JPH033809B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for forming a mounting hole for a return spring in a friction pad for a disc brake.

BACKGROUND OF THE INVENTION Disc brakes are generally configured so that a pair of friction pads is pressed against a disc rotor that rotates together with the wheels, and the rotation of the wheels is suppressed by the frictional force generated between them.

By the way, in such disc brakes,
In order to avoid the undesirable phenomenon of so-called dragging, in which the friction pads continue to slide against the disc rotor even after the brake is released, a return spring is attached to the pads to urge each pad toward a non-active position.

The mounting hole for the return spring has conventionally been formed by drilling into the back metal of the pad, but this mounting hole has a small diameter and is relatively long (deep). (The amount of charge at the end is small, making it difficult for the pad to return smoothly), which requires time and effort to process, and the tool may break or wear out.
This caused the problem of high processing costs.

Purpose of the Invention The present invention was made against the background of the above circumstances, and its purpose is to easily form mounting holes without requiring machining or tools for drilling holes. An object of the present invention is to provide a method for forming a return spring mounting hole in a friction pad for a disc brake.

Structure of the Invention In order to achieve this object, the present invention provides that, when a friction pad is formed by fixing the friction material to the backing metal, a pipe member is provided on the fixed surface side of the backing metal, the end of which is exposed to the outside. By fixing the friction material to the back plate in such a state, the pipe member is buried in the pad, and a hollow hole opened at the end of the pipe member is used as a mounting hole for the spring. It is characterized by this.

Effects of the Invention With this method, the mounting hole for attaching the return spring is formed at the same time when the friction material is fixed to the backing metal, so the trouble of drilling holes after forming the friction pad can be saved. . Therefore, since no drilling tool is used, the cost required for the tool is reduced, the working time is shortened, and the machining cost is also reduced.

Embodiment In order to further clarify these features of the present invention, one application example thereof will be described in detail below based on the drawings.

FIG. 1 shows a general-shaped friction pad and a spring mounting hole formed therein.
When the brake is applied, the friction material 14 is pressed against a disc rotor (not shown) that rotates together with the wheel, and at this time, the rotation of the wheel is suppressed based on the frictional force generated between the two.

A pair of sliding parts 16 protruding in the same direction are formed at both ends of the back plate 12 in the disk rotor rotation direction (left and right direction in the drawing), and are slidably supported by a support member (not shown). It is becoming more and more common. On the other hand, the friction material 14 includes asbestos, a friction modifier,
It is made by molding a binder or the like at a predetermined temperature and pressure, and is irremovably fixed to the back metal 12.

Near both left and right ends of the friction pad 10, a pair of return spring mounting holes 18 are provided that extend to approximately the center of the friction pad 10 in the height direction (radial direction of the disc rotor) and connect the friction material 14 and the back metal 12. The rod-shaped end of the return spring for returning the pad 10 pressed against the rotor to its non-active position is inserted therein.

Next, a specific method for forming a spring mounting hole in such a friction pad will be described.

First, as shown in FIG. 2, on the friction material fixing surface side of the backing metal 12 that has been formed into a predetermined shape, a longitudinal recess 20 with a substantially semicircular cross section is formed diagonally from the upper end of the backing metal 12 in FIG. It is formed with a predetermined length downward, that is, toward the center of rotation of the disk rotor.

This recess 20 can be easily formed by coining. Next, this back money 12,
It is set in a mold cavity for molding the friction material with its fixed surface side, that is, the side where the recess 20 is formed, facing upward. Next, the pipe member 22 is placed on the back metal 12 in this elongated recess 20 so that approximately half of the pipe member 22 in the radial direction is fitted into this elongated recess 20, as shown in FIG. This pipe member 22 has an inner diameter that allows the end of the return spring to be inserted and a length that is required as a mounting hole, and the end on the buried side is As shown in FIG. 5, it is bent in a direction perpendicular to its axis to form a pull-out prevention part 24.

Note that the recess 20 of the backing metal 12 has a recessed portion at its tip portion for accommodating the slip-off preventing portion 24 .

When the pipe member 22 is placed in the recess 20 of the back metal 12, the preformed friction material is filled into the mold cavity, and then the friction material 14 is molded and bonded to the back metal 12 at a predetermined temperature and under a predetermined pressure. and at the same time. At this time, the recess 20 of the back metal 12
The remaining half of the pipe member 22 placed inside is buried in the friction material 14 (the state shown in FIG. 4). That is, by molding the friction material 14 and adhering it to the backing metal 12, the pad 10 is formed and the pipe member 22 is buried at the same time, and the hollow hole of the pipe member 22 forms the mounting hole 18 to which the return spring is to be attached. It becomes.

