JPS6136051A - Bypass apparatus of mechanical type antilock apparatus - Google Patents

Abstract

PURPOSE:To prevent the reduction of brake power due to erroneous operation by supplying the liquid pressure proportional to the stepping force for a brake pedal independently of the operation and non-operation of an antilock apparatus into a brake by opening the bypass passage of a bypass apparatus, when a car travels at a low speed. CONSTITUTION:A rotor 22 fixed onto a shaft 21 interlocked with an axle is accommodated into a housing 20 integrally or separately formed with a mechanical type antilock apparatus. A plurality of concaved parts 24 are formed onto the outer peripheral surface of the rotor 22, and an inertia body 25 is inserted in free appearance inside the concaved part. While, a concaved part 26 and a valve chamber 27 continuous to the concaved part 26 are formed onto the inner peripheral surface of a housing 20, and an inlet 28 and an outlet 29 for the brake liquid which is not controlled by the antilock apparatus communicates with the valve chamber 27. A valve body 30 consisting of a pressing part 31 and a valve part 32 is inserted into the concaved part 26 and a part of the valve chamber 27. Therefore, in low-speed traveling, a bypass passage for short- circuiting the inlet 28 and the outlet 29 for the brake liquid of the mechanical type antilock apparatus is opened by the valve body 30, and an aimed purpose can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bypass device for preventing reduction in braking force due to malfunction of a mechanical anti-lock device for a vehicle.

[Prior art]

As shown in Fig. 2, a friction clutch 3 is attached to a rotating shaft 1 linked to an axle, which transmits the rotational force of a flywheel 2 and shaft 1 to the wheel, and converts the rotational difference between the flywheel and the rotating shaft into linear motion. The ramp end ball device 4 (Figure 3 is a sectional view of the main part of this device) is installed, and the rotation speed difference between the rotation of the axle during sudden braking and the rotational speed of the flywheel, which is free to rotate with respect to axis 1, causes the arrow in the figure to move. Push the lever 6 that swings around the fulcrum 5 with the flywheel 2 that slides in the direction, and open the dump valve 7 that is closed by the lever.
By opening the flow path 9 shown in FIG. 2 that connects to the piston chamber 8 shown in FIG. A mechanical anti-lock mechanism that blocks the passage between the fluid inlet 12 and the fluid outlet 13 and simultaneously increases the volume of brake fluid on the brake side sealed by a cut-off valve to avoid wheel lock or a dangerous situation on the verge of wheel lock. Locking devices already exist (for example, JP-A-55-3
(See Publication No. 6186).

Furthermore, when this anti-lock device is activated and the rotation of the axle increases and the rotation speed of the flywheel becomes slower than that of axis 1, the flywheel moving to the left in Fig. 2 moves to the solid line position. Upon return, the dump valve 7 is closed, and as the pressure in the piston chamber 8 is released, the pump piston 15 in the silkworm 14 communicating with that chamber acts upward as the hydraulic pressure acting downward in the figure becomes zero. The hydraulic pressure inside the brake chamber 8 is increased by repeating the action of being pushed upward by the brake fluid pressure, and then pushed down by the cam 16 that rotates together with the rotary shaft 1, and this pressure causes the expander piston 1 to
1 is pushed down, and the cut-off valve 10 is restarted accordingly. The above operations are repeated many times during braking to perform anti-lock control.

[Problem that the invention seeks to solve]

However, in a vehicle equipped with the above-mentioned device,
When starting suddenly on a road with a low coefficient of friction such as on a hill, if you press the accelerator and then release the accelerator and suddenly apply the brakes with the wheels slipping, the braking force will be extremely reduced, and the braking force will be recovered and the vehicle will come to a stop. The vehicle may move back some distance.

This phenomenon occurs because the relationship between the vehicle and the brake system is the same as the wheel lock state during sudden braking, so the anti-lock device operates and temporarily reduces brake fluid pressure. Reduces the reliability of anti-lock devices.

An object of the present invention is to eliminate the reduction in braking force under the above-mentioned circumstances.

[Means for Solving the Problems] The bypass device of the present invention, which achieves the above object, detects the difference in rotational speed between an axle and a flywheel attached to an axle linked thereto to perform anti-lock braking. The mechanical anti-lock device is built into a housing with a predetermined space between the bypass path that short-circuits the inlet and outlet of the brake fluid and the outer peripheral surface, and rotates integrally with the axle or a shaft linked thereto. A rotor, an inertial body inserted into a recess in the outer circumferential surface of the rotor so as to be able to protrude and retract at a constant pitch in the circumferential direction, and a valve body that is displaced by being pushed by the inertial body protruding from the recess due to centrifugal force. This valve body is configured to open the bypass passage when the rotor rotates at low speed and close it when the rotor rotates at high speed.

