JPH0228739B2 - DEISUKUBUREEKI - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) This invention relates to the improvement of disc brakes used for braking automobiles, and is aimed at preventing the generation of noise called squeal due to friction between the pad lining and the rotor during braking. be.

(Background Art) For example, as shown in FIGS. 1 and 2, a disc brake has a rotor 1 mounted on a support 2 that is provided to sandwich a rotor 1 that rotates together with a wheel, so that the rotor 1 can freely slide in the axial direction. A pair of pads 3 are supported, and a caliper 4 is attached to the upper part of the support 2 so as to be able to freely slide in the axial direction of the rotor 1. When braking,
When one pad 3 is pressed against one side of the rotor 1 by a piston 5 provided on the caliper 4, the caliper 4 slides as a reaction, and the other pad 3 is pressed against the other side of the rotor 1 via the caliper claws 4a. Braking is performed by pressing strongly from both sides of the rotor 1 with both pads 3, 3.

Incidentally, in a disc brake constructed and operated as described above, noise called squeal is often generated during braking. This noise is generated when the side surface of the rotor 1 and the lining surface of the pad 3 rub against each other during braking, causing the entire pad to vibrate finely, and when braking is performed frequently, the temperature of the pad increases. It is known that this is likely to occur. In order to prevent the generation of such noise, it is effective to increase the force that presses the lining of the pad 3 against the side surface of the rotor 1 on the outer circumference of the rotor 1 compared to the inner circumference.
For this reason, the thickness of the lining of the pad 3 has been conventionally formed so that it becomes gradually thicker from the inner circumferential side toward the outer circumferential side. However,
Making the thickness of the lining uneven in the radial direction of the rotor 1 in this way is effective while the pad 3 is new, but becomes ineffective when the lining becomes worn due to repeated braking. I end up.

The present invention eliminates the above-mentioned disadvantages and increases the pressing force on the outer circumference of the rotor 1 when the temperature of the pad increases, which tends to cause noise, regardless of the degree of wear of the pad lining, thereby reducing noise during braking. The purpose of this invention is to provide a disc brake that can reduce the frequency of this occurrence.

(Structure of the present invention) The disc brake of the present invention has a recess formed in the inner surface of the caliper pawl that presses one pad (the surface that presses the pad) near the outer circumference of the rotor. A compression spring made of a shape-memory alloy that expands and contracts at room temperature is inserted, so that the outer circumferential portion of the pad is compressed toward the rotor only at high temperatures.

(Embodiments of the present invention) Next, the present invention will be explained in more detail while explaining the illustrated embodiments.

FIG. 3 shows a compression spring 6 made of a shape memory alloy that is incorporated into the disc brake of the present invention, and FIG. 3A shows the state at normal temperature, and FIG. 3B shows the state at high temperature. On the other hand, in the upper part of the inner surface of the caliper claws 4a, 4a of the caliper 4 constituting the disc brake, the portion facing the outer peripheral portion of the rotor 1 has a recess 7 as shown in FIGS. 7 is formed. This recess 7, 7
has a cross-sectional area large enough to allow insertion of the compression spring 6, and when the compression spring 6 is at room temperature as shown in FIG. 3A, it completely accommodates the spring 6, but as shown in FIG. Under high temperature conditions, this spring 6 has such a depth that a portion thereof slightly protrudes from the inner surface of the caliper pawl 4a.

The compression spring 6 made of shape memory alloy as described above is
As shown in FIG. 5, the caliper pawl 4a is used by being inserted into the above-mentioned recess 7 formed on the upper inner surface of the caliper pawl 4a, and the inside surface of the caliper pawl 4a comes into contact with the back surface of one of the pads 3.

(Operation of the present invention) The disc brake of the present invention configured as described above operates as follows. During braking, pressure oil is supplied into the cylinder installed in the caliper 4, and the pair of front and back pads 3, 3 are pressed against both sides of the rotor 1 by the piston 5 (Fig. 2) and the caliper claws 4a, 4a, and braking is performed. What is done is the same as a conventional disc brake, but the distribution of the force pressing against the pad 3 changes depending on whether the pad 3 is at room temperature or high temperature. That is, at room temperature, the compression spring 6 stored in the recess has a short overall length as shown in FIG. 3A.
The pad 3 is not compressed by the compression spring 6, but if the temperature of the pad 3 rises as a result of frequent braking, the entire length (free length) of the compression spring 6 increases as shown in FIG. 3B. Naroutoshi, Patsudo 3
The outer circumferential portion of the rotor is pressed by the spring 6, and the force that presses the pad 3 against the side surface of the rotor 1 is greater on the outer circumferential side of the rotor than on the inner circumferential side. Therefore, at high temperatures where noise is likely to occur during braking, such noise can be effectively prevented from occurring.

(Example of application of the present invention) In the above-mentioned embodiment, a recess 7 is formed in each of the two caliper claws 4a, and a compression spring 6 made of a shape memory alloy is housed therein. , In order to prevent noise generation, it is not necessary to provide it on both caliper pawls, and it is not necessary to provide it on both caliper pawls.
When the rotor 1 rotates as shown by the arrow a in the figure, the recess 7 may be formed only in the left side caliper pawl 4a, and the compression spring 6 may be housed therein.

(Effects of the present invention) Since the disc brake of the present invention is configured and operates as described above, it is possible to effectively prevent the occurrence of noise at high temperatures where noise is likely to occur.
Moreover, since the pad is evenly pressed toward the rotor side at room temperature, when noise is less likely to occur, the effect can be maintained regardless of the degree of pad lining wear.

[Brief explanation of drawings]

Figures 1 and 2 show an example of a disc brake to which the present invention is applied, with Figure 1 being a front view and Figure 2 being a front view.
The figure is a sectional view taken along the line A-A in Figure 1, and Figure 3 shows a compression spring made of a shape memory alloy that is incorporated into the disc brake of the present invention. It is the state of the time. Figures 4 and 5 show the disc brake of the present invention incorporating this compression spring.
Figure 4 is a front view, Figure 5 is an enlarged view of the main part of Figure 4 B-
It is a sectional view of B. 1: Rotor, 2: Support, 3: Padded, 4:
Caliper, 4a: Caliper claw, 5: Piston,
6: Compression spring, 7: Recess.

Claims (1)

[Claims] 1 A piston 5 installed in the caliper 4, a caliper claw 4a provided at a position facing the piston 5,
In a disc brake that performs braking by pressing two pads 3, 3 against both sides of the peripheral edge of the rotor 1 rotating together with the wheel, at least one of the caliper pawls 4a, 4a on the anchor side A recess 7 is formed in the inner surface of the caliper pawl 4a at the portion of the pad 3 that presses against the outer peripheral side of the rotor, and within this recess 7, the free length at normal temperature is less than the depth of this recess 7 and the free length at high temperature is less than or equal to the depth of the recess 7. A disc brake characterized by housing a compression spring 6 made of a shape memory alloy that is larger than the depth of the recess 7.