KR20130048315A

KR20130048315A - Disk brake

Info

Publication number: KR20130048315A
Application number: KR1020110113094A
Authority: KR
Inventors: 김학수
Original assignee: 주식회사 만도
Priority date: 2011-11-02
Filing date: 2011-11-02
Publication date: 2013-05-10

Abstract

PURPOSE: A disc brake is provided to obtain a gap between a disc and a pad by the restitution force of a piston by improving the groove in which a sealing member is installed. CONSTITUTION: A disc brake(100) comprises a caliper housing(120), a piston(130), a pair of pad plates(111a,112a), a boot(150), and a sealing member(140). The caliper housing is installed on a carrier to be slid and comprises a cylinder(123). The piston is installed inside the cylinder to move to the front and to the rear. The pad plates are installed on the carrier to slide to a disc(1). The boot is installed on an inlet of the cylinder and prevents foreign substances from flowing into between the piston and the cylinder. The sealing member is installed between the inner periphery of the cylinder and the outer periphery of the piston.

Description

Disk brake

The present invention relates to a disc brake, and more particularly, a piston that presses the pad plate when the brake is released can limit the back slip, which is moved back to the pad plate, to secure the gap between the disc and the pad. Relates to a disc brake.

In general, a disc brake mounted on a vehicle is a device for decelerating a vehicle while driving or maintaining a stationary or stopped state. A disc brake strongly presses a disk-shaped disk rotating together with a wheel with a pad on both sides.

1 is a cross-sectional view schematically showing a conventional disc brake.

Referring to the drawings, the disc brake 10 according to the related art has a caliper housing 20 provided with a piston 30 that moves forward and backward by braking hydraulic pressure, and a carrier which is fixed to the vehicle body and in which the caliper housing 20 is slidably coupled. And a pair of pad plates 11a and 12a provided on a carrier so as to be slid to the disk 1 at a predetermined interval so that a part of the outer circumferential surface of the disk 1 is inserted.

At the rear of the caliper housing 20, a braking hydraulic pressure is transmitted, and a cylinder 23 is formed on which the piston 30 is installed to move forward and backward, and the front portion is bent to surround the outer pad plate 12a to be described later. Finger portion 22 is provided integrally.

In addition, a sealing member 40 is installed between the inner circumferential surface of the cylinder 23 and the outer circumference of the piston 30 to apply a restoring force to the piston 30, and a boot for preventing foreign substances from entering the inlet of the cylinder 23. 50) is installed.

The carrier (not shown) is bolted to the knuckle of the vehicle body, where a pair of pad plates 11a and 12a to which the pads 11b and 12b are attached is slidably installed in a direction facing each other.

The pair of pad plates 11a and 12a are inner pad plates 11a disposed to be in contact with the tip of the piston 30 and outer pad plates 12a disposed to be in contact with the inner surface of the finger portion 22. Are distinguished.

When the driver presses the brake pedal (not shown) while driving the vehicle having the disc brake 10 configured as described above, as illustrated in FIG. 2, the braking hydraulic pressure generated in the master cylinder (not shown) is transferred into the cylinder 23. The piston 30 moves forward.

As the piston 30 advances, the pad 11b attached to the inner pad plate 11a is instantaneously pressed onto one side of the disk 1. In addition, since the braking hydraulic pressure remains in the cylinder 23, the caliper housing 20 itself moves in the direction of arrow P1 opposite to the piston 30 and moves the outer pad plate 12a to the other side of the disk 1. Push the other side of the disk (1). As a result, the disk 1 is compressed by a pair of pad plates 11a and 12a to brake.

On the other hand, when releasing braking, when the foot is released from the brake pedal, the brake hydraulic pressure is released and the pads 11b and 12b are separated from the disk 1 as the piston 30 is restored to its original position by the sealing member 40. Disc brake initial state.

At this time, the sealing member 40 is inserted into the groove 24 formed on the inner circumferential surface of the cylinder 23 is made of a rubber material having elasticity to return the piston (30). That is, as shown in FIG. 2, when the piston 30 is advanced by the braking hydraulic pressure to maintain the sealing member 40 in a deformed state, and the braking hydraulic pressure is released, the piston (by the elastic restoring force of the sealing member 40) is released. 30) are restored together to their original positions. Thus, a gap is maintained between the disk 1 and the pads 11b and 12b when the brake is released to prevent the pads 11b and 12b from rubbing from the disk 1.

