JPS60211161A - Hydraulic control unit for automatic transmission - Google Patents

Abstract

PURPOSE:To keep a feeling of favorable acceleration, by controlling the engagement of a lockup clutch in relation to a car speed and suction throttle opening. CONSTITUTION:A governor valve 174 is connected to a port 408 of a lockup signal valve 406 while a down-shift plug 154 to a port 454, and a 3-4 shift valve 286 to each of ports 410 and 412, respectively, whereby the engagement of a lockup clutch 400 is controlled in relation to a car speed and suction throttle opening. With this constitution, in the case where the suction throttle opening is large enough, the car speed is increased, and the lockup clutch 400 is engaged after a torque ratio A comes to a value approximate to 1 so that any drop in driving force at the time of engagement of the lockup clutch 400 is prevented from occurring, thus a feeling of favorable acceleration is keepable.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a hydraulic control system for an automatic transmission having a hydraulic torque converter and a lock-up clutch connected in parallel with each other.

The torque ratio t (=turbine shaft torque/pump shaft torque) of the prior art fluid torque converter becomes a decreasing function of its speed ratio e (=turbine shaft rotation speed/pump shaft rotation speed), and
The speed ratio e becomes a decreasing function of the intake throttle opening. Therefore, when the intake throttle opening is large, the torque ratio t of the fluid torque converter is greater than 1, but if the lock-up clutch is engaged in such a case, the torque ratio t decreases to 1. As a result, the driving force decreases and the feeling of acceleration worsens.

Problems to be Solved by the Invention An object of the present invention is to provide a hydraulic control device for an automatic transmission that can maintain a good acceleration feeling by preventing a reduction in driving force caused by engagement of a lock-up clutch. It is to provide.

Means for Solving the Problems In order to achieve this object, the invention provides a hydraulic control system for an automatic transmission having a hydraulic torque converter and a lock-up clutch connected in parallel with each other, comprising: a lock-up clutch; is controlled in relation to vehicle speed and intake throttle opening.

Effects of the Invention In this way, the lock-up clutch engages when the vehicle speed and intake throttle opening reach a predetermined relationship.
Engagement of the lock-up clutch is avoided during periods when the torque ratio t of the fluid torque converter is much greater than 1 due to the large intake throttle opening. In other words, when the intake throttle opening is large, the lock-up clutch is engaged after the vehicle speed increases and the torque ratio t reaches a value close to 1, so the driving force decreases when the lock-up clutch is engaged. is prevented, and a good feeling of acceleration can be maintained. According to a preferred embodiment, the hydraulic control device receives the governor pressure related to the vehicle speed and the first hydraulic pressure related to the intake throttle opening oppositely, and locks up in relation to the governor pressure and the first hydraulic pressure. A signal valve that generates a signal pressure for lock-up engagement, and a relay valve that guides the first hydraulic medium to a side where the lock-up clutch is engaged when the signal pressure for lock-up engagement is supplied.

Preferably, the signal valve includes an output boat that generates a signal pressure for lock-up maintenance, an input boat that receives a second hydraulic acid body from the shift valve during high speed gear, and receives governor pressure and first hydraulic pressure oppositely. It has a spool that controls the connection between the input boat and the output boat in relation to the governor pressure and the first hydraulic pressure.

For example, the shift valve may be a 3-4 shift valve, and the high speed gear may be the fourth speed.

Preferably, the first hydraulic pressure is generated by a downshift plug that operates in conjunction with kickdown.

Example The invention will be explained in detail with reference to the embodiments shown in the drawings.

FIG. 2 shows the division of the entire hydraulic control circuit diagram.