The end of the pipe member 22 on the side embedded in the pad 10 is bent in a direction perpendicular to its axis to form a fall-off prevention part 24.
Recess 20 in the backing metal where approximately half of 4 extends in the same direction.
Since the remaining half is buried in the friction material 14, the pipe member 22 does not fall out from the pad 10.

In this way, according to the above method, the longitudinal recess 20 is formed in the back metal 12, and the pipe member 22 is simply placed in the recess when forming the friction material 14 and adhering it to the back metal 12. At the same time as pad 10 is formed, spring mounting hole 18 is formed. Therefore, there is no need for machining to form mounting holes after that, which saves time and effort, and there is no wear and tear on tools such as drills, which improves productivity and reduces processing costs. reduction is achieved together.

Note that the pipe member described above can be embedded in the pad 10 in various other ways.

For example, as shown in FIG. 6, it is also possible to increase the radial depth of the longitudinal recess 20 formed in the back metal 12 so that the pipe member 22 is completely embedded within this recess 20. And also the seventh
As shown in the figure, no recess is formed on the side of the back metal 12, and when the friction material 14 is formed and bonded,
By arranging the pipe member 22 at a predetermined position on the fixed surface side of the back metal 14, it is also possible to embed the entire pipe member 22 in the friction material 14 at the same time as forming and adhering the friction material 14.

The pipe member 22 is attached to the pad 1 in the manner shown in FIG.
In the case of embedding the pipe member 2 in the pipe member 2 during molding of the friction material 14 (the same applies to the embodiment shown in FIG. 4),
This has the advantage that the pipe member 22 is reliably positioned at a desired position, and when the pipe member 22 is embedded in the pad 10 in the manner shown in FIG. This has the advantage of further reducing the number of man-hours required.

In addition, the falling-off prevention part 24 of the pipe member 22 embedded in the pad 10 can be formed in various forms different from those of the above embodiments.

FIGS. 8 to 10 show specific examples thereof, and FIG. 8 shows an example in which one end of the pipe member 22 is crushed to form a fall-off prevention portion 28 that protrudes radially outward. 9 shows an example in which a part of the pipe member 30 near the end is shaved to form a slip-off prevention part 32, and FIG.
The end of the pipe member 34 is enlarged in diameter to prevent it from coming off.
An example of forming a .

In the above embodiment, a case was described in which the friction material is formed and bonded to the backing metal at the same time, but the friction material is preformed into a plate shape and then bonded to the backing metal. It is also possible to embed the pipe member in the friction pad during bonding. However, in this case, it is necessary to form a recess into which a part of the pipe member is to be fitted when molding the friction material, or to embed the pipe member in the friction material during molding. In the latter case, by fixing the friction material in which the pipe member is embedded to the back metal, the pipe member is embedded in the pad.

Furthermore, the direction in which the longitudinal recesses 20 are formed may be not only in the radial direction of the disk rotor, but may also be parallel to each other or in directions that are spaced apart from each other as they approach the center of rotation of the disk rotor.

It should be noted that the above-mentioned embodiment is merely an example of the present invention, and various modifications may be made to the present invention without departing from the spirit thereof.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a friction pad to which a specific example of the mounting hole forming method according to the present invention is applied, and Figs. 2 to 4 show a process of forming the pad and mounting hole shown in Fig. 1. 5 is a front view of the pipe member in FIGS. 1 and 4. FIG. FIGS. 6 and 7 are plan views of main parts showing friction pads and mounting holes formed according to other embodiments of the present invention, and FIGS. 8 to 10 are pipe members used in the present invention. FIG. 6 is a front view showing a different form from that shown in FIG. 5; 10: Friction pad, 12: Reinforcement back metal, 14: Friction material, 18: Return spring mounting hole, 22,
26, 30, 34: Pipe member, 24, 28, 3
2, 36: Fallout prevention part.

Claims (1)

[Scope of Claims] 1. A friction pad having a reinforcing back metal and a friction material fixed thereto and pressed against a disc rotor during braking, and a rod-shaped end of a return spring for returning the pad to a non-acting position. A method of forming a mounting hole for attaching the spring by inserting the pipe member, when fixing the friction material to the backing metal to form a friction pad, inserting the pipe member so that the end thereof is on the fixed surface side of the backing metal. The pipe member is buried in the pad by fixing the friction material to the back metal in a state where it is exposed to the outside, and the spring is attached to a hollow hole opened at the end of the pipe member. A method for forming a return spring mounting hole in a friction pad for a disc brake, which is characterized by forming a hole. 2. The pipe member is a pipe member in which a slip-off preventing portion that protrudes or recesses in the radial direction is formed in a portion of the pipe member that is to be embedded in the friction pad.
Mounting hole formation method described in section.