JP2910209B2 - Clutch shock torque prevention valve - Google Patents

Description

The present invention relates to a clutch anti-shock torque valve.

(B) Conventional technology In a manually operated vehicle, when shifting gears, the clutch pedal is depressed to temporarily disconnect the connection between the engine and the transmission, and the shift lever is operated to change the gear ratio of the gear. Thereafter, a series of shift operations of releasing the depression of the clutch pedal and restoring the connection between the engine and the transmission are performed.
If the clutch is not properly returned among these operations, the so-called clutch shock torque causes the engine to stop, the vehicle to be shocked, or the clutch to wear abnormally. Tokiko 46-6242
Japanese Patent Application Laid-Open Publication No. H11-163873 discloses that after depressing a clutch pedal to apply hydraulic pressure from the master cylinder to the operating cylinder to disengage the clutch, switch the transmission gear, and then move the operating cylinder at an appropriate speed when the clutch pedal is released. A throttle valve mechanism is shown. As a result, the throttle effect can be obtained only when the hydraulic fluid flows from the operating cylinder side to the master cylinder side, the shock torque of the clutch can be prevented, and the clutch can be connected smoothly.

In order to achieve a similar object, a needle valve having a cylindrical cylinder body, a valve body having one end fixed to the other end thereof, and a cross-sectional area of a shaft gradually changing at the other end side, is provided. There is a throttle mechanism in which an inner diameter portion is slidably fitted to a diameter portion and an outer diameter portion is slidably fitted to a cylinder body, and a piston forms a liquid passage together with a needle valve. In this throttle mechanism, the cross-sectional area of the throttle gradually changes as the piston moves with respect to the needle valve. In this case, the same effect as above can be obtained.

(C) Problems to be Solved by the Invention However, according to the above-described conventional shock torque prevention mechanism of the clutch, after depressing the clutch pedal to disengage the clutch, performing a shift operation, and then releasing the depression of the clutch pedal, However, since the return hydraulic fluid is throttled by the throttle mechanism even after the clutch is engaged and before the clutch pedal returns to the initial position, there is a problem that it takes a long time to return and the operability is poor.
An object of the present invention is to solve such a problem.

(D) Means for Solving the Problems According to the present invention, the liquid passage is narrowed most from the position where the clutch starts to be engaged to the position where the clutch is ended to the extent necessary for preventing the occurrence of shock torque. Solves the above problem by preventing the liquid passage from being restricted. That is, the present invention provides a shock torque prevention valve disposed in a hydraulic circuit between a master cylinder (4) operated by a clutch pedal (2) and an operating cylinder (8) for operating a withdrawal lever (10). (6) wherein a cylindrical chamber (12
b) having a cylinder body (12) and a cylindrical chamber (12
b) It is fixed to the cylinder body (12) and the piston (16) which is slidably fitted inside and separates it into two liquid chambers of the first liquid chamber (6a) and the second liquid chamber (6b). And a spring (18) for pushing the piston (16) toward the second liquid chamber (6b). The first liquid chamber (6a) is connected to the master cylinder (4). The second liquid chamber (6b) is connected to the operating cylinder (8),
The piston (16) is provided with a through hole (16a) for communicating the two liquid chambers (6a, 6b) with each other.
The valve body (14a) of 4) is intended to extend into the through hole (16a), and the shaft of the valve body (14a) fitted to the piston (16) of the needle valve (14) is used. A stepped portion (14d) for discontinuously changing the orthogonal cross-sectional area so as to decrease on the tip side is formed.

Note that a buffer member (22) made of a soft material such as rubber may be provided at a position where the piston (16) in the first liquid chamber (6a) faces the needle valve (14). In addition, the code | symbol in a parenthesis shows the corresponding member of an Example.