In FIG. 3, an oil pump 10 is driven by an engine to pressurize and discharge oil sucked in through a strainer 12. The line pressure oil passage 14 is connected to the discharge side of the oil pump 1o, and the relief valve 6 defines the upper limit of the line pressure PIl of the line pressure oil passage 14. The primary regulator valve 18 is connected to a boat 20 connected to the line pressure oil passage 14, a boat 24 connected to the suction side of the oil pump 1o via an oil passage 22, and the boats 20 and 24.
It has a spool 26 that controls the connection with. A first throttle pressure Pthl that is a first increasing function of the throttle opening of the intake passage is supplied to the boat 28, and as the first throttle pressure Pthl increases, oil flows out from the boat 20 to the boat 24. The flow rate decreases and the line pressure PI! , is an increasing function of the first throttle pressure Pthl. Line pressure l)4 is supplied to the boat 30 from the manual valve when in the R range or 2 range, and this causes the line pressure PI!
is decided. The oil passage 32 is connected to the line pressure oil passage 14 via an orifice 34, and the secondary regulator valve 36 is connected to a boat 40, a spring 42, and a spring 42 connected to the suction side of the oil pump 10 via an oil passage 38. 1st
has a boat 44 supplied with a throttle pressure Pt old of
Repel the oil discharge from the oil passage 32 to the boat 40 4
2 and the first throttle pressure Pthl, the oil pressure in the oil passage 32 is controlled. The oil passage 41 is connected to the oil cooler 43, and the relief valve 45 is connected to the oil passage 41.
Limit the upper limit of hydraulic pressure.

In FIG. 4, the manual valve 46 has an input port 48 connected to the oil line 14, an output port 50 connected to the input boat 48 in the R range, an output port 52 connected to the input boat 48 in the L range, and an output port 52 connected to the input boat 48 in the L range. , output port 54 connected to input port 48 when in 2 range, L,
Output port 56 connected to input port 48 when in 2.3 range, and input port 4 when in 2.3; D range
It has an output port 58 connected to 8. The two-range modulator valve 60 has an input port 4 connected to the boat 54 via an oil line 62 and an output port 8 connected to an oil line 66.
Then, a modulator pressure that is appropriately lower than the line pressure Pl is generated.

In FIG. 5, the D-2 timing valve 70 is connected to a boat 58 via an orifice 72, and is connected to a boat 74 and an oil line 6 to which line pressure PA is supplied during the forward travel range.
6 and modulator valve 6 when in 2nd range.
Input port door 6 and oil line 7 to which modulator pressure of 0 is sent
8, and a boat 86 connected to the hydraulic cylinder of the clutch C0 through an orifice 84, so that the clutch CO is engaged when shifted from the D range to the 2 range. After being reduced to waste, the modulator pressure in the input port door 6 is guided to the output port 80. The oil passage 78 is connected to a 2-3 shift valve (described later), and the 2-3 shift valve is switched from the high speed side to the low speed side by the modulator pressure from the oil passage 78, and the clutch CO is connected to the 1st speed position. This clutch is engaged to ensure engine braking in 3rd gear or 3rd gear, so if there is a shift range from D to 2nd gear, the vehicle speed will drop appropriately after clutch Co is engaged. 3rd speed is maintained until the 4th speed is changed, thereby preventing a direct shift from 4th speed to 2nd speed.

The L range modulator valve 88 has an input boat 92 connected to the boat 52 via an oil line 90 and an output port 96 connected to an oil line 94, and outputs a predetermined modulator pressure in the L range. Occurs on port 96. The control valve 98 connects the oil passage 100 from the 2-3 shift valve when the 2-3 shift valve is in the low speed side position.
Boat 1゜2.3 to which line pressure Pl is sent via
When the -4 shift valve is in the low speed position, the boat 1o6 receives line pressure PIl from the 3-4 shift valve via the oil line 104, and is connected to the boat 54 of the manual valve 46 via the oil line 62. 108 boats being
, and an output port 110 connected to the hydraulic cylinder of clutch Co. 3-4 when in 3 range
Line pressure Pl is sent from the shift valve to the boat 106, and line pressure pz is sent from the manual valve 46 to the boat 108 when in the L and 2 ranges, so 3, 2. L
When in the range, line pressure P of boat 106 or 108
J is guided to the output port 110, and the engine brake clutch Co becomes engaged.

