JPS60256655A - Oil pressure controlling device for automatic transmission - Google Patents

Abstract

PURPOSE:To enable a hydraulic actuator to be directly shifted to a specified speed change stage at the time of trouble to move a car to take refuge by connecting an oil pressure source to said specified hydraulic actuator by means of an oil pressure selector valve, at a specified position of a selector lever. CONSTITUTION:A shift lever is moved to a specified position of an R-range, etc. This movement causes an oil pressure selector valve A to cut off the feeding of oil pressure to each solenoid selector valve 31-36. While, at the same time, pressure oil is fed to a port 19, from which the pressure oil is directly fed to a specified hydraulic actuator such as a hydraulic actuator 43 through a passage 26. This pressure oil is fed to one end chamber 63 etc. of the hydraulic actuator 43 to shift it to a specified speed change stage such as a backing stage, etc. Pressure oil on the opposite side end chamber 57 is returned to a tank via a solenoid selector valve 36.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to a hydraulic control device for an automatic transmission of a vehicle.

The hydraulic circuit is automatically activated by the output of the microcomputer based on the input signals such as engine load, rotational speed, and vehicle speed.This hydraulic circuit operates the hydraulic actuator that drives the shift rod along with the clutch mechanism. The transmission is, for example, JP-A-5
This method has already been proposed in Publication No. 4-96659.

However, in conventional automatic transmissions, in the unlikely event that an electrical failure occurs, the shift rod may not operate at all. Normally, in response to such malfunctions, an emergency manual operation mechanism is provided that manually operates the end of the shift rod that protrudes from the gear box of the gear transmission, but this mechanism does not allow for manual operation from the driver's seat. This takes time and prevents vehicles from being quickly evacuated in case of an emergency.

Therefore, in view of the above problems, an object of the present invention is to directly control a specific hydraulic actuator by a hydraulic switching valve interlocked with a selector lever in an emergency such as an electrical failure of the hydraulic I control circuit that controls the IQ of the hydraulic actuator. An object of the present invention is to provide a hydraulic control device for an automatic transmission that is actuated and shifted to a specific gear.

[Configuration of the Invention] In order to achieve the above object, the configuration of the present invention includes a plurality of hydraulic actuators that drive a shift rod that shifts to an arbitrary meshing position, and an insertion connection between the hydraulic actuators and a hydraulic power source. A hydraulic control device for an automatic transmission, comprising: a hydraulic control circuit comprising a plurality of electromagnetic switching valves; and a hydraulic switching valve provided between the hydraulic actuator and the hydraulic control circuit and interlocking with a selector lever. , a circuit is provided in which the hydraulic source is connected to a specific hydraulic actuator by the hydraulic switching valve at a specific operating position of the selector lever, whereby meshing of gears of a specific gear is achieved, and the vehicle is evacuated. 1) It is designed to be movable. By inserting and connecting a malfunction prevention valve to a specific hydraulic control circuit, the hydraulic control circuit controlled by a microcomputer prevents the hydraulic actuator from shifting to a specific gear (for example, reverse gear), and prevents the hydraulic switching valve from operating. Shifted only by

As the specific hydraulic actuator, a hydraulic actuator that drives a shift rod for reverse and forward gears is generally selected, and the emergency shift rod is configured to be shifted to the reverse gear. However, for example, a five-speed transmission may be configured to be shifted to a first gear, which is not normally used, in an emergency.

The present invention will be explained based on examples. As shown in FIG. 1, a hydraulic switching valve A is inserted and connected between the hydraulic pressure 8i12 and a hydraulic control circuit B of a hydraulic actuator C that drives a shift rod. This hydraulic switching valve A is constructed by fitting a spool 2 into a valve chamber 16 of a housing 3, and a selector lever (not shown) is connected to a hole 2a provided at the end of the spool 2.・D・2・LL'>J (driving sea lion) 1. [Place the selector lever that switches the
Len; ゛It is activated when changing to i-register.

