JPH109309A - Brake abrasion warning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily attach/detach an abrasion detecting sensor without using a tool by attachably and detachably engagingly mounting the abrasion detecting sensor in the mounting hole of the back plate of a brake friction member by a snap ring, and damp a shock by interposing an elastic member between the abrasion detecting sensor and the brake friction member. SOLUTION: A brake friction member 1 is fixed on a back plate 2, and a mounting hole in which the abrasion detecting sensor 3 of the brake friction member 1 is set, is arranged in the back plate 2. A hole 1a in which the abrasion detecting sensor 3 is placed, is arranged in the brake friction member 1 matched to the position of the mounting hole of a small diametrical hole 5 and a large diametral hole 6. A ringlike projection 3a and a ringlike groove 3b in which a snap ring 4 is fitted, are arranged around the periphery of the abrasion detecting sensor 3, so that the abrasion detecting sensor 3 is prevented from being slipped off by the projection 3a and the snap ring 4. The end of the abrasion detecting sensor 3 is positioned and mounted in the position of the abrasion limit thickness of the brake friction member 1. An elastic member such as rubber and soft resin is interposed between the brake friction member 1 and the abrasion detecting sensor 3, so that this device can have buffering function for a shock.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake wear alarm device for notifying a wear limit of a brake friction material of a brake lining or a brake pad.

[0002]

2. Description of the Related Art In order to notify a wear limit of a brake friction material of a brake pad in a brake lining in a drum brake and in a disk brake, a brake wear alarm device has a wear detection sensor attached to a back metal of the brake friction material. This wear detection sensor generally uses a sensor that warns when the conductor of the detection terminal comes into contact with the brake drum or rotor due to wear of the brake friction material, or a sensor that warns when the lead wire is cut due to sliding of the brake drum or rotor. Have been.

[0003]

The above-mentioned wear detection sensor is attached to the back metal of the brake friction material by screwing or screwing to the back metal. For this reason, once mounted, it cannot be removed unless it is destroyed, or it needs to be removed using a special tool, and the shape and structure are complicated, the number of parts is large, and the cost is high.

An object of the present invention is to provide a brake wear alarm device having a structure for mounting a wear detection sensor which is simple in shape and structure and can be easily attached and detached without using a special tool.

[0005]

According to the present invention, there is provided a brake wear alarm device in which a wear detecting sensor for a brake friction material is attached to a back metal of the brake friction material. Is removably locked and attached to a mounting hole formed in the back metal by a snap ring.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a brake friction material of a brake lining or a brake pad fixed to a back metal 2. A mounting hole for setting the wear detection sensor 3 for the brake friction material 1 is formed in the back metal 2. In the embodiment shown in FIG. 1, this mounting hole has two holes, a small diameter hole 5 and a large diameter hole 6.
There are three different diameter holes. The brake friction material 1 corresponding to the mounting hole position of the small diameter hole 5 and the large diameter hole 6 is also provided with a hole 1a for allowing the wear detection sensor 3 to face.

[0007] The wear detecting sensor 3 is a brake friction material 1.
The alarm is issued when the conductor of the detection terminal comes into contact with the brake drum or the rotor due to the wear of the brake drum, or when the lead wire is cut by sliding of the brake drum or the rotor.

Therefore, the wear detecting sensor 3 is provided with a ring-shaped projection 3a and a ring-shaped groove 3b in which the snap ring 4 is fitted, as shown in FIG.
As shown in FIG. 3, a pin 3c may be used instead of the ring-shaped projection 3.

The wear detecting sensor 3 of the above-described type is inserted into the small-diameter hole 5 and the large-diameter hole 6 formed in the back metal 2 from the hole 1a formed in the brake friction material 1 and is formed into a ring-shaped projection 3.
a or the pin 3c is brought into contact with the upper surface of the backing metal 2 and the snap ring 4 is fitted into the groove 3b through the large-diameter hole 6 so that the snap ring 4
At the step 7 between the small-diameter hole 5 and the large-diameter hole 6.

As a result, the wear detecting sensor 3 is sandwiched between the back metal 2 by the ring-shaped protrusion 3a or pin 3c and the snap ring 4, and the ring-shaped protrusion 3a or pin 3c is held.
The wear detection sensor 3 is prevented from coming off by the c and the snap ring 4, and the tip of the wear detection sensor 3 is positioned and mounted at the wear limit thickness position of the brake friction material 1 in the hole 1 a of the brake friction material 1.

As shown in FIG. 4, an elastic material 10 such as rubber or soft resin is interposed between the ring-shaped projection 3a or the pin 3c of the wear detecting sensor 3 mounted on the back metal 2 and the back metal 2. In order to protect the internal structure function of the wear detection sensor 3, it is necessary to provide a shock absorbing function when the brake friction material 1 reaches the wear limit and the brake drum or the rotor comes into contact with the tip of the wear detection sensor 3. It is effective for.

FIG. 5 shows a second embodiment of the present invention. The second embodiment has a small-diameter hole 5 corresponding to the small-diameter hole 5 of the first embodiment.
Only on the back metal 2, a ring-shaped groove 3b for fitting the snap ring 4 is provided on the outer circumference of the wear detection sensor 3, and a groove 8 for locking the snap ring 4 is also provided on the inner circumference of the small diameter hole 5c. It is a structure provided.

