JPS645182B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an automatic transmission equipped with a torque converter direct coupling clutch, and more particularly to a control device for a direct coupling clutch.

(B) Conventional technology Generally, in an automatic transmission, power is transmitted from the engine via a torque converter, but during operation of the torque converter, slippage inevitably occurs between the pump impeller and the turbine liner. , This reduces power transmission efficiency and impedes improvement in fuel efficiency.

Therefore, in the relatively high-speed range of automatic transmissions, automatic transmissions equipped with a direct coupling clutch (so-called lock-up clutch) have been devised, which directly connects the pump impeller and turbine liner to eliminate the above-mentioned slip. .

(C) Problems to be Solved by the Invention By the way, when the torque converter is directly connected to two or more gears of an automatic transmission, if the automatic transmission is shifted while the accelerator pedal is pressed heavily,
Since gear shifts are performed with the torque converter directly connected, the torque converter cannot absorb torque fluctuations, resulting in a large shift shock.

Furthermore, in order to absorb the shift shock, it is conceivable to temporarily release the torque converter direct coupling clutch at the time of shifting. In this case, even if the direct coupling clutch is released at the same time as the shift command, if the shift operation is achieved by switching one frictional engagement means, then
The switching of the frictional engagement means and the temporary release of the direct coupling clutch can be timed, and no major problems will occur. This is due to the fact that when hydraulic pressure is supplied to release one frictional engagement element and engage the other frictional engagement element, the engagement of the frictional engagement element due to the hydraulic pressure supply to the hydraulic servo tends to be delayed. As a result, a time lag may occur between the gear shift operation and the clutch release operation, and the direct coupling clutch may be released before the gear shift.As a result, during this time lag, the engine may start racing and the rotation speed may increase rapidly. However, there is a risk that a large shift shock will occur.

Therefore, the present invention provides a method for shifting gears by activating a direct coupling clutch after a predetermined time delay from the time of a gear shift command, for example, during a gear shifting operation in which one frictional engagement element is released and the other frictional engagement element is engaged. The purpose of this invention is to time the operation of a direct coupling clutch, thereby solving the above-mentioned problems.

(d) Means for Solving the Problem The present invention has been made in view of the above-mentioned circumstances. For example, as shown in FIG. The determining means A, that is, the lock-up determining means that generates a lock-up permission signal when the vehicle speed is equal to or higher than a predetermined value, interacts with each other by, for example, releasing one frictional engagement element 12 and engaging the other frictional engagement element 19. Shift detection means B that temporarily issues a direct coupling clutch release command when the shift operating means 270 changes between two gears, that is, a shift detection means that issues a shift signal indicating that shifting is in progress for a predetermined period of time after the shift command; and a delay means C that is involved in the detection means B and delays the direct coupling clutch release command, and based on the delay means C, the direct coupling clutch release command of the shift detection means B causes the shift of the shift operation means 270. It is characterized in that the operation of the direct coupling clutch 50 occurs after a predetermined time delay from the time of the command so as to time the gear shifting operation.

Further, a delay means C that is involved in the speed change detection means B and delays the direct coupling clutch release command changes the delay time according to the engine load, and based on the delay means C, the direct coupling clutch release command by the speed change detection means B is delayed. is characterized in that it occurs with a predetermined time delay from when the speed change command is issued by the speed change operation means in accordance with the engine load so as to time the operation of the direct coupling clutch with the speed change operation.

As an example, the speed change operation means is an overdrive shift valve 27 that operates to switch between 3rd speed and 4th speed.
0, and the direct coupling clutch determining means A
consists of a governor control valve 310 that is controlled by hydraulic pressure supplied from the governor valve 260 through the oil passage 111, and the control valve 310 is connected to the 2-
The lock-up cut-off valve 3 connects the oil passage 113 to which hydraulic pressure is supplied from the 3rd shift valve 230 during 3rd and 4th gears.
20 to the oil passage 140 which communicates with the lock-up shift valve 300. Further, the speed change detection means B includes a lock-up cut-off valve 320,
It consists of an accumulator valve 410 and a check valve 390 with an orifice, and the oil pressure in the oil passage 141 supplied through the check valve 400 acts on the upper oil chamber 323 of the lock-up cut-off valve 320, and further passes through the check valve 390 to the accumulator. valve 410
The spool 411 of the valve 410 is gradually moved to communicate with the oil passage 146 after a predetermined period of time, and hydraulic pressure is applied to the lower oil chamber 325 of the lock-up cut-off valve 320. Further, the delay means C is connected to the check valve 400 to which oil pressure is supplied from the overdrive shift valve 270 via the oil passage 117 or 118 and to the shift detection means B via the oil passage 142 or 143.
Check valves 370, 38 with orifices connected to
0, and the check valves 370, 380 discharge quickly and supply gradually, controlling the clutch 12 and brake 19, and gradually or delaying the hydraulic pressure in the oil passages 142, 143. and rise.

Note that the check valves 370 and 380 with orifices constituting the delay means C are supplied with line pressure from the pressure regulating valve 200, that is, oil pressure that changes depending on the engine load. Based on the fact that the higher the oil pressure, the shorter the delay time is, the delay time changes depending on the engine load.

