JPS631642Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a brake fluid pressure holding device.

In automobiles, a hydraulic pressure holding valve is used in the brake hydraulic circuit between the master cylinder and the wheel cylinder in order to easily maintain the brakes on a slope and start on a slope (for example, (See 1982-34550, 1982-83557, 1982-111059, etc.).

Generally, as shown in Fig. 1, the hydraulic pressure holding valve has a ball B loosely installed in the brake hydraulic pressure passage A' of the main body A, and the ball B is held in place by a push rod D that is linked to the clutch operation so that the clutch pedal is not depressed. In the clutch-on state, ball seat C
For example, when the brake pedal and the clutch pedal are depressed on an uphill road to bring the brake into a braking state, the push rod D is retracted from the ball seat C in conjunction with the depression of the clutch pedal. , ball B rolls backwards and comes into contact with ball seat C, and even if the brake pedal is released in this state, if the clutch pedal is depressed, ball B will come into contact with ball seat C and move out of the path.
A' is closed, and the braking state can be maintained without the hydraulic pressure supplied to the wheel cylinder W/C being drained to the reserve tank side of the master cylinder M/C.

Also, if you gradually release the clutch pedal while depressing the accelerator pedal from the brake holding state, the clutch will gradually engage and at the same time the push rod D will be released.
moves forward to separate the ball B from the ball seat C, and the hydraulic pressure in the wheel cylinder W/C section is released, making it possible to easily start on a slope.

In the above, the interlocking mechanism between the clutch pedal and the push rod D has a structure in which the lever F fixed to one end of the camshaft E rotatably mounted inside the main body A and the clutch pedal are connected by a cable. Normally, the lever F is biased with a rotating force in the direction of the arrow in Fig. 1 by a spring for releasing the holding fluid pressure (not shown), and when the clutch pedal is depressed, the spring force of the spring for releasing the holding fluid pressure is applied. Against this, the lever F rotates counterclockwise in the figure, and as the cam portion E' of the camshaft E is displaced to the right in the figure, the push rod D moves to the right in the figure and is retracted from the ball seat C, causing the clutch to close. When you take your foot off the pedal, the lever F and camshaft E turn clockwise in the figure due to the spring force of the retaining fluid pressure release spring, and the push rod D is pushed by the cam part E' and moves to the left side in the figure. It moves and protrudes from the ball seat C and returns to the state shown in the first diagram.

The above-mentioned retaining fluid pressure release spring releases ball B against at least the retaining fluid pressure acting on ball B.
Needless to say, it must have a spring force that allows it to move forward.

In automobiles equipped with the brake fluid pressure retention device as described above, the depression force on the clutch pedal is approximately the same as the force required to release the retained fluid pressure, that is, the above-mentioned retained fluid pressure. It becomes heavier by the spring reaction force of the release spring. Therefore, in order to reduce the clutch pedal depression force, it is sufficient to reduce the force required to release the retained fluid pressure as much as possible.

The force required to release the retained fluid pressure is determined by the magnitude of the retained fluid pressure and the diameter of the opening of the ball seat C, that is, the seal diameter.If the retained fluid pressure is constant, the smaller the seal diameter is, the smaller the force is. .

However, in the conventional device, as shown in Fig. 1, the push rod D penetrates through the opening of the ball seat C, so the diameter of the opening of the ball seat C cannot be made very small, and the retained liquid pressure There is a problem in that the spring force of the release spring must be quite large, and therefore the pressing force on the clutch pedal becomes quite heavy.

The present invention aims to solve the above-mentioned conventional problems, and the present invention will be described below with reference to the embodiments shown in FIGS. 2 and 3.

In FIG. 2, reference numeral 1 denotes a cylindrical main body, and a ball 3 is rotatably mounted in a brake hydraulic pressure passage 2 inside.

A sliding piece 4 is fitted to the rear end of the brake hydraulic pressure passage 2 so as to be slidable in the front-rear direction, and the sliding piece 4 is fitted with an inlet 6 at the rear of the sliding piece 4 and the brake hydraulic pressure passage. 2 is formed, and a ball seat 42 is provided at the front end of the sliding piece 4. When the brake pedal (not shown) is depressed, braking fluid pressure is applied from the inlet part 6 to the sliding piece 4. 4 communication path 41
It enters the sliding hydraulic pressure passage 2 through it, and from there it is supplied to the wheel cylinder through outlets 7a, 7b.

5 is a camshaft, and a lever 51 fixed to the camshaft 5 is a clutch pedal (not shown).
It is connected by a connecting member such as a cable, and is configured to rotate in conjunction with clutch pedal operation, and to slide the sliding piece 4 in the front-rear direction as the cam portion 52 is displaced in the front-rear direction.

8 is a spring that biases the sliding piece 4 in the direction of retreating.

In the above configuration, when the brake pedal and the clutch pedal are depressed on an uphill road to bring the brake into a braking state, the sliding piece 4 is pressed by the camshaft 5 linked to the clutch operation and slides forward to the forward position, and the ball 3 The ball 3 rolls backward on the slope of the uphill road, and as shown in FIG.
occlude.

Even if the brake pedal is released in this state, as long as the clutch pedal is depressed, the hydraulic pressure supplied to the wheel cylinders is maintained and the braking state can be maintained.

When the clutch pedal is gradually released from the brake holding state while depressing the accelerator pedal, the clutch is gradually engaged, and at the same time, the sliding piece 4 is released via the camshaft 5 by the spring force of the holding fluid pressure release spring (not shown). The ball 3 gradually retreats and stops when it comes into contact with the rear end surface of the passage 2.
The ball 3 is separated from the ball seat 42 and connected to the communication path 4.
1 is opened, the brake fluid pressure in the wheel cylinder section is released, and it is possible to start on a slope easily.

As described above, the present invention has a structure in which a communicating passage to be sealed is formed in the sliding piece, which corresponds to a conventional push rod, so that the retained liquid pressure acts in the direction of pushing back the sliding piece, so that the retained liquid pressure is reduced. The force required for release can be significantly reduced, and the setting value of the spring output of the retaining fluid pressure release spring can be made extremely small, completely eliminating the conventional drawback of the clutch pedal having to be pressed too hard. This is something that can be solved and can bring about great practical effects.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional explanatory view showing a conventional brake hydraulic pressure holding device, Fig. 2 is a cross-sectional view showing an embodiment of the present invention, and Fig. 3 is a cross-sectional view of main parts showing the operating state of the device shown in Fig. 2. . DESCRIPTION OF SYMBOLS 1... Main body, 2... Braking hydraulic pressure passage, 3... Ball, 4... Sliding piece, 41... Communication path, 42... Ball seat, 5... Camshaft, 6... Inlet part, 7a, 7b...Exit part, 8...Spring.

Claims (1)

[Scope of utility model registration request] A sliding piece in which a ball is freely installed in the brake hydraulic pressure passage of the cylindrical body so as to be movable in the longitudinal direction, and the rear end of the brake hydraulic pressure passage has a communication passage inside and a ball seat at the front end. When the brake is operated, the brake fluid pressure enters the brake fluid pressure passage from the inlet of the main body through the communication passage of the sliding piece, and is supplied from this to the wheel cylinder. When the clutch pedal is depressed, the sliding piece is held in a forward position where the ball contacts the ball seat and the communication path is closed, and when the clutch pedal is released, the clutch is moved forward. A brake hydraulic pressure holding device characterized by being provided with a camshaft that slides a sliding piece to a rear position where the ball is separated from the tip ball seat.