In FIG. 6, the first throttle valve I'+2 is connected to the input boat 114 connected to the line pressure oil passage 14,
Output port connected to the oil passage 116 and generating a first throttle pressure pt] 18, controlling the flow passage area of the input boat 114 to generate a throttle pressure P corresponding to the acting force of the splash 124
A spool 120 that generates a
Spool 1 operated by throttle cam 122 via 23 to bias spool 120 via spring 124
It has 26. As the opening degree of the throttle valve in the intake passage increases, the flow cross-sectional area of the input port 114 increases, so the first throttle pressure pthl becomes an increasing function of the throttle opening degree. The cutback valve +28 connects the boat 130 and the oil line 1 to which the first throttle pressure Ptl+] is sent.
a boat 134 to which governor pressure Pgo is sent via 32;
and a boat 136 that generates a control pressure for the first throttle valve 112, the first throttle pressure P t b
1 to the governor pressure Pgo to prevent power loss of the oil pump IO. The second throttle valve 140 includes an input port 142 connected to the line pressure oil passage 14, an output port 146 connected to the oil passage 144 and generating the second throttle pressure Pth2, and an input port 146 connected to the oil passage 144 to generate the second throttle pressure Pth2.
A spool 148 that controls the flow path "!fr area of 42 to generate a throttle pressure Pth2 corresponding to the acting force of the spring 152, a throttle cam 150 that operates in conjunction with the throttle valve of the intake passage, and a throttle cam via a roller 151. 150 and the spool 14 via the spring 152
A downshift plug 154 that energizes the 8 is provided.

As the opening degree of the throttle valve in the intake passage increases, the flow cross-sectional area of the input port 142 increases, so the second throttle pressure Pth2 becomes an increasing function of the throttle opening degree. The downshift plug 154 is connected to the boat 15 when the throttle valve in the intake passage is nearly fully open, that is, during kickdown.
6 to the boat 160. Detent regulator valve 162 has an input port 166 connected to boat 160 via oil line 164;
A predetermined detent pressure is generated at the output port 170 connected to the oil passage 168. When the throttle opening reaches 85% or more, the downshift plug 154 shifts the oil passage 144! 60 and a second throttle pressure P t l+ 2 is introduced to the boat 160 .

In FIG. 7, the governor valve 174 is connected to the oil line 1 connected to the boat 58 of the manual valve 46 (the line pressure PA is introduced to the boat 58 during forward travel range).
It has an input port 180 to which line pressure pz is sent from 76 through a strainer 178, and governor pressure P related to vehicle speed is sent to an output port 182 connected to the oil passage 132.
Generate go.

The 1-2 shift valve +84 receives the governor pressure Pgo through the oil passage 132, and the valve 1-186 receives the governor pressure Pgo through the oil passage 132.
4, an input boat 190 connected to the oil line 176, and an output port 1-19 connected to the oil line 192.
4. It has a spool 198 that selectively connects the output port 194 to an input port 190 or a drain 196. The spool 198 is connected to the input port in the low speed position, that is, in the first speed position. 90 and the output port 194 and connect the output port 194 to the drain 196,
At a high speed position, that is, at a position of second speed or higher, the output port 194 is connected to the input port 190. The shift valve 200 for the L range has an input port 204 connected to the oil passage 94 via an orifice 202, and an oil passage 206 to the boat 50 of the manual valve 46 (to which line pressure Pl is introduced in the R range). The connected input boat 208, the output port 210 connected to the hydraulic cylinder of the brake B2 that is engaged in the L range and the R range, and the output port 210 connected to the input port 1
- Spool 212 connected to either 208 or 210
have. As a result, in the L range and the R range, the hydraulic pressure from the input ports 204 and 208 is guided to the brake B2'' through the output port 210, and the brake B2 is in the engaged state.In the L range, the spool 212 is 1-2 Move toward the shift valve 184 and shift to 1-2.
The spool 190 of the 2-shift valve 184 is held at the low speed side position. The first speed of the naori range is achieved by engaging the - direction clutch parallel to brake B2, and the spool 2
12 receives a force from spring 214 towards input boat 204 .