(E) Effect Based on the above configuration, when the vehicle is running at a predetermined speed or higher, for example in third gear, the governor control valve 310 that constitutes the direct coupling clutch determining means A moves downward based on the oil pressure from the governor valve 260. are doing. In this state, the oil passage 113 is in communication with the oil passage 140, and the lock-up cut-off valve 3 is in communication with the oil passage 140.
20 and the lock-up valve 30 via the oil passage 144.
applying hydraulic pressure to the oil chamber 304 of 0, switching the lock-up valve so that the direct coupling clutch 50 is connected;
keeping. That is, a lockup permission signal is issued from the lockup determination means. In this state, the overdrive shift valve 27 is
0 is switched and hydraulic pressure is supplied to the oil passage 118 and the oil passage 117 is drained, the hydraulic cylinder 12A
The pressure oil in the clutch 12 is discharged and the clutch 12 is released, and hydraulic pressure is gradually supplied to the hydraulic cylinder 19 via the check valve 380, and the brake 19 is engaged with the release of the clutch 12. can be switched quickly.

On the other hand, due to the quick drainage of the clutch hydraulic cylinder 12A via the check valve 370, the oil passage 14
2. Upper oil chamber 32 of lock-up cut-off valve 320 via check valve 400 and oil passage 141
3 and the pressure oil in the oil chamber 411 of the accumulator valve 410 is discharged, and the spool 412 of the valve 410 is further discharged.
moves upward and locks up the cut-off valve 32.
The pressure oil in the lower oil chamber 325 passes through the oil passage 146 and is discharged from the oil drain port 414, and then the oil pressure, which gradually increases through the check valve 380, flows through the oil passage 143, the check valve 400, and the oil passage 141. It acts on the upper oil chamber 323 of the lock-up cut-off valve 320 constituting the speed change detection means B through. At this time, due to the throttling action of the check valve 380, the upper oil chamber 32
3 oil pressure is applied to spool 3 against spring 322.
21, the direct coupling clutch release command is delayed by a predetermined period of time from the switching operation of the overdrive shift valve 270, that is, the transmission command from third to fourth speed. Note that the delay time based on the throttling action of the check valve 380 changes depending on the oil pressure;
Since line pressure that changes depending on the engine load acts on the check valve 380, the delay time changes depending on the engine load, and becomes shorter as the engine load increases. As a result, since the brake 19, which is engaged during gear shifting, is activated by line pressure, as the engine load increases, the time required from the gear shifting command to the start of gear shifting operation increases.
That is, the response delay of the hydraulic system is shortened, but correspondingly, the delay time due to the throttling action of the check valve 380 is also shortened. After the predetermined time, the spool 321 moves to block the oil passages 140 and 144 and communicate the oil passage 144 to the oil drain port 326 in time with the engagement of the brake 19, that is, the 3-4 gear shift operation. , thereby switching the lock-up shift valve 300 and releasing the direct coupling clutch 50. Then, the pressure oil in the oil passage 141 is supplied to the upper oil chamber 411 of the accumulator valve 410 through the orifice of the check valve 390.
2 slowly descends. Then, after a predetermined period of time, the oil passage 146 and the oil chamber 411 communicate with each other, and pressure oil is supplied to the lower oil chamber 325 of the lock-up cut-off valve 320, moves up the spool 321, and flows through the oil passages 140 and 1.
44. As a result, the lock-up shift valve 300 is switched and the direct coupling clutch 50 is connected again.

(f) Examples Examples of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic diagram showing an example of a power transmission mechanism of a hydraulic automatic transmission with an overdrive device. This automatic transmission includes a torque converter 1 with a direct coupling clutch, an overdrive mechanism 2, and a gear transmission mechanism 3 with three forward speeds and one reverse speed. The pump 5 is connected to an engine crankshaft 8, and the turbine 6 is connected to a turbine shaft 9. Turbine shaft 9 is torque converter 1
This also serves as the input shaft of the overdrive mechanism 2, and is connected to the carrier 10 of the planetary gear system in the overdrive mechanism. Further, a direct coupling clutch 50 is provided between the engine crankshaft 8 and the turbine shaft 9, and mechanically couples the engine crankshaft 8 and the turbine shaft 9 when the direct coupling clutch 50 is operated. A pralinear pinion 14 rotatably supported by a carrier 10 is connected to a sun gear 11 and a ring gear 1.
It meshes with 5. Sun gear 11 and carrier 10
A multi-disc clutch 12 and a one-way clutch 13 are located between them.
Furthermore, a multi-disc brake 19 is provided between the sun gear 11 and a housing or overdrive case 16 containing the overdrive mechanism.

