KR100381594B1 - Disc brake - Google Patents

Abstract

The present invention relates to a disc brake, and its object is to equalize the surface pressure distribution load substantially received by the pad to prevent uneven wear of the pad and to improve durability and reliability.

According to the disc brake according to the present invention, the bore 11 in which the piston 13 is installed to move forward and backward from the center line D1 of the pad plates 40 and 50 is moved forward (arrow). At the ends of the pads 40 and 50 corresponding to the inlet side of the disk 30 in the forward rotational direction and at the same time, the slopes 41a and 51a are formed so as not to contact the disk 30. Thereby, the pressure of the piston 13 is applied relatively strongly to the exit side in the forward rotational direction. However, due to the characteristics of the disc brake in which the surface pressure is to be concentrated at one end of the pads 41 and 51 corresponding to the inlet side of the forward rotation direction by the rotational torque of the disc 30, the actual pad 41 ( 51, the surface pressure acts uniformly as a whole, thereby preventing uneven wear of the pads 41 and 51, reducing braking noise, and improving durability and reliability of the overall disc brake.

Description

Disc brake

The present invention relates to a disc brake mounted on a vehicle, and more particularly, to a disc brake having a pad that exerts a braking force by friction with a disc that rotates with a wheel.

The brake mounted on the vehicle includes a drum hydraulic brake and a disk hydraulic brake.

Conventional disc brakes obtain a braking force by strongly pressing a disk-shaped disk that rotates together with a wheel instead of a drum with pads on both sides, and a disk that rotates with the wheel, a pair of pad plates installed on both sides of the disk, and a piston A caliper housing.

The caliper housing includes a bore processed to move the piston forward and backward at the center of the rear part and a finger part formed to be bent downward in the front part to surround the outer pad plate, which will be described later. The inner circumferential surface of the bore is provided with an elastic seal to restore the piston when the braking hydraulic pressure is released, the caliper housing is provided symmetrically around the bore.

The pad plate is installed in the carrier mounted on the vehicle body so as to be spaced inwardly. An inner pad is attached to one surface and an inner pad plate is disposed such that the center of the other surface is in contact with the piston tip. It is distinguished by an outer pad plate disposed to be in contact with the inner surface.

On the other hand, the disk-shaped disk is inserted into a portion of the outer circumference between the inner pad and the outer pad, when the braking action is not made, while maintaining a constant gap with them to rotate with the wheel.

When the driver presses the brake pedal while the vehicle having the disc brake configured as described above is running, the braking hydraulic pressure generated in the master cylinder is transferred into the bore through the hydraulic line. The piston advances by braking hydraulic pressure and the inner pad plate is pushed to the disk side, whereby the inner pad is pressed against the disk to generate a braking force. In addition, since the hydraulic pressure remains inside the bore, the caliper housing itself moves in the opposite direction, whereby the finger portion pushes the outer pad plate to the disk side, and the outer pad is pressed against the disk to exert a braking force.

When the driver steps on the brake pedal, the piston is restored due to the elasticity of the seal, and the inner pad and the outer pad are again spaced apart from the disk.

However, such a conventional disc brake has a problem that the pad which compresses the disc according to the continuous braking action is unevenly worn as shown in FIG. 1.

That is, even if the inner pad 2 and the outer pad 3 are in contact with the disk 4 rotating in the direction of arrow A (when the vehicle moves forward) by the piston 1, the inner pad 2 and the outer pad 3 are applied to the actual disk 4; The surface pressure of the losing pads (2) (3) is concentrated by the rotational torque of the disk (4) to the rear side corresponding to the advancing rotational direction entry side of the disk (4).

As a result, when the disc brake is used for a long time, the abrasion state of the pads 2 and 3 is biased to the rear side with respect to the center line B, and the uneven wear of the pads 2 and 3 may be a cause of deterioration of braking performance. In addition, this causes the braking noise generated between the pads 2 and 3 and the disk 4. In addition, as the life of the pads 2 and 3 is shortened, the reliability of the overall disc brake is lowered.

The present invention is to solve this problem, the object of the present invention is to uniformly the surface pressure distribution load received when the pad friction with the disk that rotates with the wheel to prevent the wear of the pad and to improve product durability and reliability It is to provide a disc brake that can be improved.

1 is a cross-sectional view showing a pad wear state of a conventional disc brake.