The second speed holding valve 216 includes an input port 218 connected to the oil line 192, an output port 222 connected to the oil passage 220, and a boat 224 connected to the oil line 78.
, boats 226, 22 of shift valve 184 for L range
8, and oil passage 176 (oil passage 17) when in the 3.2 range.
6 beams, 3, 2. In the L range, the line pressure is PA, and the spool 212 connects the boat 226 to the boat 228 in the D, 3.2 range, and connects the boat 226 to the drain 229 in the L range. ) line pressure P
7! It has an input port 232 connected to an oil passage 230 that leads to an oil passage, and a spool 234 that connects the output port 222 to the input boat 21B or 232. The spool 234 is pressed toward the boat 224 by a spring 236 in the D and 3 ranges (that is, when there is no oil pressure in the boat 224), and the 1-2 shift valve 1
When 84 is in the high speed side position, line pressure Pl of input boat 218 is guided to output port 222.

In addition, the spool 234 is connected to the boat 224 at the time of 2 ranges.
moves toward the input boat 236 due to the hydraulic pressure of the input boat 21
8 line pressure Pl is guided to the output port 222. Oil road 22
0 is connected to the 2-3 shift valve described later, and in the 2 range, the 2-3 shift valve is held at the low speed side position and leads to the clutch CO and the old brake line pressure Pl for the 2nd speed. Therefore, in the second range, the second speed is maintained by the second speed holding valve 216 and the spool 212 regardless of the vehicle speed and the throttle opening.

In FIG. 8, the 2-3 shift valve 240 is
Input boat 242 connected to channel 220, oil channel 10
Low speed side output port 244 connected to 0, oil line 2
46, a boat 252 connected to the oil passage 246 via an orifice 250, and an oil connected to the clutch C2 to be engaged in third and fourth gears. Boat 256 connected to channel 254, manual pulp 4 via oil channel 206
Boat 26 connected to R range boat 50 of No. 6
0, a boat 262 connected to the oil passage 132 and sent the governor pressure Pgo, a boat 263 to which the second throttle pressure P t 'h 2 is sent via the oil passage 144, and an oil passage connected to the oil passage 132 via the shuttle valve 264. Modulator pressure at 2 range in 78 or detent pressure P in oil passage 168
a spool 268 connecting the input boat 242 to the output port 244 or 248;
The spool 269 is pressed toward the spool 268 by the governor pressure Pgo of the boat 262, the pressing part 271 is pressed toward the spool 268 by the spring 270, and the oil passage 78
a boat 274 that applies hydraulic pressure to the pressing member 271 toward the spool 268; and a stepped portion 276 of the pressing member 271.
The boat 278 has a boat 278 that applies hydraulic pressure from the oil passage 246 to urge the pressing member 271 in a direction opposite to the spring force of the spring 270.

When the second throttle pressure Pth2 is relatively greater than the governor pressure Pgo and the spool 268 is in the second speed position, the input boat 242 is connected to the output port 244. As a result, the line pressure is sent to the hydraulic cylinder of the second combination brake Bl, and the brake B1 is brought into the engaged state.

Further, in this case, the boat 256 is connected to the boat 260, and the oil passage 206 is connected to the drain at the manual valve 46 in the D range, so the clutch C2 for 3rd and 4th speeds is in the released state. Retained.

When the governor pressure Pgo is relatively large with respect to the second throttle pressure Pth2 and the spool 268 is in the third speed position, the input boat 242 is connected to the output port 248,
Boat 252 is connected to boat 256. As a result,
Line pressure Pl is supplied to clutch C2 for third speed and fourth speed, and clutch C2 enters the engaged state. clutch C
The supply rate of line pressure Pl to 2 is controlled by orifice 250. Further, in this case, the output port 244 is connected to the two ports for brake Bl via the boat 280 and the oil passage 282.
-3 is connected to the drain of the timing valve, and the second brake old brake is released.

