JPH0550174U - Brake shoe support structure for vehicle drum brakes - Google Patents

Abstract

(57) [Summary] [Purpose] With a simple structure, the movement of the brake shoe in the direction of the back plate and the direction of the drum at the time of braking is regulated to prevent abnormal noise and uneven wear of the lining. [Structure] Wedge-shaped concave grooves 7d, 7d are formed on the contact surface of the anchor 7 with the brake shoes 3, 3, and the concave groove 7 is formed at one end of the brake shoes 3, 3 contacting the anchor 7.
Formed are tapered fitting portions 3d, 3d that can be fitted into d, 7d and become thinner toward the tip.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a brake shoe support structure arranged inside a back plate of a vehicle drum brake.

[0002]

[Prior Art]

 An anchor structure provided on the back plate as the fulcrum of expansion of the brake shoe is disclosed, for example, in Japanese Utility Model Publication No. 1-7869. This anchor structure is formed by sandwiching an anchor block between an anchor plate and a wire guide plate.The ends of both brake shoes are supported by both end faces of the anchor block, and the brake shoes are separated from the anchor block by the anchor plate. It prevents you from leaving.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned one, since the ends of both brake shoes are in contact with both side surfaces of the flat anchor block, both brake shoes move toward the back plate and the drum during braking, which causes abnormal noise. Or the brake shoe lining was worn unevenly.

Therefore, the present invention provides a brake shoe for a vehicle drum brake, which has a simple structure and can prevent movement of the brake shoe in the back plate direction and the drum direction during braking, and can prevent abnormal noise and uneven wear of the lining. It is intended to provide a support structure.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the brake shoe support structure for a vehicle drum brake according to the present invention is such that a brake shoe opposed to a back plate is used as a fulcrum with an anchor provided between one ends as the fulcrum. In a drum brake for a vehicle that spreads by an actuator arranged between them to perform a braking action, in the first configuration, a wedge-shaped groove is formed on the contact surface of the anchor with the brake shoe, and the anchor is formed. In the second configuration, a wedge-shaped groove is formed on the contact surface of the brake shoe of the anchor and the actuator. The respective end portions of the brake shoes that come into contact with the anchor and the actuator are fitted in the recessed grooves.

[0006]

[Action]

 As a result, in the first configuration, one end of the brake shoe fits into the groove formed in the anchor, and the brake shoe is prevented from freely moving on the side surface of the anchor.

Further, in the second configuration, the groove formed in the anchor and one end of the brake shoe are fitted in the groove formed in the actuator and the other end of the brake shoe, respectively, and the brake shoe moves in the back plate direction. And more reliably prevent movement in the direction of the drum.

[0008]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show a first embodiment of the present invention, in which a drum brake 1 includes a pair of brake shoes 3 and 3 arranged to face a back plate 2, a shoe hold pin 4 and a shoe. It is elastically held by the hold spring 5 and a wheel cylinder 6 is fixed between the ends 3a, 3a of the brake shoes 3, 3 and an anchor 7 is fixed between the other ends 3b, 3b.

A return spring 8 is provided between the brake shoes 3 and 3 in the vicinity of the wheel cylinder 6, and an automatic braking gap adjusting device 9 is provided in the vicinity of the return spring 8.

In the wheel cylinder 6, a pair of pistons 6b and 6b are fitted in a cylinder body 6a so as to be liquid-tight and movable, and a resilient force of a wheel cylinder spring 6c arranged between the pistons 6b and 6b. As a result, the outer ends of the pistons 6b, 6b project from the open ends on both sides of the cylinder body 6a, respectively, and the hydraulic pressure supplied to the hydraulic chamber 6d defined between the pistons 6b, 6b causes the pistons 6b, 6b to be released. Move in a direction away from each other and spread the brake shoes 3, 3 to perform a braking action.

Further, the pistons 6b, 6b have wedge-shaped recessed grooves 6e, 6e formed on the contact surfaces of the brake shoes 3, 3 of the pistons 6b, 6b.

The anchor 7 is formed by sandwiching the anchor block 7a between the anchor plate 7b and the wire guide plate 7c on the ledge surface 2a of the back plate 2 and fixing them with the rivets 10 and 10. , 3 are formed with wedge-shaped concave grooves 7d, 7d.

