JPS6221787Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a brake shoe formed to prevent so-called brake squeal in a drum brake.

It is well known that when the brakes are applied, the vibration of the brake shoe produces a sharp metallic sound.
This is the so-called brake squeal. There are many ideas to prevent this brake shoe squeal. Broadly speaking, one type is a brake shoe equipped with a metal or non-metallic damping material to absorb the vibration energy of the brake shoe and prevent squeal. The part has a two-plate structure, and the vibration energy is absorbed by the friction between the joint surfaces of the two plates. In particular, the latter was proposed in Utility Model Application Publication No. 54-57274. In this idea, the joint surface of the rim part formed in a two-plate structure is formed into a blocking surface to increase frictional resistance and absorb vibration energy, thereby preventing so-called brake squeal. However, since the outer circumferential surface of the rim portion is formed so as to press against the circumferential surface of the drum through the lining, it is formed into an arcuate curved planar shape in accordance with the curvature of the inner circumferential surface of the drum. Therefore, gaps are likely to occur at the joint surface due to variations in processing accuracy, and simply forming the joint surface as a blocking surface has the drawback that sufficient vibration energy cannot be absorbed. Furthermore, if the two plates are strongly joined together, there is a drawback that the anti-squeal effect is lost due to a slight change in the vibration system of the brake shoe.

This invention eliminates these drawbacks and provides a brake shoe for drum brakes in which a contact plate is interposed between the joint surfaces of the rim parts of two plates to increase the absorption of vibration energy of the brake shoe and prevent squealing. The purpose is to

This invention will be explained in detail based on illustrated embodiments.

FIG. 1 is an explanatory cross-sectional view of a brake shoe according to this invention, and FIG. 2 is an explanatory longitudinal cross-sectional view of the brake shoe. In the figure, reference numeral 1 denotes an outer rim portion, and a lining is provided on the outer surface of the outer rim portion as a wear material that comes into direct contact with the inner peripheral surface of the drum. Reference numeral 2 denotes an inner rim portion, which forms a pair with the inner rim portion 1 to form the rim portion of the brake shoe. 3 is a web portion which is formed integrally with the inner rim portion 2. Reference numeral 4 denotes a contact plate which is sandwiched between the joint surface of the inner rim part 2 and the outer rim part 1 and is connected by a connector 5 to form the rim part of the brake shoe.
As shown in FIG. 3, the contact plate 4 includes a contact plate main body 4a, which is made of a corrugated sheet with continuous irregularities formed on a thin steel plate, and is formed to have almost the same planar shape as the inner rim portion 2.
It is formed by sandwiching the joint surfaces of the outer rim part 1 and the inner rim part 2 and tightening them while pressing with the connector 5.

Further, as shown in FIG. 4, a contact plate main body 4b is formed by forming a mesh plate formed by weaving wire-like small-diameter metal into a mesh shape and having a planar shape substantially the same as that of the inner rim portion 2.
may be formed by being clamped onto the joint surfaces of the outer rim portion 1 and the inner rim portion 2 and tightened with the connector 5.

Further, as shown in FIG. 5, the contact plate main body 4c is formed of a scale-concave plate formed by providing grooves in a thin flat plate and pressing concavities and convexities and arranging them in a scale-like manner. It may also be formed by sandwiching the joint surface between the inner rim portion 2 and the inner rim portion 2, tightening the connector 5, and pressing the connector 5. Furthermore, the contact plate main body 4d is made of a flat plate having almost the same planar shape as the inner rim portion 2, and is made of a highly elastic material such as synthetic resin or rubber-shaped material.
The vicinity of the edge to be tightened may be covered with a thin metal plate, or a vibration-proof plywood made by combining a material with a high vibration damping ability is formed to have the same planar shape as the inner rim portion 2. You may also use it as
In other words, the contact plate is used to eliminate the formation of gaps caused by variations in machining accuracy between the outer surface of the inner rim portion 2 and the inner surface of the outer rim portion 1, that is, the joint surfaces of the two. Regardless, the contact plate 4 is forcibly brought into contact with the inner surface of the inner rim portion 2 or the inner surface of the outer rim portion 1.

According to this invention, the contact plate always makes contact with the inner rim part and the outer rim part, and has a high degree of contact, regardless of whether or not there is a gap in the joint surface caused by variations in the machining accuracy of the inner rim part and the outer rim part. Since surface pressure is obtained, vibration energy is well absorbed at the joint surface portion, and a brake shoe with high damping ability can be provided. In addition, since there is no requirement for precision in machining the inner rim portion and the outer rim portion as in the past, there is also the practical benefit that manufacturing of the brake shoe becomes extremely easy.

Furthermore, there is a contact plate with arc-shaped unevenness that makes contact,
The contact plate itself with scale-like unevenness is easy to manufacture and the manufacturing cost is low, making it possible to provide a practical anti-squeal brake shoe that does not directly lead to product prices.

[Brief explanation of drawings]

Fig. 1 is an explanatory cross-sectional view of the brake shoe according to this invention, Fig. 2 is an explanatory longitudinal cross-sectional view of the brake shoe according to this invention, and Fig. 3 is a side view of the contact plate main body showing one embodiment. , FIG. 4 is a plan view of the contact plate main body showing another embodiment, and FIG. 5 is a perspective view of the contact plate main body showing another embodiment. FIG. 6 is an explanatory cross-sectional view of the contact plate main body showing the fourth embodiment. Explanation of symbols: 1... Outer rim part, 2... Inner rim part, 3... Web part, 4... Contact plate,
5... Connector, 4a, 4b, 4c, 4d... Contact plate main body.

Claims (1)

[Claims for Utility Model Registration] (1) In a brake shoe of a two-rim drum brake in which an outer rim portion 1 provided with a lining and an inner rim portion 2 integrally formed with a web 3 are formed separately, a thin plate A steel plate is formed into the same rectangular curved flat plate as the inner rim part 2, and a continuous uneven part is provided to form the inner rim part 2.
Connector 5 is clamped onto the joint surface of the outer rim portion.
A brake shoe characterized by being fixed by being pressed with. (2) A brake shoe according to claim 1 of the utility model registration, characterized in that the concave and convex portions of a thin steel plate are formed by connected arcuate concave and convex portions. (3) A brake shoe according to claim 1 of the utility model registration, characterized in that the continuous uneven portion of the thin steel plate is formed into a scale-like convex surface by providing cut grooves in the thin flat plate.