2 is a plan sectional view of a disc brake according to the invention.

Figure 3 is a schematic view showing a pad and an eccentric bore formed in accordance with the present invention.

Figure 4 is a schematic view showing a wear state of the pad according to the present invention.

* Description of the symbols for the main parts of the drawings *

10. Housing 11. Bore

13. Piston 20 Carrier

30.Disc 40, 50..Padplate

41,51..Pad 41a, 51a .. Slope

In order to achieve the above object, the present invention provides a disk that rotates with a wheel, a pad plate attached to a side of the disk, and a piston attached to and retracted by braking hydraulic pressure to operate the pad plate. A disc brake with a caliper housing that is bore-processed to

The bore is machined eccentrically to the disc's forward rotation exit from the center line of the pad plate.

At one end of the pad corresponding to the forward rotation inlet of the disk, a slope is provided such that the friction surface center line of the pad is variable as the pad wears.

With such a configuration, the surface pressure distribution load substantially received by the pad is always uniform, thereby preventing uneven wear of the pad and improving product durability and reliability.

Hereinafter, one preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

In the disc brake according to the present invention, as shown in FIG. 2, a pair of pad plates 40 and 50 are arranged to be spaced apart at regular intervals, and the carrier 20 fixed to the vehicle body and a part of the edge of the pad plate 40 ( The disk 30 is inserted between the 50 and rotates together with the wheel (not shown), and the caliper housing 10 in which the piston 13 is built to move back and forth by the braking hydraulic pressure.

The carrier 20 is bolted to the knuckle of the vehicle body, and the inner pad plate 40 having the inner pad 41 attached thereto and the outer pad plate 50 having the outer pad 51 attached thereto have a disk 30. It is installed in the longitudinal direction so as to be freely centered. At this time, the other surface of the inner pad plate 40 is disposed in contact with the tip of the piston (13).

In addition, the caliper housing 10 is mounted on both ends of the carrier 20 so as to be spaced apart through the guide rod 60, and the bore 11 and the outer pad plate at the front are machined so that the piston 13 is built in the rear part. The finger portion 14 is formed to be bent downward to surround the 50. Reference numeral 12 is a hydraulic port processed in communication with the bore 11 to be transmitted to the braking hydraulic pressure formed in the master cylinder (not shown), 15 is the inner circumference of the bore 11 to restore the piston 13 to its own elastic force It is a seal installed on.

On the other hand, in the bore 11, the pressure of the piston 13 is applied relatively strongly to the exit rotation direction (arrow C direction) of the disk 30 starting from the center line D1 of the pad plates 40 and 50. The disk 30 is eccentrically processed toward the exit side in the forward rotational direction of the disk 30.

That is, as shown in FIG. 3, the bore 11 has a length of "E" toward the exit direction of the disk 30 in the forward rotation direction starting from the center line D1 of the pad plates 40 and 50. It is provided eccentrically, the amount of eccentricity E of the bore 11 is a value calculated in consideration of factors such as the initial thickness of the pads 41 and 51 and the coefficient of friction.

The eccentricity E of the bore 11 is expressed by the following equation when the initial thickness of the pads 41 and 51 is T and the friction coefficient of the pads 41 and 51 is F.

E = T × F

Therefore, when the bore 11 is eccentrically processed in consideration of the initial thickness T and the friction coefficient F of the pads 41 and 51, the pressing force of the piston 13 for operating the pad plates 40 and 50 is eccentric. Again, the disk 30 is biased toward the exit direction in the forward rotational direction, but a uniform surface pressure is formed on the entirety of the pads 41 and 51 that actually rub against the disk 30 by the rotational torque of the disk 30.

In addition, even if the pads 41 and 51 are worn on one end of the pads 41 and 51 corresponding to the inlet side of the disk 30 in the forward rotational direction, the pad 41 and 51 surface pressure distributions are worn. Slopes 41a and 51a are formed by chamfering, that is, edge picking, so as to uniformly bring them. Accordingly, the thickness T of the pads 41 and 51 which determines the amount of eccentricity E of the bore 11 gradually decreases, and the pads contacting the disk 30 according to the amount of wear of the pads 41 and 51 ( The frictional areas of 41) and 51 are varied so that the actual surface pressure distribution is even. That is, since the slopes 41a and 51a which are not in contact with the disk 30 are formed at one end of the pads 41 and 51, the pad 41 and 51 friction surface center lines D3 in the initial state. Is eccentrically formed by the length of "G" toward the disk 30 forward exit direction starting from the center line D1 of the pad plates 40 and 50, but as the wear of the pads 41 and 51 proceeds. The friction surface center line D3 is gradually brought closer to the center line D1 of the pad plates 40 and 50, so that a uniform uniform load is always applied to the height areas of the pads 41 and 51 at all times.