In order to return the piston 30 to the original position more efficiently by the elastic restoring force of the sealing member 40, a structure in which the shape of the groove 24 formed in the cylinder 23 is deformed is used. For example, as shown in FIG. 3, each corner portion of the first surface 24a in the forward direction of the piston 30, which is one side of the groove 24, and the second surface 24b, which is in the backward direction of the piston 30, may be formed. An extended structure has been proposed and used. Accordingly, by securing a space in which the sealing member 40 is elastically deformed, the elastic deformation of the sealing member 40 is smoothly performed, thereby transmitting the elastic restoring force to the piston 30.

However, when the brake is released, the piston 30 is elastically restored by the sealing member 40 and the caliper housing 20 slid from the carrier is also moved to the original position, where the caliper housing 20 is moved by an arrow. As the P2 is moved in the P2 direction, the backslip phenomenon in which the piston 30 slides back in the forward direction is caused by the sealing member 40 installed in the groove 24 of the cylinder 23.

That is, although the distance between the disk 1 and the pads 11b and 12b should be maintained, the pads 11b and 12b are provided in contact or compressed state with the disk 1 to provide the pads 11b and 12b. There is a problem that the friction is constantly. Accordingly, unnecessary wear and noise of the pads 11b and 12b are generated, and a problem occurs that braking is not performed smoothly during braking.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a disc brake capable of securing a gap between the disc and the pad by the restoring force of the piston by improving the groove in which the sealing member is installed.

In order to achieve the above object, the disc brake of the present invention includes a carrier provided with a pair of pad plates to be retractable, a caliper housing slidably mounted to the carrier and a cylinder formed therein, and a piston provided to be retractable within the cylinder. And a boot for preventing the inflow of foreign substances between the cylinder and the piston, and a disc brake including a sealing member provided between an inner circumferential surface of the cylinder and an outer circumferential surface of the piston, wherein the sealing member is inserted into the inner circumferential surface of the cylinder. A groove is formed, wherein the groove has a first surface in a direction in which the piston is advanced and a second surface in a direction in which the piston is retracted, wherein the first surface and the second surface have slopes corresponding to each other.

According to the present invention, the groove is formed such that the first surface and the second surface are inclined in the retraction direction of the piston from the inlet to the bottom surface from which the sealing member is inserted.

The first surface may have an angle of 100 ° to 110 ° from the inner circumferential surface of the cylinder with respect to the horizontal line, and the second surface may be formed to have an angle of 70 ° to 80 ° from the inner circumferential surface of the cylinder with respect to the horizontal line. Do.

On the other hand, it is preferable that each corner of the first surface and the second surface in contact with the inner peripheral surface of the cylinder is formed to be bent.

Disc brake according to the present invention has the effect of ensuring the gap between the pad and the disk by eliminating the backslip phenomenon caused by the restoration of the caliper housing when braking is released by improving the structure of the groove in which the sealing member is installed. In other words, the pad is unnecessarily rubbed with the disk to prevent wear and breakage of the pad, thereby eliminating problems such as noise caused by friction between the pad and the disk. In addition, it is possible to exert a smooth braking force by separating the pad and the disk at regular intervals.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described in detail with reference to the following drawings, which illustrate preferred embodiments of the present invention, and thus the technical idea of the present invention should not be construed as being limited thereto.
1 is a cross-sectional view schematically showing a conventional disc brake.
2 is an enlarged view of a portion A of FIG. 1.
3 is a view showing a groove formed in a cylinder of a conventional disc brake.
4 is a cross-sectional view schematically showing a disc brake according to a preferred embodiment of the present invention.
5 is a partially enlarged view showing a groove formed in the cylinder of the disc brake according to the preferred embodiment of the present invention.
6 is a view showing a state in which the pad and the disk provided in the disk brake spaced apart at regular intervals according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

4 is a cross-sectional view schematically illustrating a disc brake according to a preferred embodiment of the present invention, and FIG. 5 is a partially enlarged view illustrating a groove formed in a cylinder of the disc brake.

