JPS5824651A - Hydraulic control unit for automatic transmission - Google Patents

Abstract

PURPOSE:To prevent a hydraulic control unit for an automatic transmission having a fluid type torque converter with a direct coupling clutch from creating its direct clutch engagement condition when a control valve for the direct coupling is broken, by normally supplying a converter pressure into a chamber for releasing the direct coupling clutch. CONSTITUTION:A torque converter 1 in an automatic transmission includes a direct coupling clutch 50 for coupling an engine crank shaft 8 with a turbine shaft 9, which has an engaging oil chamber 53 and a releasing oil chamber 54 respectively connected to first and second oil passages 70, 103, the first oil passage 70 being connected to a control valve 80 of the direct clutch 50. The control valve 80 is connected through a fourth oil passage 72 to a hydraulic servo-mechanism for supplying pressure oil under pressure to a high speed stage of the automatic transmission which corresponds to the engagement range of the direct coupling clutch, and further, there are provided a third oil passage 111 for introducing a governor pressure and an oil discharge port 83. Further more, the control valve 80 communicates between the oil passages 70, 72 when the governor pressure is higher than a predetermined pressure, but communicates the oil passage 70 to the oil discharge port 83 when the governor pressure is lower than the predetermined pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic control system for an automatic transmission equipped with a hydraulic torque converter with a direct coupling clutch.

Switching between engagement and disengagement of a conventional direct-coupled clutch is performed by switching the supply of hydraulic pressure to a torque converter, and a spool-type direct-coupling clutch control valve is used for this switching. However, with conventional hydraulic control devices, if the spool of the one-coupling clutch control valve becomes stuck on the direct coupling clutch engagement side, the direct coupling clutch is always engaged, which causes the engine to stop when the car starts, making it impossible to drive. There was a danger of falling.

An object of the present invention is to provide a hydraulic control device for an automatic transmission equipped with a direct clutch control valve to eliminate such problems.

Next, one example of an automatic transmission equipped with the direct coupling clutch control device of the present invention will be described with reference to FIGS. 1.2.

This automatic transmission has a torque converter with a direct coupling clutch,
It includes an overdrive mechanism 2, a gear transmission mechanism 3 with three forward stages and one reverse stage, and the torque converter 1 is a well-known one that includes a pump 5, a turbine 6, and a stator 7, and the pump 5 is connected to an engine crankshaft 8. The turbine 6 is connected to a turbine shaft 9. The turbine shaft 9 forms the output shaft of the torque converter 1, which also serves as the input shaft of the overdrive mechanism 2, and is connected to a carrier 10 of a planetary gear mechanism 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 activated. A planetary pinion 14 rotatably supported by a carrier 10 meshes with a sun gear 11 and a ring gear 15. A multi-disc brake 12 and a one-sided clutch 13 are provided between the sun gear 11 and the carrier 10, and a multi-disc brake 19 is provided between the sun gear 11 and the housing or overdrive case 16 containing the overdrive mechanism. It is being

The ring gear 15 of the overdrive mechanism 2 is connected to the input shaft 23 of the gear transmission mechanism 20. A multi-disc clutch 24 is provided between the input shaft 23 and the intermediate shaft 29, and a multi-disc clutch 25 is provided between the input shaft 23 and the sun gear shaft 30.
is provided.

A multi-disc brake 28 is provided between the sun gear shaft 30 and the transmission case 18 via a multi-disc brake 26 and a one-sided clutch 27. The sun gear 32 provided on the sun gear shaft 30 includes a carrier 33, a planetary binion 34 carried by the carrier, a ring gear 35 meshing with the binion, another carrier 36, and a planetary binion carried by the carrier. 37, constitutes a two-row planetary gear mechanism together with a ring gear 38 that meshes with the binion. A ring gear 3 in one of the planetary gear mechanisms is connected to an intermediate shaft 29.

Further, the carrier 33 in this Ti star gear mechanism is connected to a ring gear 38 in the other Ti star gear mechanism, and these carrier and ring gear are connected to an output shaft 39. Further, a multi-disc brake 40 and a one-sided clutch 41 are provided between the carrier 36 and the transmission case 18 in the other planetary gear mechanism.

In such a hydraulic automatic transmission with an A-patrive device, each clutch and brake is engaged or released depending on the output of the engine and the heavy speed of the vehicle by a hydraulic control device, which will be explained in detail below. (0/D) and 4 forward gears or manual switching.
It is designed to change gears.

