JPH04145262A - Hydraulic controller of automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To use one solenoid valve alone to realize high function and low cost by using the solenoid valve for performing creep reducing control as well as for controlling a lockup clutch in combination. CONSTITUTION:A solenoid relay valve 230 is set up in space between a solenoid valve 240A and a C1 control valve 200, and interconnection between a port 236 for the C1 control valve 200 and a port 232 from the solenoid valve 240A and that between the port 232 from the solenoid valve 240A and a port 237 for a control system of a lockup clutch 24 are made so as to be selectable. In addition interconnection between the port 236 for the control valve 200 and the port 232 from a solenoid valve 240 and that between the port 236 for the control valve 200 and a port 234 for a drain tank are made so as to be selectable by dint of line pressure being produced in both first and second gear speeds of a drive range, in the solenoid relay valve 230.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a hydraulic control device for an automatic transmission for a vehicle, and in particular, when the accelerator pedal is released and the vehicle is substantially stopped, the forward clutch ( a clutch that is engaged to achieve forward travel) is released via a control valve by a control pressure generated by a solenoid valve (including when it is substantially released by reducing hydraulic pressure);
The present invention relates to a hydraulic control device for an automatic transmission for a vehicle that prevents the occurrence of creep by forming a neutral state and engages a lock-up clutch depending on the driving state.

[Prior art] Conventionally, in automatic transmissions for vehicles, when the shift range is set to a driving range such as a drive range,
Even when the vehicle speed is substantially zero, the gear transmission of the automatic transmission does not enter a neutral state but is set to the first gear (or second gear). Therefore,
Since the output of the internal combustion engine is constantly transmitted to the forward clutch of the gear transmission via the torque converter, so-called creep occurs, resulting in the need to keep the brake pedal depressed in order to keep the vehicle stationary. was there. Further, the dragging of the torque converter at this time may cause problems such as deterioration of fuel consumption efficiency and further increase in the temperature of the hydraulic oil of the torque converter. In view of this, a new control valve has been installed to control the hydraulic pressure of the forward clutch, so that when the accelerator pedal is released and the vehicle is substantially stopped, the shift range changes, even if it is the drive range. Even if the vehicle is in the forward driving range, the forward clutch is released via the control valve to automatically create a neutral state to prevent creep, improve fuel consumption efficiency, and improve torque converter control. A technique for suppressing the temperature rise of hydraulic oil is known (for example, JP-A-63-106449). Normally, when performing such transition control to a neutral state (hereinafter referred to as creep reduction control), in order to prevent the vehicle from backing up on a slope etc. A so-called hill hold control is also performed in which the brakes (within 1) are engaged. On the other hand, a technology that engages a lock-up clutch in the torque converter of an automatic transmission depending on the vehicle's driving condition to increase fuel consumption efficiency is widely known, and most vehicles currently equipped with an automatic transmission has been adopted. [Problems to be Solved by the Invention] However, in such a hydraulic control device for an automatic transmission, as described above, a solenoid valve for executing the leap reduction control and a lock-up clutch for engaging and controlling are required. Two solenoid valves are required, and this type of solenoid valve itself is expensive, resulting in a problem of significantly increasing costs. The present invention has been made in view of these conventional problems, and can realize high functionality and low cost by eliminating the need for one expensive solenoid valve while realizing recontrol without any problems. An object of the present invention is to provide a hydraulic control device for a vehicle automatic transmission.

[Means to solve the problem]

As the gist of the present invention is shown in FIG. 1, when the accelerator pedal is released and the vehicle is substantially stopped, the forward clutch is operated by the solenoid switch even if the shift range is in the forward travel range. Hydraulic control of automatic transmissions for vehicles that uses the control pressure generated by the lubricant to release via the control valve to create a neutral state and prevent the occurrence of creep, and also engages the lock-up clutch depending on the driving condition. In the device, the solenoid valve and the control valve are arranged in the middle of an oil passage communicating with each other, and can switch between the communication between the solenoid valve and the control valve and the communication between the solenoid valve and the control system of the lock-up clutch. The above object is achieved by providing a relay valve and controlling the switching of the relay valve so that the solenoid valve and the control valve are communicated with each other during the low speed stage of the forward range.

