JPH0313375Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a clutch release mechanism that connects and disconnects a clutch device in a vehicle power transmission system, and particularly to a hydraulic clutch release mechanism.

[Conventional technology]

Generally, in a vehicle hydraulic clutch release mechanism, pressure oil is supplied from the master cylinder to the release cylinder by pressing the clutch pedal.
The clutch device is released by actuating the piston of the release cylinder, and the clutch device is connected by the opposite operation.

When the vehicle is stopped with the transmission still in gear, such as when waiting at a traffic light or in traffic jams, the clutch pedal must be continuously depressed along with the brake pedal, which causes driving fatigue.

In addition, in order to start the vehicle smoothly, it is necessary to gradually engage the clutch device, but currently this relies on the skill of the driver. For this reason, especially when driving a vehicle for which a driver is a beginner or is unfamiliar with the vehicle, the clutch device may be engaged suddenly, often resulting in engine stall or wheel spin. On the other hand, if the clutch pedal is released more slowly than necessary, the half-clutch state will be maintained for a long time, causing problems such as clutch slippage or clutch disc wear. It is especially difficult to operate when starting on a slope.

Focusing on these points, conventionally an on-off valve has been installed in the middle of the oil path that communicates the master cylinder and release cylinder of the clutch, and a switch installed in the driver's cab is operated to open the oil path with the on-off valve. A vehicle clutch device (for example, Japanese Utility Model Application No. 55-28537) that maintains the clutch disengaged state without having to keep pressing the clutch pedal by disconnecting the clutch pedal, and a damping device between the brake pedal and the master cylinder. A clutch control valve that controls the connection and disconnection of the clutch device is connected to the oil path between the master cylinder and the brake device, and when the brake pedal is depressed more than a certain amount, the clutch device is released and the brake pedal is depressed. A traveling control device for a work vehicle has been proposed that allows smooth start on a slope with the brake in the braking state and the clutch in the connected state by returning the amount to a certain amount or less (for example,
Utility Model Publication No. 57-133428).

However, with the vehicle hydraulic clutch release mechanism configured as described above, it is possible to start without operating the clutch pedal, but sufficient consideration must be taken to ensure smooth start without causing engine stall etc. I can't say that.

In addition, in order to gradually connect the clutch device and make the vehicle start smoothly, it is conceivable to use an orifice to throttle the flow rate of the pressure oil that flows back from the release cylinder to the master cylinder. The timing from which the connection starts is delayed. In particular, there was a problem in which the vehicle would move backwards when starting on a slope.

Therefore, the present applicant first installed an on-off valve in the oil passage from the master cylinder to the release cylinder to close the oil passage when the brake is applied, and a first orifice with a small cross-sectional area through which the pressure oil flows mainly from the half-clutch area onwards. A second orifice with a large cross-sectional area through which pressurized oil primarily flows in the area up to the half-clutch is arranged in series, and a bypass passage is provided to bypass the on-off valve. proposed a hydraulic clutch release mechanism for vehicles equipped with a one-way valve that only allows the flow of pressure oil from the master cylinder to the release cylinder (Utility Application No. 60-048378).

In the vehicle hydraulic clutch release mechanism of this prior application, compared to the conventional configuration described above, it is possible to lengthen the region after the half-clutch for a desired period of time without causing a timing delay in reaching the clutch connection start state. It is possible to exhibit an excellent effect of making it easier to start and start, especially starting on a slope.

[Problem that the invention attempts to solve]

However, in the vehicle hydraulic clutch release mechanism of the prior application, the first orifice with a small cross-sectional area through which the pressure oil flows mainly after the half-clutch area is configured as a fixed orifice.
The flow rate of oil returning from the half-clutch state is always constant. Therefore, depending on the gradient of the slope and the amount of cargo, there is a risk that the engine may stall or the vehicle may experience a shock when starting. Therefore, although the aforementioned prior application exhibits a certain level of performance, further improvement in this point has been desired from a practical standpoint.

Therefore, the technical problem of the present invention is to improve the above-mentioned prior application so that under all operating conditions,
The purpose is to eliminate engine stall and shock when starting, and to make starting, especially starting on a slope, easier.

[Means for solving problems]

Therefore, the present invention employs the following configuration as a means for solving the above-mentioned problems.

That is, the present invention provides a first orifice with a small cross-sectional area through which the pressure oil mainly flows after the half-clutch area in the vehicle hydraulic clutch release mechanism of the earlier application, whose cross-sectional area changes depending on the operating conditions. It is characterized by being configured as a variable orifice.

