JPH0349082Y2 - - Google Patents

Description

[Detailed description of the invention] (1) Industrial application field This invention relates to a bypass device for a mechanical anti-lock device for a vehicle.

(2) Prior art A flywheel is attached to the camshaft of an anti-lock device that interlocks with the axle, and the speed difference between the rotation of the axle and the rotation of the flywheel during sudden deceleration is sensed, and the system detects when the wheels are locked or when the wheels are about to lock. Mechanical antilock devices that allow escape from dangerous situations are known in the art (for example, in Japanese Patent Application Laid-Open No.
(See Publication No. 55-36186).

(3) Problems that the invention aims to solve When a vehicle equipped with the above-mentioned device starts suddenly on an uphill road with a low coefficient of road friction, the driver depresses the accelerator and, with the wheels slipping, releases the accelerator and applies sudden braking. If this happens, the braking force will drop significantly, and the vehicle may move backwards some distance before the braking force is restored and the vehicle stops.

This phenomenon is caused by the fact that the relationship between the wheels and the brake system is the same as the wheel lock state during sudden deceleration, so the anti-lock device operates and temporarily releases the brakes.

Therefore, the purpose of this invention is to solve the problem of reduced braking force in the above situations.

(4) Means to solve the problems In order to solve the above problems, this invention
A check valve that closes in the direction of applying brake fluid pressure and a pressing member that operates the check valve in the opening direction are provided in the middle of a bypass path that short-circuits the inlet and outlet of the brake fluid of the mechanical anti-lock device. A friction clutch plate is interposed between the driven member of the ramp end ball device attached to the main shaft interlocking with the axle and the pressing member.

In addition, in this invention, the ramp end ball device is composed of a driving member fixed to the main shaft, a driven member loosely inserted around the main shaft, and a ball interposed between both members. A hemispherical recess into which the ball fits is formed in the drive member, and an inclined groove into which the ball fits into the driven member.

The above-mentioned inclined groove gradually becomes shallower in one direction from the end wall at the deepest part until it reaches the end wall at the shallowest part, and the driven member moves in the axial direction by the difference between the shallowest part and the deepest part.

(5) Effect In the above device, when the vehicle is moving forward, the main shaft that is linked to it rotates in the normal direction, so the ramp end ball device is not bound to the pressing member due to the friction clutch plate slipping. . The ramp end ball device therefore rotates with the main shaft and has no effect on the bypass path.

If the vehicle backs up with or without the driver's will, the ramp end
The drive member of the ball device rotates in reverse together with the main shaft,
Since the driven member receives resistance from the friction clutch plate, it does not immediately rotate in reverse as one unit, but the balls move toward the shallower side of the inclined groove, and this movement causes the driven member to move in the axial direction. As a result, the pressing member integrated therewith also moves to open the check valve of the bypass passage.

When the ball engages with the end wall of the shallowest portion of the inclined groove, the driven member slips on the surface of the friction clutch and rotates in reverse together with the driving member.

(6) Embodiment In the embodiment shown in the drawings, the bypass device of this invention is integrated into a mechanical anti-lock device.The main shaft of the device uses the camshaft 1 of the anti-lock device, and the bypass path 2 An example is shown in which the anti-lock device is configured in the main body 3 of the anti-lock device.

That is, an inlet 4 and an outlet 5 of the bypass passage 2 are formed in the main body 3, a valve chamber 6 is provided inside the main body 3, and a check valve 7 is incorporated in the valve chamber 6. This check valve 7 is biased in a direction to prevent flow from the inlet 4 to the outlet 5, and in a normal state closes the valve hole 8 from one side. Further, on the opposite side of the valve hole 8, a blockage release pin 10, which is a component of the pressing member 9, is slidably inserted while maintaining liquid tightness.

The pressing member 9 is made up of the above-mentioned pin 10, a pressing plate 11 that supports the pin 10, and a pressing plate 11.
The press plate 11 is slidably guided by the guide pin 12 provided in the main body 3 and the press plate 11.
A spring 13 interposed therebetween normally biases the blockage release pin 10 in a direction away from the check valve 7.

