KR20140115030A - Structure of shoe hold down for drum brake - Google Patents

Abstract

A shoe hold down structure for a drum brake is disclosed. According to an embodiment of the present invention, there is provided a shoe hold-down structure for a drum brake, in which a pair of brake shoes for friction with an inner circumferential surface of a drum to generate a braking force is provided so as to be able to flow on a back plate, A shoehold down pin having a head portion sequentially passing through the through hole formed in the back plate and having a supporting portion hooked to the back plate at the other end and having a body portion having a predetermined length connecting the head portion and the support portion; A shoe hold down washer in which a coupling hole is formed such that the head portion is inserted and coupled; And a shoe hold down spring interposed between the shoe hold down washer and the brake shoe such that the shoe hold down pin passes through the shoe hold down pin to provide an elastic force to the brake shoe and the back plate to give a constant assembly load, Wherein the slots are formed in the center of the shoe so as to have a predetermined length in the longitudinal direction and are elastically deformable by the slots.

Description

[0001] The present invention relates to a shoe hold down structure for drum brakes,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a shoe hold-down structure for a drum brake, and more particularly, to a shoe hold-down structure for a drum brake capable of improving workability by improving a structure for assembling a brake shoe .

BACKGROUND ART Generally, a drum brake mounted on a vehicle is a device for obtaining a braking force by rubbing a cylindrical drum, which rotates together with a wheel, against a lining within the drum. The conventional drum brake includes a drum rotating together with a wheel, A pair of semicircular brake shoes each having one end thereof abutted and supported, and a wheel cylinder which receives a braking hydraulic pressure and operates a pair of brake shoe outwardly in the radial direction around the anchor block.

1, the brake shoe includes a semicircular rim 2b to which a lining 2a is attached, a rim 2b which is coupled to the inner periphery of the rim 2b and has an end formed with an anchor block (not shown) And a plate-like web 2c that is in contact with and supported by a wheel cylinder (not shown) while being in contact with and supported by the wheel cylinder (not shown), so that the lining 2a rubs against the inner periphery of the drum during outward operation,

At this time, the brake shoe 2 is installed on the back plate 1 through the shoe hold down structure 3 so that it can flow with a predetermined width. The shoe hold-down structure 3 includes a mounting pin 3a extending in a rod shape having a predetermined length, a coil spring 3d disposed on the web 2c so that the end of the mounting pin 3a passes through the center portion, And a washer 3e for preventing the release of the coil spring 3d.

A first engaging portion 3b and a second engaging portion 3c are provided at both ends of the mounting pin 3a so that the first engaging portion 3b is engaged with the back plate 1 and the second engaging portion 3c And is engaged with the washer 3e. At this time, a slot 3f is formed in the washer 3e so as to penetrate the second engaging portion 3c of the setting pin 3a and a concave groove 3g is formed on the upper portion thereof so as to cross the slot 3f .

The mounting hole 1a and the through hole 2d are drilled in corresponding positions on the back plate 1 and the web 2c of the brake shoe 2 for the mounting of the shoe hold down structure 3 The through hole 2d is formed to be larger than the diameter of the mounting pin 3a so that the mounting pin 3a can pass freely and the web 2c can move in a predetermined width during operation of the brake.

The installation pin 3a is inserted into the installation hole 1a provided in the back plate 1 and the through hole 2d provided in the web 2c so as to penetrate through the web 2c in this order, The coil spring 3d is disposed at the end of the pin 3a and then the coil spring 3d is compressed so that the washer 3e is engaged with the second engaging portion 3c of the setting pin 3a, 3c are passed through the elongated hole 3f of the washer 3e and rotated by the washer 3e. This prevents the release of the coil spring 3d by the washer 3e and prevents the brake shoe 2 from flowing to the back plate 1 by the installation pin 3a, the coil spring 3d and the washer 3e. It is possible to install it.

However, there is a problem in that it is inconvenient to assemble the mounting pin 3a with the washer 3e because there is no structure for supporting the mounting pin 3a when the conventional shoe hold-down structure 3 is installed. That is, there is an inconvenience that the washer 3e must be engaged after the installation pin 3a is forcibly fixed as the installation pin 3a and the washer 3e rotate together.

Further, as the washer 3e is pushed and rotated to be assembled, there is a problem in that a worker's wrist injury risk is high due to the load of the coil spring 3d.

