JPS6227717Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disc brake pad, and more particularly to a disc brake pad structure that prevents reduction in braking force due to water caught between the disc rotor and the pad.

If a disc brake that has leaked water is activated while the vehicle is running, the braking force may be abnormally reduced compared to normal braking force or may become one-sided. This phenomenon is called water fade, and is one of the causes of deterioration in vehicle drivability.

In contrast, Japanese Patent Publication No. 38-24474 proposes forming a plurality of grooves in the friction plate of a disc brake pad. These grooves open on the surface of the friction plate that is pressed against the disk rotor, have a depth of approximately 3/4 of the thickness of the friction plate, reach the wear limit surface, and are formed on the surface of the disk rotor. The circumferentially extending grooves and the radially extending grooves are provided in a grid pattern, the circumferentially extending grooves are provided at radially spaced intervals, or the radially extending grooves are provided at circumferentially spaced intervals. It is set apart from the

The grooves provided in the friction plate in this manner serve to scrape off water adhering to the disc rotor at the opening edge of the friction plate, and also to remove water from inside the friction plate. For example, the amount of water scraped off by the grooves increases, and the area of the friction plate divided by the grooves becomes smaller, reducing the force applied to the opening edge of the grooves. Water will not be trapped and water will be effectively removed.

However, when multiple grooves are provided on a friction plate in this way, protrusions that are tall relative to the width are formed between the grooves or between the grooves and the side end surface of the friction plate, and these parts are prone to breakage. This causes a problem in that the strength of the friction plate decreases. Furthermore, the grooves cause the friction plate to be in a state equivalent to being divided into pieces, resulting in a problem that the bending rigidity is reduced.

The present invention was developed against this background, and aims to provide a pad that can obtain a sufficient water drainage effect without reducing the strength and bending rigidity of the friction plate. .

In order to achieve this purpose, the pad according to the present invention has an opening on the surface of the friction plate, has both ends opening on the side end face of the friction plate, and has a distance from the surface to the wear limit surface of the friction plate. shallower grooves,
At least one groove forming hole extending substantially parallel to the groove is provided at a position offset from the groove in a direction parallel to the surface, and the surface side portion of the groove forming hole closest to the surface is provided. It is parallel to the surface and is located on the surface side of the surface that contacts the bottom of the groove, and the part closest to the wear limit surface is located closer to the back plate than the wear limit surface. .

When the groove forming holes are provided in only one step in the thickness direction of the friction plate, the part of the same hole on the surface side of the friction plate is parallel to the surface and is located closer to the surface than the surface in contact with the bottom of the groove. At the same time, the portion on the wear limit surface side is positioned closer to the back plate than the wear limit surface.

In addition, when groove forming holes are provided in multiple stages, the surface side part of the hole closest to the surface of the friction plate is located parallel to the surface and closer to the surface than the surface in contact with the bottom of the groove. The part on the wear limit surface side is located on the front side of the wear limit surface, while the part on the wear limit surface side of the hole closest to the wear limit surface is located on the back plate side than the wear limit surface. The side portion is located closer to the wear limit surface than the surface in contact with the bottom of the groove. In this case, if the holes are provided in two stages, the part on the wear limit surface side and the part on the surface side of the holes are in contact with one of the bottoms, and the part on the wear limit surface side or It is positioned on the surface side. The same applies when holes are provided in three or more stages.

In the pad constructed as described above, water interposed between the disc rotor and the pad is removed through the groove formed in the pad. and,
Even if the groove-forming portion of the friction plate disappears as the friction plate wears out, the groove-forming hole will open on the surface before that portion completely disappears, and it will function as a groove. , grooves are formed in the friction plate that are constantly open on the surface until the friction plate is worn down to the wear limit surface.

Even if the friction plate is not cut out and a groove is not formed directly from the surface to the wear limit surface, the same effect as when such a groove is provided can be obtained, and even if multiple grooves are provided, The protrusions formed between the grooves and between the grooves and the side end surfaces of the friction plate are short in relation to their width, so that the strength and bending rigidity of the friction plate are not reduced.

Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

Figure 1 shows a disc brake.
A disc rotor 8 has a pair of friction surfaces 4, 6 on both sides and rotates together with the wheels.
Inner pad 10 and outer pad 1
2 are arranged. These inner pads 10 and outer pads 12 are composed of friction plates 14, 16 made of a friction material such as asbestos or sintered metal, and back plates 18, 20 made of metal to which these plates are fixed. A caliper 22 is disposed straddling the disc rotor 8 and the pads 10, 12 disposed on both sides thereof. The caliper 22 includes a hydraulic cylinder section 24 disposed facing the inner pad 10, a reaction section 26 disposed opposite the outer pad 12, and a bridge connecting the hydraulic cylinder section 24 and the reaction section 26. It consists of a section 28. The inner pad 1 is attached to the hydraulic cylinder section 24.
A cylinder bore 30 is formed that opens toward the zero side, and a piston 32 is slidably fitted into the cylinder bore 30 in a liquid-tight manner. Therefore, when the brake is operated, braking fluid pressure is supplied into the hydraulic cylinder section 24, the piston 32 presses the inner pad 10 against the friction surface 4 of the disc rotor 8, and the reaction force causes the reaction section 26 to move against the outer pad. 12 as friction surface 6
The rotation of the disk rotor 8 is thereby suppressed.

The inner pad 10 and the outer pad 12 are each provided with one long through hole 34 on both shoulders, and the long through hole 34 is inserted into a rod (not shown) whose both ends are fixed to the caliper 22, parallel to the axial direction of the disc rotor 8. Supported for directional movement.
Further, the caliper 8 is supported movably in parallel to the axial direction of the disc rotor 8 by a torque member (not shown) attached to a non-rotating member such as an axle tube, and the torque member is attached to the ends of the inner pad 10 and the outer pad 12. It is designed to receive braking force by coming into contact with.

As shown in FIGS. 2 and 3, the inner pad 10 has a V-shaped notch at the end surface of the friction plate 14 on the disk rotor entry side, and is inclined with respect to the circumferential direction A of the disk rotor 8. A pair of end surfaces 36 are formed. This friction plate 14 has
Each of the pair of end faces 36 and the disk rotor 8
Two grooves 40 are formed in a pair of side end surfaces 37 substantially parallel to the circumferential direction A, each opening respectively.
These grooves 40 are made shallower than the distance from the surface of the friction plate 14 to the wear limit surface of the friction plate 14, as shown in FIG.
Two groove forming holes 38 extending substantially parallel to the grooves 40 are formed at positions adjacent to each groove 40, respectively.

These two groove forming holes 38 are formed on the friction plate 1.
The holes 38 on the side closer to the surface of the friction plate 14 are formed at positions parallel to the surface of the friction plate 14 and in the thickness direction of the friction plate 14, respectively.
At a position shifted in the direction parallel to the surface, the surface side part is parallel to the surface and the groove 40
It is located on the surface side of the plane that is in contact with the bottom of the plane, or is formed so as to be in contact with that plane. Further, each of the holes 38 on the side closer to the wear limit surface defined in the vicinity of the back plate 18 of the friction plate 14 has its wear limit surface side located closer to the back plate 18 than the wear limit surface, and the front side The portion is formed so as to be in contact with a plane parallel to the surface and in contact with the bottom of the wear limit surface side of the hole 38 on the side close to the surface, or to be located on the surface side from that plane. Note that the outer pad 12 is constructed in the same manner as the inner pad 10, and detailed description thereof will be omitted.

The operation of this embodiment will be explained below. Since the inner pad 10 and the outer pad 12 have similar operations, only the inner pad 10 will be explained.

When a disc brake that has leaked water is operated, a large amount of water adhering to the surface of the disc rotor 8 is caught between the disc rotor 8 and the friction plate 14, forming a water film, which causes the pads to become wet. 10 and 12 are strongly pressed against the disc rotor 8, an abnormal decrease in braking force or one-sided braking force may occur.

However, since the pad 10 of this embodiment has a groove 40 that opens on the surface of the friction plate 14, water that has entered between the disc rotor 8 and the friction plate 14 is discharged through the groove 40. . On this occasion,
The water adhering to the surface of the disc rotor 8 is removed by the friction plate 1.
The inclination of the end face 36 on the input side of groove 4 collects the water near the bottom of the V-shape, and this collected water flows into groove 4.
Some of the water is discharged to the side end surface 37 through the groove forming hole 38 and enters between the disc rotor 8 and the friction plate 14. Less water is required. Also,
Water adhering to the surface of the disc rotor 8 is also scraped off by the opening edges of the grooves 40 and is discharged through the grooves 40. When water is discharged through the grooves 40 in this manner, the area of the portion of the friction plate 14 delimited by the grooves 40 is smaller than that in the case where only one groove is provided. Only a small amount of force is applied to the part forming the groove 40, and the water does not flow into the groove 40.
It is not trapped inside and can be easily discharged.