In order to hold the spool 2 in a predetermined range, a ball 6 is held in a cylindrical portion provided in the housing 3 and is urged by a spring 4 into a recess 7 of the spool 2. In the valve chamber 16, an input boat 8.18 connected to the hydraulic power source 12, an output port 15 connected to the hydraulic control circuit B and a boat 13.14 constantly connected to the tank 17 are arranged opposite to the boat 18. A boat 19 is provided. On the other hand, spool 2
is provided with an annular groove 11.10.9, the annular groove 11 is adapted to connect the boat 18 to the boat 19 in the R range where the right-hand recess 7 of the spool 2 engages the ball 6 of the detent mechanism 5. There is. The annular groove 9 also connects the boat 8 to the boat 15 in the D range where the ball 6 engages with the recess 7 on the left side of the spool 2. moreover,
The spool 2 is provided with an axial passage 23 and a radial passage 24 connected thereto.
is connected to the boat 13 via the passage 24.23 and the left end chamber 25 of the valve chamber 16.

The hydraulic control circuit 8 is composed of 611 electromagnetic switching valves 31 to 36. Each electromagnetic switching valve 31 to 36 is a solenoid 31a
~ 36a is in the state shown in the figure when demagnetized, and the solenoid 31
When energizing a to 36a, the state is changed from the forest state shown in the figure, and pilot pressure from the passage 22 connected to the boat 15 acts on the spool.

Hydraulic actuator C includes a hydraulic actuator 41 that drives a shift rod 54 for shifting between 4th gear and 5th gear;
Hydraulic actuator 42 drives a shift rod 55 for changing between 2nd and 3rd gears, and hydraulic actuator 4 drives a shift rod 56 for changing between reverse and 1st gears.
It can be seen from 3. Each hydraulic actuator 41, 42
．． Since the hydraulic actuator 43 has a completely similar configuration, only the case of the hydraulic actuator 41 will be described.

In the hydraulic actuator 41 manufactured by Wil1 in 3rd place, a cylindrical large-diameter cylinder 61 is fitted into a large-diameter cylinder 62, and a small-diameter piston 59 is fitted into a small-diameter cylinder 58, respectively. Further, the intermediate piston 60 is fitted to the large diameter piston 61,
and is abutted with or integrally formed with the small diameter piston 59. A small diameter piston 59 is coupled to the shift rod 54. Then, pressure oil is supplied from the hydraulic source 12 to the small diameter cylinder 58.
When supplied to both the end chamber 57 of the large diameter cylinder 62 and the end chamber 63 of the large diameter cylinder 62, it is held at the neutral position shown. Although not shown, when the pistons 61 and 59 are separated from each other, an intermediate chamber created between them is always connected to the tank 17.

In order to connect each end chamber 57, 63 of each hydraulic actuator 41 to 43 to the hydraulic power source 12 or tank 17, an electromagnetic switching valve is connected to each end chamber. That is, in the case of the hydraulic actuator 41, the passage 22 connected to the hydraulic pressure source 12 passes through the electromagnetic switching valve 31 to the large diameter cylinder 62.
The oil in the large diameter cylinder 62 is returned to the passage 21 communicating with the tank 17. Also, pressure oil flows from the passage 22 through the electromagnetic switching valve 32 to the small diameter cylinder 58.
The oil in the small diameter cylinder 58 is returned to the passage 21. Each electromagnetic switching valve 31, 32 has a return spring 31b, 3
Due to the force 2b, the end chambers 57, normally in the state shown,
63 is connected to the tank 17, and when energized the spool is moved against the force of the return springs 31b, 32b, connecting the end chambers 57, 63 to the hydraulic source 12.

