JPS5833311Y2 - disc brake - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a disc brake for a vehicle, and in particular,
This article relates to disc brakes that provide excellent braking effect when parking or stopping a vehicle.

In a so-called floating type disc brake equipped with a caliper, pressurized oil is fed into the cylinder of the caliper by pressing the foot brake pedal, and a piston built into the cylinder is activated to press the pad against the brake disc. The piston is mechanically actuated by a handbrake lever, which is operated mainly when the vehicle is parked or stopped, to press the pad against the brake disc independently of the operation of the foot brake pedal.

However, in the above-mentioned disc brake, the pad pressed against the brake disc does not have a self-energizing effect like the brake shoe of a drum brake, so when the handbrake lever is operated, the pad is pressed against the brake disc.
The drawback was poor braking performance when stopped.

In view of the above-mentioned drawbacks, the present invention aims to provide a disc brake that can exhibit an excellent braking effect even when the handbrake lever is operated, and the piston for pressing the pad is attached to the handbrake lever when the handbrake lever is operated. In order to apply hydraulic pressure from the cylinder in addition to the mechanical operating force of do.

The features of the present invention will become clearer from the following description of the illustrated embodiment. The disc brake 10 according to the present invention has a rotation axis of a wheel, as shown in FIG. a brake disc 12 rotatable integrally with the brake disc, a pair of pads 14.16 disposed on both sides of the brake disc, and both pads 14.16.
A piston 18 for pressing the brake disc 12
The hydraulic lock mechanism 22 includes a caliper 20 accommodating the caliper 20 , and a hydraulic lock mechanism 22 .

As is well known in the art, the pads 14, 16 are supported by a support member 24 so as to be movable parallel to the axis of rotation of the brake disc 12 toward or away from the brake disc 12, and 20 also has the brake disc 12 as in the conventional case.
It is supported by the support member 24 so as to be movable in parallel to the axis of rotation.

The caliper 20 has a cylinder 26 for accommodating the piston 18 on one side of the brake disc 12;
Inside the cylinder is one pad, ie, inner pad 1.
A piston 18 is accommodated, which is slidable towards 4.

Further, the caliper 20 has a claw portion 28 that extends toward the other force side of the brake disc 12 and can come into contact with the other pad, that is, the outer pad 16 .

The caliper 20 has a passage 30 (3
0a.

30b) is formed.

Therefore, when the pressure fluid corresponding to the depression of the foot brake pedal is guided to the cylinder 26, the piston 18 is pushed against one surface of the brake disc 12 of the inner pad 14 by the fluid pressure, as is well known in the art. At the same time as the caliper 20 is operated to press the outer pad 16 against the other surface of the brake disc 12, the caliper 20 is operated by the claw portion 28 to press the outer pad 16 against the other surface of the brake disc 12, and the brake disc 12 is braked by the pressure of both pads 14 and 16. .

Further, when the hydraulic pressure in the cylinder 26 is released, the caliper 20 and the piston 18 release the braking of the brake disc by the pads 14 and 16 by the action of the well-known traction seal member 32 provided in the cylinder 26. It is activated as expected.

The caliper 20 is provided with a manual operating mechanism 34 for applying an acting force to the piston 18 in order to operate the piston 18 regardless of the operation of the foot brake pedal.

As is well known in the art, the manual operating mechanism includes a shaft 36 rotatably supported at the end of the caliper 20, a first toggle 38 fixed to the shaft, and a pusher from the toggle. and a spindle 40 for transmitting pressure to the piston 18.

A lever 44 connected to a handbrake lever (not shown) is attached to the end of the shaft 36 protruding from the cover 42.
is fixed.

The spindle 40 is slidably received in the axial direction in a guide hole 46 formed in the caliper 20, and extends coaxially with the piston 18 toward a recess 48 in the piston.

A pressure receiving member 52 that can be engaged with the toggle 38 is fixed to one end of the spindle 40 protruding from an annular recess 50 formed at the open end of the guide hole 46. A countersunk 54 is disposed in contact with.

Further, the other end of the spindle 40 is provided with a conventionally well-known adjusting mechanism, and can come into contact with the piston 18 via the adjusting mechanism.

That is, a threaded portion 56 is provided on the piston 18 side of the spindle 40, and a sleeve nut 60 rotatably supported via a thrust bearing 58 is screwed into the threaded portion. One end of the sleeve nut can abut a shoulder 62 defining the recess 48 of the piston 18.

The sleeve nut 60 is provided with a clutch spring 64 that allows the sleeve nut to rotate in the forward direction and prevents it from rotating in the reverse direction.

Therefore, as is well known in the art, when the spindle 56 receives a downward pressing force in the figure from the toggle 38 due to the operation of the handbrake lever, the clutch spring 64 prevents the spindle 56 from rotating in the opposite direction. The pressing force is transmitted to the piston 18 via the sleeve nut 60 that moves integrally with the spindle 56,
As a result, the brake disc 12 is braked by both pads 14 and 16 in the same way as when the foot brake pedal is operated.

Further, when the foot brake pedal is operated, the piston 18 is pushed forward according to the wear of the pad 14.16, but at this time, the piston 18 rotates the sleeve 60 in the forward direction via the thrust bearing 58. There is a force acting on it.

As a result, the relative position of the sleep pro 0 with respect to the spindle 40 in the axial direction is changed according to the amount of wear of the pads 14, 16, so that the handbrake lever can be adjusted regardless of the wear of the pads 14, 16. The amount of operation is held constant.