A ramp end ball device 14 is attached to the cam groove 1 mentioned above. This device 14 is
A driving member 15 fixed to the camshaft 1, a driven member 16 opposing the driving member 15 and slidably and rotatably inserted through the camshaft 1, and both members 15, 1.
6 and a ball 17 interposed between balls 17. As shown in FIG. 2, the driving member 14 is formed with a hemispherical recess 18 into which the ball 17 is fitted, and the driven member 16 is formed with an inclined groove 19 into which the ball 17 is fitted.
is formed. In FIG. 2, arrow a indicates the forward rotation direction of the camshaft 1, and arrow a' indicates the reverse rotation direction, but the inclined groove 19 of the driven member 16 has the end wall 20 in the normal rotation direction at its deepest point. The end wall 21 in the reverse direction is the shallowest part.

A friction clutch plate 22 is interposed between the driven member 16 and the pressing plate 11.

Now, if the vehicle moves forward and the camshaft 1 rotates in the normal direction, the driving member 15 and the driven member 16 of the ramp end ball device 14 are integrated via the ball 17, and the driven member 16 is connected to the friction clutch plate. 22, both members 15 and 16 rotate together.

Further, when the vehicle moves backward and the camshaft 1 reverses, the driving member 15 reverses, but the driven member 16 does not reverse because it receives resistance from the friction clutch plate 22. As a result, the ball 17 moves to the shallower direction of the inclined groove 19, so the driven member 16 moves in the axial direction, and the clutch plate 22 and the pressing plate 1, which are integral with the driven member 16, move in the axial direction.
1. The unblocking pin 10 overcomes the biasing force of the spring 13 and moves. As a result, the pin 10 pushes the check valve 7 and opens its valve hole 8, so that a bypass path 2 is formed and the brake fluid pressure generated in the master cylinder is immediately transmitted to the brake circuit.

The embodiment of this invention described above is incorporated into a mechanical anti-lock device, and it is convenient that the camshaft 1 of the device can be shared, but the device of this invention does not necessarily need to be incorporated into such a device. There is no problem with it, and it can be independent from the same device.

The illustrated mechanical anti-lock device is conventionally known, so its contents will only be outlined below to the extent necessary for understanding the invention.

First, in FIG. 1, an eccentric cam 24 is attached to the camshaft 1 in a cam chamber 23 inside the main body 3, and a flywheel 26, a friction clutch plate 27 and a ball An end lamp device 28 is attached, and the lever 25 is supported by a pivot pin 29, and one end thereof is connected to the valve body 3 of a dump valve 30.
It is in contact with one end of 1.

The ball end lamp device 28 described above has the same structure except that the mounting positions of the driving member 32 and the driven member 33 are opposite to those described above,
When a difference occurs between the rotational speeds of the camshaft 1 and the flywheel 26, the ball 34 moves into the inclined groove 35 (Fig. 3).
, and the flywheel 26 is moved in a direction approaching the main body 3.

Note that 36 in FIG. 1 represents an axle, and 37 represents a timing belt.

The above dump valve 30, as shown in FIG.
It is interposed between a communication passage 40 between the pump piston chamber 38 and the expander piston chamber 39, and normally the communication passage is blocked, but when the wheels suddenly decelerate, the dump valve 30 operates to open the communication passage 40. .

As shown in FIG. 4, the main body 3 is provided with an inlet 41 communicating with the master cylinder and an outlet 42 communicating with the brake circuit. This entrance 41 and exit 4
2 are short-circuited by the aforementioned bypass path 2.

The pump piston chamber 38 is a first chamber 4 that communicates with the connection port 43 with the reservoir tank and the dump valve 30.
4 and the seal 46, 4 of the pump piston 45 itself.
Second chamber 48 and third chamber 4 divided by 7
9, the second chamber 48 communicates with the expander piston chamber 39, and the third chamber 49 communicates with the inlet 41 mentioned above. A passage 50 communicating with the first chamber 44 and the second chamber 48 is formed inside the pump piston 45, and a check valve 51 is provided in the middle of the passage 50. Further, the tip of the pump piston 45 faces the aforementioned cam chamber 23.