According to the present invention, the passage 26 connected to the port 19 is directly connected to the end chamber 63 of the hydraulic actuator 43 of a specific gear position (reverse gear position in the illustrated embodiment). Further, a malfunction prevention valve 71 is inserted and connected to the hydraulic actuator 430 circuit. This malfunction prevention valve 71 includes a stepped cylinder 73 in a housing 72, into which a stepped piston 77 is fitted and urged toward the large diameter cylinder by a spring 78. A port 79 is provided in the small diameter cylinder and connected to the electromagnetic switching valve 36. Also provided are ports 74, 76 facing the large diameter cylinder. The port 74 is connected to the electromagnetic switching valve 35, and the port 76 is connected to the end chamber 63 of the hydraulic actuator 43 (which becomes the hydraulic operating chamber for shifting to reverse gear). An annular groove 11175 is provided so that when the stepped piston 77 is moved to the left against the spring 78 by hydraulic pressure from the bow 1-79, the annular groove 75 connects the ports 74 and 76. The intermediate chamber of the attached cylinder 73 is always connected to the tank 17.

Although the above-mentioned embodiment describes a control device operated by hydraulic pressure, the present invention is not limited to this, and it goes without saying that fluid pressure such as air pressure can be used instead of hydraulic pressure. .

Next, the operation of the device of the present invention will be explained. During normal travel, that is, when the selector lever is in the D range, the recess 7 on the left side of the spool 2 of the hydraulic switching valve A is engaged with the ball 6 of the detent mechanism 5.

At this time, pressure oil is supplied from the hydraulic source 12 to the passage 22 via the port 8, the annular groove 9, and the port 15.

On the other hand, the passage 21 is connected to the tank 17.

Further, the port 19 connected to the passage 26 is closed.

And electromagnetic switching valves 31 to 3 forming the hydraulic control circuit B.
6 is selectively excited by a microcomputer according to the vehicle speed, engine speed, load, etc., and one of the hydraulic actuators 41 to 43 is driven to the right or left to achieve an optimal speed change.

Now, when the electromagnetic switching valve 36 is energized, the pressure oil from the hydraulic source 12 is sent to the end chamber 57 via the electromagnetic switching valve 36, and the small diameter piston 59 pushes the shift 0 port 56 to the left,
Meshing of gear gears is achieved. At the same time, the pressure oil in the passage 22 passes through the electromagnetic switching valve 36 and enters the malfunction prevention valve 71.
Pressure is applied from the port 79 to the right end surface of the stepped piston 77 through the through hole 80 of the stepped piston 77. Stepped piston 7
7 is pushed to the left against the force of the spring 78, and the annular groove 75 connects the port 74 with the port 76. and,
The oil in the end chamber 63 is returned to the tank 17 via the ports 76, 74 connected to each other, the electromagnetic switching valve 35 in the demagnetized state and the passage 21.

When the electromagnetic switching valve 35 and the electromagnetic switching valve 36 are excited,
Pressure oil from the hydraulic power source 12 is sent to the end chamber 57 via the electromagnetic switching valve 36, and acts on the malfunction prevention valve 71 to connect the ports 74 and 76, as described above. Further, the pressure oil in the passage 22 is connected to the electromagnetic switching valve 35 and the boat 7 connected to each other.
4.76 and is sent to the end chamber 63. Then, the hydraulic pressure acting on the large-diameter piston 61 and the intermediate piston 60 overcomes the hydraulic pressure acting on the small-diameter piston 59, and the shift rod 56 is pushed to the right, causing the large-diameter piston 61 to collide with the inner end wall of the large-diameter cylinder. At this point, it stops and assumes a neutral position.

Even if the electromagnetic switching valve 35 is energized, the stepped screw I/N 77 of the malfunction prevention valve 71 is pushed to the right by the spring 78 as shown in the figure, blocking the boats 74 and 76, so the passage 2
The pressure oil No. 2 is not supplied to the end chamber 63 and is excluded from the control of the hydraulic control circuit B.

Next, if the energizing circuit of the electromagnetic switching valve 36 or all of the electromagnetic switching valves fails, move the spool 2 to the R range where the recess 7 on the right side of the spool 2 engages with the ball 6 of the detent mechanism using the selector lever. , the boat 8 connected to the hydraulic power source 12 is cut off from the boat 15, and the boat 18 is connected to the boat 19 through the annular groove 11. Therefore, the pressure oil passes through the passage 26 and directly into the end chamber 6 of the hydraulic actuator 43.
3, and the shift rod 56 is shifted to reverse gear. At this time, the oil in the end chamber 57 is removed from the electromagnetic switching valve 36 and the passage 2.
1 and then returned to the tank 17. In the event of an electrical failure in the hydraulic control circuit B, the malfunction prevention valve 71 is closed and prevents the pressure oil in the passage 26 from overflowing into the tank 17 via the valve 71, the electromagnetic switching valve 35, and the passage 21.

