JPH02102932A - Disk brake device for vehicle - Google Patents

Abstract

PURPOSE:To effectively reduce noise due to face vibration and noise due to resonance in a high frequency area without deterioration by providing a notch part at the center part of at least one of the upper side or the lower side of a back plate on a brake pad. CONSTITUTION:Rigidity to a bending deformation in a plane parallel to the friction face of a pad 3 is changed by a notch part 10 provided on the back plate of the brake pad 3. As a result, the natural vibration of vibration in the plane is changed. Accordingly, this natural vibration is shifted from the natural vibration of the vibration of a disk plate 2, thereby brake noise due to the resonance of both the vibrations is reduced. In that case, the rigidity to the flapping deformation of the brake pad 3 is not changed substantially by the notch part 10, and therefore, the brake noise due to the resonance of the face vibration of the pad 3 and the vibration of the disk plate 2 is not worsened.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a disc brake device for a vehicle, and particularly to a disc brake device designed to reduce brake noise.

(Prior Art) A disc brake device that is widely adopted as a braking device for vehicles includes a disc plate that rotates integrally with a wheel, a pair of brake pads that are arranged oppositely on both sides of the outer circumference of the plate, and a disc brake that rotates integrally with a wheel. It consists of a caliper that applies braking force to the wheels by pressing these brake pads against the disc plate when braking hydraulic pressure is supplied, but this type of disc brake device has a problem with so-called brake noise that occurs during braking. It may happen.

This brake noise is generated by the vibration of the brake pad or disc plate, or by their resonance. For example, according to Japanese Utility Model Application Publication No. 5945332, the vibration of the brake pad is generated by the vibration between two steel plates. A device has been disclosed in which brake noise is reduced by interposing a shim sandwiching a damping material between the pad and the piston of the caliper to absorb the noise.

(Problem to be Solved by the Invention) On the other hand, regarding brake noise caused by resonance between the brake pad and the disc plate, conventionally, the friction surface of the pad A is deformed into a wavy shape as shown in FIG. Resonance with the vibration of B is emphasized as a cause, and as a countermeasure, for example, by providing a vertical slit in the center of the friction member in the brake pad, the natural frequency of the pad can be adjusted to the natural frequency of the disc plate. The number is shifted to avoid resonance between the two.

However, as pads, disc plates, etc. have become lighter in recent years, in addition to the above-mentioned surface vibration resonance, the brake pad A is deformed in a plane parallel to the friction surface, as shown in Figure 9. Noise caused by resonance in a high frequency range (for example, around 6.5 KHz) between bending vibration and vibration of the disk plate has become a problem, and the noise caused by resonance in this high frequency range can be summarized as shown in Figure 8. The challenge is how to effectively reduce noise caused by vibration without making it worse.

(Means for Solving the Problems) In order to solve the above problems, the following means are used in the present invention.

That is, the present invention includes a disc plate that rotates integrally with the wheel, a pair of brake pads that are arranged opposite to each other with the plate in between, and a caliper that presses these brake pads against the disc plate. In the disc brake device, a notch is provided in the center of at least one of the upper side and the lower side of the back metal of the brake pad.

(Function) According to the above configuration, the notch provided in the back metal of the brake pad allows the I! 11 The rigidity against bending deformation in the plane parallel to the friction surface changes, and along with this, the 9th
The natural frequency of vibration within the plane shown in the figure changes. Therefore, this natural frequency can be shifted from the natural frequency of vibration of the disk plate, and brake noise due to resonance between the two can be reduced. In this case, the rigidity of the brake pad against undulating deformation hardly changes depending on the notch, and therefore brake noise due to resonance between the surface vibration of the pad and the vibration of the disk plate is not worsened.

(Example) Examples of the present invention will be described below.

First, the general structure of the disc brake device according to this embodiment will be explained with reference to FIG. 1.2.
consists of a disc plate 2 that rotates integrally with the wheel, a pair of brake pads 3.3 located opposite to each other on both the inner and outer sides of the outer periphery of the plate 2, and a knuckle arm (not shown) that straddles these pads. It is supported by a caliper 6, etc., which are supported by a pad 3, and are arranged such that a piston 4 is located on the back of one pad 3, and a plurality of presser claws 5...5 are located on the back of the other pad 3. . When the braking pressure is supplied, the piston 4 presses one pad 3 against the disc plate 2, and at the same time, the reaction force causes the presser claws 5...5 to press the other pad 3 against the disc plate 2. The disc plate 2 is sandwiched between a pair of pads 33, so that braking force is applied to the wheel via the plate 2.

On the other hand, as shown in Fig. 3.4, the brake pad 3 includes a *t* member 7 that slides into contact with the disc plate 2 during braking, and a back metal 8 that is fixed to the back of the member 7 and backs it up. It consists of And the friction member 7
A slit 9 is provided in the center of the sliding surface in the radial direction, and notches 10 and 10 are provided in the center of the upper and lower sides of the friction member 7 and the back plate 8, respectively.