Table 1 shows the transmission gear positions and the operating states of the clutches and brakes.

5-6- Here, ◯ indicates that each clutch and brake are in an engaged state, and × indicates that they are in a released state.

This hydraulic control circuit consists of an oil reservoir 100°, an oil pump 101, a line pressure regulating valve 205, a speed selection valve 210.1-
2 shift valve 220, 2-3 shift valve 230, throttle valve 24o1 cutback valve 250, governor valve 2601 overdrive shift valve 2701 solenoid valve 280. L
/IJ-7 valve 29o1 bypass valve 300, check valve 3
30, 3401350.360.370.38o1 various valves and other hydraulic cylinders 12A124A, 2 which are the hydraulic chambers of the hydraulic pistons of the hydraulic servos that operate the clutches 12.24.25 and brakes 19.26.28.40
5A, 19A, 126A, 28A, 40A, and other various valves and various hydraulic circuits arranged between the hydraulic cylinders.

The operation of this hydraulic pressure 6111111 circuit will be explained below.

The oil pump 101 is a supply source for the working oil pressure of the hydraulic control circuit, the working oil of the torque converter 1, and lubricating oil for each part,
The oil pump 1.1 is directly driven by the engine, thereby sucking oil from the oil reservoir 100 and discharging it into the oil passage 102. The oil pressure in the oil passage 102 is the source of all working oil pressure and is called line pressure. The line pressure is adjusted to a predetermined pressure by a line pressure regulating valve 200 as described later. Relief valve 290 is a relief valve when line pressure becomes abnormally high. The pressure oil led to the oil passage 103 through the line pressure adjustment valve 200 is regulated to a lower oil pressure than the line pressure by the converter pressure adjustment valve 2.5, and is then supplied from the oil passage 103 to the torque converter 1 and each lubricating point. be done. The speed selection valve 210 has a spool 21 that moves by operating the driver's seat lever.
1, and depending on the lever selection position, the line pressure of oil passage 102 is changed to oil passage 104, 105, 106, 107 as shown in Table 2.
It serves as a guide to

The ○ mark in Table 2 indicates that the line pressure corresponds to ○ at each selected position.
It represents being guided by the oil channel of the sign.

A - symbol indicates that line pressure is not directed to the oil passage in that column at that selected position. The operation of the transmission at each position is R
The position is 112 backwards, the N position is neutral, the D position is automatic transmission with 4 forward speeds, the 2 position is automatic transmission between 1st forward speed and 2nd speed, and the position is fixed at 1st 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 described later.

Oil passage 104 leads line pressure to 1-2 shift valves 220 and 9- and governor valve 260. The 1-2 shift valve 220 is composed of spools 221, 222 and springs 223, and in the first speed, the spool 221 is located at the lower side in the figure and does not guide the pressure oil in the oil passage 104 to either direction. 2nd gear, 3rd gear,
In the fourth speed, the spool 221 moves upward in the figure due to the action of the governor pressure from the oil passage 111, and the oil passage 104
pressure oil is guided to the oil passage 112. The oil passage 112 communicates with the 2-3 shift valve 230 and is also connected to the hydraulic cylinder 28A of the brake 28, and sends pressure oil to the hydraulic cylinder 28A, and when the brake 28 is engaged, the power transmission mechanism is activated as shown in Table 1. It will be in 2nd gear. The 2-3 shift valve 230 consists of a spool 231, 232 and a spring 233,
In the first and second speeds, the spool 231 is located downward in the drawing, and in the third and fourth speeds, the spool 231 is moved upward in the drawing by the action of the governor pressure from the oil passage 111, The pressure oil is introduced into the oil passage 113 and sent to the hydraulic cylinder 25A of the clutch 25 to operate the clutch 25. When the clutch 25 is engaged, the power transmission mechanism enters the third speed state as shown in Table 1.

The A-patribe shift valve 270 includes a spool 271, a sleeve 272, a spring 273, an oil chamber 274, 275.
276, depending on the pressure oil acting on the oil chambers 274, 275, and 276, the oil passage 102, the oil passage 117, or the oil passage 11.
I am switching contact with 8.

Solenoid valve 280 is controlled by an overdrive selector switch 500 provided at the driver's seat.

When the overdrive selector switch 500 is OFF, the opening 284 is closed. Pressure oil supplied through the oil passage 102 is supplied to an oil passage 119, a check valve 330, an oil passage 120,
The check valve 3401 is supplied to the oil chamber 274 of the overdrive shift valve 270 via the oil passage 122 and the spool 27
1. Hold the sleeve 272 in the downward direction shown in the figure.