[Effect]

In the present invention, between the solenoid valve and the control valve, which were conventionally connected directly, there is a change in the communication between the solenoid valve and the control valve, and the communication between the solenoid valve and the hydraulic control system of the lock-up clutch. I am trying to arrange a relay valve to do this. Furthermore, in the present invention, the switching control of the relay valve is carried out between the solenoid valve and the control valve in the low speed gear in the forward range, and between the control system of the solenoid valve and the open clutch in the high speed gear. I'm trying to communicate with them. Because of this, when hill-hold control is required, the solenoid valve and the control valve communicate with each other, and hill-hold control can be achieved without any problems as before.On the other hand, when lock-up clutch engagement and control is required, the solenoid valve communicates with the control valve. can be used for engaging and controlling the lock-up clutch. As a result, it becomes possible to omit an expensive solenoid valve for engaging and controlling the lock-up clutch, which was conventionally provided separately, and the cost of the entire device can be reduced. Furthermore, engagement of the lock-up clutch is virtually unnecessary in the low-speed region of the forward range where hill-hold control is required, and conversely, in the high-speed region of the forward range where engagement of the lock-up clutch is required. Since there is no need for hill hold control, there is no problem in practical use even if one solenoid valve is used for both purposes.

[Embodiment 1] An embodiment of the present invention will be described in detail below based on the drawings. FIG. 2 shows an overall outline of a vehicle automatic transmission to which an embodiment of the present invention is applied. This automatic transmission includes a torque converter section 20, an overdrive m mechanism section 40, and an underdrive mechanism section 60 with three forward speeds and one reverse speed. The torque converter section 20 is of a well-known type and includes a pump 21, a turbine 22, a stator 23, and a lock-up clutch 24, and transmits the output of the crankshaft 10 of the engine 1 to the overdrive mechanism section 40. The lock-up clutch 24 is engaged by a hydraulic circuit, which will be described later, when conditions are met, and connects the pump 21 and the turbine 22. As a result, fuel consumption efficiency is improved. The overdrive mechanism section includes a sun gear 43, a ring gear 44, a planetary pinion 42, and a carrier 41.
The rotational state of this planetary gear system is controlled by a clutch CO, a brake BO2, and a one-way clutch FO. The underdrive mechanism section 60 includes a common sun gear 6
1, ring gear 62.63, planetary binion 64.
65 and carriers 66 and 67, and the rotation state of the two sets of planetary gear devices and the connection state with the overdrive mechanism are controlled by the clutch C1,
C2, brakes 81 to B3 and one-way clutch F1,
It is controlled by F2. Since the specific structure of the transmission section of this automatic transmission is well known in itself, only a skeleton diagram is shown in FIG. 2, and detailed explanation thereof will be omitted. This automatic transmission includes a transmission section as described above,
and a computer 84. The computer 84 has a throttle opening θ to reflect the load of the engine 1.
a throttle sensor 80 that detects the vehicle speed NO, a vehicle speed sensor (rotational speed sensor of the output shaft 70) 82 that detects the vehicle speed NO, and a 00 rotational speed sensor 99 that detects the rotational speed of the clutch C0.
Signals for various controls such as the following are input. The computer 84 drives and controls the solenoid valves in the hydraulic control circuit 106 according to a preset throttle opening/vehicle speed shift point map, and selects the engagement combinations of each clutch, brake, etc. as shown in FIG. Go and change gears. Here, the clutch C1 corresponds to a forward clutch that is released during creep reduction control, and the brake B1 corresponds to a brake that is engaged during hill hold H1m. That is, as is clear from FIG. 3, when the shift range is in the forward travel range, the forward clutch C1 is in an engaged state, making forward travel possible. However, when the throttle opening θ is zero (or the idle contact is ON) and the vehicle speed is zero (substantially including zero), the engagement pressure of the clutch C1 is reduced and the automatic transmission is activated. Brake B1 is engaged to shift the vehicle to the neutral state and to activate the hill hold function. Here, before explaining the configuration of the hydraulic control circuit according to the embodiment of the present invention, in order to facilitate understanding of the hydraulic control circuit, the conventional creep reduction control and The hydraulic control circuit that executes hill hold control will be explained first. Note that FIG. 5 schematically shows the main parts of the hydraulic control circuit shown in FIG. 4. In the figure, reference numeral 11o indicates a manual shift valve. This manual shift valve 110 has a hydraulic input boat 114. The hydraulic input boat 114 receives line pressure P sucked up by the oil pump 120 and regulated by the primary regulator valve 124.