In the R range, there is no governor pressure Pgo in the boat 262, so the boat 260 is connected to the boat 256. As a result, the line pressure PA of the oil passage 206 is reduced to the boats 260, 2.
56, line pressure is supplied to the R range clutch C2. The supply speed of line pressure PA to clutch C2 when shifted to R range is determined by orifice 280 in front of boat 260.

3-4 shift valve 286 changes line pressure pz when in D range
The input boat 2 is connected to the oil line 176 to which the oil is sent.
88, a low-speed side output boat 292 connected to the oil line 104, a high-speed side output boat 292 connected to the oil line 294;
1-296, song M? Connected to 5132 and governor pressure Pg
The boat 298 is connected to the oil line 144 and is supplied with the second throttle pressure Ptl+2.
300 , a boat 304 to which line pressure Pl is sent from the boat 56 of the manual valve 46 via an oil path 302 during the third range, and a spool 306 that connects the input boat 288 to the output boat 292 or 296.

When the second throttle pressure Pth2 is relatively larger than the governor pressure PgO and the spool 306 is in the low speed position, the input boat 288 is connected to the output boat 292,
The line pressure PA is applied to the control valve 9 via the oil passage 104.
Boat 8] is being guided to 06. When the governor pressure Pgo is relatively larger than the second throttle pressure Pth2 and the spool 306 is in the high speed side position, the input boat 28
8 is connected to the pressure boat 296, and the fourth speed brake B
O becomes engaged.

In FIG. 9, an accumulator antibacterial well 310 is connected to a boat 312 that is connected to an oil line 116 and receives a first throttle pressure Pthl, and a boat 312 that is connected to an oil line 14 and receives a line pressure Pl. Input boat 314, oil line 3
16, and a spool 32 that controls the flow cross-sectional area between the input boat 314 and the output boat 318 in relation to the second throttle pressure Pth2.
It has 0. Brake Bo is connected to 3 through oil passage 204.
-4 The accumulator 322 receives the line pressure Pl from the shift valve 286, and the accumulator 322 has a boat 324 that receives the line pressure Pl from the oil 914, and controls the rise and fall of the hydraulic pressure of the brake BO. The clutch C1 is connected to the oil passage 176, and the accumulator 326 is
Boat 328 to which line pressure Pl is sent from oil path 14
, and controls the rise and fall of the oil pressure of the clutch C1.

In FIG. 10, clutch C2 is connected to
The accumulator 330 is connected to the boat 256 of the -3 shift valve 240, and the accumulator 330 has a boat 332 to which control pressure is sent from the oil passage 3/6, and controls the rise and fall of the oil pressure of the clutch C2.

The 2-3 timing valve 334 is connected to a boat 338 of the second throttle valve 140 via an oil passage 336 (a boat 339 is connected to the boat 338 in relation to the position of the plug 154).
The line pressure Pl is removed. ) connected to baud 1
-340, boat 342 connected to oil line 254
, a boat 348 connected to the boat 280 of the 2-3 shift valve 240 via an oil line 282, a boat 348 connected to an oil line 316, a drain 352, and a drain 352 connected to the drain via an orifice 354. Boat 35
6, and a spool 358 that controls the connection between the boat 348 and the drain 352. When the boat 348 is shifted up from second to third gear, the boat 348 is shifted to the oil passage 282.
The 2-3 shift valve 240 is connected to the second speed brake Bl through the boat 280.244, but when the oil pressure of the third clutch C2 is still low, the boat 348
and drain 352 are disconnected, and the brake Bl
The oil is slowly discharged through the orifice 354. When the oil pressure of clutch C2 becomes high enough, boat 3
48 is connected to a drain 352, and the oil in the brake Bl is quickly drained.