(E) Action When the clutch pedal (2) is depressed from the state where the clutch is disengaged by depressing the clutch pedal (2), the hydraulic fluid from the operating cylinder (8) passes through the shock torque prevention valve (6). To return to the master cylinder (4). When the clutch pedal (2) is released rapidly, the first liquid chamber (6a) of the cylinder body (12) is released.
Since the inside is negative pressure, the first liquid chamber (6a) and the second liquid chamber (6b)
The piston (16) compresses the spring (18) due to the pressure difference between the needle valve (14) and the valve body (14a) of the needle valve (14) while compressing the spring (18). Move in the direction The fluid passage is most narrowed at the position where the stepped portion of the needle valve (14) is in the through hole (16a) of the piston (16). Hold for a while. When the clutch is completely engaged, the pressure difference before and after the throttle becomes small, the piston (16) moves, and the through hole (16a) of the piston (16) comes out of the stepped portion to a related position. As a result, the throttle area increases, and the hydraulic fluid remaining in the operating cylinder (8) can quickly return to the master cylinder (4), and the clutch pedal (2) can quickly return to the initial position. ,
There is no loss of operability.

(F) Embodiment FIG. 1 shows an embodiment of the present invention. The operation of the clutch pedal 2 is transmitted to the master cylinder 4 connected thereto, and the hydraulic fluid sent out therefrom flows into the operating cylinder 8 through the shock torque prevention valve 6. One end of a withdrawal lever 10 is connected to the operating cylinder 8.
The other end of 10 is connected to a clutch (not shown). The cylinder body 12 constituting the shock torque prevention valve 6 is
It is formed in a tubular shape having a small-diameter hole 12a and a larger-diameter hole 12b, and a connection port 12c is provided at one end thereof to communicate with the small-diameter hole 12a. The needle valve 14 has a valve body 14a having a stepped portion 14d at one end, a flange 14c at an intermediate portion, and a small-diameter hole in the cylinder body 12 at the other end. Fixed to 12a. The valve element portion 14a on one end side of the needle valve 14 has a shape in which a part of the shaft is cut off in the stepped portion 14d in the axial direction in parallel with the axis. The other end of the needle valve 14 and the outer diameter of the collar portion 14c are partially cut away in the axial direction to form a flow path 14b. The collar portion 14c of the needle valve 14 is fitted into the hole 12b of the cylinder body 12. Furthermore, the hole 12b of the cylinder body 12
The outer diameter portion of a piston 16 formed in a double cylindrical shape is slidably fitted to the piston. The through hole 16a inside the piston 16 is slidably fitted in the valve body 14a of the needle valve 14. As the piston 16 moves with respect to the needle valve 14, the throttle area of the liquid passage formed by the valve body 14a of the needle valve 14 and the through hole 16a of the piston 16 changes stepwise. . Needle valve 14
A cushioning member 22 made of a soft material such as rubber is disposed between the flange 14c and the left end of the piston 16 in the drawing. The collar portion 14c of the needle valve 14 functions as a stopper member that regulates the rightward stroke of the piston 16 in the drawing. That is, the buffer member 22 comes into contact with the flange portion 14c, and the buffer member 22
The minimum throttle area of the liquid passage is determined in a state where the left end of the piston 16 in the figure contacts the piston 16. A spring 18 is arranged between the collar portion 14c of the needle valve 14 and the cylindrical hole of the piston 16. Spring 18 is a piston
16 is pushed in the direction to increase the drawing area in the right direction in FIG. The space in which the spring 18 is arranged forms the first liquid chamber 6a. A female screw is provided on the right end side of the cylinder body 12 in the figure, and a joint 20 having a connection port 20a is provided on the female screw.
Is screwed. In FIG. 1, the left end of the joint 20 is
The piston 16 also serves as a positioning member for setting a right stop position in the drawing. A second liquid chamber 6b is formed between the joint 20 and the piston 16 so that the hydraulic fluid flowing from the operating cylinder 8 presses the right end of the piston 16 in the drawing. The inner diameter of the cylinder body 12 and the joint
A seal member 24 is provided between the outer diameter portion of the screw 20 and the cylinder body 12. The cylinder body 12 is fixed to a vehicle body (not shown) by a bracket 26.