The position of the groove 8 provided on the inner periphery of the small-diameter hole 5c is such that when the snap ring 4 is locked, the tip of the wear detecting sensor 3 is inserted into the hole 1a of the brake friction material 1. Is set so as to be positioned at the wear limit thickness position or the like.

In the case of the second embodiment, the wear detection sensor 3 can be set into the small-diameter hole 5 from either the brake friction material 1 side or from the backing metal 2 side. it can.

The wear detection sensor 3 is prevented from coming off by a snap ring 4 which is engaged with the ring-shaped groove 3b on the outer periphery of the wear detection sensor 3 and the groove 8 on the inner periphery of the small-diameter hole 5c. The tip of the wear detection sensor 3 is positioned and mounted in the hole 1 a of the material 1 at a wear limit thickness position or the like of the brake friction material 1.

Therefore, in the second embodiment, the large-diameter hole 6 of the back metal 2 and the ring-shaped projection 3 of the wear detection sensor 3 of the first embodiment are provided.
a or the pin 3c can be omitted.

In the second embodiment, the shock buffering action when the brake friction material 1 reaches the wear limit and the brake drum or the rotor comes into contact with the tip of the wear detection sensor 3 is performed by the elasticity of the snap ring 4. Will be

FIG. 6 shows a third embodiment of the present invention. In the third embodiment, a small-diameter hole 5a and a large-diameter hole 6a formed in the back metal 2 are provided with a large-diameter hole 6a on the brake friction material 1 side and a large-diameter hole 6a on the outer surface side of the back metal 2, contrary to the first embodiment. A small-diameter hole 5a is provided, and a ring-shaped groove 3b for fitting the snap ring 4 is provided on the outer periphery of the wear detection sensor 3, and the snap ring 4 and the brake friction material 1 are interposed in the large-diameter hole 6a. The snap ring 4 is pressed and locked to the step 7 of the small-diameter hole 5a and the large-diameter hole 6a by the spring member 9 provided.

The spring member 9 is, as shown in FIG.
The coil spring 9a of (A) or the wave washer 9b of (B) is suitable.

In the third embodiment, the wear detecting sensor 3 is set by inserting a spring member 9 through the small diameter hole 5 of the back metal 2 and reducing the snap ring 4 previously fitted in the groove 3b of the wear detecting sensor 3 with a fingertip. In this state, the small diameter hole 5 is passed through and the large diameter hole 6a is desired, and the wear detection sensor 3 is expanded by releasing the reduction by the fingertip, and the small diameter hole 5a and the large diameter hole 6a are The snap ring 4 is pressed against the step portion 7 to prevent the wear detection sensor 3 from coming off, and the tip of the wear detection sensor 3 is positioned in the hole 1a of the brake friction material 1 at the wear limit thickness position of the brake friction material 1. .

Also in the third embodiment, as shown in FIG. 8, an elastic material 10 such as rubber or soft resin is interposed between the brake friction material 1 and the wear detection sensor 3, so that the brake friction material 1 is worn. It is effective to protect the internal structure function of the wear detection sensor 3 by providing a shock buffering function when the brake drum or the rotor reaches the limit and comes into contact with the tip of the wear detection sensor 3.

As shown in FIG. 9, the snap ring 4 used in the first to third embodiments is suitably a ring-shaped one shown in FIGS. 9A and 9B or a bifurcated pin-shaped one shown in FIG.

[0023]

As described above, according to the present invention, since the wear detecting sensor is detachably locked and mounted by the snap ring in the mounting hole formed in the back metal of the brake friction material, the shape and structure are simple. Therefore, the wear detection sensor can be easily attached and detached without using a tool, and the cost can be reduced. In addition, the elastic material is interposed between the wear detection sensor and the backing metal or the brake friction material, so that when the brake friction material reaches the wear limit and the brake drum or rotor comes into contact with the tip of the wear detection sensor, the shock is applied. This has the advantage that the internal structure function of the wear detection sensor can be protected.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a first embodiment of the present invention.

FIG. 2 is a perspective view of a wear detection sensor used in the first embodiment.

FIG. 3 is a perspective view showing a modified example of the wear detection sensor used in the first embodiment.

FIG. 4 is a sectional view of a main part showing a buffer mechanism in the first embodiment.

FIG. 5 is a sectional view of a second embodiment of the present invention.

FIG. 6 is a sectional view of a third embodiment of the present invention.

FIG. 7 is a view showing various forms of a spring member used in a third embodiment.

FIG. 8 is a sectional view of an essential part showing a shock absorbing mechanism in a third embodiment.

FIG. 9 is a view showing various forms of a snap ring used in the first to third embodiments.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Brake friction material 1a Hole facing wear detection sensor 2 Back metal 3 Wear detection sensor 3a Ring-shaped projection 3b Groove 3c Pin 4 Snap ring 5 Small diameter hole 5a Small diameter hole 6 Large diameter hole 6a Large diameter hole 7 Step 8 groove 9 Spring member 10 Elastic material

Claims (1)

[Claims] 1. A brake wear alarm device in which a wear detection sensor for a brake friction material is attached to a back metal of a brake friction material, wherein the wear detection sensor is detachably engaged with a mounting hole formed in the back metal by a snap ring. A brake wear alarm device characterized by the following.