A ring gear 15 of the overdrive mechanism 2 is connected to an input shaft 23 of the gear transmission mechanism 3. A multi-plate clutch 24 is provided between the input shaft 23 and the intermediate shaft 29, and a multi-plate clutch 24 is provided between the input shaft 23 and the sun gear shaft 3.
A multi-plate clutch 25 is provided between the clutches 0 and 0.
Sun gear shaft 30 and transmission case 18
A multi-disc brake 26 and a one-way clutch 27 are provided between the
A multi-disc brake 28 is provided via. The sun gear 32 provided on the sun gear shaft 30 includes a carrier 33, a planetary pinion 34 supported by the carrier, a ring gear 35 meshing with the pinion, another carrier 36, a planetary pinion 37 supported by the carrier, Together with the ring gear 38 that meshes with the pinion, a two-row planetary gear mechanism is configured. A ring gear 35 in one of the planetary gear mechanisms is connected to an intermediate shaft 29. Also, the carrier 33 in this planetary gear mechanism
is connected to a ring gear 38 in the other planetary gear mechanism, and these carriers and ring gear are connected to an output shaft 39. Further, a multi-disc brake 40 and a one-way clutch 41 are provided between the carrier 36 and the transmission case 18 in the other planetary gear mechanism.

Such a hydraulic automatic transmission with an overdrive device engages and releases each clutch and brake according to the engine output and vehicle speed by a hydraulic control device, which will be explained in detail below. It is designed to perform four forward gear shifts including O/D) or one reverse gear shift by manual switching.

Figure 3 shows the gear position and the operating conditions of the clutch and brake.

Here, ◯ indicates that each clutch and brake are in an engaged state, and × indicates that they are in a released state.

FIG. 1 is a hydraulic circuit showing an embodiment of a hydraulic control system for an automatic transmission including a torque converter direct-coupled clutch control system of the present invention. This hydraulic control device includes an oil reservoir 100, an oil pump 101, and a pressure regulating valve 2.
00, speed selection valve 210, 1-2 shift valve 220, 2
-3 Shift valve 230, throttle valve 240, cutback valve 250, governor valve 260, overdrive shift valve 270, solenoid valve 280, relief valve 290, lock up shift valve 300, governor control valve 310 according to the present invention, lock up cut Off valve 320 and accumulator valve 410, as well as check valves 330, 340, 35 with orifices and check balls.
Hydraulic cylinders 12A, 24A, 25A are hydraulic chambers of hydraulic pistons of hydraulic servos that operate various valves 0,360, 370, 380, 390, 400 and other clutches 12, 24, 25 and brakes 19, 26, 28, 40. , 19A, 26A, 2
8A, 40A, and other various valves and various hydraulic circuits arranged between the hydraulic cylinders.

The operation of this hydraulic control device will be explained below.

Hydraulic control device hydraulic pressure, torque converter 1
The source of hydraulic oil and lubricating oil for each part is oil pump 1.
01 and the oil pump 10 directly by the engine.
1 is driven, it sucks oil from the oil reservoir 100 and discharges it to the oil passage 102. Oil road 102
This oil pressure is the source of all working oil pressure and is called line pressure. The line pressure is adjusted to a predetermined pressure by a pressure regulating valve 200 as described later. Relief valve 29
0 is a relief valve when the line pressure becomes abnormally high. Oil is supplied from oil passage 103 to torque converter 1 and each lubricating location through pressure regulating valve 200 . The speed selection valve 210 consists of a spool 211 that moves by operating the driver's seat lever.
Depending on the lever selection position, the line pressure of the oil passage 102 is changed to the oil passages 104, 105, 106, 10 as shown in Fig. 4.
It serves as a guide to 7.

In Fig. 4, the circle mark indicates that the line pressure is guided to the oil passage indicated by the circle at each selected position, and the - mark indicates that the line pressure is not guided to the oil passage marked in that column at the selected position. represent. The operation of the transmission at each position is: R position is reverse, N position is neutral, D
Position is forward 4 speed automatic transmission, 2 position is forward 1st speed,
Automatic shifting between the second speed and the L position is the fixed position for the first forward speed.

In the D position, line pressure is sent from the oil passage 104 to the hydraulic cylinder 24A, and the clutch 24 is always engaged. Further, in the first, second, and third forward speed states, the clutch 12 is engaged as will be described later. The oil passage 104 changes the line pressure to the 1-2 shift valve 22.
0 and governor valve 260. 1-2 shift valve 2
20 is the spool 221, 222 and the spring 2
23, and in the first speed, the spool 221 is located at the lower side in the figure and does not guide any of the pressure oil in the oil passage 104. In the second, third, and fourth speeds, the spool 221 moves upward in the drawing due to the action of the governor pressure from the oil passage 111, and guides the pressure oil in the oil passage 104 to the oil passage 112. Oil passage 112 is connected to 2-3 shift valve 23
0 and communicates with the hydraulic cylinder 28A of the brake 28 to send pressure oil to the hydraulic cylinder 28A and operate the brake 28. When the brake 28 is engaged, the power transmission mechanism enters the second speed state as shown in FIG. The 2-3 shift valve 230 consists of spools 231, 232 and a spring 233. In the first and second speeds, the spool 231 is located lower in the figure, and in the third and fourth speeds, the governor pressure from the oil passage 111 is lowered. As a result of this action, the spool 231 moves upward in the drawing, leading the pressure oil in the oil passage 112 to the oil passage 113, and the hydraulic cylinder 25 of the clutch 25.
Send pressure oil to A and operate the clutch 25. When the clutch 25 is engaged, the power transmission mechanism is in the third speed as shown in FIG.

