JPH0219625Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a brake shoe holding device for a drum brake.

(Prior Art) A drum brake is provided with a brake shoe holding device that positions the center of the shoe web relative to a bucking plate in order to prevent the brake shoe from falling during braking.

In particular, as a brake shoe holding device that reduces the sliding resistance of the brake shoe with the bucking plate when the brake is released, a brake shoe holding device as shown in Fig. 2 was proposed in Japanese Utility Model Application No. 59-43735. has been disclosed.

The tip of the shoe hold pin 10 that fixes the base to the backing plate reinforcing plate 2 is inserted into the elongated hole 3b' of the shoe web, and is screwed into the pin 10,
The show web 3b is sandwiched between the washer 8 and the receiving surface 11a of the adjustment nut 11, which is positioned with the pin 12, and the nut 9 is screwed onto the tip side of the show hold pin 10, which is then positioned with the pin 12a. There is. 13 is a drum.

In this way, the shoe rim 3a of the brake shoe is held floating above the bucking plate 1, and during braking, the shoe web 3b can slide against the receiving surface 11a and the washer 8 through the elongated hole 3b'.

(Problems to be Solved by the Invention) A clearance in which the shew web 3b can slide between the receiving surface 11a and the washer 8 is provided as follows.

After positioning the adjustment nut 11 on the shoe hold pin 10, fully tighten the nut 9 onto the shoe hold pin 10 via the washer 8, and then tighten the nut 9 until the brake shoe 3 moves lightly in the drum radial direction. is loosened, and the pin 12a is inserted and fixed.

In order to fix the nut 9 screwed onto the shoe hold pin 10 with the pin 12a, the brake shoe slides in order to align the through hole provided in the shoe hold pin 10 with the pin 12a. If the required play space is not constant and the play space is large,
Brake shoe 3 had a tendency to collapse.

(Means for solving the problem) The present invention provides a brake shoe holding device that provides a constant clearance necessary for the brake shoe to slide, and its configuration is as follows. It is.

A nut member consisting of a head and a cylindrical part is screwed onto a showhold pin whose base is fixed to the backing plate reinforcing plate, and is inserted into an elongated hole provided in the show web, and a pair of washers is fitted onto the nut member. Hold the show web with the sleeve, fit the sleeve onto the nut member, insert a C ring with a small gap in the width direction into the annular groove provided at the tip of the nut member, and hold one washer between the show web and the sleeve with the sleeve. This is the brake shoe holding device that is pressed.

(Operation) The brake shoe is lifted from the bucking plate by holding its shoe web between a pair of washers that are fitted onto a nut member that is screwed onto a shoe hold pin whose base is fixed to the bucking plate reinforcing plate. The brake shoe is supported by the show hold pin in an upward state, and during braking, the brake shoe is operated with a clearance between both washers and the show web provided within the range of the minute gap between the annular groove of the nut member and the C ring. , the long hole provided in the shew web is guided by the shewhold pin to smoothly slide between the washers.

(Example) An example of the brake shoe holding device according to the present invention will be described based on FIG.

1 is a bucking plate, 2 is a bucking plate reinforcing plate, and 3 is a brake shoe consisting of a shoe rim 3a, a shoe web 3b, and a lining 3c, and the shoe web 3b is provided with a long hole 3b'. Reference numeral 4 designates a shewhold pin consisting of a base 4a and a shaft 4b.The base 4a is fixed to the backing plate reinforcing plate 2 by welding, screwing, or other ordinary fixing means, and the shaft 4b is fixed with a screw. 4b' is screwed on. 5 is a nut member consisting of a head 5a and a cylindrical portion 5b, and an annular groove 5 is provided at the tip of the cylindrical portion 5b.
b′ is provided. The show-hold pin 4 with the nut member 5 screwed therethrough is inserted through the elongated hole 3b' with a washer 7a interposed therebetween that supports the show web 3b. The nut member 5 adjusts its position relative to the show hold pin 4 to support the show web 3b with a washer 7a, and is fixed to the show hold pin 4 using a pin not shown. Also, the washers 7b and washers 7a can be used to create a show web 3b.
The sleeve 6 is fitted onto the nut member 5 so as to sandwich the C-ring 6a, and the sleeve 6 is fitted onto the nut member 5 so as to sandwich the C-ring 6a.
into the annular groove 5b' of the nut member, and then insert the sleeve 6
is integrated with the nut member 5, and the washer 7b is pressed against the shew web 3b by the sleeve 6. A constant clearance of approximately 0.3 mm is provided between the width of the C-ring 6a and the width of the annular groove 5b' to absorb manufacturing errors in each part such as the washer, shew web, and C-ring.

The brake shoe 3, whose intermediate portion is supported by the brake shoe holding device in this way, has one end secured to the piston of a wheel cylinder (not shown), and the other end secured to the wheel cylinder body or anchor device, etc. It is incorporated into the drum brake.

Next, the effect will be explained.

The brake shoe 3 is supported by both washers 7a and 7b with its shoe rim 3a floating above the bucking plate 1 so as not to fall over.
Since a certain minute gap is provided between the width of the annular groove 5b' and the width of the annular groove 5b', the shew web 3b is
It can slide smoothly between a and 7b.

(Effects of the Invention) As understood from the above explanation, the brake shoe holding device according to the present invention has the following effects.

In order to prevent the brake shoe from sliding against the bucking plate during braking and creating resistance, and to cope with minute changes in the thickness of each component, the annular groove provided at the tip of the nut member and the C-ring. The brake shoe can move smoothly by dealing with the minute gap in the width direction, and the minute gap can be kept constant. It's not like I'm going to fall over.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of a brake shoe holding device according to the present invention, and FIG. 2 is a sectional view of a conventional brake shoe holding device. 1: Bucking plate, 2: Bucking plate reinforcement plate, 3: Brake shoe, 3b: Shoe web, 3b': Long hole, 4: Shoe hold pin,
4a: base, 4b: shaft, 4b': screw, 5: nut member, 5a: head, 5b: cylinder, 6: sleeve, 6a: C ring, 7a, 7b: washers.

Claims (1)

[Scope of utility model registration request] A nut member consisting of a head and a cylindrical part is screwed onto a showhold pin whose base is fixed to the backing plate reinforcing plate, and is inserted into an elongated hole provided in the show web, and a pair of washers is fitted onto the nut member. Hold the show web with the sleeve, fit the sleeve onto the nut member, insert a C ring with a small gap in the width direction into the annular groove provided at the tip of the nut member, and hold one washer between the show web and the sleeve with the sleeve. A brake shoe holding device characterized by being pressed.