L is supplied via oil passage 126. This manual shift valve 110 is a manual shift lever (not shown).
The hydraulic input boat 114 is connected to the D range boat 116 when the manual shift range is the D range. Further, when the manual shift range is the S range, the hydraulic input boat 114 is connected to the S range boat 118. D range boat 116 is 2-
The S range boat 118 is connected to the boat 148 of the 2-3 shift valve 140 by an oil line 304. The 2-3 shift valve 140 has a spool 142. Spool 142 is in a raised position shown in the right half of the figure when oil pressure is not being supplied to boat 144, communicating boat 146 with boat 150, and connecting boat 146 to boat 150.
48 to the boat 152. On the other hand, when hydraulic pressure is supplied to the boat 144, the boat 144 is in the lowered position shown in the left half of the figure, cutting off communication between the boat 146 and the boat 150, and also blocking the communication between the boat 146 and the boat 150.
and disconnect the boat 152 from the drain boat 154.
It will be communicated to. Hydraulic pressure is supplied to the boat 144 in a well-known manner using a solenoid valve (not shown), and hydraulic pressure is supplied to the boat 144 only when the third gear or overdrive gear is achieved. Therefore, the spool 142 is in the raised position when the first gear or the second gear is achieved, and is in the lowered position when the third gear or the overdrive gear is achieved. The boat 150 is connected to the boat 186 of the 81 control valve 180 by an oil passage 306. boat 1
52 is connected to the boat 172 of the check valve 170 via an oil passage 308, a second coast modulator valve 160, and oil N310. In addition to the inlet boat 172, the check valve 170 has another inlet boat 174 and one outlet boat 176, and when hydraulic pressure is supplied to the inlet boat 172 by the action of a check ball 178, the inlet boat 174 is opened. When closed, the entrance boat 172 is closed when hydraulic pressure is supplied to the entrance boat 174. Inlet boat 174 is connected to boat 188 of brake control valve 180 by oil line 312, and outlet boat 176 is connected to boat 136 of 1-2 shift valve 130 by oil line 314. 1-2 shift valve 130 has a spool 132. Spool 132 is in a raised position shown in the left half of the figure when hydraulic pressure is not being supplied to boat 134, providing communication between boats 136 and 138;
When hydraulic pressure is being supplied to the drain boat 139, the drain boat 138 is in the lowered position shown in the right half of the figure, cutting off the boats 136 and 138 and communicating the boat 138 with the drain boat 139. Hydraulic pressure is supplied to the boat 134 only when the first gear is achieved by the action of a solenoid valve (not shown), so that the spool 132 is in the raised position when the second gear, third gear, or overdrive gear is achieved. Therefore, the lowered position is reached only when the first gear is achieved. Boat 138 is connected to brake B1 by oil line 316. B1 control valve 180 has a sgur 182 and a plug 184. Spool 182 is connected to boats 186 and 188 when in the raised position shown in the right half of the figure.
The drain boat 198 is connected to the drain boat 198 by blocking the boats 190 and 192. On the other hand, when in the lowered position shown in the left half of the figure, the boat 186 is closed, allowing the boat 188 to communicate with the drain boat 187, and also allowing the boats 190 and 192 to communicate with each other. Boat 190 is connected to D range boat 116 of manual shift valve 110 by oil line 314 and oil line 300, and boat 192 is connected to boat 208 of 01 control valve 200 by oil line 316. The spool 182 is driven by the oil pressure applied to the boats 194 and 196, and when a signal oil pressure Ps of a predetermined value p5set or more is supplied to at least one of the boats 194 and 196, the spool 182 is at the left half position, that is, the hill hold control release position. Located in Also, boats 194 and 19
Signal oil pressure Ps of predetermined value p 5set or more for any of 6
When is not being supplied, it is located at the right half position, that is, the hill hold control position. The boat 194 is connected to the oil passage 320 by an oil passage 318, and is supplied with the signal oil pressure ps of the oil passage 320. Further, the boat 196 is supplied with throttle oil pressure or servo oil pressure (engaging pressure) of the clutch C1 through an oil passage (not shown). The solenoid valve 240 is configured to generate a signal pressure PS in the oil passage 320 according to the duty ratio of the pulse signal applied to the electromagnetic coil. The solenoid valve 240 is constituted by a so-called normally closed type solenoid valve, so that the signal oil pressure Ps of the oil R320 decreases as the duty ratio applied to the electromagnetic coil increases. The oil passage 320 is connected to the throttle 280 and the oil f to be supplied with the original oil pressure.
