JPS6349095B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention separates the main body and lining portion of the brake shoe in a drum brake, makes the lining portion pad-shaped, and forms the brake shoe main body only from a web so that both can be separated. This relates to a pad-type drum brake that is detachable.

The present applicant previously developed a cassette-type shoe lining in which the lining part of the brake shoe was separated from the brake shoe body and the lining part was detachably attached to the brake shoe body. (Japanese Patent Application Laid-Open No. 55-86930), this is a system in which a pad-shaped lining part is inserted into the brake shoe body in the axial direction of the brake drum.

The present invention further improves this by making the brake shoe main body in the shape of only a web without a rim, providing a notch on its outer periphery, and cutting grooves at the front and rear of the pad-type lining. The pad type lining is removably inserted into the outer periphery of the brake shoe body in the radial direction of the drum using the grooves and grooves, and the lining part is inserted in the axial direction of the brake drum and in the rotational direction of the drum. The lining part is also restrained from changing in the radial and rotational directions of the brake drum by a pad clip made of, for example, a wire spring that engages the lining part with the brake shoe body. .

According to the present invention, the lining of the drum brake is made into a pad type separate from the brake shoe body, which not only makes it possible and easy to replace only the lining, but also makes the brake shoe body a web without a rim. The structure is even simpler and lighter because it is made of only one piece.

Moreover, the padded lining can be attached and detached simply by removing the padded clip, which significantly improves the workability of replacing the friction material.

Furthermore, according to experiments conducted by the present inventors, the pad-type drum brake of the present invention is characterized in that sufficient effectiveness and stable braking performance can be obtained by using a pad-type lining portion with a low coefficient of friction. It is possible to obtain stable braking effectiveness by using semi-metallic pads with a low coefficient of friction, and the advantages include the fact that it is easy to use non-asbestos friction materials, which has recently become a demand for practical use due to the prevention of pollution. is brought about.

Furthermore, in carrying out the present invention, if a plurality of pad-type lining parts are set apart along the outer periphery of the brake shoe main body, there is a space between the lining parts, so that heat fade, This is advantageous because particularly excellent effects on water fade can be obtained.

In addition, if the above-mentioned pad type lining part is provided with a friction material in a convex shape on the flat plate-shaped back metal, and the curvature of this convex surface is set to be slightly smaller than the curvature of the inner surface of the brake drum that applies the brake, the brake can be applied. Advantageously, the desired brake friction surface is achieved as the maneuver progresses.

The present invention will be explained below with reference to embodiments shown in the drawings.

FIG. 1 shows the entire pad-type drum brake, and the left and right shoe bodies 1, which are incorporated into the inside of a brake drum (not shown), have a shape consisting only of webs without rims.

As shown in FIG. 2, a plurality of angular notches 2 are provided along the outer periphery of the shoe body 1 and spaced apart from each other. Although the number of cutouts 2 is two in the drawing, it is not limited to this number.

The pad type lining part 3 to be set in the notch 2 has a structure in which a convex friction material b is integrally molded on a flat plate-like back plate a, leaving both side edges e. However, concave grooves 4, 4 are cut into approximately the center of the front and rear of this pad-type lining portion 3.

Therefore, the above-mentioned lining part 3 fits into the above-mentioned notch part 2 between the groove bottoms of the above-mentioned concave groove parts 4, 4, and the outer circumferential parts c, c at the front and rear of the notch part 2 of the shoe body 1 fit into the above-mentioned concave groove part 4. .

The pad clip 5 is a spring material made by bending a wire rod, and in the illustrated example, the pad clip 5 is passed through a pair of holes d and d provided near the notch 2 of the brake shoe body 1, and then inserted at each end. The drum radius of the pad-type lining part 3 is engaged with the front and rear edges e of the pad-type lining part 3 and the upper part of the pad-type lining part 3 to press the backing metal a from the front or rear and above, and to sandwich the friction material b from the left and right sides. It is held so as to prevent it from wobbling in the rotational direction of the drum.

In the drawing, 6 indicates the left and right brake shoe bodies 1,
1 is a wheel cylinder part for expanding and applying braking force to the inner surface of the drum, 7 is a return spring for restoring the expanded brake shoe bodies 1, 1, and 8 is a part between the brake shoe body 1 and the drum. 9 indicates the brake mounting hole.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the entire pad-type drum brake excluding the drum according to an embodiment of the present invention, and Fig. 2 is an exploded explanation showing the relationship between the brake shoe body and the pad-type lining part in the same as above. It is a diagram. DESCRIPTION OF SYMBOLS 1... Brake shoe body, 2... Notch, 3... Pad type lining part, 4... Recessed groove part, 5... Pad clip.

Claims (1)

[Claims] 1. In a drum brake in which the lining part of the brake shoe is separate from the brake shoe body and the lining part is detachably attached to the brake shoe body, the lining part is made into a pad type with a back metal. On the other hand, the brake shoe body is formed only from a web, and grooves are cut in the front and rear of the pad type lining portion, and a cutout portion for setting the lining portion is provided on the outer periphery of the brake shoe body. , the above-mentioned pad-type lining section is set in the above-mentioned notch section in a state where it is restrained against fluctuations in the drum axis direction and the drum rotation direction by insertion fitting between the concave groove section and the brake shoe main body, and A pad type drum brake characterized in that rattling in the drum radial direction and drum rotational direction is restrained by a pad clip that engages the pad type lining portion with the brake shoe body at the set position. 2. A patent claim in which a plurality of pad-type lining parts are set apart along the outer periphery of the brake shoe main body by providing a plurality of notches spaced apart from each other along the outer periphery of the brake shoe main body. Pad-type drum brakes described in scope 1. 3. The pad-type drum brake according to claim 1 or 2, wherein the pad-type lining portion has a friction material provided in a convex shape on a flat plate-shaped back metal.