KR101113569B1 - drum break of vehicle - Google Patents

Abstract

The present invention relates to a drum brake of an automobile, wherein the front and rear portions of the lining 55 are uniformly opened as a whole when the leading shoe 53 and the trailing shoe 54 are rotated toward the drum to generate a braking force. As a result, uneven wear of the lining 55 is prevented, thereby enabling the vehicle to always exhibit the optimum braking performance and to further increase the intermission.

Description

Drum break of vehicle

1 to 3 is a perspective view and a front view illustrating a drum brake according to a conventional structure,

4 and 5 are a front view and a plan view for explaining a drum brake according to the present invention,

6 and 7 is an exploded perspective view of the drum brake according to the present invention.

<Description of Symbols for Main Parts of Drawings>

51-Backplate 52-Cam

53-Reading Shoe 54-Trailing Shoe

56-anchor pin 61-leading shoe

62-trailing shoepin 63-leading shoe wire

64-trailing shoe pin 65-spring bracket

66,67-Coupling Pin 68-Leading Shuttle Spring

69-trailing shree turn spring 71-coil spring

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drum brake of a motor vehicle, and more particularly, to a drum brake of a motor vehicle capable of preventing uneven wear of the lining and exerting an optimum braking force.

In general, a brake system of a vehicle is used to reduce or stop the speed of a vehicle in driving, and is classified into a main brake, a parking brake, and an auxiliary brake.

Here, the air brake used as a kind of the main brake is a device that presses the brake shoe to the drum by using the force of compressed air and generates a braking force by using the friction force, which is usually a large truck, bus or trailer that requires a large braking force. Mainly used for.

Meanwhile, FIGS. 1 to 3 illustrate drum brakes, which are a type of air brakes.

That is, the conventional drum brake is provided with a bolt on the wheel hub as shown, the drum (not shown) to rotate with the wheel, the back plate 11 is installed to be fixed to the axle, and the back plate 11 Cam 12 is rotatably received by the power from the slack adjuster (T;) on the upper end of the cam shaft 12a and cast iron installed on both front sides of the back plate 11 Leading shoe 13 and trailing shoe 14 of the material, the lining 15 which is attached to the outer surface of the leading shoe 13 and trailing shoe 14 is a friction material that generates a braking force by being in direct contact with the drum, The lower end of the back plate 11 and the leading shoe 13 and trailing shoe 14 so that the lower end of the leading shoe 13 and trailing shoe 14 are rotatably supported with respect to the back plate 11. Anchor bushes 16 and anchor pins 17 which are installed to penetrate the lower ends, respectively. , Leading shoe bushes 18, leading shoe pins 19, and trailing shoe bushes 21 installed to penetrate the upper ends of the leading shoe 13 and the trail ring shoe 14 to be in direct contact with the cam 12. ) And the trailing shoe pin 22 and the spring shoe 23 and 24 coupled to the upper ends of the leading shoe 13 and the trailing shoe 14 to be fixed to both ends, respectively. It is composed of a return spring 25 which gives elastic restoring force to the operation of the trailing shoe 14.

Here, the leading shoe 13 and the trailing shoe 14 are configured of the front brackets 13a and 14a and the rear brackets 13b and 14b, respectively, and the front brackets 13a and 14a and the rear brackets, respectively. 13b and 14b are provided as spaced apart from each other, as shown.

The spring pins 23 and 24 are coupled to the front bracket 13a of the leading shoe 13 and the front bracket 14a of the trailing shoe 14, and thus the return spring 25 Is configured to have a structure connected to the front bracket (13a) of the leading shoe 13 and the front bracket (14a) of the trailing shoe 14 through the spring pins (23, 24).

Therefore, when the diaphragm is moved forward by the compressed air delivered to the brake chamber during the operation of the main brake pedal, the push rod of the brake chamber is interlocked to transfer the operating force of the diaphragm to the slack adjuster (T).

Then, the slack adjuster (T) is rotated by the linear movement of the push rod, and at the same time the cam 12 of the drum brake also interlocked with the operation of the slack adjuster (T) received through the cam shaft (12a). The gap between the leading shoe bush 18 and the trailing shoe bush 21 is widened in both directions while the rotary motion is performed.

Accordingly, the leading shoe 13 and the trailing shoe 14 are rotated outwardly with the anchor pin 17 as the center of rotation, and at this time, the lining 15 attached to each shoe 13 and 14. Is pressed on the drum to generate a braking force by the friction force.

As a result, the drum, which has been rotating with the wheels, is gradually reduced in rotation by the braking force generated through the lining 15, so that the running vehicle can be stopped.