! @322, modulator valve 250, oil F via oil path 324! @126, thereby connecting the oil path 322
A modulated hydraulic pressure regulated to a predetermined constant pressure by a modulator valve 250 is supplied to the hydraulic pressure. The oil passage 320 is connected to the boat 194 of the 81 control valve 180 by an oil passage 318, and is connected to the C1 control valve 20 via the oil passage 326 and the throttle 282.
It is communicatively connected to the boat 210 of 0. The C1 control valve 200 has spools 202 and 2
and two plugs 204 and 206. Spool 202 is connected to oil passage 3 by oil passage 328.314.
Boat 21 connected to 00 and supplied with line pressure PL
The hydraulic pressure of the outlet boat 214 is regulated by controlling the communication level for the second drain boat 216. This pressure adjustment value increases in accordance with an increase in the urging force applied to the spool 202 by the compression coil spring 218 and the pressing force applied directly to the spool 202 by the plugs 204 and 206. Exit boat 214
is connected to the clutch C1 via the throttle 284 and the oil passage 330. Further, the oil passage 328 and the oil passage 330 are connected by the oil passage 314 and the check valve 260. This check valve 260 is connected to the oil passage 320 from the oil passage 330.
It is configured to allow only oil flow to, that is, oil drain flow. Manual shift range is set to D range.
1-2 shift valve 1 when the 1st gear is established
The spool 132 of the 2-3 shift valve 140 is in the lowered position and the spool 142 of the 2-3 shift valve 140 is in the raised position. While the creep reduction control and hill hold control have not yet started and the OFF signal is given to the solenoid valve 240, the signal oil pressure PS of the oil passage 320 is set to the same oil pressure as the output oil pressure Pi of the modulator valve 250. , this oil pressure is 81 control valve 180 boat 194
and the boat 210 of the C1 control valve 200. Therefore, at this time, the spool 180 of the B1 control valve 180 is located at the left position, that is, at the hill hold control starting position 1, thereby closing the boat 186 and communicating the boat 188 with the drain boat 187. 192, line pressure PL from oil passages 300 and 314 is transferred to oil passage 31.
Boat 208 of C1 control valve 200 via 6
From this point on, the 01 control valve 200 is placed in the left position, that is, the normal mode position, by the action of the line pressure P1 supplied to the boat 208 in addition to the signal oil pressure Ps supplied to the boat 210. As a result, the drain boat 216 is completely closed and the boat 2
The line pressure PL given to 12 is not reduced,
Clutch C from boat 214 via oil passage 330.
1 will be introduced. Therefore, at this time, clutch C1
are fully engaged and the first trap stage is achieved. Also, since the boat 186 of the B1 control valve 180 is closed, the boat 188 is connected to the drain, and the boat 136 of the 1-2 shift pulp 130 is also closed, so the boat 138 is connected to the drain.
