JPH0749076Y2 - Clutch booster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a clutch booster equipped with a control valve.

b. Conventional Technology A conventional clutch operating system is shown in FIG. In this operation system, the master pedal 2 is operated by the clutch pedal 1, and the control valve 4 of the clutch booster 3 is operated by the hydraulic pressure supplied from the master cylinder 2. Then, the piston 7 of the power cylinder 6 is operated by the compressed air supplied from the air reservoir 5 via the valve 4, and the push rod 8 for clutch operation is operated by the force generated by the operation of the piston 7. .

As shown in FIG. 5, the control valve 4 comprises a valve housing 9 and a valve lifter 10 to form a valve housing 11
Inside, a pneumatic chamber 12 communicating with the air reservoir 5, a variable pressure chamber 13 communicating with the power cylinder 6, and a master cylinder 2
And a hydraulic chamber 14 that communicates with each of the above. Then, in this control valve 4, the valve lifter is driven by the oil liquid pressure-fed from the master cylinder 2 to the hydraulic chamber 14.
10 is moved to the right, the valve lifter 10 abuts the valve body 9, and the valve body 9 is opened. Then, compressed air flows from the pneumatic chamber 12 into the variable pressure chamber 13, and is further supplied from the variable pressure chamber 13 to the power cylinder 6. In this way, when compressed air flows into the variable pressure chamber 13, the pressure in the variable pressure chamber 13 increases, and the pressure acts on the valve lifter 10 and, together with the biasing force of the spring 15, pushes the valve lifter 10. return. Along with that,
The valve body 9 is also closed by the urging force of the spring 16. Then, equilibrium is maintained in the state shown in FIG. here,
When the depression force of the clutch pedal 1 is released and the pressure in the hydraulic chamber 14 is released, the valve lifter 10 is returned to the state shown in FIG. 5 by the pressure in the variable pressure chamber 13 and the biasing force of the spring 15. In this state, the compressed air in the variable pressure chamber 13 is discharged to the outside from the port 17 through the passage 10a of the valve lifter 10.

c. Problems to be Solved by the Invention By the way, in such a control valve, A ₁ = the cross-sectional area of the small diameter portion of the valve lifter A ₂ = the cross-sectional area of the large diameter portion of the valve lifter A ₃ = the valve body 9 and the valve housing Pressure acting area of the valve body 9 on the variable pressure chamber side when contacting 11 is A ₄ = Area in the annular valve seat facing the valve body 9 of the valve lifter 10 F ₁ = Spring 15 when the valve body 9 is opened by the valve lifter 10 Load F ₂ = Spring 16 set load f ₁ = Valve lifter 10 sliding resistance P ₀ = Pneumatic chamber 12 pressure P ₁ = Pressure increasing hydraulic chamber 14 pressure P ₁ ′ = Pressure decreasing When the pressure in the hydraulic chamber 14 is P ₂ = the pressure in the variable pressure chamber 13, when the pressure in the hydraulic chamber 14 is increased by depressing the clutch pedal 1, the following equilibrium equation is established.

A ₁ P ₁ + P ₂ (A ₃ −A ₄ ) P ₂ (A ₂ −A ₄ ) + A ₃ P ₀ ＋ F ₁ ＋ F ₂ ＋ f ₁ …
… Also, when the depression force of the clutch pedal 1 is released and the pressure in the hydraulic chamber 14 is decreasing, A ₁ P ₁ ′ = P ₂ (A ₂ −A ₄ ) + F ₁ −f ₁ ……… holds. .

Therefore, the hysteresis H of the control valve 4 is calculated from the above equation Becomes

In the clutch booster equipped with such a control valve 4, it is difficult to reduce the hysteresis H. That is, to reduce the hysteresis, A ₁
Can be made larger and A ₃ , A ₄ can be made smaller, but A ₃ , A ₄ can be
In order to secure a certain size, a certain size is required, and if A ₁ is increased, A ₂ must be increased to obtain the desired performance, and the entire valve becomes very large, and the hysteresis Is difficult to reduce. If the hysteresis H is large, a large pedal effort is required when the clutch is disengaged, and a considerably small pedal effort is sufficient when the clutch is engaged. That is, if the pedaling force when the clutch is disengaged is reduced, the pedaling force when the clutch is engaged becomes too small, and it becomes difficult to feel the reaction force in the half-clutch state, and the operation feeling deteriorates. Therefore, the operating force of the clutch pedal 1 cannot be made too small.

Therefore, the applicant has previously provided a clutch booster that can reduce the operating force of the clutch pedal by reducing the hysteresis (Actual Application 1-5100).
No. 7).