Then, when the stepping force applied to the main brake pedal is removed, the diaphragm and the push rod are retracted while being released by the air pressure generated in the brake chamber, and the slack adjuster (T) and the cam 12 receiving the operating force thereof are It rotates in the opposite direction and returns to its original state.

Accordingly, the leading shoe 13 and the trailing shoe 14, which are spaced apart from each other, are rotated inward by the restoring force of the return spring 25, and as a result, the lining 15 is removed from the drum. As it separates, the braking force is released.

However, in the conventional drum brake as described above, when the leading shoe 13 and the trailing shoe 14 are rotated to the drum side to generate a braking force, the rear brackets 13b and 14b are more than the front brackets 13a and 14a. As a result of the larger number of), there is a problem in that uneven wear of the lining 15 occurs.

That is, when the leading shoe 13 and the trailing shoe 14 are rotated to the drum side by the rotation of the cam 12, the front bracket 13a and the trailing shoe 14 of the leading shoe 13 are rotated. Since the front bracket 14a of the front bracket 14a is restrained by the return spring 25, the front brackets 13a and 14a of the leading shoe 13 and the trailing shoe 14 are respectively rear brackets 13b. Less than 14b).

Accordingly, the lining 15 coupled to the leading shoe 13 and the trailing shoe 14 has a rear portion more outward than the front portion constrained by the return spring 25 as shown in FIG. 2. A lot of opening (marked as the length of the arrow), and as a result, the lining 15 has a relatively less constrained rear portion of the return spring 25, and wears faster when contacted with the drum. will be.

The uneven wear phenomenon of the lining 15 results in a partial loss of braking force, and as a result, the vehicle develops into a problem of having an unstable braking property.

Accordingly, the present invention has been made to solve the above problems, by preventing the braking phenomenon of the leading shoe and trailing shoe squeezed on the drum when the braking force is generated to always provide the optimum brake performance of the automobile brake The purpose is to provide.

The present invention for achieving the above object, the cam coupled to the back plate by the air pressure generated during the operation of the main brake pedal rotates, the leading shoe and trailing shoe anchored to receive the rotational movement of the cam In a drum brake of an automobile which generates a braking force by a pressing force of a lining and a drum by rotating the rotational movements with respect to each other about a pin, a spring bracket which is installed through the camshaft so as to be located between the cam and the back plate. Wow; A coupling pin coupled to the leading shoe and the trailing shoe by an elastic clip coupled to both ends while passing through the front and rear brackets of the leading shoe and the front and rear brackets of the trailing shoe; One end is coupled to be hooked to the left and right portions of the spring bracket, respectively, the other end is inserted into the space between the front and rear brackets of the leading shoe and the space between the front and rear brackets of the trailing shoe and the intermediate point of the coupling pin. It is characterized in that it is configured to include; leading Shuritten spring and trailing Shuriton spring coupled to be caught on.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to the accompanying drawings.

4 and 5 are a front view and a plan view for explaining a drum brake according to the present invention, Figures 6 and 7 is an exploded perspective view of the drum brake according to the present invention.

The drum brake according to the present invention, as shown in Figs. 4 to 7, a drum (not shown) installed on the wheel hub via a bolt to rotate with the wheel, and the back plate 51 is fixed to the axle And a cam 52 that is rotatably installed by receiving power from a slack adjuster on the top of the back plate 51 through a cam shaft 52a, and both front sides of the back plate 51. Lining, which is a friction material that generates braking force by being attached to the leading shoe 53 and trailing shoe 54 of the cast iron material installed on the part, and the outer surface of the leading shoe 53 and trailing shoe 54 to be in direct contact with the drum. 55 is basically configured.

Here, the leading shoe 53 and the trailing shoe 54 are composed of a front bracket (53-1, 54-1) and a rear bracket (53-2, 54-2), respectively, the front bracket 53-1 and 54-1 and rear brackets 53-2 and 54-2 are installed as spaced apart from each other as shown.

An anchor pin 56 penetrates through the lower end of the back plate 51, and leading shoe bushes 57 and trailing shoe bushes are formed on both sides of the cam 52 at the upper end of the back plate 51. 58 is positioned, respectively, the leading shoe bush 57 and the trailing shoe bush 58 is coupled to the leading shoe pin 61 and the trailing shoe pin (62).

On the other hand, the upper and lower ends of the front bracket 53-1 and the rear bracket 53-2 constituting the leading shoe 53 to partially wrap the outer peripheral surface of the leading shoe pin 61 and the anchor pin 56 (that is, , So that the outer circumferential surface of the leading shoe pin and the anchor pin can be partially fitted), the semi-circular leading shoe pin groove 53a and the anchor pin groove 53b are formed, respectively.

