JPS6021255B2 - Friction pad assembly for disc brakes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a friction pad assembly for use in a disc brake and a disc brake incorporating the friction pad assembly.

In most constructions of disc brakes, friction pads are supported on or between guide surfaces, and braking torque is transmitted from the friction pads to the guide surfaces and thus to the vehicle frame.

It is necessary to provide a certain amount of clearance with respect to this guide surface so that the pad can freely slide forward and backward relative to the disc when the brake is applied. However, as a result, the pad wobbles within the guide surface. To alleviate this problem, it is known to use elastic means (usually springs) to permanently press the pad against one side of the guide surface. When such elastic means, especially springs, are used... Conventional springs have been associated with many of the following problems. {1- It is not possible to apply substantially the same force between the pad and the guide surface throughout the life of the pad.

[21] It is not easy to attach or detach the brake.

'3} Generates a force or torque that displaces the pad from a predetermined position and posture within the brake caliper. {4} The rubber boot provided to protect the piston inside the brake caliper is damaged.

{5} Equipment and assembly costs are not particularly low.

{6}. It requires space, thus sacrificing space that would otherwise be taken up by other components that improve the performance of the brake, and especially the stiffness of the brake. In order to solve at least some of these problems, a structure disclosed in Japanese Patent Application Laid-Open No. 51-89970 was proposed.

This secures the spring to the diamond plate of the friction pad assembly prior to mounting the pad assembly on the disc brake (preferably during manufacture of the friction pad assembly). The primary purpose of the spring is to prevent rattling by constantly pressing the pad assembly against the guide surface within the disc brake. There are several advantages to pre-attaching this anti-rattle spring to the pad assembly. For example, it is ensured that the spring is correctly installed in the brake.
Also, because the spring cannot change its sliding position, there is less chance of damaging the steerable boot that is normally provided in disc brakes to protect the hydraulic piston and cylinder from dirt and moisture. The above Japanese Patent Publication No. 5
In the embodiment disclosed in Japanese Patent No. 1-89970, the wire spring that prevents the pad from wobbling has its coiled portion attached to the back plate of the pad assembly using rivets.

This construction requires some free space within the disc brake to allow the necessary movement of the pad assembly. An object of the present invention is to provide a friction pad assembly in which a spring is fixed to prevent rattling of the pad.
The object of the present invention is to improve the location and mounting method of the springs so that the design of the friction pad assembly can be freely adapted to the shape of the part to which the pad assembly is to be mounted.

The present invention provides a friction pad assembly for a disc brake consisting of a diamond plate and a pad made of friction material fixed to the diamond plate, in which the back plate is a flat member, and the edge of the back plate is At least a portion of an anti-rattle spring, which has a groove divided along a plane parallel to the plane and which constantly presses the friction pad assembly against the sliding guide surface of the disc brake, is attached to the side wall of the groove. The device is characterized in that it is held in the groove by the engagement of the provided hole, recess or convex portion with the spring.

In one embodiment of the invention, the protruding portion of the backing plate that does not have friction material is centrally located in the upper portion of the friction pad assembly when inserted into the brake.

The protruding portion is divided by a plane parallel to the plane of the back plate to form a groove, and the central portion of the wire spring is disposed in the groove. Both or one of the groove-forming portions of the protrusion are bent to form a convex portion, and the spring is fixed to the back plate. The free ends of the wire springs extend outwardly to either side of the protrusions to support pad support pins or disc brake gear IJs.
Engaging the underside of the pub, the central portion of the spring exerts a downward force on the bottom of the groove, constantly pressing the pad assembly against the guide surface. As an alternative construction, one or both of the side protrusions forming the groove may be provided with a hole or recess opening into the groove and engaging a central bend bent in one plane of the spring.

The central bent portion of the spring is inserted into the groove and then rotated about its length to secure the spring to the back plate by ironing the central bent portion into the hole or recess. In the above description, the protrusion is located in the center of the back plate of the pad assembly, but the present invention is equally applicable to any shape of back plate as long as a groove is provided in the green of the back plate. be able to.

The present invention is also particularly useful in friction pad assemblies that employ composite backings, ie, backings made of several layers.

An example of such a composite backing plate is U.S. Pat. No. 3,885.
It is described in No. 651. In this U.S. patent, the backing plate is comprised of a first layer of metal that secures a pad of friction material, a second layer of damping material, and a third layer of metal on which the hydraulic piston of the disc brake acts. It is what it is. Composite backing plates are also described in US Pat. No. 3,490,563, No. 3,378,116 and British Patent No. 1,033,158. In a backing plate of the type of U.S. Pat. No. 3,885,651, the first and third layers extend out of the second layer of noise-damping material to form a groove into which a spring can be inserted. .