Note that when the selector lever is set to the N range, both end chambers 63° 57 of all the hydraulic actuators 41 to 43 are connected to the tank 17, and any shift levers 54 to 56 can be operated manually.

The embodiment shown in FIG. 2 shows a four-speed transmission in which the shift rod 56a is used only for reverse gear shifting. In this case, a single-acting hydraulic actuator 44 is connected to the shift rod 56a. Suna'Ion, ＞”1548′″
``'') 46'''ILTIK +, +・End chamber 47
The passage 26 is connected to the other end chamber 49 and the passage 21 is connected to the end chamber 49.
connected to. The return spring 4 accommodated in the end chamber 49
The piston 46 connecting the shift rod 56a is pushed back by the force of 5. Malfunction prevention valve 7
1 is not required.

In this example, if the selector lever is set to R range,
Pressure oil is supplied from the hydraulic source 12 to the boat 18, 19 and the passage 26.
is sent to the end chamber 47 of the hydraulic actuator 44, and the shift rod 56a is pushed to the right by the piston 46, thereby achieving a shift to the reverse gear.

When the selector lever is set to the N range, the boat 19 is connected to the tank 17, so the piston 46 is pushed back by the force of the spring 45, and the oil in the end chamber 47 is returned to the tank 17. In this way, the shift to the reverse gear is released.

[Effects of the Invention] As described above, the present invention provides a system between a specific hydraulic actuator, generally the hydraulic actuator 43 that operates a forward/reverse gear shift rod, and the hydraulic 113111 circuit 8 consisting of the electromagnetic switching valve 35, 36. In addition, a malfunction prevention valve is provided, and the hydraulic switching valve A linked to the selector lever connects the hydraulic power source directly to the hydraulic actuator 43. Therefore, one of the electromagnetic switching valves constituting the hydraulic control circuit B Or, if all of them are inoperative due to an electrical fault, operation of the selector lever sends pressure oil to a specific hydraulic actuator to achieve gear meshing for a given gear, thereby shifting the vehicle to the desired position. You can move to a location and evacuate.

[Brief explanation of drawings]

Figure 1 shows the oil pressure w of the automatic transmission according to the first embodiment of the present invention.
Fig. 2 is a block diagram of a hydraulic control system for an automatic transmission according to a second embodiment of the present invention. A: Hydraulic switching valve B: Hydraulic control circuit C: Hydraulic actuator 2 varnish spool 5: Detent mechanism 8.15
．． ．． 18.19: Boat 9,11: Annular groove 17: Tank 21.22: Passage 31-36: Solenoid switching valve 4
1 to 44: Hydraulic actuator 56: Shift rod for reverse/1st gear 56a: Shift rod for reverse gear 71:
Malfunction prevention valve patent applicant Isuzu Motors Co., Ltd. Patent applicant Kawasaki Heavy Industries Co., Ltd. Agent Patent attorney Toshio Yamamoto Figure 1 6

Claims (2)

[Claims] (1) A hydraulic control circuit consisting of a plurality of hydraulic actuators that drive a shift rod that shifts to an arbitrary meshing position, and a plurality of electromagnetic switching valves inserted and connected between the hydraulic actuators and a hydraulic power source; A hydraulic control device for an automatic transmission comprising a hydraulic switching valve provided between the hydraulic actuator and the hydraulic control circuit and interlocking with a selector lever, wherein the hydraulic switching valve is operated at a specific operating position of the selector lever. A hydraulic control device for an automatic transmission, comprising a circuit in which the hydraulic power source is connected to a specific hydraulic actuator. (2) The hydraulic control device for an automatic transmission according to claim (1), wherein a malfunction prevention valve is inserted and connected between the hydraulic control circuit and the specific hydraulic actuator.