The second engaging portion 3c of the mounting pin 3a is seated in the groove 3g formed in the washer 3e when the washer 3e is rotated by the rotation of the washer 3e, Likewise, there is a problem that the problem of the assembling failure in which the second latching portion 3c is not seated in the groove 3g and is coupled in an unstable state occurs intermittently.

The present invention has been made to solve the above-mentioned problems, and provides a shoe hold down structure for a drum brake capable of improving the assembling property by improving a coupling structure of a pin for allowing a brake shoe to flow on a back plate It has its purpose.

According to an aspect of the present invention, there is provided a shoe hold down structure for a drum brake, wherein a pair of brake shoes for friction with an inner circumferential surface of a drum to generate a braking force is provided on a back plate so as to be able to flow, And a shoe holder having a body portion having a predetermined length for connecting the head portion and the support portion, wherein the head portion is provided with a head portion sequentially passing through the through hole formed in the back plate and the brake shoe at one end, Down pin; A shoe hold down washer in which a coupling hole is formed such that the head portion is inserted and coupled; And a shoe hold down spring interposed between the shoe hold down washer and the brake shoe such that the shoe hold down pin passes through the shoe hold down pin to provide an elastic force to the brake shoe and the back plate to give a constant assembly load, Wherein the slots are formed in the center of the shoe so as to have a predetermined length in the longitudinal direction and are elastically deformable by the slots.

According to another aspect of the present invention, there is provided a shoe hold down structure for a drum brake, wherein a pair of brake shoes for friction with an inner circumferential surface of a drum to generate a braking force are provided on a back plate so as to be able to flow A head portion having a through hole formed in the back plate and the brake shoe in order and having a body portion having a predetermined length for connecting the head portion and the support portion, Hold down pin; And a shoe hold down spring formed between the head and the brake shoe to provide an elastic force to impart a constant assembly load to the brake shoe and the back plate, Wherein the slots are formed in the center of the shoe so as to have a predetermined length in the longitudinal direction and are elastically deformable by the slots.

In addition, the head may be elastically deformed when passing through the coupling hole, and may be restored by the elastic restoring force after passing through the coupling hole, so that the head can be prevented from being separated from the coupling hole.

The head portion may have a plurality of protrusions protruding from the outer circumferential surface of the head portion, the protrusions protruding from the outer circumferential surface of the head portion.

Meanwhile, the shoe hold down spring of the shoe hold down structure for drum brake according to another embodiment of the present invention may be constructed such that the plate spring having a bar length is bent so that both ends of the plate spring face each other.

The shoe hold down structure for a drum brake according to an embodiment of the present invention is configured such that a slot is formed in a head portion of a shoe hold down pin so that a head portion is elastically deformable by a slot, It is possible to combine the shoehold down spring in the form of a washer or a plate spring only by pressing the spring, and the assembling workability can be improved. Accordingly, there is no need for a separate supporting structure for preventing the shoe hold down pin from rotating, and also it is possible to eliminate the structure for rotating the washer by rotating the washer and to solve the problem of assembling between the mounting pin and the washer according to the rotation angle .

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 partial cutaway perspective view showing a state in which a brake shoe is installed on a back plate by a conventional shoe hold-down structure;
2 is a plan view showing a problem in an assembled state by a conventional shoe hold down structure;
3 is an exploded perspective view showing a state in which a brake shoe is installed on a back plate by a shoe hold down structure for a drum brake according to a preferred embodiment of the present invention.
Fig. 4 is an assembled perspective view of Fig. 3; Fig.
5A to 5C are views showing a state in which a shoe hold down pin provided in a shoe hold down structure for a drum brake according to a preferred embodiment of the present invention is engaged.
6 is a perspective view showing a state in which a brake shoe is coupled to a back plate by a shoe hold down structure for a drum brake according to another preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 and 3, a shoe hold down structure for a drum brake according to an embodiment of the present invention includes a pair of brake shoe 20 which rubs against an inner circumferential surface of a drum (not shown) to generate a braking force, To the back plate (10). At this time, the drum brake includes a cylindrical drum (not shown) rotated together with a wheel (not shown) of the vehicle, a back plate 10 fixed to the vehicle body, A pair of brake shoe (20) provided with a lining (21) so as to be able to generate braking force by friction with the inner circumferential surface of the drum, a wheel cylinder which operates the brake shoe (20) radially outwardly, A return spring (not shown) for restoring the brake shoe 20 and an adjuster (not shown) for compensating a gap between the lining 21 and the drum. Such a drum brake is well known in the art, and a detailed description thereof will be omitted.