An object of the present invention is to provide an improved clutch booster that improves the feeling of clutch operation.

d. Means for Solving the Problems In the clutch booster of the present invention, when the master cylinder is in the non-operating state, the valve body shuts off the pneumatic chamber and the variable pressure chamber, and the variable pressure chamber communicates with the atmosphere. By actuating the valve lifter against the biasing force of the spring by stepping on the cylinder, the valve lifter actuates the valve element to communicate the air pressure chamber and the variable pressure chamber,
A relay valve for shutting off the variable pressure chamber from the atmosphere and a release valve are provided, and the urging force of the release valve to the valve lifter is set to be larger than the urging force of the relay valve to the valve lifter, and The variable pressure chamber and the variable pressure chamber of the release valve are selectively communicated with the power cylinder via the switching valve, the switching valve is linked to the master cylinder, and the switching valve is made to respond to the pressure increasing operation of the master cylinder. The relay chamber of the relay valve to communicate with the power cylinder,
The variable pressure chamber of the release valve is communicated with the power cylinder in response to the depressurizing operation of the master cylinder.

e. Function In the clutch booster of the present invention, the operation start pressure of the relay valve is set lower than the operation start pressure of the release valve, and the compressed air in the air reservoir is relayed by the switching valve when boosting the master cylinder. It is supplied to the power cylinder via a valve, and when the master cylinder is depressurized, the compressed air in the power cylinder is discharged to the atmosphere via the release valve.

That is, the clutch booster of the present invention uses the increasing path of the hysteresis loop in the relay valve when the clutch is disengaged, and uses the decreasing path of the hysteresis loop in the release valve when the clutch is connected. Therefore, the hysteresis loop of the relay valve and the hysteresis loop of the release valve do not overlap with each other, and the relay valve and the hysteresis loop of the release valve are positioned so that the hysteresis loop of the release valve is located on the higher master cylinder hydraulic pressure side. By adjusting the release valve, the clutch can be disengaged with a small pedaling force, and a sufficient reaction force can be obtained when the clutch is engaged.

f. Embodiment Hereinafter, the present invention will be described in detail based on an illustrated embodiment.

FIG. 1 shows an embodiment of the present invention, in which a clutch booster 20 has a power cylinder portion 21, a hydraulic cylinder portion 22, a control valve portion 23 and a switching valve portion 24.

The power cylinder portion 21 has a cylindrical cylinder shell 26 attached to a housing 25, and a power piston 27 slidably arranged in the cylinder shell 26. The power piston 27 is biased in the direction of arrow a in FIG. 1 by a return spring 29 arranged in the atmospheric pressure chamber 28,
When compressed air is introduced into the pressure chamber 30, the power piston 27
Is moved in the direction of arrow b in FIG. 1 against the return spring 29.

The hydraulic cylinder portion 22 includes a cylinder hole 31 formed in the housing 25 and a relay piston 32 arranged in the cylinder hole 31. This relay piston 32
One end is in contact with the tip of the piston rod 33 of the power piston 27, and the other end is in contact with one end of the output rod 34. The other end of the output rod 34 is connected to the clutch lever 35.

Further, the cylinder hole 31 of the hydraulic cylinder portion 22 is
A guide bush 36 for guiding the piston rod 33 is fitted therein, and seal rings 37a and 37b are arranged on both sides of the guide bush 36. The leftward movement of the guide bush 36 in FIG. 1 is restricted by the pressing ring 38 and the retaining ring 39, and the rightward movement of the guide bush 36 in FIG. 1 is the seal ring 37b.
The stop spacer 40a is regulated by the cylindrical spacer 40 that is in contact with the stepped surface of the cylinder hole 31. A plurality of oil passage holes 40b are formed on the peripheral wall of the spacer 40.
Further, an oil liquid port 41 is provided at the lower end of the housing 25, and the oil liquid port 41 is connected to the oil liquid chamber via a passage 42.
It is connected to 43.

The control valve portion 23 is composed of a relay valve 44 and a release valve 45 which are arranged in parallel at an upper portion of the housing 24 from the hydraulic cylinder portion 22 side with an interval upward. Both the relay valve 44 and the release valve 45 have valve bodies 46, 47 and valve lifters 48, 49, which allow the interior of the housing 25 to have air pressure chambers 50, 51, variable pressure chambers 52, 53 and oil liquid chamber 54. , 55, respectively.

The hydraulic chambers 54, 55 communicate with the oil liquid chamber 43 via the passage 56.