4 and 5, the disc brake 100 is provided with a caliper housing 120 provided with a piston 130 that moves forward and backward by braking hydraulic pressure, and is fixed to the vehicle body, and the caliper housing 120 is slidably coupled thereto. A carrier (not shown) and a pair of pad plates 111a and 112a installed on the carrier so as to be slid to the disk 1 at a predetermined interval so as to press the disk 1 rotating together with the wheel. .

The carrier (not shown) is fixed to the knuckle of the vehicle body through a mounting bolt (not shown), the caliper housing 120 is slidably fastened to both ends through a guide rod (not shown). In addition, a pair of pad plates 111a and 112a are longitudinally spaced apart from the center of the carrier so as to be slidable in a direction facing each other.

The pair of pad plates 111a and 112a are disposed to contact the piston 130 to be described later, and an inner pad plate 111a having an inner pad 111b attached to an inner side thereof, and a finger part 122 to be described later. The outer pad plate 112a is disposed to be in contact with the outer pad 112b, and the outer pad 112b is attached to the inner surface thereof.

At this time, the disk 1 is made of a disk shape that rotates with the wheel (not shown) of the vehicle, a part is rotated in a state inserted between a pair of pad plates (111a) (112a).

The caliper housing 120 includes a finger portion 122 for operating the outer pad plate 112a and a cylinder 123 having an inlet 121 so that a braking hydraulic pressure can be transmitted.

The finger portion 122 is formed to bend downward from the front portion of the caliper housing 120 to surround the outer pad plate 112a from the outside. Accordingly, the outer pad plate 112a is pushed toward the disk 1 by the finger part 122 as the caliper housing 120 slides from the carrier, i.e., moves in the direction of the arrow P1 during braking. Pressurized.

The cylinder 123 is formed at the rear of the caliper housing 120 so that the braking hydraulic pressure formed in the master cylinder (not shown) is transmitted, and the piston 130 is installed to move forward and backward. That is, the piston 130 installed in the cylinder 123 moves forward and backward in the cylinder 123 by braking hydraulic pressure.

In addition, a sealing member 140 made of a louver material is installed on the inner circumferential surface of the cylinder 123 to provide an elastic force in the direction of restoring the piston 130 with its own elastic force, and the piston 130 at the inlet of the cylinder 123. ) And a soft boot 150 is installed to prevent foreign matter from flowing into the minute gap formed between the cylinder 123 and. Here, the boot 150 is configured in the form of a corrugated pipe to enable expansion and contraction to a predetermined width in accordance with the advancing and moving of the piston 130.

On the other hand, the inner circumferential surface of the cylinder 123 is recessed in the circumferential direction toward the outer circumferential surface so that the sealing member 140 is inserted is formed.

According to the present invention, the groove 124 is formed to be inclined in an oblique direction. More specifically, the groove 124 has a first surface 124a in the direction in which the piston 130 advances and a second surface 124b in which the piston 130 retreats, and the first surface 124a and The second surface 124b is formed to be inclined in the direction in which the piston 130 retreats from the inlet into which the sealing member 140 is inserted to the bottom surface of the groove 124. In this case, the first surface 124a and the second surface 124b have inclination angles α and α ′ corresponding to each other. For example, the first surface 124a has an inclination angle α of 100 ° to 110 ° from the inner circumferential surface of the cylinder 123 with respect to the horizontal line, and the second surface 124b has the inclination angle of the cylinder 123 with respect to the horizontal line. It has the inclination angle (alpha ') of 70 degrees-80 degrees from an inner peripheral surface.

On the other hand, in relation to the numerical range with respect to the inclination angle α (α ′), when the inclination angle α of the first surface 124a exceeds the upper limit, the inclination of the first surface 124a is inclined rapidly and the piston When the 130 is moved forward, the sealing member 140 may be excessively deformed, which is not preferable. If the lower limit is less than the lower limit, the elastic restoring force for restoring the piston 130 is reduced due to insufficient deformation of the sealing member 140. I can't. In addition, when the inclination angle α 'of the second surface 124b exceeds the upper limit, the movement of the piston 130 backslid by the caliper housing 120 may not be limited, and when the lower angle falls below the lower limit, the braking is released. The force that resists the elastic restoring force that restores the piston 130 is increased, which prevents the piston 130 from returning to its original position.