On the other hand, the pair of brake shoe (20) includes an arc-shaped rim (22) having a lining (21) attached to the outer circumferential surface thereof, and a rim And a web 23 coupled to the inner circumferential surface of the rim 22 for reinforcing the rigidity of the rim 22.

The pair of brake shoes 20 as described above are respectively installed on the back plate 10 by means of the shoe hold down structure 100 for drum brake according to an embodiment of the present invention.

The shoe hold down structure 100 for a drum brake according to an embodiment of the present invention includes a shoe hold down pin 110, a shoe hold down spring 130 and a shoehold down washer 120, .

The shoe hold down pin 110 has a body portion 112 formed in a rod shape having a predetermined length and a head portion 114 provided at one end of the body portion 112 and a body portion 112 extending in the radial direction from the other end of the body portion 112 And a support portion 116 formed in the through-hole 14 of the back plate 10 to be supported. The body portion 112, the head portion 114, and the support portion 116 are integrally formed.

At this time, in order to allow one end of the shoehold down pin 110, that is, the head 114, to pass through the back plate 10 and the web 23, the back plate 10 and the web 23 are provided with Through holes (14, 24) are formed, and the through holes (14, 24) are formed at positions corresponding to each other. The through hole 14 formed in the back plate 10 has a diameter smaller than the diameter of the support portion 116 and has a diameter larger than the diameter of the body portion 112 and the head portion 114. [ The support portion 116 is supported on the back plate 10 without coming out in a direction in which the shoe holding down pin 110 is inserted. The through holes 24 formed in the web 23 allow the shoe hold down pin 110 to pass therethrough so that the width of the web 23 is larger than the diameter of the body portion 112 .

A slot 113 is formed in the head 114 of the shoe hold down pin 110 so as to have a predetermined length in the longitudinal direction of the shoe hold down pin 110 at the center. So that the head 114 is made elastically deformable by the slot 113. More specifically, the head portion 114 has a plurality of protruding portions 114a which are spaced a predetermined distance along the outer circumferential surface thereof and protruded in the radial direction. The head portion 114 is configured to have a tapered shape with its top portion being sharp. So as to easily engage with the shoe hold down washer 120 to be described later. Although the head 114 is illustrated as having two protrusions 114a by the slot 113, the head 114 is not limited thereto, and may include three or more protrusions radially spaced from the center axis It can be formed to be elastically deformable.

The fitting hole 124 is formed in the shoe hold down washer 120 so that the head part 114 passes through the fitting hole 124. Referring to FIGS. 5A to 5C, the engaging hole 124 is formed in the head part 114, as shown in FIG. 5A, (D1) smaller than the diameter (d2). 5B, when the head 114 passes through the coupling hole 124, the projection 114a of the head 114 is elastically deformed by the slot 113 to penetrate the coupling hole 124 . At this time, the head portion 114 has a tapered shape with an upper portion, so that the head portion 114 can be easily inserted into the coupling hole 124 along the outer inclined surface of the head portion 114. The protrusions 114a are restored by the elastic restoring force after the head 114 passes the coupling hole 124 and the lower end of the head 114 is supported on the upper surface of the shoe hold down washer 120 And is prevented from separating from the engaging hole 124. That is, the assembly is fastened by the pressing operation of the shoehold down washer 120. [ Therefore, it is not necessary to support the conventional shoe hold-down structure 3 in such a manner that the installation pin 3a (shoe hold down pin) is not rotated during assembly, and the washer 3e (shoehold down washer) It is possible to solve the problem of poor assembly between the installation pin 3a and the washer 3e according to the removal of the structure and the rotation angle.

Referring again to Figures 3 and 4, the shoehold down spring 130 is in the form of a coil spring. The shoe hold down spring 130 is interposed between the shoe hold down washer 120 and the brake shoe 20 so that the shoe holding down pin 110 passes through the inside of the brake shoe 20 and the back shoe 20, And serves to provide an elastic force to give a constant assembly load. The shoe hold down pin 110 as described above is configured such that the head portion 114 sequentially moves the through hole 14 of the back plate 10 and the through hole 24 of the web 23 and the shoe hold down Down washer 120 through the center of the spring 130. [ In other words, when the shoehold down washer 120 presses the other end and is engaged with the head 114 in a state where one end of the shoehold down spring 130 is supported by the web 23, The head 114 and the shoe hold down washer 120 are kept in close contact with each other by the elastic restoring force.