The valve bodies 46 and 47 are slidably arranged in the air pressure chambers 50 and 51, respectively, and are biased toward the valve lifters 48 and 49 by the compression springs 57 and 58, and the end faces thereof are located in the housing 25.
The air pressure chambers 50, 51 and the variable pressure chambers 52, 53 are cut off by abutting the valve seats 59, 60.

The valve lifters 48, 49 include one end portion 48a, 49a, central portion 48b, 4
9b and the other end 48c, 49c, and the central part 48
b, 49b and the other ends 48c, 49c are slidably arranged in the housing 25. A chamber 6 defined by the central portions 48b and 49b of the valve lifters 48 and 49, the other end portions 48c and 49c, and the housing 25.
1, 62 are in communication with the atmosphere via port 63. Further, exhaust passages 64, 65 are formed inside the valve lifters 48, 49 along the axial direction thereof.
Has one end open to the end face of one end 48a, 49a and the other end to the chamber 6
It communicates with 1,62.

The valve lifters 48 and 49 are respectively compressed by the compression springs 66 and 67 arranged in the variable pressure chambers 52 and 53, respectively.
The valve seats 48d and 49d, which are urged in the direction of the side of 4,55 and are in contact with the end walls of the hydraulic chambers 54 and 55, and which are formed on the peripheral edges of the openings of the exhaust passages 64 and 65, are the end faces of the valve bodies 46 and 47. It is designed to be maintained in a state of being separated from. The compression spring 66 and the other compression spring 67 are arranged, for example, with different set loads, whereby the biasing force of the relay valve 44 on the valve lifter 48 toward the hydraulic chamber 54 acts on the valve lifter 49 of the release valve 45. It is set to be smaller than the biasing force to the hydraulic chamber 55 side. The relay valve 44 and release valve 45 are
As shown in FIG. 2, the hysteresis loop is configured to be different depending on 6,67.

Further, the switching valve section 24 has a double rod piston 69 at the center of the housing 68, and the piston is the housing.
The cylinder 68a of 68 is slidably arranged. Further, notches 68b and 68c are partially formed in the cylinder 68a. Ball check valves 70, 71 are provided at the tips of the rods 69a, 69b of the piston 69 so as to face the tips. In these check valves 70 and 71, of the springs 74 and 75 that bias the balls 72 and 73, the set load of the spring 75 is set to be larger than that of the spring 74, and the total length of the piston 69 is set to the balls 72 and 73. It is longer than the distance. Therefore, in the normal position of the piston 69, the ball 72 is moved by the piston rod 69a into the spring 74.
The input side chamber 76 and the output side chamber 77 are communicated with each other, and only the ball 73 blocks between the input side chamber 78 and the output side chamber 79. Also, the piston 69 has an orifice
80 is provided so that the pressure chambers 81 and 82 defined on both sides of the piston 69 are communicated with each other by the orifice 80.

In the clutch booster 20, the pneumatic chambers 50 and 51 of the control valve portion 23 are provided in the passage 8 formed in the housing 25.
3 are communicated with each other, and the pneumatic chamber 50 is connected to the air reservoir 85 via the pipe line 84. In addition, the variable pressure chamber 52 of the relay valve 44 is connected to the input side chamber 78 of the switching valve unit 24 via the conduit 86.
The variable pressure chamber 53 of the release valve 45 is connected to the input side chamber 76 of the switching valve unit 24 via the pipe line 87. Both output side chambers 77, 79 of the switching valve portion 24 are connected to each other by a passage 88, and the passage 88 is connected to the pressure chamber 30 of the power cylinder portion 21 by a pipe 89. Furthermore, the pressure chamber 81 of the switching valve unit 24 is connected to the master cylinder 91 via a pipe line 90, and the pressure chamber 82 is connected to the oil liquid port 41 of the hydraulic cylinder unit 22 via a pipe line 92. .

The clutch booster 20 is operated as follows.