Next, the operation of this embodiment will be described. When the clutch pedal 2 is depressed for shifting, the piston of the master cylinder 4 is pushed and the hydraulic fluid is discharged. The discharged hydraulic fluid flows into the first liquid chamber 6a from the connection port 12c of the shock torque prevention valve 6 via the flow path 14b, and pushes the piston 16 to the right position in the drawing to push the piston body 16a to the valve body 14a of the needle valve 14. 16 through holes 16a
Then, the throttle of the liquid passage formed by the above is opened, and the liquid flows into the operating cylinder 8 from the connection port 20a through the second liquid chamber 6b. By this liquid pressure, the piston of the operating cylinder 8 is pushed rightward in the figure, and the withdrawal lever 10 is pushed rightward in the figure. As a result, the clutch (not shown) is disengaged, and the shift gear is switched by operating the shift lever (not shown). After the switching is completed, when the depression of the clutch pedal is released, the withdrawal lever 10 is pushed leftward in the figure by the return spring of the clutch (not shown), and the piston of the operating cylinder 8 is pushed in the same direction. Also, the piston of the master cylinder 4 is about to be returned to the initial position by the return spring (not shown). At this time, if the release of the clutch pedal 2 is sudden,
Since the inside of the first liquid chamber 6a of the cylinder body 12 has a negative pressure, the piston 16 is pushed leftward in the drawing against the force of the spring 18 due to the differential pressure between the first liquid chamber 6a and the second liquid chamber 6b. And stepped part 14d
Is located in the through hole 16a, and the restriction of the liquid passage is reduced. As a result, the hydraulic fluid returns to the master cylinder 4 through the flow path 14d while adjusting the flow rate. By doing so, the movements of the piston of the operating cylinder 8 and the withdrawal lever 10 become gentle, and the generation of the shock torque of the clutch can be prevented, so that the clutch can be connected smoothly. After the connection of the clutch is completed, the pressure difference before and after the throttle rapidly decreases, and in response to this, the piston 16 is pushed by the spring 18 and quickly returns to the position shown in the drawing, and the throttle area of the liquid passage rapidly increases. The working fluid remaining in the operating cylinder 8 can return to the master cylinder 4 quickly. As a result, the clutch pedal 2 can return to the initial position quickly, and does not impair operability. When the pressure difference before and after the throttle is large, the piston 16 collides with the needle valve 14 via the buffer member 22, so that
Low noise due to collision. Also, valve body
Since 14a is formed in a shape having a stepped portion 14d,
Even if the thickness of the buffer member 22 becomes smaller due to repeated collisions, the diaphragm area does not change, so that stable characteristics can be maintained.

In this embodiment, the stepped portion 14d is provided only in one stage. However, as long as the return performance of the clutch pedal 2 can be improved, the stepped portion 14d is provided in two or more stages so that the throttle characteristic can be adjusted according to the stroke of the piston 14. May be changed.

(G) Effects of the Invention As described above, according to the present invention, it is possible to prevent the generation of shock torque by surely restricting the liquid passage of the shock torque prevention valve from the start to the end of engagement of the clutch. After the clutch has been connected, the liquid passage can be opened and the clutch pedal can be quickly returned to the initial position, so that operability is not hindered.

[Brief description of the drawings]

FIG. 1 is a sectional view of a clutch anti-shock valve according to an embodiment of the present invention. 2 ... clutch pedal, 4 ... master cylinder, 6 ...
Clutch anti-shock valve, 6a ... first liquid chamber, 6b ... second
Liquid chamber, 8 Operating cylinder, 12 Cylinder body, 14 Needle valve, 14d Stepped part, 16
… Piston, 16a …… Through hole, 18 …… Spring, 22…
... A cushioning member.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16D 25/08-25/14

Claims (2)

(57) [Claims] An anti-shock torque valve disposed in a hydraulic circuit between a master cylinder operated by a clutch pedal and an operating cylinder for operating a withdrawal lever, having a cylindrical chamber therein. A cylinder body, a piston which is slidably fitted into a cylindrical chamber and divides the two into a first liquid chamber and a second liquid chamber, a needle valve fixed to the cylinder body, and a piston. A spring pushing in the direction of the second liquid chamber;
And the first liquid chamber is connected to the master cylinder,
The second fluid chamber is connected to the operating cylinder, and the piston is provided with a through hole for communicating the two fluid chambers with each other, and the valve body of the needle valve extends into the through hole. A shock torque prevention valve for a clutch, characterized in that a stepped portion is formed in a body portion so as to discontinuously change an axial cross-sectional area of the body portion so as to decrease on a tip end side. 2. The anti-shock torque valve for a clutch according to claim 1, wherein a buffer member is provided at a position in the first liquid chamber where the piston and the needle valve face each other.