The ribs can be fixed to the back plate by bending the first layer and/or the second layer to form a convex portion. Or alternatively, the first
Holes or recesses can be provided in the layer and the third layer, into which the bends of the spring can rest as described above. These friction pad assemblies using composite materials are extremely inexpensive and convenient and can combine the advantages of both anti-squeal with a composite backing and the fixed position of anti-rattle springs.

By fixing the position of the spring that prevents the pad from wobbling, there is no chance of incorrectly installing the spring, there is no risk of damaging other parts, and the pad assembly remains in the correct operating position throughout the life of the friction pad. This has the effect of not sacrificing much space that would otherwise be occupied by other brake components. Embodiments of the present invention will be described below with reference to the drawings.

The friction pad assembly shown in FIGS. 1 and 2 consists of a flat hair plate 1 and a pad 2 of friction material affixed thereto.

In the center of the upper edge 3 when the friction pad assembly is in use is a tab 4 which is integral with and forms part of the hair plate. At both ends of the upper green 3 are provided laterally projecting shoulders 5, which skins engage the guide surfaces of the disc brake during use. The tab 4 has two parts 6, 7 similar to the upper edge 3 of the back plate.
It is divided into. For this purpose, grooves 8 are formed which lie in a plane parallel to the plane of the back plate. A spring 9 for preventing the pad from rattling is attached to the portion 6 forming the side wall of the groove 8.
7 into the groove 8. The central bend of the spring 1 is bent in a plane approximately perpendicular to the planes of the free ends of the spring and is brought into and engaged with the hole 12 in the portion 6. In other embodiments (not shown) holes may be provided in both parts 6, 7, or recesses may be provided instead of holes. Place the spring in the groove 8 with the central bend 10 of the spring 9 and its adjacent parts 13, 14 lying in a single plane parallel to the plane of the groove 8, then rotate the spring to The bent portion 10 is fitted into the hole 12 and the spring is fixed to the back plate. A second embodiment of the invention is shown in FIGS. 3 and 4. This friction pad assembly and FIGS.
The main difference from that shown in the figure is that part of the section 6 is bent towards the section 7 of the tab to form a convex portion 15, while the straight section 16 in the center is held in the groove 8. (Figure 4)
. FIG. 4A shows a modification of the embodiment of FIG. 3. this is,
The back plate is made of a composite material in which a layer 19 of noise absorbing material is deposited between metal layers 17 and 18. layer 17
, 18 extend outward from the layer 19 to form the side walls of the groove 8, and a portion of the layer 17 is bent towards the layer 18 to form a convex portion 20 retaining the central portion 16 within the groove. . Layer 19 may be made of a thermally insulating material. The friction pad assembly of FIGS. 1-4A rides on laterally spaced guide surfaces of the disc brake and is secured by a spring 9 that engages other parts of the disc brake, such as the caliper springs. is pressed upwards against the guide surface to prevent wobbling.

However, it is equally applicable to a friction pad assembly in which the back plate is supported by a pair of spaced apart parallel pins when used in a disc brake. Such a friction pad assembly is shown in FIG. This friction pad assembly has a pad 2 made of friction material fixed to a back plate 21. As shown in FIGS. 5 and 6, the upper edge of the hair plate 21 is free of friction material, and ears 22 protrude upward from both ends thereof. The upper edge 23 and each lug 22 are divided to form a groove 24 (FIG. 6). The grooves lie in a plane parallel to the plane of the hair plate 21 across the friction pad assembly. The anti-rattle spring 25 is inserted into the groove 24 and its central portion 26 rests on the bottom surface 27 of the groove 24. The spring bends upwardly and then outwardly from the central portion 26 (FIG. 5), with the free end 28 extending to the ear 22. The ear 22 is provided with a hole 29 through which a pad support pin 30 engages the free end 28 of the spring. The spring 28 engages with the lower surface of the pin 30 to absorb the gap between the pin 30 and the hole 29 and prevent rattling. As can be seen in FIG. 6, the spring 25 is secured within the groove 24 by bending a portion of one side wall of the groove 24 over the central portion 26 of the spring to form a protrusion 31. Similar to FIG. 4A, FIG. 6A also shows a composite backing plate 32.
An example of the present invention using .

