that is, if it is a D3 backup, the process advances to step 1020 and the same processing is performed thereafter.

By the way, in step 1000, it is not in the driving range (
If the answer is NO, the process proceeds to step 1040 where the fourth subroutine is executed, and the process proceeds to step 1007 with line pressure control skipped to perform duty output.

By performing the above program processing, the backup pressure control device 200 of this embodiment has D range 4 speed (D
4) or when downshifting from 3rd gear (D3) to 2nd gear in manual range ■ range or I range,
The duty ratio of the duty solenoid 24 is controlled according to the data shown in FIG. 7, and the line pressure is controlled via the pressure regulator valve 20. That is, when downshifting to the second speed in the manual range, the overrun clutch pressure reducing valve 62
(Line pressure as backup pressure is supplied to the -run clutch ORP, and the engine brake is applied.By the way, this backup pressure (line pressure) at the time of second gear is the pressure of the duty solenoid 24 as shown in FIG. The line pressure is changed by duty ratio control, and when the 2nd speed engine brakes due to a downshift from D4, the line pressure is controlled according to the D4 select backup data characteristic (a) in Figure 7, and the 2nd gear is changed by a downshift from D3. When the speed engine is braking, the line pressure is controlled according to the D3 select backup data characteristic (b) in Figure 7. Therefore, even when the second speed engine is braking, the gear position before shifting is D3. In this case, the line pressure, that is, the backup pressure, is set lower than in the case of D4.In other words, in the case of pre-shift gear position D4, the overrun clutch OR High backup pressure is required to prevent slipping of /C and band brake B/H, and the D4 select backup data characteristic (a) is set to satisfy this requirement, and at the same time, to prevent unnecessary high pressure from being supplied. This setting prevents the engagement shock from occurring.On the other hand, when the gear position before shifting is D3, the vehicle speed is lower than in the case of D4, so the Ds select backup data characteristic (b) is set as described above. By setting it lower than the D4 select backup data characteristic (A), unnecessary engagement shock of the overrun clutch OR/C and band brake B/H is prevented.The above-mentioned D3 select backup data It goes without saying that even if the line pressure is controlled according to characteristic (b), the overrun clutch OR/C and band brake B/B should be set to prevent slipping.

Furthermore, in this embodiment, the D4+D3 select backup data characteristics (41 ports) are set so that the line pressure increases depending on the vehicle speed Vsp, so that the line pressure increases when the engine brake is applied from the same gear position. Even if the vehicle speed is high, the backup pressure is increased to prevent overrun clutch OR/C and band brake B/B from slipping, and the lower the vehicle speed is, the backup pressure is decreased to prevent overrun clutch OR/C from slipping. This is to reduce the engagement shock of /C and band brake B/B. Therefore, the backup control device 20 of this embodiment
0, the backup pressure is controlled according to the gear position and vehicle speed before shifting to manual range 2nd gear, so when engine braking is applied in manual range 2nd gear, overrun clutch OR/C and band brake B/H are activated. In other words, while the engine brake is reliably applied, the engagement shock of the overrun clutch OR/C and the band brake B/B, that is, the shift shock during downshifting, is significantly reduced.

Furthermore, the backup pressure control device 20G of this embodiment is provided with drive torque detection means 204, and based on the detection signal from this means 204, the course is determined as shown in step 1002 in the flowchart of FIG. One criterion for determining whether or not to perform a backup is whether or not the data is in a backup state. Therefore, when coasting is released by depressing the accelerator, that is, when drive torque is generated, step 1008
The backup flag is cleared under normal driving conditions (
The line pressure is controlled according to vehicle speed and throttle opening. Therefore, if you turn on the accelerator and select D range again from manual range, ■
When upshifting, such as when selecting from range to range, the high backup pressure is released and normal line pressure is generated, so the friction elements that are engaged when upshifting are engaged by the normal line pressure. The occurrence of shock is prevented.

As described in detail, in the backup pressure control device for an automatic transmission of the present invention, the generation of backup pressure is released at the time when drive torque is generated, so when the accelerator is turned ON, the automatic transmission is changed from the manual range to the automatic transmission. When the shift range is selected, the backup pressure has already been released due to drive torque generation, so the line pressure will be reduced to the normal line pressure when the automatic shift range is selected. Therefore, in the automatic transmission range, the friction elements are smoothly engaged,
It is possible to significantly reduce or prevent shift shock when selecting from the manual range to the automatic shift range. Furthermore, even when the accelerator is turned on and the manual range is shifted up from 1st gear to 2nd gear, it is possible to prevent the generation of backup pressure in 2nd gear, which is an excellent feature that can significantly reduce or prevent the shift shock at the time of upshifting. be effective.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the concept of a backup pressure control device of the present invention, and FIG. 2 is an overall circuit diagram showing an embodiment of a hydraulic pressure control device for an automatic transmission in which the engine torque detection device of the present invention is used. FIG. 3 is a schematic diagram showing an embodiment of a power transmission train of an automatic transmission to which the hydraulic control device shown in FIG. 2 is applied;
FIG. 4 is a schematic structural diagram showing an embodiment of the backup pressure control device of the present invention, FIG. 5 is a flowchart of an embodiment of executing the program of the backup pressure control device of the present invention, and FIG. 6 (A) , (B), (C), and (D) are flowcharts showing subroutines of the flowchart shown in FIG. The figure is a characteristic diagram of line pressure with respect to the duty ratio of a duty solenoid, and FIG. 9 is a hydraulic characteristic diagram of a conventional backup pressure control device. 200... Backup pressure control device, 201... Throttle opening detection means, 202... Vehicle speed detection means, 2
03... Range position detection means, 204... Drive torque detection means, 205... Pre-shift gear position detection means, 206... Microcomputer, 207.
... Traveling range judgment means, 208... Coasting state judgment means, 209... Backup pressure judgment means,
210... Backup pressure calculation means, 211... Drive means, OR/C... Overrun clutch (friction element). 2 people Figure 7 Figure 8 Vs-keishi (・/,)

Claims (1)

[Claims] (1) In an automatic transmission that supplies backup pressure to a friction element that is engaged when the automatic transmission range is selected from the manual range, a means for detecting the generation of drive torque, and a means for detecting the drive torque. 1. A backup pressure control device for an automatic transmission, comprising a control means for canceling generation of backup pressure based on a torque generation signal.