Overdrive shift valve 270 is spool 27
1, sleeve 272, spring 273, oil chamber 2
74, 275, 276, oil chamber 274, 2
75, 276 depending on the pressure oil acting on the oil passage 102.
The communication between the oil passage 117 or the oil passage 118 is switched. Solenoid valve 280 is controlled by an overdrive selector switch 500 provided at the driver's seat.

When overdrive selector switch 500 is OFF, opening 284 is closed. The pressure oil supplied through the oil passage 102 is supplied to the oil passage 119 and the check valve 3.
30, oil path 120, check valve 340, oil path 12
The oil chamber 274 of the overdrive shift valve 270 is supplied through the spool 271 and the sleeve 27.
2 as shown below.

When overdrive selector switch 500 is ON, opening 284 is opened. The pressure oil in the oil chamber 274 is supplied to the oil passage 122, the check valve 340, the oil passage 120,
It is discharged from the discharge port 285 via the check valve 330, the oil passage 119, and the opening 284. A check valve 340 and an oil passage 122 are connected to the oil chamber 274 from the oil passage 108.
Throttle pressure is supplied to the oil chamber 276 through the oil passage 111, and cabana pressure is supplied to the oil chamber 276 from the oil passage 111, and the spool 271 is controlled in relation to the sizes of both.

When the overdrive selector switch 500 is OFF, the line pressure of the oil passage 102 is acting on the oil chamber 274 of the overdrive shift valve 270, so the spool 271 and the sleeve 272 are held downward in the figure, and the pressure of the oil passage 102 is Oil is oil path 117,
It is sent to the hydraulic cylinder 12A of the clutch 12 through the check valve 370, and the clutch 12 is actuated.

When the overdrive selector switch 500 is ON, the oil chamber 2 of the overdrive shift valve 270
Throttle pressure is applied to the oil passage 74 from the oil passage 108. The spool 271 of the overdrive shift valve 270 is controlled by pressure oil acting on an oil chamber 274 and an oil chamber 276.
In the third speed state, the oil passage 102 is located at the lower part of the diagram.
Pressure oil is sent to the hydraulic cylinder 12A via the oil passage 117 and the check valve 300 to operate the clutch 12.

When the governor pressure increases and the spool 271 moves upward in the figure, the oil passage 117 is connected to the oil drain port 278, the clutch 12 is released, and the oil passage 10
2 pressure oil is sent to the hydraulic cylinder 19A of the brake 19 via the oil passage 118 and the check valve 380, the brake 19 is activated, and the fourth speed (overdrive) is reached.
becomes the state of

In the second position, line pressure is supplied to oil passage 104 and oil passage 105. The pressure oil led to the oil passage 105 is led to the oil chamber 234 of the 2-3 shift valve 230, and holds the spools 231 and 232 in the downward direction in the figure.
The spool 27 is also guided to the oil chamber 274 of the overdrive shift valve 270 via the check valve 330, oil passage 120, check valve 340, and oil passage 122.
1. Hold the sleeve 272 in the lower position shown in the figure. The pressure oil in the oil passage 104 is supplied to the hydraulic cylinder 24 of the clutch 24.
A and the 1-2 shift valve 220. When the 1-2 shift valve 220 is not in the first speed state, the pressure oil in the oil passage 104 is sent to the hydraulic cylinder 28A via the oil passage 112, and the brake 28 is operated. Further, the pressure oil in the oil passage 105 is supplied to the hydraulic cylinder 26A of the brake 26 via the 2-3 shift valve 230 and the oil passages 114 and 115, and the brake 26 is operated. When the clutches 24, 12 and the brakes 26, 28 are engaged, the power transmission mechanism is in the second speed state as shown in FIG. When the 1-2 shift valve 220 is in the first speed state, the spool 221 moves downward in the figure, and the oil passage 112 moves to the oil drain port 2.
Pressure oil in the hydraulic cylinder 28A is connected to the oil drain port 225 via the oil passage 112, and the brake 28 is released.
26, the pressure oil of the hydraulic cylinder 26A is discharged from the oil drain port 226, the brake 26 is released, and the power transmission mechanism enters the first speed state.

In the L position, oil passages 104, 105, 10
Line pressure is introduced to 6. The pressure oil led to the oil passage 104 operates the clutch 24 in the same manner as in each gear position in the D position. The pressure oil guided to the oil passage 105 passes through the oil chamber 234 and holds the spools 231 and 232 of the 2-3 shift valve 230 in the downward direction in the figure, and also holds the spool 2 of the overdrive shift valve 270.
71, hold the sleeve 272 in the downward direction shown in the figure. The pressure oil led to the oil passage 106 is transferred to the 1-2 shift valve 220
The oil acts on the oil chamber 224 to hold the spools 221 and 222 in the downward direction in the figure, and is also sent to the hydraulic cylinder 40A of the brake 40 through the oil passage 116 to operate the brake 40. When the clutches 24, 12 and brake 40 are engaged in this way, the third
As shown in the figure, the power transmission mechanism is in the first speed state.

