JPH068346Y2 - Vehicle drum brakes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a vehicle drum brake including a wheel cinder that hydraulically operates a brake shoe.

[Conventional technology]

Generally, in this type of drum brake in which the brake shoe arranged on the back plate is hydraulically operated, the end of the brake shoe on the expansion side is supported by the piston of the wheel cylinder, and the inlet of the wheel cylinder base is
An oil bolt that connects the brake pipe and a bleeder screw that discharges the residual air in the wheel cylinder are screwed to the inlet portion provided so as to project from the opening of the back plate to the rear surface.

In the drum brake, a brake drum that rotates integrally with the wheels is provided so as to cover the brake shoes and the wheel cylinders, and the outer periphery of the back plate is protected from dust and rainwater by the brakes. A dust cover that forms a labyrinth-like gap with the rim of the drum is provided.

[Problems to be solved by the invention]

However, in the above-mentioned drum brake, since the oil bolt and the bleeder screw protrude from the back plate to the outside, there is a possibility that flying stones or the like may come into contact with them and loosen, which is not preferable.

Then, this invention aims at providing the drum brake which protected the inlet part of a wheel cylinder.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a vehicle drum brake in which a dust cover is provided around the outer periphery of the back plate and the inlet of the wheel cylinder to which the brake pipe is connected faces the back surface of the back plate. ,
It is characterized in that a part of the dust cover is extended to cover the inlet portion.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In the drum brake 1, a brake shoe 3 is pivotally supported by a back plate 2 fixed to the vehicle body, and a wheel cylinder 4 for hydraulically expanding the brake shoe 3 is provided at an expansion side end portion of the shoe 3. It is arranged.

The wheel cylinder 4 is attached to the back plate 2 by arranging the inlet portion 4a of the cylinder body base so as to project from the opening 5 of the back plate 2 to the outside of the back surface and bolting the mounting flange 4b to the inner peripheral edge of the opening 5. In the cylinder hole 7 into which the piston 6 for pushing the expansion side end of the brake shoe 3 is inserted, the inlet port 8 for introducing the pressure liquid into the hole 7 and the bleeder hole for discharging the residual air are provided. And 9 are provided so as to open in the inlet portion 4a, and an oil bolt 11 that connects the brake pipe 10 to the opening portion of the inlet port 8 and a bleeder hole 9 are provided.
A bleeder screw 13 to which a cap 12 is attached is screwed into each of the openings.

A ring-shaped dust cover 14 is welded to the outer surface of the outer peripheral portion of the back plate 2. The cover 14 covers the drum brake 1 together with the flange 2a of the back plate 2 that is bent inward of the drum brake 1. A labyrinth-like gap is formed between the mouth edge 15a of the brake drum 15 arranged to cover the brake drum 15.

Inlet portion 4a protruding to the back surface of the back plate 2
The oil bolt 11 and the bleeder screw 13 protruding from the opening are covered with a guard plate 16.

The guard plate 16 is provided with an extending portion at a part of the inner circumference of the dust cover 14 near the inlet portion 4a, and the extending portion is bent into a substantially U-shape to form the guard plate 16. Covers the inlet portion 4a in the vertical direction to protect the oil bolt 11 and the bleeder screw 13. The brake pipe 10 connected to the oil bolt 11 is a two-pronged portion formed on the tip side of the guard plate 16. The leg pieces 16a are inserted in the gap 17 between the leg pieces 16a.

In this embodiment, since the oil bolt 11 and the bleeder screw 13 of the inlet portion 4a are covered by the guard plate 16 extended to the dust cover 14, the stepping stone during traveling or the unitized drum brake 1 is conveyed. In this case, the transport case or pallet will not be loosened or damaged.

Further, since the brake pipe 10 is inserted into the gap 17 of the guard plate 16, even if the brake pipe 10 receives an external force, the leg pieces 16a, 16a can minimize the damage to the oil bolt 11. it can.

As a result, the oil bolt 11 and the bleeder screw 1
It is possible to protect the sealing member such as the gasket mounted on the No. 3 and to exert a reliable sealing property.

Generally, the guard plate 16 is preferably thinner than the back plate 2 and is preferably provided on the dust cover 14 that is easily bent. The back plate 2 is difficult to be integrally formed due to its shape and thickness. However, it is disadvantageous in terms of manufacturing and cost.

Therefore, by integrally forming the guard plate 16 on the dust cover 14, it is possible to provide the device with excellent processability and manufacturability and at low cost.

FIG. 3 shows another embodiment of the present invention, which is a dust cover 1
In the guard plate 20 extended to 4, the fork-shaped front leg pieces 20a, 20a for covering the heads of the oil bolt 11 and the bleeder screw 13 and the side leg pieces 20b, 2 for covering both side portions are provided.
0b is provided, and the tips of the side leg pieces 20b, 20b are folded under the oil bolt 11 to cover substantially the entire inlet portion 4a, the oil bolt 11, and the bleeder screw 13, and are connected to the oil bolt 11. The brake pipe 10 is inserted through the gap 21 between the front leg pieces 20a, 20a, and further protection is achieved in the present embodiment.

[Effect of device]

As described above, the drum brake of the present invention extends a part of the dust cover around the outer periphery of the back plate to cover the inlet portion of the wheel cylinder provided on the back surface of the back plate. When carrying stepping stones inside or drum brakes unitized,
Do not loosen or damage the oil bolts or bleeder screws that are arranged to project at the inlet part in the transport case or pallet.

Therefore, the seal member such as the gasket mounted on the oil bolt or the bleeder screw can be protected, and reliable sealing performance can be exhibited.

[Brief description of drawings]

FIGS. 1 and 2 show an embodiment of the present invention. FIG. 1 is a sectional side view of a main part of a drum brake, FIG. 2 is a perspective view of the main part seen from the back side of the back plate, and FIG. FIG. 9 is a perspective view of a main part as seen from the back side of the back plate showing another embodiment. 1 ... Drum brake, 2 ... Back plate, 3 ...
Brake shoe, 4 wheel cylinder, 4a inlet part, 4b mounting flange, 5 opening, 8
Inlet port, 9 bleeder hole, 10 brake pipe, 11 oil bolt, 13 bleeder screw, 14 dust cover, 15 brake drum, 15a rim, 16 Guard plate,
16a ... leg pieces, 17 ... gap

Claims (1)

[Scope of utility model registration request] 1. A drum brake for a vehicle, wherein a dust cover is provided around an outer peripheral portion of a back plate, and an inlet portion of a wheel cylinder to which a brake pipe is connected faces a back surface of the back plate. A drum brake for a vehicle, wherein the drum brake is extended to cover the inlet portion.