JPH05280561A - Disk brake pad - Google Patents

Abstract

PURPOSE:To prevent decrease of a friction coefficient and generation of noise, vibration, etc., even when braking is repeated at a high load by forming an irregular part in the external side surface of a friction member of a brake pad formed of a back metal and the friction member. CONSTITUTION:An irregular part 5 is formed in the external side surface of a layer 2 outside a friction member, and when occupied ratio of a protruding part in the irregular part 5 is set to 10 to 40% by volume relating to the friction member, a pad can be used excellent in a cooling effect further with no problem in also strength. When the layer 2 outside the friction member is constituted of molded material of containing steel fiber and when a layer 3 inside is constituted of molded material of not containing the steel fiber, it is preferable because a brake is effectively applied at a low temperature to prevent easy generation of noise and vibration excellent in mechanical strength and heat conductivity and also providing excellence in radiation of the disk pad. Further when total volume of the layer 3 inside is increased larger than the total volume of the layer 2 outside, it is preferable in the point of friction performance. By the above constitution, since the disk pad itself has a cooling effect, a friction coefficient is prevented from decreasing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in disc brake pads (hereinafter referred to as disc pads).

[0002]

2. Description of the Related Art Generally, a disc brake is used as a braking device for automobiles and the like, and a disc pad is used as the braking. Since the disc pad may become hot during use, at present, a cooling efficiency is achieved by forming a slit (groove) in the substantially central portion of the friction member or scraping off a corner portion in the longitudinal direction of the friction member. Is increasing.

[0003]

However, the above-mentioned conventional disc pad has the following problems when the temperature is relatively low.
The friction coefficient is high, so that the wheels of a running vehicle are well braked, and there is almost no noise or vibration that makes passengers in the vehicle uncomfortable. Temperature rises, the friction coefficient decreases, sufficient braking cannot be obtained, and noise and vibration frequently occur.

The present invention provides a disc pad that improves the cooling effect of the disc pad itself even when repeated high-load braking is performed, the friction coefficient does not decrease, and noise and vibration do not occur.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a disk pad comprising a backing and a friction member, wherein the uneven surface is formed on the outer surface of the friction member.

In the present invention, it is preferable that the ratio of the convex portion to the concave and convex portion is 10 to 40% by volume with respect to the friction member because the cooling effect is excellent and the strength can be used without any problem. The friction member has a two-layer structure,
If the outer layer is made of a molded product containing steel fibers, while the inner layer is made of a molded product not containing steel fibers, the braking effect is good at low temperatures, noise is hard to occur, mechanical strength, It is preferable because it is excellent in heat conductivity and heat dissipation of the disk pad. Further, it is preferable in terms of friction performance to make the total volume of the inner layer of the friction member larger than the total volume of the outer layer.

The friction member in the present invention includes thermosetting resins such as phenol resin, epoxy resin and melamine resin, synthetic rubber such as NBR and SBR, in addition to the above-mentioned steel fibers.
Fibrous substances such as aramid fibers, calcium silicate fibers, and copper fibers, and if necessary, fillers such as graphite, barium sulfate, friction dust, carbon black, alumina, and silica are used.

There is no particular limitation on the shape and number of the irregularities formed on the outer surface of the friction member. Also, the means for providing the uneven portion is not particularly limited, and any conventionally known means may be used.

[0009]

EXAMPLES Examples of the present invention will be described below. Example 1 The components shown in Table 1 were blended, kneaded for 3 minutes with a 10 l open kneader, and then dried for 30 minutes at 70 ° C. in a drier to obtain a molding powder for forming an outer layer (hereinafter referred to as an outer layer). ..

On the other hand, the components shown in Table 1 were blended in the same manner as described above, kneaded for 5 minutes with a 10 l open kneader, and then dried at 80 ° C. for 50 minutes with a drier to form an inner layer (hereinafter referred to as an inner layer). A molding powder was obtained. Then, the dried inner layer molding powder is put into a mold and then at room temperature at a pressure of 3.92 × 10 5.
Preforming was performed under the condition of ⁶ Pa (40 kgf / cm ² ).

Next, the preform is placed in the center of the void of the thermoforming die having an uneven portion on the inside (the portion which becomes the outer surface of the friction member), and then the gap between the preform and the die. Then, the molding powder for the outer layer obtained above is charged to the above, and then at 180 ° C. for 4.9
A friction member was obtained by heat-pressing and molding under a condition of × 10 ⁷ Pa (500 kgf / cm ² ) for 5 minutes and further heat-treating at 250 ° C. for 5 minutes.

After that, the friction member is ground to a thickness of 18 mm and then bonded to a predetermined backing metal 1 by a conventionally known method as shown in FIG. 1, and then a slit 4 is formed substantially in the center of the friction member. Put one, and uneven part 5 on the outer surface of the outer layer 2
Thus, a disk pad having the above was obtained. The ratio of the projections in the projections and depressions 5 of the obtained disk pad is the outer layer 2
And 10% by volume based on the friction member including the inner layer 3.

Comparative Example 1 The components shown in Table 1 were blended, kneaded for 5 minutes in a 10 l open kneader, dried in a dryer at 80 ° C. for 50 minutes to obtain a molding powder, and then preformed under the same conditions as in Example 1. Then, the preform was put into a thermoforming die, and the same steps as those in Example 1 were performed to obtain a friction member.

Thereafter, the friction member is ground to a thickness of 18 mm and then bonded to a predetermined backing metal by a conventionally known method in the same manner as in Example 1, and then one slit is formed substantially in the center of the friction member. A disc pad having a one-layer structure of the friction member put therein and having no uneven portion on the outer surface was obtained.

[0015]

[Table 1]

Next, the disc pads obtained in Example 1 and the disc pad obtained in Comparative Example 1 were subjected to a comparison test of friction coefficient under the following test conditions and test codes using an inertia dynamometer tester. The results are shown in Table 2.

Test conditions Brake type: AD22V Equivalent moment of inertia: 4.5 kg-m-s ² Tire radius: 0.292 m Test code adjustment ... Initial speed 50 km / hour, deceleration 2.94 m / s ² , braking frequency 200 times Durability test ... initial speed 150km / hour, deceleration 2.94
m / s ² , braking frequency 5 × 10 ³ times

[0018]

[Table 2]

As shown in Table 2, it can be seen that the disk pad according to the present invention has a low surface temperature and a stable high friction coefficient during the test. In the durability test, the disc pad of Comparative Example 1 slightly generated noise and vibration, but none of the disc pads of the present invention existed.

[0020]

The disk pad according to the present invention has a cooling effect even when high-load braking is repeated, so that the friction coefficient does not decrease, noise, vibration, etc. do not occur, and it is industrially available. It is a very suitable disc pad for.

[Brief description of drawings]

FIG. 1 is a plan view of a disk pad according to an embodiment of the present invention.

[Explanation of symbols]

 1 Back metal 2 Outer layer 3 Inner layer 4 Slit 5 Uneven part

Claims (5)

[Claims] 1. A disc brake pad consisting of a back metal and a friction member, wherein a concavo-convex portion is formed on the outer surface of the friction member. 2. The disc brake pad according to claim 1, wherein the proportion of the convex portion in the uneven portion is 10 to 40% by volume with respect to the friction member. 3. The disc brake pad according to claim 1, wherein the friction member has a two-layer structure. 4. The disc brake pad according to claim 1, 2 or 3, wherein the outer layer of the friction member is made of a molded product containing steel fibers, and the inner layer is made of a molded product not containing steel fibers. 5. The disc brake pad according to claim 1, wherein the total volume of the inner layer of the friction member is larger than the total volume of the outer layer.