That is, when the clutch pedal 91a is depressed, the master cylinder 9
The oil liquid of 1 is supplied to the pressure chamber 81 of the switching valve unit 24 via the pipe 90.
1 and is supplied to the pressure chamber 82 through the orifice 80, and further the pipe 69, the oil liquid port 41 of the hydraulic cylinder portion 22, the passage 42, and the hydraulic chamber. It is fed to the hydraulic chambers 54, 55 of the control valve portion 23 via the passages 43, 56. The piston 69 moves upward, and the lower edge of the piston 69 has a notch 68b.
When the pressure reaches, the hydraulic pressure in the pressure chamber 81 is sent to the pressure chamber 82 also via the notch 68b. Therefore, the check valve 71 of the switching valve portion 24 is opened by the piston rod 69b,
The variable pressure chamber 52 of the relay valve 44 and the pressure chamber 30 of the power cylinder portion 21 are communicated with each other. Further, in the control valve section 23, the oil liquid fed to the hydraulic chambers 54, 55 causes the valve lifter 48 of the relay valve 44 to move forward against the urging force of the compression spring 66, thereby moving the valve seat 48d to the valve body. Abut on 46 and exhaust passage 6
Block 4 Further, when the valve lifter 48 is moved forward, the valve body 46 is separated from the valve seat 59 by the valve lifter 48 (A ₁ point in FIG. 2). Therefore, the relay valve 44
Compressed air from the air reservoir 85 flows into the variable pressure chamber 52 through the pneumatic chamber 50, and the compressed air passes through the pipe line 86, the input side chamber 78, the output side chamber 79, and the pipe line 89 of the switching valve section 24. It is introduced into the pressure chamber 30 of the power cylinder section 21. Then, the pressure causes the power piston 27 to move in the direction of arrow b in FIG. 1 against the biasing force of the return spring 29. When the power piston 27 moves in the direction of arrow b, the piston rod 33
The relay piston 32 is pushed through the
34 is pushed, and the clutch lever 35 is rotated to the release side. Thus, the position of the characteristic line in FIG. 2 in the state where the clutch is completely disengaged is the point A ₂ . On the other hand, in the meantime, also in the release valve 45, the valve lifter 49 is moved forward against the urging force of the spring 67, the valve seat 49d is brought into contact with the valve body 47, and the exhaust passage 65 is closed. Is separated from the valve seat 60. Therefore, the compressed air of the air reservoir 85 is also supplied to the variable pressure chamber 53 through the pneumatic chamber 50, the passage 83, and the pneumatic chamber 51, but the input side chamber 76 and the output side chamber 77 of the switching valve unit 24 are closed. Therefore, the compressed air in the variable pressure chamber 53 does not affect the power cylinder portion 21 at all.

Although the shift operation is performed in the state where the clutch is completely disengaged, during that period, that is, when the state in which the clutch pedal 91a is stepped on is maintained, the pressure chambers 81 and 82 of the switching valve unit 24 of the switching valve unit 24 are maintained during that period. The pressures are equalized and the piston 69 is returned to the original position shown in FIG. 1 by the biasing force of the spring 75. In this state, the check valve 71 is closed and the check valve 70 is opened. Therefore, the variable pressure chamber 53 of the release valve 45 and the pressure chamber 30 of the power cylinder section 21 are communicated with each other, and the variable pressure chamber 52 of the relay valve 44 and the power cylinder section are communicated with each other.
The pressure chamber 30 of 21 is cut off (A _{3 in} FIG. 2). At this time, the output of the clutch booster decreases from A ₂ to A ₃ (A ₂
If the value of −A ₃ ) is set to be less than or equal to the hysteresis of the operating force possessed by the clutch body side (see FIG. 3), the change in the clutch pedal depression force due to the decrease in output will not occur. After that, the power cylinder portion 21 of the booster 20 is controlled by the release valve 45.

Next, when the clutch pedal 91a is released, the valve lifter 49 of the release valve 45 is returned to the left in FIG. 1 by the urging force of the compression spring 67, the valve seat 49d is separated from the valve body 47, and the exhaust passage 65 Is opened to the transformer room 53. Therefore, the compressed air in the pressure chamber 30 of the power cylinder portion 21 is supplied to the conduit 89, the output side chamber 77, the input side chamber 76 and the conduit of the switching valve portion 24.
It is returned to the variable pressure chamber 53 of the release valve 45 via 87, and further discharged to the atmosphere via the exhaust passage 65 and the port 63 of the valve lifter 49. During the operation of the release valve 45, the relay valve 44 is also operated, and the variable pressure chamber 52 is connected to the exhaust passage 64 and the chamber.
Although the variable pressure chamber 52 is disconnected from the pressure chamber 30 of the power cylinder portion 21 by the switching valve portion 24, the relay valve 44 operates in the power cylinder portion 21 though it is opened to the atmosphere via 61, 62 and the port 63. It has no effect.

Therefore, the relay valve 44 and the release valve 45 are the second
If the clutch has hysteresis characteristics H ₁ and H ₂ as shown in the figure, the clutch is shown in FIG. 2 as points A ₀ , A ₁ , A ₂ and A ₂ .
It is controlled according to the characteristics of ₃ , A ₄ , and A ₀ . That is, the control when releasing the clutch is performed by the hysteresis characteristic (A ₀ , A ₁ , A ₂ ) of the relay valve 44, and the control when connecting the clutch is performed by the hysteresis characteristic (A ₃ , A ₄ ,
A ₀ ).

