JP2000065107A - Abrasion warning device of frictional material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve accuracy of an arranging position of an insulated wire, and to prevent damage of the insulated wire by fastening and arranging the inside surface of the U-shaped top part of the insulated wire in a frictional limit of a frictional material, and surrounding at least the inside surface of the U-shaped top part by a probe main body. SOLUTION: In a state of allowing the inside surface of the U-shaped top part 24 of an insulated wire 20 to abut to the upper surface of the electric wire guide part 14 of a probe main body 10 one of contractive tubes 30 fitted around the respective parts of the insulated wire 20 projecting from the rear end of the probe main body 10 is fitted around small projections 15, 15 to be fastened to the contractive tubes 30. Thus the inside surface of the U-shaped top part of a conductor 21 can be accurately set to a wire W being a frictional limit position of a frictional material 42, and the tip more than this wire W, in other words, the outer periphery of the frictional material 42 side top part 24, that is, the outside surface side more than the U-shaped top part is constituted so as to be surrounded by the tip of the probe main body 10 to thereby reduce a danger of damaging the U-shaped top part 24 at handling time or by a stepping stone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wear warning device which electrically detects a wear limit of a friction material for braking a member to be braked and issues a warning.

[0002]

2. Description of the Related Art Conventionally, when a friction material is worn and reaches a wear limit, a U-shaped top of an electric wire is disconnected and a warning is given as a friction material wear warning device which issues a warning. There are known an embedded type embedded in the probe main body and an exposed type in which the U-shaped top of the electric wire projects from the tip of the probe main body.

[0003]

The above-mentioned frictional material wear warning device has the following problems. <B> In the former embedded type, since the U-shaped part of the wire is buried, the location of the U-shaped top of the wire, which requires accuracy, with respect to the probe body cannot be checked after being buried, and reliability is high. Poor. <B> In the latter exposed type, a U-shaped top is formed so as to protrude so that only the electric wire is shaved. However, since the electric wire is made of highly ductile copper as a raw material, erroneous detection may occur that the powder once shaved is not immediately scattered but is connected in a foil shape. <C> Further, in the latter exposed type, since the U-shaped top of the electric wire is exposed from the probe main body, there is a possibility that the electric wire may be damaged at the time of handling or by a flying stone.

[0004]

The invention according to claim 1 is
A probe assembly is attached to a back plate for fixing the friction material, and when the friction material is worn and reaches a wear limit, a U-shaped top of an electric wire constituting the probe assembly is disconnected and a warning is issued. In a friction material wear warning device, a through hole parallel to the axial direction is provided in a solid columnar probe body, and the U-shaped portion of an insulated wire in which a conductor is covered with an insulator in the through hole is used as the friction material. Side, and the inner surface of the U-shaped top of the conductor is arranged and fixed at the wear limit position of the friction material, and at least the inner surface of the U-shaped top is surrounded by the probe body. A wear warning device for a friction material. According to a second aspect of the present invention, in the wear warning device for a friction material according to the first aspect, a keyhole-shaped notch is formed in a back plate to which the friction material is fixed, and a probe body having a shape corresponding to the notch. A wear warning device for a friction material, characterized in that the outer periphery of the intermediate portion is fitted non-rotatably. According to a third aspect of the present invention, in the wear warning device according to the first or second aspect, the through hole on the anti-friction material side of the probe main body is formed in a small protrusion, and the probe body extends between the protrusion and the electric wire. A wear warning device for a friction material, wherein a contraction tube is fitted and an electric wire is fixed to a probe main body.

[0005]

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

<A> Overall Image of Friction Material Abrasion Warning Device The friction material abrasion warning device according to the present invention is designed such that when a friction material for braking a movable body reaches a wear limit, an electric wire is worn and disconnected. A probe main body attached to a back plate to which a friction material is fixed, and an insulated electric wire which is inserted through the probe main body and whose U-shaped top is disposed at a predetermined position, and the like. I have.

<B> Probe Body The probe body 10 has a substantially columnar, substantially rivet-like shape, and is formed of a circular head 11 and a body 12 having a smaller diameter than that of the head 11 connected to one of the heads 11. The lower neck 13 has a keyhole cross section. The front end of the head 11 is concavely recessed to form an electric wire guide 14 at the center, and two small projections 15, 15 juxtaposed at the rear end of the body 12 project from each other. Two through-holes 16, 16 are arranged in parallel from the inside of the probe body 10 so as to sandwich the electric wire guide 14. An annular groove 17 is formed on the outer periphery of the rear of the body 12.

The probe body 10 is made of an insulating material,
For example, using a thermosetting material in which various fillers such as glass fibers and inorganic fillers are blended based on a silicone resin, the above-described shape is integrally formed by molding.

<C> Insulated Wire The insulated wire 20 is composed of a conductor 21 made of copper and an insulator 22 made of vinyl, polyethylene, or the like that covers the conductor 21. Thus, the insulated wire 20 is formed by folding one wire and one is formed in a U-shape, and the inner surface of the top 24 of the U-shaped portion 23 is formed by the wire guide portion 14 of the probe body 10.
The two electric wires 20 that abut on the upper surface and extend from the upper surface are respectively inserted into the through holes 16 and 16 and are connected to a power supply via a warning light (not shown) or the like. The method of attaching the electric wire 20 to the probe main body 10 may be such that the electric wire 20 is folded back into a U-shape in advance, and the electric wire 20 is inserted into the through holes 16, 16 from the tip end side of the probe main body 10, Alternatively, the straight electric wire 20 may be inserted into one through hole 16 from the direction of the small protrusion 15 and then folded back into the other through hole 16.