At the R position, line pressure is introduced into the oil passages 106 and 107. The pressure oil led to the oil passage 107 is led to the oil chamber 206 of the pressure regulating valve 200 and acts to increase the line pressure, and is also led to the oil passage 113 via the 2-3 shift valve 230 to the clutch 2.
Activate 5. Also, the pressure oil in the oil passage 107 is 1-2
The oil is guided to the oil passage 116 via the shift valve 220 and operates the brake 40. Clutch 24 is also actuated. When the clutches 24, 12 and the brake 40 are engaged in this manner, the power transmission mechanism is placed in the reverse state as shown in FIG.

Governor pressure 260 is attached to output shaft 39 in FIG. The governor valve 260 has a hydraulic pressure (governor pressure) that is a function of the output shaft rotational speed due to a balance between centrifugal force, spring force, and hydraulic pressure, that is, a hydraulic pressure that increases as the output shaft rotational speed increases. is occurring in the oil passage 111.

The throttle valve 240 includes a spool 241, a downshift plug 242, and springs 243, 24.
4. Consisting of oil chambers 245, 246, the force of the spring 244 and the oil chamber 245 due to the movement of the downshift plug 242 in conjunction with the movement of the accelerator pedal.
246, a throttle pressure proportional to the throttle opening is generated in the oil passage 108. The throttle pressure of the oil passage 108 is 1
It is connected to the -2 shift valve 220, the 2-3 shift valve 230, and the overdrive shift valve 270, and controls the timing of gear changes according to the engine load state. In addition, when a hard down is necessary, if the accelerator pedal is strongly depressed, the downshift plug 242 moves upward and the oil passage 102 connects with the oil passage 109, and the line pressure of the oil passage 102 passes through the oil passage 109 to the 1-2 shift valve 220, 2-3 through the shift valve 230 and check valve 350 to the overdrive shift valve 270, and the spools 221, 231,
A downshift is performed from 4th gear to 3rd gear, from 3rd gear to 2nd gear, or from 2nd gear to 1st gear in balance with the governor pressure acting on the lower end of 271.

The cutback valve 250 generates cutback pressure in the oil passage 110 by balancing pressure oil.
The cutback pressure in the oil passage 110 is controlled by the throttle valve 24.
0 to lower the throttle pressure and prevent unnecessary power loss due to the oil pump.

The pressure regulating valve 200 generates line pressure in the oil passage 102 by the balance between the pressure oil and the force of the spring 203. Further, the throttle pressure of the oil passage 108 is supplied to the oil chamber 207 to generate line pressure according to the engine load.

The check valves 370, 380, 390, and 400 each consist of a check ball, an orifice, and a hole.

Next, the control circuit for the direct coupling clutch 50 of the torque converter 1, which is the gist of the present invention, will be explained.

The lock-up shift valve 300 is a spool 30.
1, a spring 302, and oil chambers 303 and 304, and line pressure is always applied to the oil chamber 303. When the line pressure is not acting on the oil chamber 304, the spool 301 is positioned downward in the figure due to the line pressure acting on the oil chamber 303, and communicates the oil passage 103 and the oil passage 130. The pressure oil in oil passage 103 is oil passage 1.
30, the direct coupling clutch 50 is released, the oil circulates within the torque converter 1, and the oil is connected to the oil passage 1 via the oil passage 131.
It is discharged from 32. When line pressure acts on the oil chamber 304, the spool 301 is moved upward in the drawing by the spring 302, thereby connecting the oil passage 103 and the oil passage 131. Pressure oil in oil passage 103 operates direct coupling clutch 50 via oil passage 131.

The governor control valve 310 is connected to the spool 31
1, a spring 312, and an oil chamber 313, and when the governor pressure used in the oil chamber 313 is below a predetermined value, the spool 311 is positioned upward in the figure by the spring 312 and blocks the oil passage 113. Oil chamber 31
When the governor pressure acting on 3 exceeds a predetermined value,
The spool 311 moves downward in the figure against the spring 312 and connects the oil passage 113 to the oil passage 140. The governor control valve 310 constitutes a direct coupling clutch determining means that issues a command to connect or release the direct coupling clutch 50 depending on the vehicle speed.

The lock-up cut-off valve 320 is the spool 3
21, spring 322, oil chamber 323, 324,
325, and the spring 322 is connected to the oil chamber 325.
The oil chamber 323 is connected by an oil passage 141 to an accumulating oil chamber 411 of an accumulator valve 410 (described later) via a check valve 390, and also to a check valve 400.
are in communication with oil passage 117 and oil passage 118 via oil passage 142 and oil passage 143, respectively.

The accumulator valve 410 is connected to the pressure accumulation oil chamber 41.
1, a spool 412, and a spring 413. When hydraulic pressure enters the oil chamber 411, the spool 412 gradually moves downward in the figure, and after a certain period of time, the oil chamber 3 of the lock-up cut-off valve 320 is released through the oil passage 146.
25 and oil passage 141 are connected.