By appropriately selecting the increase path (A _{1 to} A ₂ ) of the hysteresis loop H ₁ of the release valve 44 and the decrease path (A _{3 to} A ₄ ) of the hysteresis loop H ₂ of the release valve 45, the clutch pedal Various hysteresis of operating force can be set.

Further, in the above embodiment, the switching valve portion 24 is provided with the piston 69 operated by the oil liquid of the master cylinder 91, and the check valve 7 is operated by operating the piston 69.
A valve is employed that activates 0, 71, thereby selectively connecting the conduits 86, 87 to the conduit 89. However, in the present invention, the invention is not limited to such a valve, the operation of the master cylinder 91 is detected, the electromagnetic valve is operated based on the detection signal, and the conduit 86, 8 is operated by the electromagnetic valve.
You may choose to select 7.

Further, in the switching valve section 24 of the above-mentioned embodiment, two check valves 70 and 71 are adopted.
Is normally opened. With this configuration, it is possible to improve the responsiveness when the compressed air in the pressure chamber 30 is discharged. However, in the present invention, both check valves 70 and 71 may be closed in the normal state of the switching valve portion 24.

g. Effect of the Invention As described above, the clutch booster according to the present invention appropriately eliminates the hysteresis by setting the hysteresis characteristic of the relay valve alone and the hysteresis characteristic of the release valve alone. It is possible to increase the reaction force when the clutch is engaged, and thus the feeling of operating the clutch pedal can be improved.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the clutch booster according to the present invention, FIG. 2 is an input / output characteristic diagram showing hysteresis of the device, and FIG. 3 is hysteresis of the clutch body side. FIG. 4 is a characteristic diagram, FIG. 4 is a system diagram of a clutch operation conventionally performed, FIG. 5 is a cross-sectional view showing a control valve of a conventional clutch booster, and FIG. 6 shows an operating state of the control valve. FIG. 20 …… Clutch booster, 21 …… Power cylinder, 22
...... Hydraulic cylinder part, 23 ...... Control valve part, 24 ...... Switching valve part, 25 ...... Housing, 27 ...
… Power piston, 30 …… Pressure chamber, 32 …… Relay piston, 33 …… Push rod, 34 …… Output rod, 41 ……
Oil liquid port, 42 ... first passage, 44 ... relay valve,
45 …… Release valve, 46,47 …… Valve element, 48,49 …… Valve lifter, 48d, 49d …… Valve seat, 50,51 …… Pneumatic chamber, 52,53
...... Transformer room, 54,55 ...... Hydraulic room, 56 ...... Second passage, 57,
58 …… compression spring, 59, 60 …… valve seat, 61, 62 …… chamber,
63 …… Port, 64,65 …… Exhaust passage, 66,67 …… Compression spring, 69 …… Piston, 69a, 69b …… Piston rod, 70,71 …… Check valve, 72,73 …… Ball, 74 , 7
5 …… Spring, 76 …… Input side chamber, 77 …… Output side chamber, 7
8 …… Input side chamber, 79 …… Output side chamber, 80 …… Orifice, 8
1,82 …… Pressure chamber, 83 …… Passage, 84 …… Pipe, 85 …… Air reservoir, 86,87 …… Pipe, 88 …… Passage, 89,90 …… Pipe, 91 …… Master cylinder , 91a …… Clutch pedal.

Claims (1)

[Scope of utility model registration request] 1. When the master cylinder is in a non-operating state, the valve body shuts off the air pressure chamber and the variable pressure chamber, the variable pressure chamber is communicated with the atmosphere, and the master cylinder is stepped on so that the valve lifter acts as an urging force of a spring. And a release valve, which activates the valve body by the valve lifter to operate the valve body by the valve lifter to communicate the pneumatic chamber with the variable pressure chamber and shuts off the variable pressure chamber from the atmosphere. Of the relay valve is set to be larger than the biasing force of the relay valve to the valve lifter, and the variable pressure chamber of the relay valve and the variable pressure chamber of the release valve are selectively powered via a switching valve. In addition to communicating with the cylinder, the switching valve is linked to the master cylinder, and the switching valve responds to the pressure increasing operation of the master cylinder. The relay chamber of the relay valve is communicated with the power cylinder, and the variable chamber of the release valve is communicated with the power cylinder in response to a depressurizing operation of the master cylinder. .