The 3-2 kickdown control valve 364 is connected to the boat 244 of the 2-3 shift valve 240 via an oil line 366, and the oil fl! 513
Boat 372 receives governor pressure Pgo through 2.
, a boat h 376 connected to the brake 131 via an oil line 374, and a boat 368 connecting the boat 376 to the boat 368.
Alternatively, it has a spool 378 connected to 370. Since the governor pressure Pgo of the boat 372 is low during a normal downshift to the second speed, the line pressure pz of the oil passage 366 is quickly sent to the brake B1 via the boat 368,376. However, due to the kickdown, the shift to 2nd gear was 1-
When the boat 372 is brought down, if the governor pressure Pgo of the boat 372 is high, the line pressure Pl is sent to the old brake through the boat 370, 376, that is, through the orifice 380, so that the engagement of the old brake is delayed. Ru.

As a result, a direct downshift from @4th speed to 2nd speed is avoided, and a downshift to 2nd speed via @3rd speed is avoided.

The accumulator 386 has a boat 388 connected to the oil passage 316, and controls the rise and fall of the hydraulic pressure of the brake B1.

In FIG. 11, an automatic transmission fluid torque converter 392 has a pump impeller 394 connected to a crankshaft, a stator 396, and a turbine runner 398 connected to a gearing input shaft. There is. Lock-up clutch 400 is provided in parallel to fluid torque converter 392.

A lock-up signal valve 406 is connected to a boat 408 which is supplied with governor pressure Pgo via an oil line 132, and an oil line 29.
Input port 41O1 oil line 1 connected to high-speed side output port 296 of 3-4 shift valve 286 via 4
Boat 412 and oil line 41 connected to low speed side output port 292 of 3-4 shift valve 286 via 04
4 connected to boat 416, and boat 410
and 416. 3-4 shift valve 286 is in the high speed side position,
When the governor pressure Pgo exceeds a predetermined value, the boat 41
Line pressure PI of boat 420 on 6! is guided.

The relay valve 422 is connected to a boat 424 connected to the oil line 4] and an input boat 42 connected to the oil line 32.
6. Second throttle valve 140 via oil passage 336
boat 428 connected to the boat 338 of the lock-up clutch 400;
A boat 436 connected to the open side of
36 has a spool 438 connected thereto. boat 4
24, the boat 426 is connected to the bolt 432 and the lock-up clutch 400 is engaged.

The main parts of an actual fishing example are explained in Fig. 1.

The lock-up signal valve 406 is connected to a boat 408 which is supplied with governor pressure Pgo from the governor valve 74 via an oil line 132, and which receives line pressure Fil from the output port 296 of the 3-4 shift valve 286 via an oil line 294 during fourth gear.
The input boat 410 is supplied with line pressure Pl from the output port 292 of the 3-4 shift valve 286 through the oil passage 104 during the third gear or lower gears.
2. Output port 4 that generates signal pressure for lock-up maintenance
16. A spool 418 that controls the connection between the input boat 410 and the output port 4/6;
8, a plug 452 that can come into contact with the spool 418, and a plug 452 that can be brought into contact with the spool 418;
Throttle pressure Pth2 (during kickdown, the flow passage cross-sectional area between the input port 142 and the output port 146 of the second throttle valve 140 is sufficiently large, so pth
2=pA), and a drain 456.

At gears below 3rd gear, the line pressure P of the boat 412
1, the spool 418 is held in a position on the boat 408 side, and the output port 416 is connected to the drain 456. Since line pressure Pl is not introduced to the input boat 410, the output port 416 has a lockup. No signal pressure for clutch engagement is generated. Therefore, the spool 438 of the relay valve 422 is connected to the line pressure Pl of the boat 458.
is pushed to the position on the boat 424 side, and the entry port 4
26 is led to the boat 436, and the lock-up clutch 400 is in the released state.