The hand brake lever is mainly operated when the vehicle is parked or stopped. At this time, the hydraulic lock mechanism is activated to apply hydraulic pressure to the piston 18 in addition to the mechanical pressing force from the spindle 40. 22 are provided.

The hydraulic locking mechanism 22 according to the present invention includes the passage 30
a recess 6 formed therein and open to one end of the caliper 20;
6 and a check valve 68 fitted within the recess.

The recess 66 has a reduced diameter portion 70 at its bottom which communicates with the cylinder 26 via the passage 30a and which communicates with the mask via the passage 30b at the side of the recess 66. It communicates with the connection port to the cylinder.

The check valve 68 includes a valve member 76 having a flange 72 at one end protruding from the recess and a head 74 at the other end facing the reduced diameter portion 70, and an elastic member attached to the head 74. A sealing member 78 made of a body is provided.

An annular seal member 80 is provided on the outer periphery of the valve member 76 and is pressed against the circumferential surface of the recess 66, so that the valve member 76 is directed toward or away from the reduced diameter portion 70 of the recess 66. The direction can be slid in an airtight manner.

The valve member 76 includes a first passageway 82 extending across the valve member 76 alignably with the passageway 30b, and a second passageway 84 communicating with the passageway and extending toward the head 74.
and a third passage 86 that communicates with the passage, extends parallel to the first passage 82, and opens on both sides of the head 74, and both openings of the third passage can be opened and closed. The seal member 78 is installed to ensure this.

The sealing member 78 is a valve that covers the circumferential surface of the head 74 of the valve member 76 and allows the flow of pressurized liquid from the third passage 86 toward the reduced diameter portion 70 but prevents flow in the opposite direction. It includes a portion 78a and a flange portion 78b continuous with the valve portion and covering the shoulder portion of the valve member 76.

The flange 72 of the valve member 76 and the caliper 20
A compression coil spring 8σ is disposed between the end of the check valve 68 and the upper end of the check valve 68, and a buffer spring 84' having a seat 8z is disposed within the flange 72. It is located.

The buffer spring 84' may also be omitted.

A second toggle 83 for overcoming the biasing force of the spring 80' and moving the check valve 68 downward in the figure is formed at a position where the tube of the shaft 36 faces the seat 82'. .

The second toggle 83 extends in the same direction as the first toggle 38, so that when the spindle 40 is subjected to a pressing force by the first toggle 38, the second toggle 83 simultaneously causes the check valve 68 to is the passage 30
b and said passageway 82 are held in an aligned position, ie, in an operating position.

In its operating position, the check valve 68 connects the cylinder 26 from the passage 30b through the passage 30a.
Although pressure fluid is allowed to flow into the cylinder 26, pressure fluid is prevented from flowing out from the cylinder 26, that is, from the passage 30a toward the passage 30b.

Therefore, even if the foot brake pedal is released by operating the handbrake lever while the foot brake pedal is depressed, the pressurized liquid can be contained in the cylinder 26, and the piston 18 can be moved from the spindle 40 to the cylinder 26. In addition to the mechanical pressing force, the hydraulic fluid action force within the cylinder 26 can be used as an auxiliary force, thereby increasing the braking effect when the vehicle is parked or stopped.

Also, by temporarily depressing the foot brake pedal after operating the handbrake lever, the pressure fluid can be sealed in the cylinder 26 in the same manner as described above.

The locking mechanism can be released by releasing the handbrake lever.

When the pressing force from the second toggle 83 is released by operating the handbrake lever, the check valve 68 is displaced upward in the figure by the biasing force of the spring 8σ, thereby being held in the non-operating position. Ru.

In this non-operating position, said passage 30b and passage 30a
is the recess 66 without passing through the check valve 68.
Since the cylinder 2 is placed in communication via
The hydraulic pressure in 6 is released.

Therefore, in the unlocked state of the locking mechanism, as described above, the pressure fluid corresponding to the depression operation of the foot brake pedal can be applied to the piston 18, thereby providing the same braking effect as the normal foot brake pedal operation. can be obtained.

According to the present invention, as described above, by temporarily depressing the foot brake pedal at the same time as operating the hand brake lever, hydraulic pressure is applied to the piston of the caliper in addition to the mechanical pressing force caused by operating the hand brake lever. This makes it possible to improve braking performance when parking or stopping.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing a disc brake according to the present invention. 12 brake disc, 14, 16: pad, 18:
Piston 20: Caliper, 22: Hydraulic lock mechanism, 2
6: Cylinder, 30 (30a, 30b): Passage, 68:
Check valve, 8σ: biasing means, 83 Nidoguru.

Claims (1)

[Scope of utility model registration request] A caliper formed with a cylinder that accommodates a piston for pressing a pad against a brake disc, a passage formed in the caliper for guiding pressurized fluid to the cylinder by operation of a foot brake pedal, and a handbrake lever. a shaft having a first toggle pivoted relative to the cylinder for actuating the piston independently of actuation of the pedal; a hydraulic locking mechanism for blocking said passageway, said hydraulic locking mechanism being a check valve disposed in said passageway, said hydraulic locking mechanism being in an inoperative position for opening said passageway and for outflow of pressurized fluid from said cylinder; a check valve movable to an operating position to prevent
a biasing means for applying a biasing force to the check valve toward the non-operating position; and a biasing means provided on the shaft for overcoming the biasing force of the biasing means to operate the check valve toward the operating position. A disc brake characterized by comprising a second toggle.