Meanwhile, each corner of the first surface 124a in contact with the inner circumferential surface of the cylinder 123 and the second surface 124b in contact with the inner circumferential surface of the cylinder 123 is formed to be bent at least once. This is to prevent the tearing of the sealing member 140 when the elastic member is formed by the sharp corners. For example, each corner of the first surface 124a and the second surface 124b in contact with the inner circumferential surface of the cylinder 123 may be formed to be rounded.

By the groove 124 having such a structure, the sealing member 140 prevents the hydraulic fluid from leaking into the fine gap formed between the cylinder 123 and the piston 130 and, of course, the piston 130. ) Easily returns to its original position.

Next, an operation state in which the disc brake of the present invention having the above structure is activated and deactivated will be described.

First, in the case of braking the brake, when the driver presses the brake pedal, the braking hydraulic pressure generated in the master cylinder is transferred into the cylinder 123 to advance the piston 130. The inner pad plate 111a presses the disk 1 as the piston 130 moves forward, and the caliper housing 120 is opposite to the advance direction of the piston 130 by the braking hydraulic pressure remaining in the cylinder 123. Direction, the outer pad plate 112a is squeezed toward the disc 1 to move in the direction of arrow P1. At this time, the sealing member 140 installed in the groove 124 formed on the inner circumferential surface of the cylinder 123 is elastically deformed toward the first surface 124a in the forward direction of the piston 130.

In this state, when the brake is released, when the driver releases the brake pedal, the braking hydraulic pressure that pressurizes the piston 130 is released while the piston 130 returns to its original position by the elastic restoring force of the sealing member 140. Will return. At this time, when the brake hydraulic pressure is released, the caliper housing 120 is slid from the carrier to move in the direction of arrow P2, which is the forward direction of the piston 130, where the cylinder 123 of the caliper housing 120 is The backslip phenomenon in which the piston 130 is advanced again by the sealing member 140 as it moves forward is prevented by the second surface 124b. That is, since the second surface 124b is formed to have a shape protruding in the forward direction of the piston 130, even if the cylinder 123 is advanced, the sealing member 140 is toward the second surface 124b, unlike the prior art. It is not elastically deformed. This is because the space for elastic deformation of the sealing member 140 toward the second surface 124b is narrow, whereby the movement of the piston 130 due to the backslip phenomenon of the piston 130 is limited.

As a result, by improving the structure of the groove 124 as described above to limit the movement of the piston 130 according to the backslip phenomenon, as shown in Figure 6, the pad (111b) 112b and the disk (1) The interval C therebetween can be maintained at a constant interval. Accordingly, it is possible to prevent unnecessary friction between the pads 111b and 112b, as well as to prevent noise and wear of the pads. In addition, by keeping the pads 111b and 112b and the disk 1 at a constant interval, it is possible to perform smooth braking during brake braking.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

100: disc brake 120: caliper housing
123: cylinder 124: groove
130: piston 140: sealing member

Claims

A carrier having a pair of pad plates retractable, a caliper housing slidably mounted to the carrier, a piston formed in the cylinder, a piston provided retractably in the cylinder, and preventing foreign substances from entering between the cylinder and the piston In the disk brake comprising a boot and a sealing member provided between the inner peripheral surface of the cylinder and the outer peripheral surface of the piston,
Grooves are formed on the inner circumferential surface of the cylinder so that a sealing member is inserted and installed.
And the groove has a first surface in a direction in which the piston is advanced and a second surface in a direction in which the piston is retracted, wherein the first surface and the second surface have slopes corresponding to each other.

The method of claim 1,
The groove is a disc brake, characterized in that the cross section is formed such that the first surface and the second surface is inclined in the retraction direction of the piston toward the bottom surface from the inlet to which the sealing member is inserted.

The method of claim 1,
The first surface has an angle of 100 ° to 110 ° from the inner peripheral surface of the cylinder relative to the horizontal line, the second surface is formed to have an angle of 70 ° to 80 ° from the inner peripheral surface of the cylinder relative to the horizontal line Disc brake.

The method of claim 1,
Disc brake, characterized in that each corner of the first surface and the second surface in contact with the inner peripheral surface of the cylinder is formed to be bent.