<D> Method of Attaching Insulated Wire to Probe Body As described above, under the condition that the inner surface of the U-shaped top 24 of the insulated wire 20 is in contact with the upper surface of the wire guide portion 14 of the probe body 10. One of the contraction tubes 30 externally fitted to the respective portions of the electric wire 20 protruding from the rear end of the probe body 10 is externally fitted to the small projections 15, 15, and then the contraction tube 3
0 is heated to about 100 ° C. to fix. As a result, as shown in FIG. 2, the inner surface of the U-shaped top of the conductor 21 can be accurately set to a line W which is a wear limit position of the friction material 42 described later, and the tip side of the line W, in other words, the friction material 42 The outer periphery of the outer side of the outer side of the top portion 24, that is, the inner surface of the U-shaped top is surrounded by the tip of the probe body 10. Therefore, the abnormality of the U-shaped top 24 of the electric wire 20 can be visually checked, and the risk of damage to the U-shaped top 24 due to handling or stepping stones is small. Also, shrink tube 3
By fitting the “0” between the small protrusion 15 and the electric wire 20, local deformation of the protruding portion of the electric wire 20 from the small protrusion 15 can be avoided, and there is no risk of damage.

<E> Structure for Attachment of Probe Assembly to Braking Member As described above, the probe assembly P is connected to the probe body 10,
It comprises an insulated wire 20 and a shrink tube 30. The braking member B shown in FIG. 1 is a known brake pad used for a disc brake, and is composed of a back plate 40 and a friction material 42 fixed thereto. A keyhole-shaped notch 41 is formed in the upper part at the center of the direction of rotation of a certain disk rotor. Thus, the wire 20 part of the probe assembly P that has come off from the probe main body 10 is inserted from the opening side of the notch 41,
After fitting the lower part 13 of the probe main body 10 so as to match the shape of the keyhole of the notch 41, the disc spring 50 is externally fitted from the rear of the probe main body 10, and the disc spring 50 is compressed into the annular groove 17. The retainer 52 is fitted. With the above-described configuration, the probe body 10 is non-rotatably fitted to the back plate 40, so that the electric wire 20 is not twisted, and the stepped lower surface of the probe body 10 is always elastically attached to the surface of the back plate 40. Since they are in contact with each other, the fitting portion does not wear or break even when vibration is applied. Although the example in which the biasing force in the axial direction of the probe main body 10 is applied by the disc spring 50 has been described, the present invention is not limited to this, and a coil spring or the like can be easily used. In this embodiment, the present invention is applied to a disc brake, but it is apparent that the present invention can be applied to a drum brake and the like.

<F> State at the time of disconnection of the insulated wire Now, when the friction material 42 is worn down to the inner surface of the U-shaped top of the conductor 21, that is, the position of the line W in FIG. Is issued to notify the use limit of the friction material 42. Once the conductor 21 has been cut, the probe body 10 surrounding the U-shaped portion 23 wears out as well as the U-shaped portion 23, so that these are mixed and scattered as fine powder, and the highly ductile conductor 21 becomes a foil. It will not be connected.

[0013]

According to the present invention, the following effects can be obtained. <A> Since at least the inner surface of the U-shaped top of the conductor constituting the insulated wire is surrounded by the probe main body, even if the conductor is cut once and is continuously used, the highly ductile conductor and the solid probe main body are finely divided. There is no erroneous detection that the powder is mixed and scattered, and is connected in a foil shape. <B> Further, by setting the inner surface of the U-shaped top of the conductor at the wear limit position of the friction material, the accuracy of the arrangement position is improved. <C> Further, since the U-shaped top of the insulated wire is surrounded by the probe body, there is no damage when handling the probe assembly or due to flying stones. <D> Since the probe body is fitted to the back plate to which the friction material is fixed in a hook shape and cannot rotate, there is no possibility that the insulated wire is twisted and damaged. <E> The projecting portion of the insulated wire from the rear end of the probe main body is prevented from being locally deformed by the shrinkable tube fitted between the small projection of the probe main body and the electric wire, so that there is no fear of breakage.

[Brief description of the drawings]

FIG. 1 is a front view of a brake pad according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG.

FIG. 3 is a sectional view taken along the line III-III of FIG. 2;

[Explanation of symbols]

 P Probe assembly B Braking member 10 Probe body 11 Head 12 Trunk 13 Lower neck 14 Wire guide 15 Small projection 16 Through hole 17 Annular groove 20 Insulated wire 21 Conductor 22 Insulator 23 U-shaped part 24 Top 30 Shrink tube Reference Signs List 40 back plate 41 notch 42 friction material 50 disc spring 52 retainer

Claims (3)

[Claims] 1. A probe assembly is attached to a back plate for fixing a friction material, and when the friction material is worn and reaches a wear limit,
An abrasion warning device for a friction material which issues a warning when a U-shaped top of an electric wire constituting the probe assembly is broken, and a solid pillar-shaped probe main body is provided with through holes parallel to an axial direction in parallel with each other. The U-shaped portion of an insulated wire having a conductor covered with an insulator is arranged and fitted on the friction material side, and the inner surface of the U-shaped top portion of the conductor is arranged at the wear limit position of the friction material and fixed. A wear warning device for a friction material, wherein at least an inner surface of the U-shaped top is surrounded by a probe body. 2. The wear warning device for a friction material according to claim 1, wherein a keyhole-shaped notch is formed in a back plate to which the friction material is fixed, and an intermediate portion of a probe body having a shape corresponding to the notch. Characterized in that the outer periphery is fitted non-rotatably,
Wear warning device for friction material. 3. The wear warning device according to claim 1, wherein a through-hole on the anti-friction material side of the probe main body is formed in a small projection, and a shrink tube is provided between the projection and the electric wire. A wear warning device for a friction material, wherein the device is fitted and an electric wire is fixed to a probe body.