When the A-patrive changeover switch 500 is ON, the opening 284 is opened. Pressure oil in the oil chamber 274 is supplied to the oil passage 122,
It is discharged from the discharge port 285 via the check valve 340, the oil passage 1201 check valve 330, and the oil passage 199° opening 284. A check valve 340 is connected to the oil chamber 274 from the oil passage 108.
, throttle pressure is supplied through the oil passage 122, and the oil chamber 2
Governor pressure is supplied to 76 from oil passage 111, and spool 271 is controlled in relation to the size of both.

When the overdrive selector switch 500 is OFF, the line pressure of the oil chamber 102 is acting on the oil chamber 274 of the overdrive shift valve 270, so the spool 271
The sleeve 272 is held at the lower side in the figure and the oil passage 102
The pressure oil is sent to the hydraulic cylinder 12A of the clutch 12 via the oil passage 117 and the check valve 370, and the clutch 12 is operated.

When the overdrive selector switch 500 is ON,
The oil chamber 274 of the overdrive shift valve 270 has an oil passage 1.
Throttle pressure has been operating since 08. The spool 271 of the overdrive shift valve 270 is connected to the oil chamber 274 and the oil chamber 2.
In the first, second, and third speed states where the governor pressure is low, the oil passage 1 is located at the lower part of the diagram.
02 is supplied to the hydraulic cylinder 12.02 through the oil passage 117 and the check valve 300. Activate the feed clutch 12 at A.

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 and the clutch 1
2 is released, and the pressure oil in the oil passage 102 flows into the oil passage 11.
8. The signal is sent to the hydraulic cylinder 19A of the brake 19 via the check valve 380, and the brake 19 is operated to enter the fourth speed (overdrive) state.

2 (In position D, line pressure is supplied to oil passage 104 and oil passage 105. Pressure oil led to oil passage 105 is 2-3
The spool 231. is guided to the oil chamber 234 of the shift valve 230.
232 is held at the lower position as shown in the figure.

In addition, check valve 3301 oil passage 1201 check valve 34
0, overdrive shift valve 270 via oil passage 122
The spool 271 and sleeve 272 are guided to the oil chamber 274 of
Hold it in the downward direction shown. Pressure oil in oil passage 104 is supplied to clutch 2
It is guided to the No. 4 hydraulic cylinder 24A and also to the 1-2 shift valve 220. When the 1-2 shift valve 220 is open 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 also operated. Also, is the pressure oil in oil passage 105 a 2-3 shift valve? 30,
The oil is supplied to the hydraulic cylinder 26A of the brake 26 through oil passages 114 and 115, and the brake 26 is actuated. When the clutch 24.12 and brake 26.28 are engaged, the power transmission mechanism enters the second speed state as shown in Table 1. 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.
25, and the pressure oil in the hydraulic cylinder 28△ is connected to the oil passage 11.
2, the oil is discharged from the oil drain port 225, and the brake 28 is released, and the oil passage 115 is connected to the oil drain port 226, and the pressure oil in the hydraulic cylinder 26A is discharged from the oil drain port 226, the brake 26 is released, and the power is The transmission mechanism is in the first speed state.

In the position, line pressure is introduced into the oil passages 104, 105, 106. The pressure oil led to the oil passage 104 operates the clutch 24 in the same way as in the D position gear. The pressure oil led to the oil passage 105 passes through the oil chamber 234 and holds the sprues 14--231 and 232 of the 2-3 shift valve 230 in the lower position as shown in the figure, and also holds the spool 271 and sleeve 272 of the overdrive shift valve 270 in the lower position as shown in the figure. Hold downward. The pressure oil guided to the oil passage 106 acts on the oil chamber 224 of the 1-2 shift valve 220 to hold the spools 221 and 222 in the downward direction in the figure.
Hydraulic cylinder 40A of brake 40 via oil passage 116
and operates the brake 40. When the clutch 24.12 and brake 40 are engaged in this way, Table 1
As shown in , the power transmission mechanism is in the first speed state.