The brake shoe 3 has a lining 3c mounted on the outer periphery thereof, and the lining 3c slides on the inner peripheral surface of a brake drum (not shown) to perform a braking action. Further, the one ends 3a, 3a of the brake shoes 3, 3 are tapered fitting portions 3d, 3d which can be fitted into the recessed grooves 6e, 6e formed in the pistons 6b, 6b and which become thinner toward the tip. Similarly, the other ends 3b, 3b are also formed with tapered fitting portions 3e, 3e which can be fitted into the concave grooves 7d, 7d of the anchor 7 and which become thinner toward the tip.

In the disc brake 1 thus formed, when the brake shoes 3 and 3 are assembled, the fitting portions 3d and 3d formed at the ends 3a and 3a of the brake shoes 3 and 3 are fitted to the pistons 6b and 6b. The recessed portions 6e, 6e are fitted together, and the fitting portions 3e, 3e formed at the other ends 3b, 3b are fitted into the recessed grooves 7d, 7d formed in the anchor 7.

As a result, the brake shoes 3, 3 are positioned with respect to the back plate direction of the pistons 6b, 6b and the anchor 7 and the drum direction, the brake shoes 3, 3 do not rattle during braking, and abnormal noise is heard. Uneven wear of the linings 3c and 3c can be prevented.

4 and 5, the brake shoes 3 and 3 have one end 3a and 3a, the other end 3b and 3b, the recessed grooves 6e and 6e of the pistons 6b and 6b, and the recessed grooves 7d and 7d of the anchor 7, respectively. It shows a second embodiment of the present invention in which the fitting portions 3f, 3f, 3g, 3g having rounded shapes which can be fitted are formed, and the fitting portion is angled as in the first embodiment. Can also be easily formed.

In addition, according to the present invention, as shown in each of the above-described embodiments, wedge-shaped concave grooves are respectively formed on the contact surfaces of the anchor and the wheel cylinder with the brake shoe, and the wedge shoe is fitted with the fitting portion of the brake shoe. It is not limited to the above-mentioned ones, but at least the ones in which the brake shoe and the anchor are fitted on the anchor side may be used. Further, in the case of expanding the brake shoe by rotating the cam, a groove may be formed on the contact surface of the cam with the brake shoe.

[0019]

[Effect of the device]

 As described above, the present invention forms a wedge-shaped groove on the contact surface of the anchor with the brake shoe, and fits one end of the brake shoe into the groove, or connects the brake shoe of the anchor and the wheel cylinder. A concave groove inclined like a wedge is formed on the contact surface of the brake shoe, and each end of the brake shoe that contacts the anchor and the wheel cylinder is fitted into the concave groove, so that the brake shoe has a simple structure. Vibration in the plate direction and drum direction can be prevented, and abnormal noise and uneven wear of the lining can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view taken along line I-I of FIG.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a front view of a drum brake showing a first embodiment of the present invention.

FIG. 4 is a sectional view of a main part showing a second embodiment of the present invention.

FIG. 5 is a sectional view of the same main part.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Drum brake, 2 ... Back plate, 3 ... Brake shoe, 3a ... One end, 3b ... Other end, 3c ... Lining, 3d, 3e ... Fitting part, 6 ... Wheel cylinder, 6a
… Cylinder body, 6b… Piston, 6e… Concave groove, 7…
Anchor, 7d ... concave groove

Claims (2)

[Scope of utility model registration request] 1. A brake shoe arranged to face a back plate, with an anchor arranged between one ends as a fulcrum,
In a vehicle drum brake that expands by an actuator arranged between the other ends to perform a braking action, a wedge-shaped concave groove is formed on the contact surface of the anchor with the brake shoe, and the anchor contacts with the anchor. A brake shoe support structure for a vehicle drum brake, wherein one ends of the both brake shoes are fitted in the groove. 2. A wedge-shaped groove is formed on the contact surface of the brake shoe of the actuator, and the other ends of the brake shoes contacting the actuator are fitted in the groove. Item 1. A brake shoe support structure for a vehicle drum brake according to Item 1.