Since the drain is connected, no hydraulic pressure is supplied to the brake B1, and the brake B1 maintains the released state. When the manual shift range is set to D range, when the throttle opening of engine 1 is returned to the idle opening position (idle contact ON) and L also falls below a predetermined value close to the vehicle speed or zero, creep occurs. In order to perform reduction control and hill hold control, the solenoid valve 24
A pulse signal is applied to 0, and the deinity ratio is increased as time passes. In response to this increase in duty ratio, the signal oil pressure Ps of the oil 1i 320 gradually decreases over time, and when the signal oil pressure Ps drops to a predetermined value P5set, the spool 182 of the B1 control valve 180 moves to the right side in the figure. The communication boat of the boat 188 is switched from the drain boat 187 to the boat 186. Also, the communication boat of the boat 192 or the boat 190 is switched to the drain boat 198. Therefore, line pressure PL is no longer supplied to the boat 208, so the pressure regulation value of the C1 control valve 200, that is, the engagement pressure of the clutch C1 is set by the signal oil pressure Ps given to the boat 210, and as the signal oil pressure Ps decreases, Drain boat 216 is now opened. As a result, the engagement pressure supplied from the boat 214 to the reflash latch C1 decreases, causing the clutch C1 to slip. This puts the automatic transmission in the same state as in neutral, reducing idle vibration and preventing creep. That is, creep reduction control is executed. On the other hand, at this time, since the boats 186 and 188 of the 81 control valve 180 are in communication with each other as described above, the spool 142 of the 2-3 shift pulp 140 achieves the raised position, that is, the first gear or the second gear. If the line pressure PL of the D range boat 116 of the manual shift valve 110 is in the switching position
-3 boats 146 and 150 of shift valve 140, oil #1306, boat 1 of B1 control valve 180
86 and 188, oil passage 312, check valve 170,
Boat 1 of 1-2 shift pulp 130 via oil path 314
It reaches up to 36. Therefore, at this time, if the spool 132 of the 1-2 shift pulp 130 is in the raised position, that is, in the position to achieve the second gear, the third far position, or the overdrive stage, the line pressure PL of the boat 136 is 138, oil is supplied to brake B7 via oil #r316, plate IrB1 is engaged, and the sun gear is fixed. Therefore, each of the front sun gear and the rear sun gear is prevented from rotating, and the output shaft is prevented from rotating in the backward direction of the vehicle by the action of the one-way clutch 92, so that so-called hill hold control is executed. In such conventional devices, the solenoid valve 24
FIG. 6 shows an example (embodiment of the present invention) in which 0A is also used for the control system of the lock-ag clutch 24. In this embodiment, first, the solenoid valve 24OA
and the 01 control valve 200, a lenoid relay valve 230 is arranged between the control valve 200 and the 01 control valve 200.
■Communication between the boat 236 to the C1 control valve 200 and the boat 232 from the solenoid valve 240A,
(2) Communication between the boat 232 from the solenoid valve 240A and the boat 237 to the control system of the lock-up clutch 24 can be switched. This switching is performed by line pressure (hydraulic pressure in oil passage 307) generated at the first and second speeds of the drive range. By this switching, when the automatic transmission is in the first gear or the second gear, the linear solenoid valve 240 is communicated with the C1 control valve 200, and the leap reduction control and hill hold control are performed as described above. is executed as before. On the other hand, when the automatic transmission is in the third gear or the fourth gear (overdrive gear), the linear solenoid valve 240A communicates with the boat 237 to the lock-up clutch control system, and It can now be used for engagement and control. In addition, the reference numeral 280 in the figure is a lock-up relay valve, 2
90 indicates a lock-up control valve,
Regarding the engagement control of the lock-up clutch 24 by the solenoid valve 240A, the lock-up relay valve 280, and the lock-up control valve 290, a conventionally well-known configuration is employed as is. Briefly, the lock-up relay valve 280 is a valve that switches between engagement and release of the lock-up clutch 24. This switching is performed depending on whether the control oil pressure generated by the solenoid valve 240A exceeds a certain threshold value. The hydraulic pressure at the time of this switching is set to the solenoid valve 240A.
By gradually increasing and decreasing the amount, the lock-up clutch 24 can be smoothly engaged (while slipping transiently) and disengaged. On the other hand, the lock-up control valve 290 is for controlling the engagement pressure (differential pressure between the oil chambers 24A and 24B) when the lock-up clutch 24 is engaged (or released). Linear solenoid valve 240A
The control hydraulic pressure generated by this is used as the pilot pressure for control at that time. Thereby, the lock-up clutch can be engaged with the necessary and sufficient hydraulic pressure depending on the output torque of the engine or the torque transmitted via the lock-up clutch. According to this embodiment, when the automatic transmission is in the third and fourth gears, the solenoid relay valve 230 transfers the hydraulic pressure generated by the solenoid valve 240A to the lock-up clutch control system (lock-up relay valve 280
, lock-up control valve 290, etc.), the lock-up clutch can be controlled in the third and fourth gears in the same manner as before. By the way, although this embodiment does not correspond to a direct embodiment of the present invention, when a failure occurs in the C1 control valve 200 or the solenoid valve 24OA, the clutch C1 is not engaged, and as a result, forward travel is impossible. In order to prevent this from happening, fail-safe measures in 2.3 are implemented. For example, when trying to perform creep reduction control and hill hold control using such a conventional device, if the solenoid valve 240A sticks in a state where it generates a low control pressure due to a problem such as a foreign object or poor processing, The engagement pressure of the forward clutch produced by the C1 control valve can only be a low oil pressure value, causing a problem that the transmission capacity of the clutch is insufficient and forward travel is no longer possible. Furthermore, if the driver strongly depresses the accelerator pedal in this state, the engine rotational speed and the rotational speed of the input member (ring gear 44) of the clutch C1 increase, causing the clutch C1 to continue to slip. This also prevents damage to the friction material of the clutch C1. Therefore, in order to prevent this problem, in this device, the characteristics of the conventional solenoid valve 240 are first changed from a normally closed type to a normally open type.
