JPH0349083Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a bypass device for a mechanical anti-lock device for a vehicle.

[Prior art] A flywheel is attached to the camshaft of an anti-lock device that works 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 a dangerous situation where the wheels are locked or on the verge of locking. Mechanical anti-lock devices designed to escape from the state are known in the art (for example, Japanese Patent Application Laid-Open No. 55-36186
(see publication).

[Problem that the invention attempts to solve]

When a vehicle equipped with the above device starts suddenly on an uphill road with a low coefficient of road friction, if you press the accelerator and the wheels slip and then release the accelerator, the braking force will drop significantly and the braking force will not recover. The vehicle may move back approximately 1 to 2 meters before coming to a stop.

This phenomenon occurs when there is a difference between the rotation speed of the axle and the rotation speed of the flywheel of the anti-lock device, resulting in a state similar to that of wheel lock, which causes the anti-lock device to operate and temporarily release the brake. This is due to

Therefore, this invention attempts to prevent the above dangerous situation from occurring by preventing the anti-lock device from operating when the vehicle is reversing.

[Means for solving problems]

In order to solve the above problems, this invention provides an on-off valve for the bypass path that short-circuits the inlet and outlet of the brake fluid of the mechanical anti-lock device, and a valve that is connected to the on-off valve. The member is fitted around a main shaft that interlocks with the axle, a female thread is formed in the fitting hole of the opening/closing member, and a shaft part that loosely fits the female thread on the main shaft, and a main shaft reversible part is provided at one end of the shaft part. The valve opening/closing member is configured to have a male threaded portion that is threadedly engaged with the female thread to move the valve opening/closing member in the valve opening direction.

[Effect]

In the above device, when the shaft is moving forward, the main shaft that is interlocked with the shaft rotates in the normal direction, so the valve opening/closing member is not coupled to the main shaft. Therefore, the valve opening/closing member maintains the opening/closing valve of the bypass passage in a closed state.

In addition, if the vehicle backs up with or without the driver's will, the main shaft will reverse, so the female thread of the valve opening/closing member will fit into the male thread of the main shaft and move along the axis of the main shaft. and move it in the valve opening direction to open the bypass path.

〔Example〕

In the embodiment shown in the drawings, the bypass device of this invention is integrated into a mechanical anti-lock device. An example of the configuration is shown below.

That is, an inlet 4 and an outlet 5 of the bypass passage 2 are formed in the main body 3, and the bypass passage 2 is
A valve seat 6 is provided in the middle of the valve seat 6, and an on-off valve 7 that approaches and separates from the valve seat 6 is incorporated therein. The on-off valve 7
The valve stem 8 is connected to a valve opening/closing member 9 on the outside of the main body 3.

The valve opening/closing member 9 is plate-shaped and is fitted around the camshaft 1 so that it can be moved in the length direction of the camshaft 1 by means of a guide pin 10 protruding from the main body 3. However, a first spring 12 is interposed between the collar 11 provided on the camshaft 1 and the valve opening/closing member 9, and a second spring 13 is interposed between the other surface of the member 9 and the main body 3. By setting the value to be larger than 13, the on-off valve 7 is always urged in the closing direction through the member 9 and the valve rod 8, and the bypass path 2 is closed.

Further, a female thread 14 is formed in the part of the member 9 that fits into the camshaft 1, and the female thread 14 loosely fits into the shaft portion 15 in a normal state. Furthermore, a male threaded portion 16 is formed at the outer end of the shaft portion 15. The male threaded portion 16 is screwed to the female threaded portion 14 only when the camshaft 1 is reversed. Therefore, when the camshaft 1 rotates in the normal direction, the valve opening/closing member 9 is loosely fitted to the camshaft 1, but when the camshaft 1 rotates in the reverse direction, the female screw 14 screws into the male screw portion 16. Since they are connected, the member 9 advances on the male threaded part 16 and closes the on-off valve 7.
is removed from the valve seat 6. Further, when the camshaft 1 returns to the normal rotation state while the member 9 is moving on the male threaded portion 16, the member 9 also retreats on the male threaded portion 16 and returns to its original position. If it takes a long time for the camshaft 1 to rotate in reverse, the member 9 will loosely fit around the other shaft part 15' of the camshaft 1 beyond the male threaded part 16, and
The connection with the camshaft 1 is removed, but when the camshaft 1 returns to normal rotation, it returns to its original state.

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 even if it is 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 18 is attached to the camshaft 1 in a cam chamber 17 inside the main body 3, and a flywheel 20, a friction clutch plate 31', and a ball are connected to the tip of the eccentric cam 18 via a lever 19. - The end lamp device 21 is installed,
The lever 19 is supported by a pivot pin 22, and one end thereof is in contact with one end of the valve body of the dump valve 23.

The ball end lamp device 21 described above includes a driving member 24 fixed to the camshaft 1, a driven member 25 facing the driving member 24 and slidably and rotatably inserted into the camshaft 1, and both members 24, 25
It consists of a ball 26 interposed therebetween. As shown in FIG. 2, the drive member 24 is formed with a hemispherical recess 27 into which a ball 26 is fitted.
The driven member 25 has an inclined groove 2 into which a ball 26 is fitted.
8 is formed. In FIG. 2, arrow a indicates the forward rotation direction of the camshaft 1, and arrow b indicates the reverse rotation direction, but the inclined groove 28 of the driven member 25 has the end wall 29 in the normal rotation direction at its deepest point. , the end wall 30 in the reverse direction is the shallowest part. A friction clutch plate 31 is interposed between the driven member 25 and the flywheel 20.