In 4th gear, lock-up signal valve 4o6 input boat 410 line pressure P7! is guided, and the line pressure to boat 4I2 is P7! It won't come. Since the boat 454 line pressure pz is not supplied when the throttle opening is low such as during non-kickdown, when the vehicle speed exceeds a predetermined value, the spool 418 is activated by the spring 45 due to the governor pressure Pgo of the boat 408.
0 and is suppressed to a position on the plug 452 side, and a lock-up clutch retaining signal pressure is generated at the output port 416. Thus, spool 438 of relay valve 422
is located on the boat 428 side, and the lock-up clutch 400 is in an engaged state. On the other hand, when the throttle is open such as during kickdown, the boat 454 line pressure Pl is supplied, so the plug 452 is connected to the spool 418.
urges the spool 418 toward the boat 408. Therefore, when governor pressure Pgo is low, input port h 410 is still not connected to output port 416, and engagement of lock-up clutch 400 is suspended. When the vehicle speed gradually increases as the intake throttle opening increases and the torque ratio t of the fluid torque converter 392 approaches 1, the sprue 418 resists the biasing force of the spring 450 and the plug 452 and closes the plug 452. The lock-up clutch 400 is engaged due to the signal pressure generated at the output port 416.
The cross-sectional area of the land of the spool 418 on which the governor pressure Pgo of 0.08 acts is larger than the cross-sectional area of the plug 452.

FIG. 12 shows a shift diagram of the embodiment.

1 to 4 represent the first to fourth speeds, respectively.
On and off mean an engaged state and a released state, respectively. As a result of the lock-up signal valve 406 receiving the line pressure Pl to the boat 454 during kick-down, the vehicle speed when the lock-up clutch 400 is switched to the engaged state becomes a high value during kick-down. In addition, although there is a lock-up clutch 400 engagement region in the third speed in FIG. 12, in reality, the line pressure PA is not introduced to the input port 410 of the lock-up signal valve 406 in the third speed, so the lock-up clutch is engaged. 400 is in a released state. Furthermore, when the intake throttle opening is very small, the lock-up clutch 400 remains in the released state even at high vehicle speeds because the boat 42 of the relay valve 422
This is because an eight line pressure of 1'V is introduced.

Although the invention has been described with reference to the embodiments shown in the drawings, it will be apparent to those skilled in the art that various modifications and changes can be made within the spirit of the claims.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the main parts of an embodiment according to the present invention, FIG. 2 is a diagram showing divisions in the overall hydraulic control circuit diagram, and FIG.
11 to 11 are partial views corresponding to each division in FIG. 2, and FIG. 12 is a shift diagram. 154... Downshift plug, 174... Governor valve, 392... Fluid torque converter, 400...
...Lockup clutch, 4o6...Lockup signal valve, 422...Relay valve. Patent Applicant: Toyota Motor Corporation, Y.) Representative: Patent Attorney Osamu Naka: H: II
:'Q-・ Figure 3

Claims (1)

[Claims] 1. In a hydraulic control system for an automatic transmission having a fluid torque converter and a lock-up clutch connected in parallel to each other, engagement of the lock-up clutch is determined in relation to vehicle speed and intake throttle opening. A hydraulic control device for an automatic transmission. 2. The governor pressure related to the vehicle speed and the first hydraulic pressure related to the intake throttle opening are received oppositely so that the governor pressure and the first hydraulic pressure are
a signal valve that generates a lock-up engagement signal pressure in relation to the hydraulic pressure of the lock-up clutch; and a relay valve that guides the first hydraulic medium to a side that engages the lock-up clutch when the lock-up retaining signal pressure is supplied. A hydraulic control device according to claim 1, characterized in that it is equipped with: 3. The signal valve includes an output port that generates a signal pressure for lock-up maintenance, an input port that receives the second hydraulic medium from the shift valve during high-speed gear, and an input port that receives the governor pressure and the first hydraulic pressure oppositely to generate the governor pressure. 3. The hydraulic control device according to claim 2, further comprising a spool for controlling the connection between the input boat and the output port in relation to the first hydraulic pressure and the first hydraulic pressure. 4. The hydraulic control device according to claim 3, wherein the shift valve is a 3-4 shift valve, and the high speed stage is a fourth speed. 5. The hydraulic control device according to any one of claims 1 to 4, wherein the first hydraulic pressure is generated by a downshift plug that operates in conjunction with kickdown.