This embodiment is a variation of the embodiment of FIGS. 5 and 6, with the only difference being that backing plate 32 consists of layers 33, 34 and 35 superimposed. Layers 33 and 34 are metal with a layer 35 of noise absorbing material sandwiched between them. Layer 35 may also be a thermal insulator. Layers 33 and 34 extend outside of layer 35 to form side walls on either side of the groove, with a portion of layer 34 bent toward layer 33 to form a protrusion 37 for fixing the manufacturer 25. 7 and 8 show a fourth embodiment of the invention.

This embodiment is similar to the embodiment of FIG. 6A, with the backing plate consisting of three layers 38, 39 and 40. layer 4
layers 38 and 39 are layers 40
A groove 41 is formed between the grooves 41 and extending outward. As can be seen in FIG. 7, the upper green 42 of the layer 40 forms the bottom of the groove 41, and approximately in the center of the groove 41, the edge 42 is provided with a concave surface 43. In this embodiment, the spring 44 for preventing sagging of the pad has a curved part 45 in the center, which curved part 45 is bent by the above-mentioned concave surface 43 and has a circular convexity formed by the deformation of the layer 38. The portion 46 closes the groove 41 and connects the spring to the convex portion 46 and the concave surface 43.
fixed between. FIG. 9 is similar to the pad assembly shown in FIG. 5, but the structure is different.

The spring 47 is not symmetrical about the central portion 48 as shown in FIG. The protrusion 31 formed by bending the plate and the engagement portion are fixed. The spring moves the pad circumferentially towards one of its abutting surfaces.
This prevents the pad assembly from hitting the above contact surface when the brake is applied. Asymmetric springs in the shape of reservoirs can be used with various shapes of back plates to achieve similar effects. In the embodiments described above, wire springs were used.

Although wire springs are easy to mold and have the necessary resiliency and small dimensions for fitting into grooves, it is of course possible to use other forms of springs as well.

[Brief explanation of the drawing]

FIG. 1 is a front view of a portion of an embodiment of the friction pad assembly of the present invention. 2 is a plan view of the assembly shown in FIG. 1; FIG. FIG. 3 is a front view of a portion of a second embodiment of the friction pad assembly of the present invention. FIG. 4 is a partial sectional view taken along the line AA in FIG. 3. FIG. 4A is a partial cross-sectional view similar to FIG. 4, but showing a friction pad assembly using a diamond plate made of a composite material. FIG. 5 is a front view of a portion of a third embodiment of the friction pad assembly of the present invention. Figure 6 is B of Figure 5.
-B partial cross-sectional view. FIG. 6A is a partial cross-sectional view similar to FIG. 6, but using a composite backing plate for the friction pad assembly. FIG. 7 is a partial front view of a fourth embodiment of the friction pad assembly of the present invention. FIG. 8 is a partial sectional view taken along the line CC in FIG. 7.
FIG. 9 is a partial front view showing a modified example of the pad rattling prevention spring in the embodiment shown in FIG. 5; 1・
... Back plate, 2 ... Pad, 3 ...
・Green, 4...Protrusion, 6, 7...Each part of the protrusion, 8, 24, 41...Groove, 9, 25, 47...Spring, 11...Freedom of the spring Mr., 12... Hole, 15, 20,
31, 37, 46... Convex portion, 16... Central part of the spring, 17, 18, 19... Layer.・-F/G. '-・・-f'62. -・ -F/G3. ... ・One F'G. Child--1F'6. Chi A← ・-F/G. S... ・-F'G. 6-・・-F/G. 64r・・-F/G. Z-・・-F′G. 8"・.-F'G.9.-.

Claims (1)

[Claims] 1. In a disc brake friction pad assembly comprising a back plate and a pad of friction material fixed to the back plate, the back plate 1 is a flat member, and the edge of the back plate rattling prevention springs 9, 25, 44, 47 for constantly pressing the friction pad assembly against the sliding guide surface of the disc brake; is retained in the groove by engagement of the spring with a hole, recess or protrusion 12, 15, 20, 31, 37, 46 provided in the side wall of the groove. A friction pad assembly characterized by: 2. The friction pad assembly according to claim 1, wherein the bent portion 10 of the spring is removably fitted into the hole 12 or recess provided in the side wall of the groove. 3. In the friction pad assembly according to claim 1, the protrusions 15, 20, 31, 3 provided on the side wall of the groove
7, 46, a friction pad assembly formed by bending a portion of the side wall against the spring within the groove to permanently retain the spring; 4. In the friction pad assembly according to claim 1, the back plate is made up of a number of laminated layers 17, 18, 19, the outer layers on both sides forming the side walls of the groove, and the remaining layers forming the side walls of the groove. A friction pad assembly characterized in that a layer forms the bottom surface of the groove.