In the above-mentioned ramp end ball device 21, when a difference occurs between the rotational speeds of the camshaft 1 and the flywheel 20, the ball 26 moves along the inclined groove 28 and moves the flywheel 20 in a direction approaching the main body 3. urge

In addition, 31 in FIG. 1 indicates an axle, and 32 indicates a timing belt.

The dump valve 23 described above, as shown in FIG.
It is interposed between a communication passage 35 between the pump piston chamber 33 and the expander piston chamber 34.

The main body 3 is also provided with an inlet 36 communicating with the master cylinder and an outlet 37 communicating with the brake circuit. The inlet 36 and outlet 37 are short-circuited by the aforementioned bypass path 2.

The pump piston chamber 33 is a first chamber 3 that communicates with the connection port 38 with the reservoir tank and the dump valve 23.
9 and the seals 41, 4 of the pump piston 40 itself.
A second chamber 43 and a third chamber 4 divided by 2
4, the second chamber 43 communicates with the expander piston chamber 34, and the third chamber 44 communicates with the inlet 36 mentioned above. A passage 45 communicating with the first chamber 39 and the second chamber 43 is formed inside the pump piston 40, and a check valve 46 is provided in the middle of the passage 45. Further, the tip of the pump piston 40 faces the aforementioned cam chamber 17.

The expander piston 47 is provided with a cut-off valve 48 that shuts off and releases the brake fluid. Under normal conditions, the expander piston 47 is biased by a spring 49, so the cut-off valve 48 is opened. There is. Therefore,
The brake fluid pressure generated in the master cylinder is directly supplied to the brake circuit.

However, when the vehicle is suddenly decelerated, the dump valve 23 is opened due to the above-mentioned movement of the flywheel 20, so the hydraulic pressure inside the expander piston chamber 34 decreases, and the expander piston 47 is operated, causing the cut-off. Valve 48 is shut off and the brake is released.

Furthermore, by shutting off the cut-off valve 48, the hydraulic pressure acting on one end of the pump piston 40 increases, and the tip of the pump piston 40 comes into contact with the eccentric cam 24, so that the pump piston 40 reciprocates as the eccentric cam 24 rotates. Exercise.

On the other hand, when the brake is released, the rotational speed of the camshaft 1 increases, and eventually the flywheel 20 returns to its original position due to the action of the ramp end ball device 21, and the dump valve 23 is closed again. When the dump valve 23 is closed and the pump piston 40 moves reciprocatingly as described above, the pump piston 40 opens the check valve 46 when moving toward the cam chamber 17 side, sucks liquid from the reservoir tank, and moves the pump piston 40 toward the cam chamber 17. 17
When the expander piston 47 moves in the direction of exiting the expander piston, the check valve 46 is closed to increase the hydraulic pressure in the expander piston chamber 34, and the expander piston 47 is pushed back. As a result, the hydraulic pressure in the brake circuit also increases, and when the brake hydraulic pressure reaches a certain level or higher, 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 47 is pushed back to its original position by the force of the spring 49, and at this time the cut-off valve 48 is released to prepare for the next brake operation.

〔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, thereby reducing the braking force when backing up. There is a guaranteed effect.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the embodiment, FIG. 2 is a partial sectional view of the ramp-end ball device, and FIG. 3 is a sectional view of the embodiment at another position. 1...Cam shaft, 2...Bypass path, 3...Main body, 4...Inlet, 5...Outlet, 6...Valve seat, 7...
...Opening/closing valve, 9...Valve opening/closing member, 14...Female thread,
15, 15'...Shaft part, 16...Male thread part, 17
...Cam chamber, 18...Eccentric cam.

Claims (1)

[Scope of utility model registration request] A flywheel is attached to a rotating member interlocking with the axle through a ramp-end ball device and a friction clutch, the flywheel having an inlet leading to a master cylinder of the vehicle and an outlet leading to a wheel brake, the flywheel being connected to a rotating member connected to the axle through a ramp-end ball device and a friction clutch, the speed of the rotating member being controlled. When the speed of the rotating member falls below the speed of the flywheel, the communication between the inlet and the outlet is cut off 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 anti-lock device having a hydraulic pressure control means for repressurizing the brake fluid pressure of the wheel brake, an on-off valve for the bypass path is provided in the middle of the bypass path that short-circuits the above-mentioned inlet and outlet, and the above-mentioned on-off valve A valve opening/closing member connected to the valve opening/closing member is fitted around a main shaft interlocking with the axle, a female thread is formed in the fitting hole of the valve opening/closing member, and a shaft part loosely fits into the main shaft with the female thread, and the shaft. A bypass device for a mechanical anti-lock device, wherein a male screw portion is formed at one end of the portion to engage the female screw when the main shaft is reversed, thereby moving the valve opening/closing member in the valve opening direction.