→24OA), that is, the control valve C1 is changed so that the control hydraulic pressure increases as the duty ratio increases, and the C1 control valve changes the hydraulic pressure PS generated by the solenoid valve 24OA.
The configuration is such that the pressure regulation value of the boat 214 decreases as the pressure increases. To that end, specifically, the same feedback pressure as the boat 214 is applied to the 01 control valve 20.
The hydraulic pressure of the boat 214 is controlled by applying the control pressure Ps of the solenoid valve 240A to the boat 219 in the same direction as the direction in which it acts on the spool 204, and by applying the modulator pressure pi of the solenoid modulator valve 250 to the opposite side. Adjust the pressure. As a result, a structure can be provided in which the pressure regulation value of the boat 214 decreases in accordance with an increase in the control pressure ps of the solenoid valve 24OA. Note that the D range line pressure is applied to this 01 control valve 200 from the boat 192 of the B1 control valve 180 in the hill hold release mode as before. This hydraulic force acts on the spool 204 in the opposite direction to the control pressure ps from the solenoid valve 240A,
The oil passage 328 to which the D range line pressure of the C1 control valve 200 is guided is communicated with the boat 214 to the clutch C1. In addition, in this device, as another fail-safe measure, the solenoid relay valve 230 is activated by the line pressure (hydraulic pressure in the oil passage 307) generated in the first and second gear stages of the drive range.
0 to the boat 236 and the solenoid valve 240 to the boat 232, and ■C1 control valve 2
Boat 236 to 00 and boat 234 to drain tank
A function has been added that allows you to switch between communication with and. By this switching, even if the linear solenoid valve 240 fails in a high pressure state, that is, in a state where the oil pressure of the output boat 214 in the C1 control valve 200 is low, the automatic transmission is switched to the third or fourth gear of the drive range. By switching to the gear state (1
By switching the -2 shift valve 130), the solenoid relay valve 230 can be switched and the high pressure condition of the linear solenoid valve 240 can be prevented from reaching the C1 control valve 200. As a result, forward travel using the third or fourth gear becomes possible. This 1-2 shift pulp 130 switching is performed by a gear switching solenoid, but it can also be done by some method (for example, by detecting whether the oil pressure of clutch C1 does not increase even after a predetermined period of time has elapsed since the idle contact has been turned OFF). Method)
All you have to do is to detect a failure and switch the gear shift solenoid based on that. Further, in this embodiment, although it is not a direct embodiment of the present invention, a C1 relay valve 270 is arranged as another fail-safe measure. This means that if the spool 202 of the C1 control valve 200 is stuck in a reduced pressure state due to a defect such as a foreign object or poor processing, the computer will then send a signal to the solenoid valve 240 to run forward in normal mode. This is because, even when the vehicle is in use, the engagement pressure of the clutch C1 is not sufficiently increased, resulting in insufficient transmission capacity of the clutch, resulting in a problem that forward travel is no longer possible. Therefore, in this device, the C1 relay valve 270 is disposed in the middle of the oil passage 330 that communicates the boat 214 of the C1 control valve 200 and the clutch C1. On top of that, C1 control valve 20
0 boat 214 and C1 relay valve 270 boat 2
72 through the oil passage 330. In addition, the clutch C1 and the boat 276 of the relay valve 270 are connected to the oil passage 34.