In addition, the upper and lower ends of the front bracket 54-1 and the rear bracket 54-2 constituting the trailing shoe 54 may partially wrap the outer peripheral surfaces of the trailing shoe pin 62 and the anchor pin 56 ( That is, semicircular anchor pin grooves 54b are formed to allow the outer circumferential surfaces of the leading shoe pin and the anchor pin to be partially fitted).

Further, wire coupling grooves 53c and 54c are formed at the side portions of the leading shoe pin groove 53a and the trailing shoe pin groove 54a, respectively, and spring holes are formed at the side portions of the anchor pin grooves 53b and 54b, respectively. 53d and 54d are formed, and pinholes 53e and 54e are formed in an intermediate portion between the wire coupling grooves 53c and 54c and the spring holes 53d and 54d.

Meanwhile, the leading shoe pin 61 fitted to the leading shoe bush 57 and the trailing shoe pin 62 fitted to the trailing shoe bush 58 are led by the leading shoe pin wire 63 and the trailing shoe pin wire 64. It has a structure that is coupled to the shoe 53 and the trailing shoe (54).

That is, the leading shoe pin wire 63 and the trailing shoe pin wire 64 are formed in the shape of a circle whose both ends can surround the outer peripheral surface of the leading shoe pin 61 and the trailing shoe pin 62, both ends Intermediate portions connecting the wires are elastically fitted into the wire coupling grooves 53c and 54c, respectively, to be coupled to the leading shoe 53 and the trailing shoe 54.

To this end, the leading shoe pin wire (63) and the trailing shoe pin wire (64), each end of each end so as to surround the outer circumferential surface of the leading shoe pin (61) and the trailing shoe pin (62) in one direction Pin coupling portions (63a, 64a) formed in the shape of an open circle, and bent from the pin coupling portions (63a, 64a) and the wire coupling groove formed in the leading shoe (53) and the trailing shoe (54) 53c and 54c, respectively, and are formed to have coupling groove fitting portions 63b and 64b coupled to each other.

In addition, a spring bracket 65 is installed between the cam 52 and the back plate 51, and the spring bracket 65 is installed as penetrated by the cam shaft 52a.

In addition, as the pinholes 53e and 54e formed in the leading shoe 53 and the trailing shoe 54, the coupling pins 66 and 67 pass through the leading shoe 53 and the trailing shoe 54, respectively. Fitted and combined.

That is, the coupling pins 66 and 67 are the front and rear brackets 53-1 and 53-2 of the leading shoe 53 and the front and rear brackets 54-1 and 54- of the trailing shoe 54. 2) through the leading shoe 53 and the trailing shoe 54 in this way, both ends are maintained in a state coupled by the elastic clips (66a, 67a).

In addition, the left and right sides of the spring bracket 65 and the coupling pins 66 and 67 are provided so that both ends of the leading shree return spring 68 and the trailing shrew spring 69 are engaged with each other.

In other words, the leading shree spring (68) is coupled to one end is caught on the left side of the spring bracket 65, the other end of the front and rear brackets 53-1 constituting the leading shoe 53 , 53-2) is coupled to be caught between the intermediate points of the coupling pin (66).

In addition, the trailing shree spring (69) is coupled to the one end is caught on the right side of the spring bracket 65, the other end of the front and rear brackets 55-1 constituting the trailing shoe (55) , 55-2) is inserted to be coupled to the intermediate point of the coupling pin (67).

To this end, the spring bracket 65, the cam shaft hole (65a) is formed so that the cam shaft 52 penetrates, the leading shoe pin 61 and the trailing on the left and right sides of the cam shaft hole (65a) A body portion 65d having flanges 65b and 65c formed to support one end of the shoe pin 62 and protrudes toward the front of the back plate 51 from the flanges 65b and 65c of the body portion 65d. While being bent, one end of the leading shree return spring 68 and the trailing shree spring 69 is caught and coupled to the spring hook portions 65e and 65f, and both ends of the spring hook portions 65e and 65f. It is formed to have a reinforcing portion (65g) to connect.

In addition, a coil spring for coupling the lower end of the leading shoe 53 and the trailing shoe 54 to the spring holes 53d and 54d formed in the leading shoe 53 and the trailing shoe 54 using an elastic force. Both ends of 71 are provided so that each may be caught.

The operation process of the drum brake according to the present invention configured as described above is the same as the conventional structure described above with reference to Figures 1 to 3, the description thereof will be omitted.

However, when the leading shoe 53 and the trailing shoe 54 are rotated toward the drum to generate the braking force, the leading shoe 53 is opened while winning the elastic force of the leading shoe return spring 68. The trailing shoe 54 is opened while winning the elastic force of the trailing shoe spring (69).