In the R position, line pressure is introduced into oil passages 106, 107. The pressure oil guided to the oil passage 107 is introduced to the oil chamber 201 of the in-pressure regulating valve 200 and acts to increase the line pressure, and is also introduced to the oil passage 113 via the 2-3 shift valve 230. Activate clutch 25. Further, the pressure oil in the oil passage 107 is supplied to the oil passage 11 through the 1-2 shift valve 220.
6 to operate the brake 40. Also clutch 1
2 is also activated. In this way clutch 25.12,
When the brake 40 is engaged, the power transmission mechanism enters the reverse state as shown in Table 1.

Governor valve 260 is attached to output shaft 39 in FIG. The governor valve 260 uses centrifugal force, spring force,
In balance with the oil pressure, a hydraulic pressure (governor pressure) is generated in the oil passage 111 that is a function of the output shaft rotation speed, that is, a hydraulic pressure (governor pressure) that increases as the output shaft rotation speed increases.

The throttle valve 240 includes a spool 241, a downshift plug 242, springs 243, 244, and an oil chamber 245.
246, and due to the balance between the force of the spring 244 due to the movement of the downshift plug 242 in conjunction with the movement of the accelerator pedal and the force of the hydraulic pressure acting on the oil chamber 245, 246, the oil passage 108 has a force proportional to the throttle opening. Generating throttle pressure. The throttle pressure of the oil passage 108 is 1
-2 shift valve 220. It is connected to the 2-3 shift valve 230 and the overdrive shift valve 270, and controls the timing of gear changes according to the state of the engine load.

Also, when kickdown is necessary, if the accelerator pedal is strongly depressed, the downshift plug 242 moves upward and the oil passage 102 is connected to the oil passage 109, and the line pressure of the oil passage 102 is passed 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 spool 221.23
1.271 Downshift from 4th gear to 3rd gear, or 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 the gear.

The cutback valve 250 closes the oil passage 1 by balancing the pressure oil.
Cutback pressure is generated at 10.

The cutback pressure in the oil passage 110 acts on the throttle valve 240 to lower the throttle pressure and prevent unnecessary power loss due to the oil pump.

The line pressure adjustment valve 200 generates line pressure in the oil passage 102 by the balance between the pressure oil and the force of the spring 203. The converter pressure regulating valve 205 generates a converter pressure in the oil passage 103 that is lower than the line pressure.

Check valve 370.380 is check ball, 17- Each consists of an orifice and a hole.

Next, control of the direct coupling clutch, which is the essential part of the present invention, will be explained based on an embodiment shown in the drawings.

1 is a torque converter of an automatic transmission; 5 is a pump impeller connected to an engine crankshaft 8; 6 is a turbine runner connected to a turbine shaft 9; 7 is a stator; 50 is a 11
This is a direct coupling clutch of a torque converter that connects the crankshaft 8 and the turbine shaft 9.

The direct clutch 50 includes a clutch piston 51 and a friction plate 52
, an oil chamber 53 for engaging the direct clutch, and an oil chamber 54 for disengaging the direct clutch, the oil chamber 53 is connected to a first oil passage 70 which is an oil passage for engaging the direct clutch, and the oil chamber 54 guides converter pressure. It is connected to the second oil passage 103.

The direct-coupling clutch control valve 80 is equipped with a spool 82 on one side of which is coated with a spring 81, and is a hydraulic servo that supplies pressure oil to the high speed gear (in this embodiment, during overdrive) of an automatic transmission located in the direct-coupling clutch engagement area. A fourth oil passage 7 connected to
2. The first oil passage 70, 18- communicates with the third oil passage 111, which guides the governor pressure, and the oil drain port 83.

Next, the operations of the direct coupling clutch 50 and the direct coupling clutch control piece 80 will be explained.

A governor pressure is guided through an oil passage 111 to an oil passage 84 at the lower end of the direct coupling clutch control valve 80 in the figure, and when the speed exceeds a preset heavy speed and a governor pressure of a predetermined value or more is generated, the spool 82 is activated. When the spool 82 moves upward in the figure against the force of the spring 81 and the oil passage 72 and the oil passage 70 are brought into communication, and the governor pressure is low, the spool 82 is set to the lower position in the illustration by the action of the spring 81 and the oil passage 70 is communicated with the oil drain port 83, and the oil passage 72 is blocked.

On the other hand, pressure oil is guided to the oil passage 72 only when the spool 271 of the overdrive shift valve 270 is set to the position shown in the figure and the oil passage 102 and the oil passage 118 communicate with each other, that is, during overdrive. In other cases, the oil passage 118 is communicated with the oil drain port 279.