Specifically, as shown in FIG. 1, an on-off valve 10 that closes the oil passage 3 when the brake is applied is connected to the oil passage 3 from the master cylinder 2 to the release cylinder 4, and the pressure oil mainly flows from the half-clutch area onward. A switching valve 30 is arranged in series to switch between a first orifice 30a with a small cross-sectional area and a second orifice 30b with a large cross-sectional area through which the pressure oil flows mainly up to the half-clutch. A one-way valve 20 that only allows pressure oil to flow from the master cylinder 2 to the release cylinder 4 is disposed in the bypass passage 3a, and a first orifice 30a is provided.
is constructed as a variable orifice whose cross-sectional area changes depending on the operating conditions.

[Effect]

According to the above-described means, first, when the brake pedal is depressed, the on-off valve 10 closes the oil passage 3.
Next, when the clutch pedal 1 is depressed, the pressure oil discharged from the master cylinder 2 passes through the bypass passage 3a and passes through the first orifice 30 of the switching valve 30.
a, which is then fed through the second orifice 30b to the release cylinder 4, actuating the release fork and releasing the clutch device 9. When the brake is applied, even if the depression of the clutch pedal 1 is released, the on-off valve 10 and the one-way valve 20 do not allow pressure oil to flow back to the master cylinder 2, and the clutch device 9 is maintained in the released state.

Then, when the brake pedal is released, the on-off valve 10 opens the oil passage 3. Then, the release fork is urged in the return direction by the spring force within the clutch device 9, causing the piston of the release cylinder 4 to retreat. Then, as shown in FIG. 7, the pressure oil in the release cylinder 4 passes through the second orifice 30b of the switching valve 30 and quickly returns to the master cylinder 2. When the clutch reaches the half-clutch region, the second orifice 30b closes and the first orifice 30a with a small cross-sectional area opens, as shown in FIG. The clutch device 9 is loosely connected.

At this time, the first orifice 30a is configured as a variable orifice whose cross-sectional area changes depending on the operating conditions, so the cross-sectional area (orifice diameter) of the orifice automatically changes depending on the slope slope, load, vehicle speed, etc. To be changed (adjusted). This changes the flow rate of the return oil from the half-clutch state,
The optimum clutch connection operation is always performed according to the driving conditions.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows a hydraulic clutch release mechanism for a vehicle according to one embodiment of the present invention.

1 indicates the clutch pedal, and clevis 1
It is connected to the push rod 2a of the master cylinder 2 at point a. The master cylinder 2 is communicated with a release cylinder 4 through an oil passage 3. The push rod 4b that is in contact with the piston 4a of the release cylinder 4 is connected to the ball shaft 6 of the clutch housing 6.
The release fork 5 is connected to the outer end of the release fork 5, which is supported so as to be able to swing around a as a fulcrum. The release fork 5 moves the bearing hub 8 that is slidably supported on the protruding cylindrical part 7a of the bearing retainer 7 fixed to the transmission and carries the release bearing 8a, and presses the diaphragm spring 9a of the clutch device 9. clutch device 9
It is designed to release. Then, by depressing the clutch pedal 1, the master cylinder 2 is activated.
Pressure oil is supplied to the release cylinder 4 through the oil passage 3, and the piston 4a is actuated to release the clutch device 9, and the clutch device 9 is connected by the reverse operation.

Also, in the middle of the oil path 3 from the master cylinder 2 to the release cylinder 4, when the brake is applied, the oil path 3
An on-off valve 10 is provided for closing. This on-off valve 10 is an electromagnetic on-off valve, and a switch 13 interlocked with a brake is disposed in the middle of a conductor 12 connecting the electromagnetic on-off valve 10 and a power source 11. A bypass passage 3a is provided that has a one-way valve 20 that bypasses the on-off valve 10 and only allows communication of pressure oil from the master cylinder 2 to the release cylinder 4.

Furthermore, these on-off valves 10 and bypass passages 3
a and the release cylinder 4, there is a first orifice 30a with a small cross-sectional area through which the pressure oil flows mainly from the half-clutch area onwards, and a second orifice 30a with a large cross-section through which the pressure oil mainly flows up to the half-clutch area. A switching valve 30 for switching the orifice 30b is arranged in series. A piston 32 is slidably fitted into the cylinder body 31 of the switching valve 30, and is urged toward the master cylinder 2 by a return spring 33. A first orifice 30a is provided on the outer periphery of the piston 32 at the piston return position.
An annular groove 32a is formed which communicates with the oil passage 3, and this annular groove 32a communicates with the oil passage 30c.
It seems to be communicating with. 34 is a breather hole.

