JPH0396725A - Pad assembly for disc brake - Google Patents

Abstract

PURPOSE:To reduce rising and distortion of fill to easily make a back plate with small pressure by joining a friction material to the front of a back plate where there is an air vent hole of the required minimum size in such a manner that a part of the friction material fills up a recess portion. CONSTITUTION:A recess portion 6 is provided on the front of a back plate 1, and a fine air vent hole piercing the back of the back plate is provided in the central portion of the recess portion. A friction material 2 is pressure- molded on the back plate and stuck to the front of the back plate 1 by an adhesive 3. A through hole is punched, and the recess portion 6 is plastic-forged concentrically with the through hole while the back is supported. Thus, rising and distortion of fill can be reduced, and the back plate can be easily made with small pressure.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a vanod assembly for a disc brake used in a vehicle, etc., and more specifically, to a joint between a friction material that is brought into sliding contact with a disc and a back metal that supports it. This article is about an ingenious bad assembly. (Prior art) In this type of pad assembly, the friction material and the backing metal are joined together to prevent the friction material from falling off from the backing metal due to vibration when the braking force is released, even if mechanical strength or adhesive strength decreases. Therefore, (a) Generally, as shown in Fig. 4, a relatively large through hole called a mold hole 4 is provided in the back metal 1, and a part of the friction material 2 is inserted into the hole. It's set.

(Explanation) As shown in Fig. 5, a small protrusion 5 whose protrusion length is within the wear limit of the friction material is integrally provided on the back metal 1, and this is inserted into the friction material to form a mechanical hook. There are some things. (c) As shown in FIG. 6, it has also been proposed that a recess 6 is formed in the back metal 1 by half-shear processing, and a friction material is inserted into the recess 6 for joining. [Problem to be solved by the invention] In case (a) above, ■ I! passes through the mold hole. Moisture that has penetrated into the inside of the JM material reaches the adhesive surface (3 is the adhesive) and induces rust, leading to a decrease in adhesive strength and premature cracking of the pore-filling portion of the friction material.

■ When the friction material is pressure-molded on the backing metal, the pressure distribution around the mold hole is disturbed, so the physical properties of the friction material are not constant in each part, and the friction characteristics fluctuate. Furthermore, in case (b), if the disc is used beyond the wear limit by mistake, scratches will be generated on the sliding surface of the disc.

Furthermore, in case (c), the protrusion 7 punched out on the back metal by the half shear interferes with the caliper and piston when replacing the butt assembly, and therefore extra space is required in the axial direction of the piston to avoid this. ,
This results in larger or more complicated brakes. Here, as a solution to the above-mentioned problems, see Figure 6(b).
It is effective to make the shape as shown in Fig. 7 without the protrusion 7. However, in order to obtain such a shape, cutting the recess 6 or scraping off the punched protrusion on the back after half-shearing increases the processing effort.Also, as an alternative method, it is difficult to create the recess by simple plastic forging. The following problems arise: ■ Huge press pressure is required; ■ Excess material from the backing metal that spreads during forging builds up around the recess and distorts the backing metal, requiring correction work; and ■ Significant wear and tear on the mold. This is not practical in any case.

SUMMARY OF THE INVENTION An object of the present invention is to provide a band assembly in which a concave portion of a backing metal can be easily and inexpensively formed by plastic forging without causing the above-mentioned problems.

[Means to solve the problem] The pad assembly of the present invention has a concave portion on the front surface which is plastically forged concentrically with the through hole with the free surface thereof, and the through hole is formed in the center of the concave portion by the surplus material that expands during forging of the concave portion. It is characterized by the fact that a part of the friction material is bonded to the front surface of the metal backing, which has an air vent hole of the minimum necessary size created by crushing, by filling the recess with a portion of it. C action]

The backing metal surplus material that spreads during plastic forging of the recessed portion escapes to the free surface side using the through hole provided in the backing metal as a free surface. Therefore, the press pressure is kept low, and the buildup of meat on the front side of the back metal and distortion of the back metal are also prevented.