Spool 3 of lock-up cut-off valve 320
21 is positioned upward in the figure by the action of the spring 322 when a predetermined or higher hydraulic pressure acts on the oil chamber 323 and the spool 412 of the accumulator valve 410 is positioned at the lower side in the figure and hydraulic pressure is introduced into the oil chamber 325. The oil passage 140 and the oil passage 144 are connected, and the oil chamber 3
Even when the oil pressure acting on 23 is below a predetermined level, the spring 322 causes the oil passage 23 to be positioned upward in the figure and communicate between the oil passage 140 and the oil passage 144. Furthermore, when the oil pressure in the oil chamber 323 increases from a state below a predetermined value to a predetermined value or more, first, when the oil pressure in the oil chamber 323 reaches the set value, the spool 321 is moved downward in the figure, and the oil passage 140 is moved downward.
is shut off, and the oil passage 144 communicates with the oil drain port 326, and this state is maintained for a predetermined period of time determined by the check valve 390 and the pressure accumulation oil chamber 411. The spool 321 is the spool 412 of the accumulator valve.
reaches the lower end in the figure, the oil passage 146 and the oil chamber 411 communicate with each other, and the oil pressure is supplied to the oil chamber 325, and then returns to the upper part in the figure again. The lock-up cut-off valve 320, the accumulator valve 410, and the check valves 390 and 400 constitute a shift detection means that issues a direct coupling clutch release command when two gears are shifted next to each other, such as during a 3-4 shift.

During first and second forward speeds...Lock-up shift valve 300 is closed due to no pressure oil being supplied to oil passage 113.
Pressure oil does not act on the oil chamber 304, and the spool 301 is positioned at the lower side in the figure due to the line pressure acting on the oil chamber 303, and communicates the oil passage 103 and the oil passage 130.
Pressure oil supplied from the oil passage 103 passes through the oil passage 130, releases the direct coupling clutch 50 of the torque converter 1, circulates within the torque converter 1, passes through the oil passage 131, and is discharged from the oil drain port 132 via the lock 300 valve. be done. That is, the direct coupling clutch 50 is released during the first and second forward speeds.

At 3rd forward speed...In the 3rd forward speed state, the vehicle speed increases and the spool 311 of the governor control valve 310
moves downward in the figure, the oil passage 113 becomes the oil passage 14.
Contact 0. Lock-up cut-off valve 320
Line pressure is guided to the oil chamber 323 through oil passages 117, 142, and 141, and the spool 412 of the accumulator valve 410 is located at the bottom in the figure, and the oil passage 141 is locked by the oil passage 146. Since the spool 321 is guided to the oil chamber 325 of the up cut-off valve 320, the spool 321 is positioned upward in the figure due to the action of the spring 322, and the oil passage 140 and the oil passage 14
4 is in contact. The pressure oil in oil passage 113 is oil passage 1.
40,144 through the lock-up shift valve 30.
0, the spool 301 is moved upward in the drawing, the oil passage 103 is connected to the oil passage 131, and the direct coupling clutch 50 is engaged.

3-4 During upshift...The vehicle speed increases from the third forward speed state (direct coupling clutch 50 engaged), the spool 271 of the overdrive shift valve 270 moves upward in the figure, and the oil passage 102 connects with the oil passage 118. When the oil passage 117 communicates with the oil drain port 278, the pressure oil in the hydraulic cylinder 12A of the clutch 12 is discharged, and the pressure oil is gradually supplied to the hydraulic cylinder 19A of the brake 19. At this time, changes in the oil pressure in each hydraulic cylinder are effected by the check valves 370 and 380, so that the pressure oil in the hydraulic cylinder 12A is quickly discharged and the pressure oil is gradually supplied to the hydraulic cylinder 19A. Also, the pressure oil in the oil chamber 323 of the lock-up cut-off valve 320 and the oil chamber 411 of the accumulator valve 410, which are connected to the hydraulic cylinder 12A through the oil passage 142 and the oil passage 141, is supplied to the check valve 390,
400, and is quickly discharged through oil passages 141, 142, and 117. Along with this, the oil chamber 323 and the oil chamber 4
11 is a hydraulic cylinder 19A with oil passages 143 and 14.
1, pressure oil is supplied more slowly through oil passages 143 and 141 and check valves 390 and 400. When the pressure in the oil chamber 323a and the oil chamber 411 decreases to below a predetermined value, the spool 412 of the accumulator valve 410 is moved upward in the figure by the action of the spring 413, and the oil chamber 325
communicates with the oil drain port 414 of the accumulator valve 410 via the oil passage 146. In this state, the spool 321 is held upward in the figure by the spring 322, so the oil passage 140 and the oil passage 144 are in communication, and the oil pressure in the oil chamber 304 of the lock-up shift valve 300 is maintained. Next, oil passages 118, 14
3, 141, and when the oil pressure in the oil chamber 323 rises to a predetermined value or higher, the spool 321 moves downward in the figure and closes the oil passage 1.
44 is connected to the oil drain port 326, and the pressure oil in the oil chamber 304 of the lock-up shift valve 300 is discharged. When the pressure oil in the oil chamber 304 is discharged, the spool 301 moves downward in the drawing, connects the oil passage 103 to the oil passage 130, and releases the direct coupling clutch 50. During the release time of the clutch 50, after the spool 321 moves downward in the figure, pressure oil is supplied to the oil chamber 411 of the accumulator valve 410 through the orifice of the check valve 390, and the spool 412 moves downward in the figure. It is determined by the time it takes for the oil chamber 411 and the oil passage 146 to communicate with each other.