Now, in this embodiment, the first orifice 30a, which has a small cross-sectional area and through which the pressure oil flows mainly from the half-clutch area onward, has a cross-sectional area that changes depending on the driving conditions such as the slope slope, the load, and the vehicle speed. It is configured as a variable orifice.

That is, the first orifice 30a senses the slope slope from the slope sensor 40, the load condition from the load sensor 50, and the vehicle speed from the vehicle speed sensor 60, and the electromagnetic spill 35 is controlled by the control circuit 70 based on these detection signals. This allows the orifice diameter to be controlled to the optimum clutch engagement operation.

Incidentally, the tilt sensor 40 in this embodiment is as follows.
As shown in FIG. 2, a pendulum 42 is attached to be swingable about a fulcrum 41, a detection shaft 44 is pivotally attached to the upper end of the pendulum 42 by a shaft 43, and the detection shaft 4
and a detecting section 45 that detects the axial position of No. 4. The pendulum 42 always maintains a vertical state due to gravity. For example, when the vehicle enters a slope, the detection shaft 44 moves in the axial direction about the fulcrum 41. The slope slope is detected from the position of the detection axis 44 by the detection section 45.

As shown in FIG. 3, the control circuit 70 includes a random access memory (RAM) 71, a read-only memory (ROM) 72, a central processing unit (CPU) 73, an input/output port 74, Mainly consists of a microcomputer including output port 75, RAM71, ROM72, CPU
73, input/output port 74, and output port 75 are connected by a bus 76.

The input/output port 74 includes buffers 77A to 77.
C. Tilt sensor 40, load sensor 50 and vehicle speed sensor 60 via multiplexer (MPX) 78 and analog-to-digital (A/D) converter 79
is connected. The MPX 78 and A/D converter 79 are controlled by signals output from the input/output port 74, and transmit signals from the tilt sensor 40, load sensor 50, and vehicle speed sensor 60 to the RAM 7
1 or the CPU 73 sequentially.

The electromagnetic spill 35 is connected to the output port 75 via a drive circuit 80. of the control circuit 70
The ROM 72 contains a map determined based on the graph showing the correlation between orifice diameter and slope shown in FIG.
A map determined based on the graph showing the correlation between the orifice diameter and the load shown in FIG. , the electromagnetic spill 35 is controlled. Note that s ₀ in Fig. 5 is the maximum possible slope, and s 0 in Fig.
g ₀ in the figure indicates the maximum load capacity.

Next, the processing executed by the control circuit 70 will be explained based on the flowchart of FIG. 4.

First, in step 100, it is determined whether the vehicle speed V detected by the vehicle speed sensor 60 is lower than a predetermined vehicle speed _V1 . If the determination in step 100 is negative, that is, if the vehicle speed V is higher than the predetermined vehicle speed _V1 , the shock caused by the clutch engagement operation is small, so the process proceeds to step 110, where the orifice diameter is set to the maximum _A1 . Step 100 is a positive judgment,
That is, if the vehicle speed V is lower than the predetermined vehicle speed _V1 ,
Processing from step 120 onwards is executed.

In step 120, the orifice diameter A is determined based on the gradient taken in from the inclination sensor 40 using the formula A=-as+ _A1 . The orifice diameter B is determined based on the following equation: B=-bg+ _B1 .

Then, in step 140, step 120
and the orifice diameter A determined in step 130.
and orifice diameter B are compared. Step 14
If 0 is a positive judgment, that is, orifice diameter A and orifice diameter B are equal, and orifice diameter A is smaller than orifice diameter B, step 1
Proceed to step 50, set the orifice diameter to A, and proceed to step 1.
If 40 is a negative determination, that is, orifice diameter A is larger than orifice diameter B, step 16
0, and the orifice diameter is set to B. (Whether the orifice diameter is set to A or B is selected depending on the slope and the load, whichever has a greater influence.)

In the vehicle hydraulic clutch release mechanism configured as described above, first, when the clutch pedal is depressed to stop the vehicle, the switch 13 is turned on and the on-off valve 10 is turned on, as shown in FIG. It operates and closes the oil passage 3.

Next, when you depress clutch pedal 1,
Pressure oil discharged from the master cylinder 2 passes through the bypass passage 3a and is supplied to the switching valve 30. Then, the piston 32 of the switching valve 30 retreats against the return spring 33, and the second orifice 30b
Pressure oil is supplied to the release cylinder 4 through
The clutch device 9 is released by actuating the release fork 5 in the same manner as in the prior art. During this brake operation, even if the depression of the clutch pedal 1 is released, the pressure oil in the release cylinder 4 cannot be returned to the master cylinder 2 by the on-off valve 10 and the one-way valve 20, and the clutch device 9 It is kept in a free state.