When the braking force is released, the leading shoe 53 and the trailing shoe 54 which are opened toward the drum are returned to their original positions by the elastic restoring force of the leading shoe return spring 68 and the elastic restoring force of the trailing shoe spring 69, respectively. Will be returned.

On the other hand, when the leading shoe 53 and the trailing shoe 54 is rotated to the drum side to generate a braking force, the front brackets 53-1 and 54-1 and the rear brackets 53-2, respectively, 54-2 are opened equally to each other, so that the lining 15 coupled to the leading shoe 53 and the trailing shoe 54 is also the same (uniform) as shown in FIG. (Indicated by the length of the arrow).

That is, conventionally, the front bracket 13a of the leading shoe 13 and the front bracket 14a of the trailing shoe 14 are restrained by the return spring 25, so that they are rearward from the front brackets 13a and 14a. The brackets 13b and 14b become more wide open, which causes the lining 15 to also open more rearward to the outside than the front part constrained by the return spring 25, resulting in uneven wear of the lining 15. It happened.

However, the structure of the present invention is inserted between the front and rear brackets (53-1, 53-2), one end of the leading shree spring (68) and trailing shree spring (69) respectively constitute a leading shoe (53) And coupled to be caught by the intermediate point of the coupling pin 66, while being inserted between the front and rear brackets 55-1 and 55-2 constituting the trailing shoe 55, the intermediate point of the coupling pin 67. By being coupled to the hook, the front shoe (53-1, 54-1) and the rear bracket (53-2, 54) when the leading shoe 53 and the trailing shoe (54) rotates to the drum side -2) are equally (uniformly) apart from each other in the outward direction, and thus the lining 15 coupled to the leading shoe 53 and the trailing shoe 54 also has the same (uniform) front and rear portions. You will have a movement.

As such, when the front and rear portions of the lining 15 coupled to the leading shoe 53 and the trailing shoe 54 have the same (uniformly) movement between each other, it is possible to prevent uneven wear of the lining 15. As a result, the vehicle can always exhibit the optimum braking performance and at the same time, it is possible to secure even more increased scrutiny.

As described above, according to the present invention, when the leading shoe and the trailing shoe are rotated toward the drum to generate the braking force, the front and rear portions of the lining have a uniformly widening movement, thereby preventing uneven wear of the lining. As a result, the vehicle can always achieve the optimal braking performance, and at the same time, it is possible to secure even more stability during the period.

Claims (2)

The cam coupled to the back plate is rotated by the air pressure generated during the operation of the main brake pedal, and the leading shoe and the trailing shoe, which receive the rotational movement of the cam, are rotated relative to each other about the anchor pin. In a drum brake of an automobile which generates a braking force by the pressing force of the lining and the drum, A spring bracket (65) installed as penetrated through the cam shaft (52a) so as to be located between the cam (52) and the back plate (51); The front and rear brackets 53-1 and 53-2 of the leading shoe 53 and the front and rear brackets 54-1 and 54-2 of the trailing shoe 54 are coupled to both ends. A coupling pin (66,67) coupled to the leading shoe (53) and the trailing shoe (54) by an elastic clip (66a, 67a); One end is coupled to the left and right sides of the spring bracket 65, respectively, and the other end is spaced between the front and rear brackets 53-1 and 53-2 of the leading shoe 53 and the trailing shoe ( 54 is a leading shroud spring 68 and a trailing shree spring spring which are inserted into the space between the front and rear brackets 54-1 and 54-2 and are engaged to be caught by the intermediate points of the coupling pins 66 and 67. 69); Reading shoe pins 61 and trails respectively inserted into the leading shoe bushes 57 and the trailing shoe bushes 58 so that the leading shoe bushes 57 and the trailing shoe bushes 58 are fitted to both sides of the cam 52. Leading shoepin wire (63) and trailing to wrap the outer circumferential surface of the ring shoe pin (62) so that the leading shoe (61) and trailing shoe pin (62) is coupled to the leading shoe (53) and the trailing shoe (54) Scoopwire 64; The drum brake of the car is equipped with. The method of claim 1, wherein the spring bracket 65, A camshaft hole 65a is formed so that the camshaft 52a penetrates, and a flange is formed so as to support one end of the leading shoe pin 61 and the trailing shoe pin 62 at left and right sides of the camshaft hole 65a. A body portion 65d having 65b and 65c formed thereon; It is formed to be bent from the flange (65b, 65c) of the body portion (65d) toward the front of the back plate 51, while one end of the leading Shuritten spring 68 and the trailing Shuriturn spring (69) is caught Spring hanger portions 65e and 65f coupled to each other; Reinforcing parts (65g) connecting both ends of the spring hook parts (65e, 65f); Drum brake of a vehicle, characterized in that it is formed to have.

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