In addition, the air vent hole created in the center of the recess makes it easier for air to escape from the adhesive surface when pressurizing the friction material on the back metal surface, and after mounting on the brake, moisture can escape from the back metal surface. While suppressing penetration to a range that does not cause any actual damage, when the so-called fade phenomenon occurs, the gas generated from the friction material is released, making it difficult for flammable gas to ignite due to disk heat.

〔Example〕

FIG. 1 shows an embodiment of the present invention.

As shown in the figure, a recess 6 is provided on the front surface of the back metal 1, and a minute air vent hole 8 is provided in the center of the recess to allow the air to escape to the back surface of the back metal. When the friction material 2 is pressure-molded on the front side of this backing metal and attached with adhesive 3, a pad assembly 10 of the present invention is obtained. The concave portion 6 of the back metal in this annoassembly is processed as follows.

That is, first, as shown in FIG.
The recess 6 of ad) is plastically forged to a depth of L. At this time, the meat of the (φD-φd)·L1 portion flows toward the free surface using the hole S as a free surface.

Therefore, the air vent 7L8 shown in FIG. 3 is created in the center of the recess so that the expanding remaining material does not completely eliminate the hole S. The size of the air vent hole 8 is determined by the amount of spread of the remaining material D d {π(−)2−π( −T− ) ” )・t, and the effective volume of the hole 9 π(T)2 ・L1 Adjust the relationship and change freely {ascend.

Note that if a ring-shaped ring having a diameter larger than φD is previously coined on the back surface of the back metal 1 coaxially with the rl through hole 9, the effect of preventing distortion during forging of the recess 6 will be further enhanced.

In addition, the air vent hole 8 can be easily closed off by coining around its opening or outlet so as to form a small pocket. [Effects] The pad assembly of the present invention described above has the effects listed below.

(1) Since the recess is plastically forged with the through hole as a free surface,
To easily produce a backing metal with little bulging or distortion of the meat and without any punching protrusions on the back surface by using a small press pressure.

(2) Since there is no through-mold hole in the backing metal, the rigidity of the backing metal is increased, and the plate thickness is made thinner to reduce weight, and the effective wall thickness of the friction material is increased by the amount of axial space that can be afforded, resulting in wear and tear. It is possible to extend the lifespan.

(3) There is a small air vent hole in the center of the concave part of the back metal, so
The shape of the friction material makes it easy for air to escape from the adhesive interface during adhesion. In addition, during use, it is possible to limit the penetration of moisture from the back side of the back metal to a level that can cause actual damage, while allowing the gas that is said to be produced by thermal decomposition of the binding material of the friction material to escape during fading. (4
) By appropriately selecting the depth of the recess, it is possible to ensure sufficient ability to prevent the friction material from falling off when the adhesive strength decreases, and to even out the pressure distribution when the friction material is in full force, thereby stabilizing the friction characteristics. Leads to.

[Brief explanation of drawings]

FIG. 1 is a front view of an embodiment of the present invention {FIG. 1(a)}
2 and 3 are diagrams showing the manufacturing process of the backing metal, and Figures 4 to 6 are front views of the conventional panod assembly {(a) in each figure. )} and cross-sectional view {( of each figure)
b)}, and FIG. 7 is a front view {FIG. 7(a)} and a cross-sectional view {FIG. 7(b)} showing a desirable shape of the band assembly. 1...Back metal, 2...Friction material, 3...Adhesive, 6...Recess, 8...Air vent hole, 10. ...Banodoano assembly. Patent distributor: Sumitomo Electric Industries Co., Ltd., Sera Seikosha Co., Ltd. Agent: Aya Kamata Figure 1 Figure 5 652 Figure 3 ♂ Figure 6 Figure 4 Figure 7 (a) (b) 2 6

Claims (1)

[Claims] (1) The front surface has a recess that is plastically forged concentrically with the through hole, with the through hole as a free surface, and the through hole is created in the center of the recess by being crushed by the remaining material that expands when forging the recess. A pad assembly for disc brakes in which a friction material is bonded to the front side of a metal backing, which has an air vent hole of the minimum necessary size, by filling the recess with a portion of the material.