From this state, the oil pressure of the hydraulic cylinder 12A further decreases, the clutch 12 is released, and the hydraulic cylinder 19
When the oil pressure at A increases and the brake 19 is engaged, the gear position changes to fourth speed and the 3-4 upshift is completed. Furthermore, from this state, the oil pressure of the hydraulic cylinder 19A increases, and at the same time that the brake 19 is engaged, the oil pressure of the oil chamber 325, which communicates with the oil chamber 411 via the oil passage 146, moves the spool 321. When the spool 321 moves upward in the figure, the oil passage 140 and the oil passage 144 communicate again, and the spool 321 of the lock-up shift valve 300 moves upward in the figure.
1 moves upward in the figure, the oil passage 103 and the oil passage 130 are brought into communication and the direct coupling clutch 50 is engaged again. As described above, during a 3-4 upshift, the direct coupling clutch 50 is released and the gears are shifted between each gear stage in synchronization with the timing, and after the gear shift is completed, the direct coupling clutch 50 is re-engaged. Note that the check valves 370 and 380 having orifices delay the direct coupling clutch release command from the shift detecting means B by a predetermined period of time from the time of the shift command, and release the direct coupling clutch 50.
A delay means C is configured to time the operation of the gear shifter with the speed change operation.

4-3 At the time of downshift...The vehicle speed decreases from the state in which the direct coupling clutch 50 is engaged in the fourth forward speed, and the spool 27 of the overdrive shift valve 270
1 moves downward in the figure, and the oil passage 118 connects to the oil drain port 27.
9 and the oil passage 102 communicates with the oil passage 117, the pressure oil in the hydraulic cylinder 19A is discharged and the pressure oil is supplied to the hydraulic cylinder 12A. In this case, the oil pressure changes due to the action of the check valves 370 and 380, so that the pressure oil in the hydraulic cylinder 19A is quickly discharged, and the pressure oil is gradually supplied to the hydraulic cylinder 12A. Oil chamber 323 connected to hydraulic cylinder 19A
and the oil pressure in the oil chamber 411 is connected to the oil passages 141, 143, 1
When the oil is discharged through 18 and falls below a predetermined value, the spool 412 moves upward in the figure and connects the oil passage 146 to the oil drain port 414. In this state, the spool 321 is held upward in the drawing by the action of the spring 322, the oil passage 140 and the oil passage 144 are in communication, and the oil pressure in the oil chamber 304 of the lock-up shift valve 300 is maintained. Next, oil passages 117, 142, 14
1. Pressure oil is gradually supplied through the check valves 390 and 400, and when the oil pressure in the oil chamber 323 reaches the predetermined value, the spool 321 moves downward in the figure, and the oil passage 14
0 and connects the oil passage 144 with the oil drain port 326. As a result, the lock-up shift valve 30
0 spool 301 moves downward in the figure, and the direct coupling clutch 50 is released. The release time of the clutch 50 is determined by the time during which pressure oil is supplied to the oil chamber 411 of the accumulator valve 410 and the spool 412 is moving in the direction shown.

When the oil pressure in the hydraulic cylinder 19A further decreases and the brake 19 is released, and the oil pressure in the hydraulic cylinder 12A increases and the clutch 12 is engaged, the gear position becomes the third speed and the 4-3 downshift is completed. When the oil pressure of the hydraulic cylinder 12A further increases from this state and reaches a predetermined value or more, the spool 321 moves upward in the drawing to connect the oil passage 140 and the oil passage 144, and moves the spool 301 of the lock-up shift valve 300 upward in the illustration. Then, the oil passage 103 and the oil passage 131 are connected, and the direct coupling clutch 50 is engaged again. In this manner, during a 4-3 downshift, the gear change between each gear is performed in synchronization with the release state of the direct coupling clutch 50, and after the shift is completed, the direct coupling clutch 50 is engaged again.

It goes without saying that the present invention can be applied not only to the 3-4 shift, but also to two gears in which the direct coupling clutch is engaged.

(G) Effects of the Invention As explained above, according to the present invention, when shifting at a predetermined speed or higher in two adjacent gears, the direct coupling clutch 50 is temporarily released, so that torque fluctuations are reduced in the torque converter. However, based on the delay means C, the direct coupling clutch release command by the shift detecting means B is delayed by a predetermined time from the time of the shift command, and the direct coupling clutch operation is timed to the gear shifting operation. Since the configuration is such that the hydraulic pressure is generated in one hydraulic servo 12A, the hydraulic pressure in one hydraulic servo 12A is discharged and the other hydraulic servo 19A is
Even if there is a slight delay in the speed change operation in which oil pressure is supplied to the engine, engine racing and speed change shock can be reliably prevented by eliminating the timing between the direct coupling clutch operation and the speed change operation.