Further, when the brake pedal is released, the switch 13 is turned off and the on-off valve 10 opens the oil passage 3. Then, the release fork 5 is urged in the return direction by the spring force of the diaphragm spring 9a in the clutch device 9, and the push rod 4b is
The piston 4a is retracted via. In the region up to the first half-clutch, the pressure oil in the release cylinder 4 quickly flows back to the master cylinder 2 through the second orifice 30b of the switching valve 30, as shown in FIG. Next, as shown in FIG. 8, the piston 32 is returned to the right in the figure by the return spring 33 of the switching valve 30, and the second orifice 30b is closed by the land portion of the piston 32. In the region after the half-clutch, the first orifice 30a automatically adjusts the orifice diameter according to the above-mentioned operating conditions, and the flow is gradually returned to the master cylinder 2, and the clutch device is gradually closed. 9 is connected, and the clutch device 9 is fully connected.

Therefore, according to this embodiment, when the vehicle is stopped with the transmission in gear, such as when waiting at a traffic light or in traffic jams, even if the clutch pedal 1 is released, the brake pedal is not depressed. If so, the clutch device 9 can be held in the released state.

Further, when starting, if the brake pedal is released without returning the clutch pedal 1, a half-clutch state can be quickly obtained, and the vehicle can start smoothly. Particularly, when starting on a slope, there is no timing delay before the clutch starts to engage, and there are no problems such as when the vehicle backs up.

Furthermore, the first orifice 30a, which has a small cross-sectional area and through which the pressure oil mainly flows after the half-clutch area, is configured as a variable orifice whose cross-sectional area changes depending on the operating conditions, so it is possible to create the optimum clutch for all operating conditions. You can perform connection operations.
As a result, it is possible to eliminate engine stalls and shocks when starting, making starting, especially starting on a slope, easier.

Although the present invention has been described above in detail with reference to a specific embodiment, the present invention is not limited to this embodiment, and includes various embodiments within the scope of the claims for utility model registration. For example, a bypass passage having an on-off valve and a one-way valve and a switching valve may be arranged in reverse. Further, the on-off valve may be a hydraulic on-off valve that operates in conjunction with a brake, and the switching valve may be configured as an electromagnetic switching valve.

[Effect of idea]

As described above, according to the present invention, driving fatigue caused by depressing the clutch pedal can be reduced, and
Under all driving conditions, it is possible to eliminate engine stalls and shocks when starting, and it is possible to make starting, especially starting on a slope, easier.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a hydraulic clutch release mechanism for a vehicle according to one embodiment of the present invention, FIG. 2 is a schematic diagram showing an example of a tilt sensor, and FIG. 3 is a diagram showing the control circuit of FIG. 1. Block diagram showing an example, No. 4
The figure is a flowchart showing the program contents of the computer in Figure 3, Figure 5 is a graph showing the correlation between orifice diameter and slope, Figure 6 is a graph showing the correlation between orifice diameter and cargo, Figures 7 and 8. FIG. 2 is an explanatory diagram showing different operating states of the switching valve. Explanation of symbols, 1...Clutch pedal, 2...Master cylinder, 3...Oil passage, 3a...Bypass passage, 4...Release cylinder, 4a...Piston, 9...Clutch device, 10...Opening/closing valve , 20
... One-way valve, 30 ... Switching valve, 30a ... First orifice (variable orifice), 30b ... Second orifice, 35 ... Electromagnetic spill, 40 ... Inclination sensor, 50 ... Load sensor, 60 ... ... Vehicle speed sensor, 70 ... Control circuit, 80 ... Drive circuit.

Claims (1)

[Scope of Claim for Utility Model Registration] A hydraulic clutch release for a vehicle in which pressure oil is supplied from a master cylinder to a release cylinder when the clutch pedal is depressed, and the clutch device is released by the operation of the piston of the release cylinder. In the mechanism, the oil passage from the master cylinder to the release cylinder is provided with an on-off valve that closes the oil passage when the brake is applied, a first orifice with a small cross-sectional area through which pressurized oil mainly flows from the half-clutch area onwards, and a first orifice mainly for the half-clutch area. A second orifice with a large cross-sectional area through which pressure oil flows in the area extending from A vehicle hydraulic pressure system, characterized in that a one-way valve that only allows flow of pressure oil is provided, and the first orifice is configured as a variable orifice whose cross-sectional area changes depending on operating conditions. Type clutch release mechanism.