Although the shoe hold down structure 100 for a drum brake as described above has been shown and described as being composed of three parts and being installed on the back plate 10 so that the brake shoe 20 can flow, Alternatively, the shoe hold down structure may be composed of two parts.

6 shows a structure of a shoe hold down structure for a drum brake according to another embodiment of the present invention. Here, the same reference numerals as in the drawings shown above indicate members having the same function.

Referring to FIG. 6, the shoe hold down structure 200 according to the present embodiment includes a shoe hold down pin 110 and a shoe hold down spring 230. At this time, the shoehold down pin 110 performs the same structure and the same function as the shoehold down pin 110 of the previous embodiment, and a detailed description thereof will be omitted.

The shoe hold down spring 230 is disposed between the head portion 114 of the shoe hold down pin 110 and the brake shoe 20 so as to apply a constant assembly load to the brake shoe 20 and the back plate 10. [ And is coupled to the head 114. [ More specifically, the shoehold down spring 230 is formed by bending a leaf spring having a predetermined length. That is, both ends of the leaf spring are bent so as to face each other. At both ends of the leaf spring, coupling holes 231 and 234 are formed so as to penetrate the head portion 114 at positions corresponding to each other. At this time, the engaging hole located on the web 23 side of the brake shoe 20 is referred to as a lower engaging hole 231, and the engaging hole engaged with the head portion 114 is referred to as an upper engaging hole 234. [ The lower coupling hole 231 is formed to have a larger diameter than the diameter of the head portion 114 and the upper coupling hole 234 is formed to have a smaller diameter than the diameter of the head portion 114. The head 114 is elastically deformed when it passes through the upper engaging hole 234 after passing through the lower engaging hole 231 and is restored by the elastic restoring force after passing through the upper engaging hole 234, And is prevented from being separated from the hole 234.

As a result, when the brake shoe 20 is installed to be movable in the back plate 10 through the shoe hold down assembly 100 and 200 as described above, the head 114 of the shoe hold down pin 110 is inserted into the slot The downward movement of the shoehold down washer 120 and / or the shoehold down spring 230 having a plate spring shape is completed by the elastic deformation of the shoehold down washer 113. [ That is, the shoe hold-down structures 100 and 200 can be easily installed, and workability is improved.

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.

10: back plate
20: Brake Shoe
100, 200: shoe hold down structure
110: shoehold down pin
113: Slot
114: Head
120: Shoehold down washer
130, 230: Shoehold down spring

Claims (5)

A shoe hold down structure for a drum brake, comprising: a pair of brake shoats which frictionally contact an inner circumferential surface of a drum to generate a braking force,
And a shoe holder having a body portion having a predetermined length for connecting the head portion and the support portion, wherein the head portion is provided with a head portion sequentially passing through the through hole formed in the back plate and the brake shoe at one end, Down pin;
A shoe hold down washer in which a coupling hole is formed such that the head portion is inserted and coupled; And
And a shoe hold down spring interposed between the shoe hold down washer and the brake shoe such that the shoe hold down pin penetrates the inside of the shoe hold down pin to provide an elastic force to apply a constant assembly load to the brake shoe and the back plate,
Wherein the head is formed with a slot having a predetermined length in the longitudinal direction at its center, and is elastically deformable by the slot. A shoe hold down structure for a drum brake, comprising: a pair of brake shoats which frictionally contact an inner circumferential surface of a drum to generate a braking force,
And a shoe holder having a body portion having a predetermined length for connecting the head portion and the support portion, wherein the head portion is provided with a head portion sequentially passing through the through hole formed in the back plate and the brake shoe at one end, Down pin; And
And a shoe hold down spring which is provided between the head and the brake shoe to provide an elastic force to apply a constant assembly load to the brake shoe and the back plate,
Wherein the head is formed with a slot having a predetermined length in the longitudinal direction at its center, and is elastically deformable by the slot. 3. The method according to claim 1 or 2,
Wherein the head portion is elastically deformed when passing through the engagement hole and is restored by an elastic restoring force after passing through the engagement hole to prevent the head portion from being separated from the engagement hole. 3. The method according to claim 1 or 2,
Wherein the head portion has a plurality of protrusions protruding from the outer circumferential surface of the head portion at a predetermined interval and radially protruding therefrom, and has a tapered shape with a top portion thereof being sharp. 3. The method of claim 2,
Wherein the shoe hold down spring is formed by bending a plate spring having a bar length so that both ends of the plate spring face each other.

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