Next, the operation of this embodiment will be explained with reference to FIG. 5, which shows the results of an experiment in which the distribution of the natural frequencies of the disc plate 2 and brake pad 3 was confirmed.

First, regarding the surface vibration of the disc plate 2 and the pad 3, the brake pad 3 has a frequency of about 1.1 KHz, 2.2 KHz, 2 KHz, 8 KHz, as shown by (*) in FIG.
At each frequency of Hz, 4 KHz, 1 KHz, and 5.2 KHz, peaks of surface vibration occur as shown in the vibration modes shown in FIG. 6 (1) to (5), respectively. Here, the dashed lines in the drawings of these vibration modes indicate vibration nodes, and +
, - symbols indicate the state in which each part of the pad approaches or moves away from the disk plate 2 with this node as a reference (this approach and separation are alternated every half cycle of vibration). Also, regarding the disk plate 2, as shown by (·) in Fig. 5, the peaks of the surface vibration of the modes shown in Fig. 7 (1) and (2>) occur at approximately 2.5 KHz and 3 KH2, respectively. Occur.

Regarding this surface vibration, for example, the slit 9 provided in the friction member 7 of the pad 3 shown in the above embodiment can be used.
The peak frequencies of the pad 3 and the disc plate 2 are prevented from matching, and brake noise due to resonance of this surface vibration has already been reduced to the required level.

On the other hand, the brake pad 3 has conventionally been subjected to bending mode vibration that deforms in a plane parallel to the R1 friction surface at approximately 6.3 KHz, as shown by (0) in Fig. 5 (see Fig. 6 (6)). ), and on the other hand, the disk plate 2 has a peak of vibration in a radially displaced mode at about 6.6 kHz (see Figure 7 (3)), as also indicated by (○). Conventionally, brake noise due to resonance in the vicinity of 6.5 KHz has been a problem based on these vibrations.

However, in this embodiment, as shown in FIGS. 3 and 4, a notch 10.10 is provided at the center of the upper and lower side of the back plate 8 of the brake pad 3, as shown in FIG. )
As shown in , the peak frequency of the bending vibration of the pad 3 is reduced from about 6.3KH2 to about 5.8KHz, and as a result, resonance between this bending vibration and the radial vibration of the disk plate 2 is avoided. The brake noise caused by this resonance is reduced. Then, the notch 1
0.10, the surface vibration of the brake pad 3 in the mode shown in FIG. At the same time, the noise caused by the resonance of the bending vibration is reduced.

In addition, in this embodiment, since the caliper is provided with three presser claws 5...5, the presser claws 5...
- For the brake pad 3 placed on the 5 side, the central part, where the rigidity may be reduced due to the notch 10.10, is directly pressed against the disc plate 2 by the central presser pawl 5 during braking. Therefore, the surface of the friction member 7 comes into uniform sliding contact with the disk plate 2, and uneven wear on this surface is prevented.

(Effects of the Invention) As described above, according to the disc brake device according to the present invention, bending vibration deforming in a plane parallel to the friction surface can be suppressed without affecting the natural frequency of the brake pad against surface vibration. It becomes possible to change the natural frequency. As a result, it is possible to effectively reduce the brake noise caused by the resonance in the high frequency range between the bending vibration and the disk plate vibration without worsening the brake noise caused by the resonance between the surface vibration and the disk plate vibration. As a result, a disc brake device with reduced brake noise can be realized.

[Brief explanation of the drawing]

1 to 7 show examples of the present invention, in which FIG. 1 is a schematic front view of a disc brake device, FIG. 2 is a sectional view thereof,
Fig. 3.4 is a front view and a plan view of the brake pad in this disc brake device, and Fig. 5 shows the natural frequency distribution of the brake pad and disc plate in this disc brake device together with a conventional brake pad. Distribution map, Figures 6 (1) to (6) and Figure 7 (
1) to (3) are schematic diagrams showing the vibration modes of the brake pad and the disc plate at each frequency. Further, FIG. 8 is an explanatory diagram of surface vibration of the brake pad, and FIG. 9 is an explanatory diagram of bending vibration. 1... Disc brake device, 2... Disc plate, 3... Brake pad, 6... Caliper, 8
...back metal, 10...notch part. Figure Figure

Claims (1)

[Claims] (1) A disc brake device consisting of a disc plate that rotates integrally with the wheel, a pair of brake pads that are placed opposite each other with the plate in between, and a caliper that presses these brake pads against the disc plate. A disc brake device for a vehicle, characterized in that a notch is provided in the center of at least one of the upper side and the lower side of the back metal of the brake pad.