Connect by 0. Furthermore 1, C1 relay valve 270
The D range line pressure PL generated in the D range boat 116 of the manual valve 110 is guided to the boat 274 of the manual valve 110 through an oil passage 336. As the hydraulic pressure for controlling this C1 relay valve 270, the hydraulic pressure Ps (hydraulic pressure for controlling engagement of the clutch C1) from the solenoid valve 240 is applied via the oil passage 334. Note that the same effect can be obtained by applying the hydraulic pressure from the boat 192 of the 81 control valve 180 (the engagement pressure that should go to the clutch C1) in the opposite direction via the oil path 332 instead of the hydraulic pressure ps of the solenoid valve 240. can get. The boats 274 and 276 are designed to communicate with each other in the normal running mode (that is, in the case of the above-described configuration, the ps pressure is small) by the action of this hydraulic pressure ps. In this embodiment, since the C1 relay valve 270 is added in this way, even if either or both of the B1 control valve and the C1 control valve fail, the output pressure Ps of the linear solenoid 240 remains at a predetermined level. As long as the oil line 336, C1
Since the line pressure PL from the D range boat 116 of the manual valve 110 is guided to the clutch C1 via the relay valve boats 274 to 276 and the oil path 340, forward travel can be performed. Furthermore, even if the C1 relay valve 270 itself is stuck, for example, when the boats 272 and 276 are in communication, as long as the C1 control valve 200 (and the B1 control valve ISO, etc.) is operating normally, the oil passage will be maintained. Since the D range line pressure is introduced to 330, forward travel is possible without any trouble. Further, even if the boats 276 and 274 of the C1 relay valve 270 are stuck in communication, creep reduction control becomes impossible, but forward travel is possible. That is, according to this embodiment, the solenoid valve 24
Regarding the 0A and C1 control valves 270 and the B1 control valve 180, the fail-safe function for ensuring forward running is improved to a greater degree than in the past. In addition, as the control pressure for the C1 relay valve 270, a throttle pressure can also be applied. As a result, the higher the throttle pressure pth is, the farther the C1 relay valve can be switched, and the sooner the line pressure from the D range boat 116 of the manual valve 110 can be guided to the Clara C1. Even if the solenoid 240A does not fail, forward travel is possible by pressing the accelerator pedal (increasing the throttle pressure). Effects of the Invention As explained above, according to the present invention, in an automatic transmission that employs creep reduction control, the solenoid valve for executing the creep reduction control is replaced by the solenoid valve for controlling the lock-up clutch. Can be used with
An excellent effect is that one system of expensive relayoid valves and solenoid modulator valves for sending constant hydraulic pressure to the relayoid valves can be omitted without any deterioration of the actual control function, and the cost can be reduced accordingly. can get.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the gist of the present invention, and FIG. 2 is a block diagram showing the gist of the present invention.
FIG. 3 is a skeleton diagram showing the transmission section of an automatic transmission for a vehicle to which the present invention is applied, and FIG. Fig. 4 is a hydraulic control circuit diagram showing the configuration of the device part for executing the conventional (and basic in this embodiment) creep reduction control and hill hold control, and Fig. 5 is the circuit shown in Fig. 4. A hydraulic control circuit diagram schematically showing the functions of the main parts in the figure. FIG. 6 is a hydraulic control circuit diagram similar to FIG. 5 showing an embodiment of the present invention. C1...Clutch (forward clutch), B1...
・Brake (brake to be engaged during hill hold control), 24...Lock-up clutch, 110...Manual valve, 180...B1 control valve, 200...C
1 control valve, 230... solenoid relay valve, 240... solenoid valve. 270...C1 Relay valve.

Claims (1)

[Claims] (1) When the accelerator pedal is released and the vehicle is substantially stopped, the forward clutch is released via the control valve by the control pressure generated by the solenoid valve even if the shift range is in the forward drive range. In a hydraulic control device for a vehicle automatic transmission that forms a neutral state to prevent the occurrence of creep and also engages a lock-up clutch depending on the driving condition, the oil that communicates between the solenoid valve and the control valve is provided. a relay valve disposed in the middle of the road and capable of switching communication between the solenoid valve and the control valve and communication between the solenoid valve and the hydraulic control system of the lock-up clutch, and controlling the switching of the relay valve. A hydraulic control device for an automatic transmission for a vehicle, characterized in that the solenoid valve and the control valve are communicated with each other during a low speed stage of a forward range.