A cut-off valve 53 is provided between the master cylinder fluid inlet 41 and the brake circuit outlet 42 to cut off and release the brake fluid. Under normal conditions, the expander piston 52 is biased by a spring 54. Therefore, the cutoff valve 53 is open. Therefore, the brake fluid pressure generated in the master cylinder is supplied as is to the brake circuit.

However, when the vehicle is suddenly decelerated, the dump valve 30 is opened due to the above-mentioned movement of the flywheel 26, so the hydraulic pressure inside the expander piston chamber 39 decreases, and the expander piston 52 is activated to release the cutoff. Since valve 53 is shut off, the brake is released.

Furthermore, due to the cut-off valve 53 being shut off, the balance between the hydraulic pressure acting on the pump piston second chamber 48 and the hydraulic pressure acting on one end of the pump piston 45 is disrupted, and the tip of the pump piston 45 comes into contact with the eccentric cam 24. , the pump piston 45 is connected to the eccentric cam 2
It reciprocates according to the rotation of 4.

On the other hand, when the brake is released, the rotational speed of the camshaft 1 increases, and eventually the flywheel 26 returns to its original position due to the action of the ramp end ball device 28, and the dump valve 30 is closed again. When the dump valve 30 is closed and the pump piston 45 reciprocates as described above, the pump piston 45 opens the check valve 51 when moving toward the cam chamber 23 side, sucks liquid from the reservoir tank, and moves the pump piston 45 toward the cam chamber 23 side. When the expander piston 52 moves in the direction of exiting from the expander piston, the check valve 51 is closed to increase the hydraulic pressure in the expander piston chamber 39, and the expander piston 52 is pushed back. As a result, the hydraulic pressure in the brake circuit also rises, and when the brake hydraulic pressure reaches a certain level, the above-described anti-lock operation is repeated again, and thereafter the same operation is repeated to gradually reduce the speed of the vehicle.

Note that when the brake pedal is released, the expander piston 52 is pushed back to its original position by the force of the spring 54, and at this time the cut-off valve 53 is opened to prepare for the next brake operation.

(7) Effect Since this device is a bypass device attached to the mechanical anti-lock device as described above, when the vehicle is backing up, the bypass path can be opened and the anti-lock function can be lost. This has the effect of securing braking force.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the embodiment, FIGS. 2 and 3 are partial cross-sectional views of the lamp end ball device, and FIG. 4 is a cross-sectional view of the device of FIG. 1 at another location. DESCRIPTION OF SYMBOLS 1...Cam shaft, 2...Bypass path, 3...Main body, 4...Inlet, 5...Outlet, 6...Valve chamber, 7...
...Check valve, 8... Valve hole, 9... Pressing member, 14...
...Ramp end ball device, 15...Driving member, 16...Driven member, 17...Ball, 18
... recess, 19 ... inclined groove, 20, 21 ... end wall, 22 ... friction clutch plate.

Claims (1)

[Scope of utility model registration request] A flywheel is mounted via a ramp-end ball arrangement and a friction clutch to a rotating member interlocking with the axle, the flywheel having an inlet communicating with the vehicle's master cylinder and an outlet communicating with the vehicle brake; When the speed of the rotating member falls below the speed of the flywheel, the passage between the inlet and the outlet is blocked to reduce the brake fluid pressure of the vehicle brake, and conversely, when the speed of the rotating member exceeds the speed of the flywheel. In a mechanical antilock device having a hydraulic pressure control means that repressurizes the brake fluid pressure of the wheel brake, there is a bypass path that short-circuits the above-mentioned inlet and outlet. A stop valve and a pressing member for operating the check valve in the opening direction are provided, and a friction clutch plate is interposed between the driven member of the ramp end ball device mounted on the main shaft interlocking with the axle and the pressing member. Mechanical anti-lock device bypass device.