JPS59144836A - Disc pad - Google Patents

Abstract

PURPOSE:To prevent the generation of rust by bonding zinc particles with trivalent chromium compound to form a coat, forming the coat having a thickness more than a specified value on the surface of a back metal and adhering a pad onto the coat through adhesives. CONSTITUTION:A mixed treatment liquid of chromic acid and zinc particles 4 is applied to the surface of an iron back metal 1 by brushing, dipping or the like, treated by heating in a baking furnace at 300-330 deg.C to reduce sexivalent chromium to trivalent chromium, and the surface of the back metal 1 and the surfaces of the zinc particles 4 are coated with trivalent chromium compound 3 to interpose between the particles 4 and form a coat 2 integral therewith. The thickness of the coat 2 is more than 5mu in consideration of rust preventive capability. Accordingly, the controlled self-sacrifice protection of the zinc particles 4, the passive state of the back metal surface caused by chromic acid, barrier action of trivalent chromium compound are effected doubly or trebly to produce strong rust-preventive capability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in disc pads for disc brakes. A disc band is made up of a band made of friction material bonded to a metal backing, and a pad presses the disc that rotates once, and the friction force is used to stop the rotation of the disc and stop the vehicle from moving. Disc pads are not only subjected to strong shearing force and frictional heat, but also exposed directly to the outside air, so they are exposed to wind, rain, and dust, and are therefore exposed to very harsh environments in terms of mechanical strength and corrosion conditions.

For safety reasons, disc brakes cannot afford to have a brake failure, so the adhesive surface between the pad and the back metal, especially in the disc pad, must have adhesive strength that will never break.

For this reason, conventionally, uneven portions are formed on the surface of the back metal by shot to mechanically strengthen the adhesive force with the pad. However, while this method is effective while the brakes are new,
When used for a long period of time, or when driving on roads containing salt in particularly cold regions, rust will develop in the boss hole of the backing metal, and this will gradually spread to the adhesive surface between the pad and the backing metal, causing the pad and the backing metal to separate. There was a risk of a brake malfunction during driving due to a decrease in the traction force, which could eventually lead to an accident.

The present invention was made to solve the problem of sloping, and its purpose is to provide a disc band that is capable of hanging by forming a corrosion-resistant film on the bonding surface between the backing metal and the band in advance to prevent rusting. It's about doing.

The present invention relates to a disk pad formed by forming a film on the surface of a metal backing in which zinc particles are bonded with a trivalent chromium compound to a thickness of at least 5 μm, and adhering a pad onto the film via an adhesive.

To further explain the present invention in detail with reference to FIG. 1, the surface of the back metal 1 mainly made of iron-based material.

Forming a film 2 in which zinc particles 4 are bonded by a chromium compound 3 in which hexavalent chromium is reduced to trivalent chromium,
The anti-corrosion ability of this film 2 prevents the adhesive strength from decreasing due to rusting of the bonded part. Apply by coating, dipping, etc., and then bake in a baking oven: 3
By heating at 00 to 330°C, the hexavalent chromium contained in the treatment solution is reduced to trivalent chromium, and the trivalent chromium compound 3 covers the surface of the backing metal 1 and the surface of the zinc particles 4, resulting in IF lead. By being interposed between particles 4, it acts as a binder.

These are integrally formed.

This film 2 has a strong anti-corrosion effect due to the self-sacrifice guarantee that pH lead particles 4 are controlled, the passivation of the surface of the backing metal 1 by chromic acid, and the barrier effect by trivalent chromium compound 3. It is something that demonstrates one's ability. Further, the thickness of the coating 2 can be adjusted to ~M by repeating coating and firing, but it does not exhibit its rust-preventing ability and requires a thickness of 15 B or more. If the thickness is 50 mm or more, the moving bed will be saturated, and it will take time to apply and fire the material instead of applying it with force. Embedding of about 10 μm to 30 μm is preferable.

Furthermore, if the concentration of eggs in the treatment solution is less than 1, the anti-corrosion effect will be low, and if it is still more than 50%, the curling of the treatment solution will increase and the coating process will become difficult. 50%
is preferred.

6 is a pad mainly made of asbestos, and 5 is an adhesive for bonding the pad 6 and the film 2, and although there is no particular restriction, phenol RFFJ resin or the like is usually used.

Hereinafter, the invention will be explained with reference to examples.

Example 1 The surface of a back metal made of 5S-41, which is an iron-based material, was shot-processed, and zinc particles with an average particle size of 5 μm raised to the 5th power M, %
A chromic acid treatment solution containing chromic acid (containing 30 heavy needles of chromic acid) was applied and heat treated in a baking oven at 300° C. for 3 hours to form a film with a thickness of 10 μm.

A pad made of phenolic resin was applied to the film (50 parts of asbestos, 20 parts of phenolic resin, 10% by weight of barium ft acid, 10 parts of copper powder).

A disc band was obtained by adhering Nori Crayon Dust (consisting of 10 layers).

Example 2 A disk pad was produced in the same manner as in Example 1 except that 5APH-41, which is an iron-based material, was used as the backing metal.

Comparative tests were conducted on the disk bands obtained in Examples 1 and 2 and on a conventional disk pad, that is, a disk pad 7 in which an IF contact pad was adhered to the back metal surface of shot-processed 5APH-41 as a comparative example.

The test method was to use a cast liquid containing sodium chloride as the main component (JIS D 0201').
1 for 5 minutes, then dried in a dryer at 70'C for 55 minutes, repeating this operation 8 times a day (leaving in the air for 16 hours) for 5 days, and leaving it in the air for 2 days for 1 week. 1
A 1.1 o cycle was carried out. The test results are shown in Table 1.

As is clear from Table 1, in the case of Examples 1 and 2,
Rust did not occur even at the 10th cycle and the adhesive strength did not change much, whereas in the case of Hiro, rusting occurred from the 4th cycle and a significant decrease in adhesive strength was observed at the 10th cycle. .

According to the present invention, a film with ambiguous corrosion resistance is formed on the backing metal, and the pad is adhered to the film, so that even when used in harsh environments, the bonding strength between the backing metal and the band does not deteriorate or peeling occurs due to rusting. Without.

The effect is very dog-like.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of a disk pad according to an embodiment of the present invention. Explanation of symbols

Claims (1)

[Claims] 1. A disk pad formed by forming a film of at least 5 μm in thickness on the surface of a metal backing in which zinc particles are bonded with a trivalent chromium compound, and adhering a pad onto the film via an adhesive.