Further, a delay means C is provided which is involved in the shift detection means B and delays the direct coupling clutch release command according to the engine load, and based on the delay means C, the direct coupling clutch release command from the shift detection means B is delayed depending on the engine load. Since the direct coupling clutch is configured to time the gear shifting operation with a delay of a predetermined time from the gear shifting command of the gear shifting operation means in accordance with the engine load condition, the direct coupling clutch can always be controlled to release in an optimum manner according to the engine load condition. Under any engine load condition,
By eliminating the time lag between direct clutch operation and gear shift operation, it is possible to reliably prevent engine racing and gear shift shock.

[Brief explanation of drawings]

Fig. 1 is a hydraulic control circuit including a torque converter direct-coupled clutch control circuit of the present invention, Fig. 2 is a schematic diagram showing the power transmission mechanism of an automatic transmission, and Fig. 3 is a diagram showing the operating state of each element at each shift position. FIG. 4 is a diagram showing the communication state of the oil passage at each position of the speed selection valve. A... Direct coupling clutch determination means (lockup determination means), B... Speed change detection means, C... Delay means,
50...Torque converter direct connection clutch, 270
...speed change operation means (overdrive shift valve),
300... Lock-up shift valve, 310... Governor control valve, 320... Lock-up cut-off valve, 410... Accumulator valve, 37
0,380,390...Check valve with orifice.

Claims (1)

[Scope of Claims] 1. A direct coupling clutch that directly couples a torque converter, and a shift operation means that releases one frictional engagement element and engages the other frictional engagement element to switch between two adjacent gears. , wherein the direct coupling clutch is configured to be connected at a predetermined speed or higher in each of the two adjacent gear stages, and is configured to be temporarily released when the gear shift operating means operates to change the gear. A direct coupling clutch determining means for issuing a command to connect or release the direct coupling clutch according to the vehicle speed, a shift detecting means for temporarily issuing a command to release the direct coupling clutch when the shift operating means operates to shift, and the shift detecting means. delay means for delaying the direct coupling clutch release command by taking part in the delay means, and based on the delay means, the direct coupling clutch release command from the shift detection means is delayed by a predetermined time from the time of the shift command from the shift operating means. An automatic transmission equipped with a torque converter direct-coupled clutch, characterized in that the direct-coupling clutch operation is generated in a manner that synchronizes the gear shifting operation. 2. A direct coupling clutch that directly couples a torque converter, and a shift operation means that releases one frictional engagement element and engages the other frictional engagement element to switch between two adjacent gears, In an automatic transmission, the clutch is configured to be connected at a predetermined speed or higher in each of the two adjacent gears, and is configured to be temporarily released when the gear shift operating means is engaged in a gear shift operation, according to the vehicle speed. a direct coupling clutch determining means for issuing a command to connect or release the direct coupling clutch; a shift detecting means for temporarily issuing a command to release the direct coupling clutch when the shift operation means operates; a delay means for delaying a clutch release command according to the engine load, and based on the delay means, the direct coupling clutch release command from the speed change detection means is delayed from the time of the speed change command from the speed change operation means according to the engine load. An automatic transmission equipped with a torque converter direct coupling clutch, characterized in that the direct coupling clutch operation occurs after a predetermined time delay so as to time the gear shifting operation. 3. A shift detecting means for emitting a shift signal indicating that a shift is in progress for a predetermined period of time after a shift command; and a lock-up determining means for emitting a lock-up permission signal when the vehicle speed is equal to or higher than a predetermined value in a middle gear or a high gear. In the automatic transmission, the torque converter with a direct coupling clutch is switched from a lock-up state to a torque converter state even when a lock-up permission signal is issued from the lock-up determining means while a shift signal is issued from the shift signal. 1. An automatic transmission equipped with a clutch directly connected to a torque converter, characterized in that a delay means is added to provide a time delay in the generation of the shift signal, thereby generating the shift signal in synchronization with the shift operation. 4. A shift detecting means for emitting a shift signal indicating that a shift is in progress for a predetermined period of time after a shift command; and a lock-up determining means for emitting a lock-up permission signal when the vehicle speed is equal to or higher than a predetermined value in a middle gear or a high gear. In the automatic transmission, the torque converter with a direct coupling clutch is switched from a lock-up state to a torque converter state even when a lock-up permission signal is issued from the lock-up determining means while a shift signal is issued from the shift signal. A delay means is added to cause a time delay in the occurrence of the shift signal, and the time delay to be obtained by the delay means is changed in accordance with the engine load, so that the shift signal is always timed to the shift operation regardless of the engine load. An automatic transmission equipped with a clutch directly connected to a torque converter, characterized in that the torque is generated by the torque converter.