Next, the operation and effects of the disc brake according to the present invention will be described.

First, when the driver steps on the brake pedal (not shown) when the vehicle moves forward, a braking hydraulic pressure is formed in the master cylinder, which is transmitted into the bore 11 through the hydraulic port 12 so that the piston 13 moves forward.

Subsequently, the inner pad plate 40 is pushed inward by the advance of the piston 13 and the disk 30 and the inner pad 41 are rotated, and the caliper housing 10 is caused by hydraulic pressure remaining in the bore 11. As the) moves in the opposite direction to the piston 13, the finger portion 14 pushes the outer pad plate 50, whereby the outer pad 51 is pressed against the disk 30 to exert a braking force.

This braking force is exerted by the forward and backward motion of the piston 13, and since the bore 11 in which the piston 13 is built is eccentrically processed by " E " toward the forward rotation direction side of the disk 30, the piston 13 A uniform distribution load is applied to the pads 41 and 51 by applying an eccentric pressure to the inner pad plate 40.

That is, due to the eccentric machining of the bore 11, the front end of the piston 13 is relatively strong at the exit side of the disk 30 in the forward rotation direction of the inner pad plate 40 from the center line D1 of the pad plate 40. Pushed. In addition, due to the characteristics of the disc brake, the surface pressure of the inner pad 41 and the outer pad 51 applied to both sides of the disc 30 by the rotational torque of the disc 30 is determined by the inlet of the disc 30 in the forward direction of the vehicle. I'm trying to focus on the side.

Accordingly, the pressure applied from the piston 13 to the inner pad plate 40 and the outer pad plate 50 acts eccentrically toward the outlet of the disk 30 in the forward rotation direction, but the inner pad 41 during the actual braking action. The outer pad 51 and the outer pad 51 as a whole by rubbing at a uniform pressure on the side of the disk 30, the braking force is further improved, as well as the wear state of the inner pad 41 and the outer pad 51 is uniform, the braking noise is It is reduced and durability is improved.

Meanwhile, as shown in FIG. 4, the thickness T ′ of the pads 41 and 51, which is a variable, decreases with wear of the pads 41 and 51, but the pads 41 and 51 through chamfering. The friction surface center line D3 of the pads 41 and 51 gradually approaches the center line D1 of the pad plates 40 and 50 by the slopes 41a and 51a formed at one end thereof. G ') is also reduced. As a result, the eccentric pressure exerted from the piston 13 is slightly less than the initial state (see FIG. 3), so that even if the pads 41 and 51 are worn, the surface pressures of the actual pads 41 and 51 are uniform. It works.

As described in detail above, according to the disc brake according to the present invention, the bore in which the piston is installed to be moved forward and backward from the center line of the pad plate is machined eccentrically toward the forward direction of the disc and at the same time the inlet of the disc is rotated forward. By forming the slope at one end of the pad corresponding to the side so as not to contact the disk, the pressure of the piston is applied relatively strongly to the exit side in the forward rotational direction. However, due to the characteristics of the disc brake which tries to concentrate the surface pressure on one end of the pad corresponding to the forward rotation direction inlet by the rotating torque of the disk, the surface pressure acts uniformly on the actual pad during braking action. This prevents braking noise and reduces the durability and reliability of the overall disc brake.

Claims (1)

A disk rotating with a wheel, a pad plate with a pad disposed adjacent to the side of the disk, a piston moving back and forth by braking hydraulic pressure to operate the pad plate, and a caliper housing with a bore installed to install the piston. In disc brake with The bore 11 is eccentrically processed to the exit direction of the forward rotation direction of the disk 30 from the center line D1 of the pad plate 40, 50, As the wear of the pads 41 and 51 progresses at one end of the pads 41 and 51 corresponding to the inlet side of the disk 30 in the forward rotation direction, the friction surfaces of the pads 41 and 51 are advanced. A disk brake, characterized in that the slopes 41a and 51a are provided so that the center line D3 is variable.