That is, anti-lock control is necessary when the vehicle speed is above a certain value, and is not necessary when the vehicle is running at low speed. This invention focuses on this point, and by opening the bypass path of the bypass device when driving at low speeds, hydraulic pressure proportional to the pedal force applied to the brake pedal is supplied to the brakes regardless of whether the anti-lock device is activated or not. Therefore, the required braking force can be obtained even if the anti-lock device moves erroneously on a climbing road or the like.

On the other hand, when the vehicle is running at high speed, the valve body of the bypass device is displaced by the centrifugal force of the inertial body and the bypass passage is closed, so that the anti-lock device operates normally. Therefore, desirable braking will be performed under any circumstances.

〔Example〕

An embodiment of the present invention is shown in the attached FIG. 1.

Reference numeral 20 in the figure denotes a housing that may be integrated with or separate from the mechanical anti-lock device, in which a rotor 22 fixed to an axle or a shaft 21 moving on the axle is accommodated. A predetermined space 23 is secured between the outer circumferential surface of the rotor 22 and the inner circumferential surface of the λ housing 20, and recesses 24 are provided at a constant pitch in the circumferential direction on the outer circumferential surface of the rotor. An inertial body δ is inserted therein so as to be freely retractable.

On the other hand, a recess 26 and a valve chamber 27 are provided in the middle of the inner peripheral surface of the housing 20, and the valve chamber 27 has an inlet 28 and an outlet 29 for brake fluid that is not controlled by the anti-lock device.
are connected.

Further, a valve body 30 consisting of a pressing part 31 and a valve part 32 by an inertial body is inserted into a part of the recess 26 and the valve chamber 27 in a fluid-tight manner.
When the valve body is in the solid line position, a bypass path formed by the inlet 28, the outlet 29, and the cavity of the valve chamber is opened, and when the valve body 33 moves upward in the figure, the bypass path is closed. It has become.

The movement of the valve body 30 in the valve closing direction is performed by the pushing force of the inertial body protruding from the concave T24 due to centrifugal force. Therefore, the bypass passage is closed when the rotor 22 rotates at a speed that overcomes the gravity of the inertial body. In other words, only when the axle is rotating at high speed, the bypass path is always open during low speed rotation when the anti-lock device may malfunction.

Note that in the illustrated bypass device, the valve body 30 is biased in the valve opening direction by the weaker spring 33, but if this device is installed in the same state as shown in the figure, the valve body will move to the solid line position due to its own weight during low speed driving. It is possible to omit the sublin 34 because it is maintained at .

Further, in the illustrated device, a sphere is adopted as the inertial body 25, but this inertial body may have another shape, for example, a vane shape.
may be coaxial.

〔effect〕

As described above, the bypass device of the present invention opens the bypass path that short-circuits the brake fluid inlet and outlet of the mechanical anti-lock device when driving at low speeds, and directly supplies brake fluid pressure proportional to the pedal force to the brakes. It is possible to eliminate the reduction in braking force caused by malfunction of the anti-lock system.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of the bypass device of the present invention, FIG. 2 is a cross-sectional view of a flywheel attachment part of a known mechanical anti-lock device, and FIG. 3 is a main part of the ramp-end ball device. 4 is a sectional view of the expander piston and pump piston assembly of the apparatus of FIG. 2; FIG.

Claims (2)

[Claims] (1) The passage between the inlet and outlet of brake fluid is detected when the rotational speed of the flywheel increases by detecting the difference in rotational speed between the axle and the flywheel, which is freely rotatably mounted on the axle linked to the axle. A housing that creates a predetermined space between the outer peripheral surface and a bypass path that short-circuits the inlet and outlet of the brake fluid of the mechanical anti-lock device that blocks the brake fluid and expands the volume of the brake fluid sealed on the brake side. a rotor that is built into the rotor and rotates together with the axle or a shaft linked thereto; an inertial body that is inserted into a recess on the outer circumferential surface of the rotor so that it can freely move in and out at a fixed pitch in the circumferential direction; A bypass device for a mechanical anti-lock device, comprising a valve body that is displaced by being pushed by an inertial body protruding from a location, and the valve body opens the bypass port when the rotor rotates at low speed and closes it when the rotor rotates at high speed. . (2) A bypass device for a mechanical anti-lock device according to claim (1), wherein the inertial body is a spherical body.