When the direct coupling clutch is engaged...During overdrive in which line pressure is introduced into the oil passage 72, when the governor pressure becomes sufficiently high and the spool 82 of the direct coupling clutch control valve 80 is set to the upper position shown in the figure, the oil passage 72 The line pressure is supplied to the direct clutch engagement oil chamber 53 via the oil passage 70. The line pressure is
Since this pressure is higher than the converter pressure that is constantly supplied to the direct coupling clutch release oil chamber 54, the clutch piston 51 of the direct coupling clutch 50 moves to the left in the figure, and the direct coupling clutch is engaged.

Even if the spool 82 of the direct clutch control valve 80 is stuck in this state and the oil passage 70 and the oil passage 72 are in communication with each other, when the gear is shifted from the overdrive stage, the oil that is communicating with the oil passage 72 is The passage 118 communicates with the outlet 279 of the overdrive shift valve 270, and the oil pressure in the oil passage 70 is communicated with the oil passage 72.
, the oil passage 118 and the discharge port 279, and the oil passage 10
The direct coupling clutch is released by the converter pressure that is constantly guided to the release oil chamber 54 via the converter pressure.

When the direct-coupled clutch is released...When the governor pressure is lower than a predetermined value and the spool 82 of the direct-coupled clutch control piece 80 is set to the lower position shown in the figure, or when the condition is not overdrive and hydraulic pressure is supplied to the oil passage 72. If not, the oil passage 70 is communicated with the oil drain port 83 or the oil drain port 279 of the overdrive shift valve 270. Therefore, the converter pressure guided through the oil passage 103 is guided to the direct coupling clutch release oil chamber 54 to release the direct coupling clutch 50, circulates within the torque converter, and is discharged through the oil passage 70 and the direct coupling clutch control valve 80. The oil is discharged from the oil drain port 279 via the port 83 or the oil path 70, the direct clutch control valve 80, the oil path 72, the oil path 118, and the overdrive shift valve 270.

As described above, according to the present invention, converter pressure is constantly supplied to the oil chamber for releasing the direct coupling clutch, so even if the direct coupling clutch control valve becomes inoperable due to stick etc. and loses its function, the governor pressure remains unchanged. The direct coupling clutch will not be engaged unless the shift valve is placed in the high speed side position due to a predetermined value or more.

In other words, it is possible to prevent a lock-up state due to malfunction when engagement of the direct clutch is undesirable (for example, at low speeds).

Furthermore, although this embodiment shows a configuration in which the lock-up state occurs only when the gear is in the fourth gear, it is possible to configure the lock-up state to occur in other gears other than the fourth gear. This can be easily inferred from the present invention.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a power transmission mechanism of an automatic transmission to which the present invention is applied, and FIG. 2 is a hydraulic circuit diagram of a hydraulic control device of the present invention. Fig. 1 Torque converter 50 Direct clutch 70 First oil passage 72 Fourth oil passage 111 Third oil passage 103 Second oil passage 80...Direct clutch control valve 81...Spring 22- 82...Spool 83...Oil drain port Patent applicant Representative of Aisin Warner Co., Ltd.
Masashi Nishimura 23- Figure 1

Claims (1)

[Claims] In a hydraulic control device for an automatic transmission having a torque converter consisting of a pump impeller, a turbine runner, and a stator, the torque converter has a direct coupling clutch, and the direct coupling clutch has an oil chamber for engaging a direct coupling Clara 1 and an oil chamber for disengaging the direct coupling clutch. and a first oil passage communicating with the engaging oil chamber and a second oil passage communicating with the releasing oil chamber, and the releasing oil is provided through the second oil passage. A hydraulic pressure lower than the line pressure is always supplied to the chamber, and a direct coupling clutch control valve is provided in the first oil passage, and the direct coupling clutch control valve is connected to a third oil passage to which a governor pressure corresponding to the vehicle speed is supplied. , a fourth oil passage to which line pressure is supplied and an oil drain port Ml (abbreviated); the fourth oil passage reaches a shift valve for switching and setting the gear stage of the automatic transmission; When the gear side position is set, line pressure is guided to the fourth oil passage, and when the lower speed gear side position is set, the fourth oil passage is communicated with the oil drain port, and the direct coupling clutch control valve connects the first oil passage and the fourth oil passage when the governor pressure is lower than a predetermined pressure;
A hydraulic control device for an automatic transmission, characterized in that when the governor pressure is lower than a predetermined pressure, the first oil passage is communicated with the discharge port.