As braking is repeated, the friction plate 14 wears out, and the portion forming the groove 40 wears out, causing the groove 40 to disappear. However, before the groove 40 completely disappears, the surface of the friction plate 14 The groove-forming hole 38 on the side closer to the disk is opened to the surface to form a groove, and water interposed between the disc rotor 8 and the friction plate 14 is discharged through the groove. Further, as braking is performed further, the portion of the friction plate 14 that forms the groove forming hole 38 on the side closer to the surface wears out, and the groove formed by the hole 38 disappears. Before the water completely disappears, the groove-forming holes 38 on the side closer to the wear limit surface open to the surface, and the water is discharged through the grooves formed by the holes 38.

In this way, until the friction plate 14 wears down to its wear limit, a plurality of grooves are constantly formed on the surface of the friction plate 14 to drain water, thereby preventing abnormalities in the braking force of the disc brake. However, these grooves do not directly reach the wear limit surface from the surface of the friction plate 14, but are formed by grooves 40 that are shallower than the distance between both surfaces.
Since the grooves formed in the friction plate 14 on the surface are formed by groove forming holes 38 provided to open in a different part from the part where the grooves are opened, even if there are multiple grooves, the friction plate 14 The strength and bending rigidity of the material will not decrease.

Next, another embodiment of the present invention will be described.

In the inner pad 42 shown in FIG.
An end surface 48 of the friction plate 46 fixed to the back plate 44 on the input side of the disc rotor 8 is formed obliquely in a single-sided manner with respect to the circumferential direction C of the disc rotor 8. Two grooves 54 are formed in the end surface 48 and the side end surface 50 which is substantially parallel to the circumferential direction C of the disk rotor 8 and opens toward the center of the disk rotor, and the friction plate 46 has two grooves 54 formed therein. A plurality of groove forming holes 52 extending in parallel are formed. These grooves 54 and groove forming holes 52 are formed on the friction plate 46 as in the previous embodiment.
It is provided so as to form a groove that is constantly open on the surface until it wears down to the wear limit surface.

The above-mentioned embodiment is merely one embodiment of the present invention, and various modifications may be made to the present invention without departing from the spirit thereof.

For example, the end faces 36, 48 of the friction plates 14, 46 on the retraction side with respect to the disc rotor 8 are formed for rotation in the forward direction of the vehicle, which is usually used most frequently, but conversely, It may also be formed for rotation in the direction. In this case, the shape is symmetrical in FIGS. 2 and 4, and there is an advantage that the parts of the inner pad and the outer pad can be interchanged.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a disc brake including pads according to an embodiment of the present invention. 2 and 3 are a front view showing the embodiment of FIG. 1 and - of FIG.
FIG. FIG. 4 is a front view showing another embodiment of the present invention. 8... Disc rotor, {10... Inner pad, 12... Outer pad} (Pad), 14,1
6, 46... Friction plate, 18, 20, 44... Back plate, 36, 48... End face on input side, 37, 50...
... Side end surface, 38, 52 ... Groove forming hole, 40, 5
4...Groove.

Claims (1)

[Claims for Utility Model Registration] A friction plate that contacts the friction surface of the disc rotor on its surface and a back plate that is fixed to the back surface of the friction plate, and is pressed against the friction surface of the disc rotor to suppress its rotation. In a pad of a disc brake, the friction plate has a groove that is open to the surface and has both ends opened to side end surfaces of the friction plate, and is shallower than the distance from the surface to the wear limit surface of the friction plate, and the groove. at least one groove extending substantially parallel to the groove at a position offset from the groove in a direction parallel to the surface.
A book groove forming hole is provided, and a surface side portion of the groove forming hole closest to the surface is located parallel to the surface and closer to the surface than a surface in contact with the bottom of the groove. , and a portion of the pad closest to the wear limit surface that is closer to the wear limit surface is located closer to the back plate than the wear limit surface.