JPS58171603A - Alarm device indicating abrasion of friction lining of brake pad - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an alarm device for indicating wear of a friction lining on a brake pad/t, particularly a brake pad of a disc brake, which comprises an electrical conductor and a longitudinal groove for accommodating the electrical conductor. The present invention relates to an alarm device including a plug having a shaft and a head through which an electrical conductor passes.

In this type of wear-indicating alarm device, the plug acting to secure the electrical conductor is observable, containing approximately radially extending holes, if the brake lining is of the type intended for disc brakes. Should be equipped with a friction lining.

Furthermore, it is provided closely adjacent to the support plate for the friction lining. Usually the electrical conductor is inserted into the longitudinal groove of the U-shaped loose plug and fixed together with the plug in the friction lining, and the plug is inserted into the hole in the lining, into which the tightening or expansion action or compounding in the hole It is held by filling it with resin or other material. The electrical conductor is generally a strand within an insulating sheath, and as the friction lining wears out, the brake disc exposes a plug that is connected to an electrical circuit that is closed when the electrical conductor is touched. If the electrical conductor is in the form of a loop, it can also form part of a closed circuit that is broken by the action of the brake disc upon wear of the friction lining.

In a known alarm device of the first defined type (German utility model registration DE-0M No. 8024362), the longitudinal groove extends along two opposing surface lines of the shaft, around its ends, and the head has two holes aligned with these surface lines, through which conductors inserted in a U-shape in the longitudinal groove pass. On the head, the electrical conductor is unprotected and unguided, so damage to its insulation due to heat radiation from the brake disc or contact with moving parts of the brake can occur when assembling the brake or installing new brake pads. You can't avoid this if you place the conductor with the utmost care.

It is therefore an object of the present invention to improve a wear-indicating alarm device of the type initially identified in such a way that the risk of damage to the electrical conductors due to careless assembly is reduced.

This object is achieved according to the invention by forming a protective shield on the plug, extending upwardly from its head and positioned laterally offset relative to the longitudinal groove.

When the wear indicator alarm device according to the invention is secured to a brake band, a protective shield separates the area through which the electrical conductors pass above the head from the brake area where heat is generated and wear occurs. Additionally, the protective shield avoids direct contact between electrical conductors and movable or peripheral parts of the brake, such as restraint springs supported on the brake pad support plate.

The protective shield 5 preferably has an upper edge with a disk-like slope. In this way, the protective shield is generally adapted to the installation space formed by the roof-type brake caliper or yoke.

The protective shield has an extension projecting in a direction toward the common central plane of the shaft and the longitudinal groove spaced above the head. This extension ensures that the electrical conductor forms a loop and does not project entirely upwardly in the direction of the brake 9 component moving relative to the individual brake pads.

The latter feature is that the extension protrudes beyond the central plane and is deformed to extend downward like a hook.

This modification provides easily understandable assembly instructions on how to properly position the electrical conductors, and further ensures that the electrical conductors do not move accidentally during assembly and during brake operation.

In the alarm device according to the invention, if the longitudinal groove extends in a manner known per se along two opposing surface lines of the shaft and around its ends, the electrical conductor also extends around the ends of the shaft. It's convenient if it fits the mold. Another advantageous refinement of the invention in this case lies in the fact that the head has, in addition to the flutes, a slot on either side, making it possible to embed the electrical conductor therein. This makes it much easier to provide the electrical conductor to the plug, as there is no need to intertwine it through a hole in the head, as required with known alarm devices. Strands of electrical conductor simply threaded upward through slots in the head protect the strands of electrical conductor from being twisted together on the head in the area protected by the white protective shield 8 or from its accidental separation from the plug. This is prevented by passing under the inventive extension of the shield.

Furthermore, it is advantageous if the longitudinal grooves deepen towards the end of the shaft. This measure also serves to protect the electrical conductor during its installation, since it reduces the risk of damaging the electrical conductor when introducing the plug with its shaft into the bore of the friction lining.

The risk of making mistakes during assembly and thereby damaging the electrical conductors can be avoided by forming the protective shield with an outer surface facing away from the center plane of the shaft and placing that outer surface further from the center plane than the opposing outer surface of the head 9. You can reduce it by positioning it. The different spacing of these two outer surfaces from the central plane is adapted to the construction of the corresponding brake disc such that a lateral reverse mounting of the plug is excluded, thereby allowing the protective shield to perform its protective task. do.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The brake pad 10 shown in FIG. 1 is of the type customary for spot disc brakes and includes a support plate 12 formed with a pair of shoulders 14 for guiding the brake pad onto a brake carrier or caliper. It also has a protrusion 16 that protrudes upward at the center, and a restraining spring 20 is attached to the hollow IJ.
It is pivotably supported by a gate 18.

A friction lining 22 is fixed, for example by gluing, to the front side of the support plate 12, which is partially shown in FIG. A wear indicating alarm device 24, described in detail below, is secured to the friction lining 22. The alarm device 24 includes an electrical conductor 26 formed of an insulated wire strand and a plastic plug 28.
including.

Plug 28 has a generally cylindrical shaft 30, a parallelepiped-shaped head 32, and a protective shield A34 extending upwardly from the head. The shaft 30 is mounted in a hole 36 drilled generally radially in the friction lining 22 along the front end side of the support plate 12 and from the outside. shaft 3
0 are three annular ribs 3 formed on the shaft within the hole 36
Be tightened by 8. A longitudinal groove 40 is formed in the shaft 30 from two opposite sides. That is shaft 30
is symmetrical about the center plane 42 of the shaft and the lower end 44 of the shaft.
extend around. The depth of the longitudinal groove 40 is equal to the depth of the shaft end 44.
increases on both sides toward .

The head 32 is formed from two opposed sides and has a longitudinal groove 4.
It has two slots 46 aligned at 0.

The electrical conductor 26 has a U around the shaft 30 in its central plane 42.
It is shaped and located in the longitudinal groove 40 of the shaft and in the slot 46 of the head 32.

The protective shield 34 is offset laterally with respect to the longitudinal groove 40, parallel to the central plane 42 and at a distance clearly greater than the distance of the axis of the bore 36 of the friction lining 22 from the plane in front of the projection 16 of the support plate 12. It has an outer surface 48 extending from the central plane 42 by an amount, this distance being referred to as the aperture space. Opposite the outer surface 48, a parallelepiped-shaped head 32 is provided and has an outer surface 50, also parallel to the central plane 42 and spaced from the central plane by a distance slightly less than the space of the bore.

Perpendicular to the outer surfaces 48 and 50, the head 32 further has two outer surfaces 52 and 54 located at a distance greater than the aperture spacing.

The hole 36 is slightly offset from the center of the brake pin 10, and the head 32 of the plug 28 is inserted into the hollow rivet 18.
However, the protrusion 16 is still in an overlapping relationship with the protrusion 16. Due to this configuration and the above-described distance relationship, the plug 28 can be inserted with its shaft into the hole 36 unless the outer surface 50 of the head 32 faces the protrusion 16. Therefore, the space in which the conductor 26 extends upwardly from the slot 46 is protected by the environment between the protrusion 16 and the protective layer 34.

As shown in FIGS. 2 and 3, the protective shield 34 is formed above the head 32, with an extension 56 projecting in the direction toward the central plane 42, and extending the space between the protrusion 16 and the protective shield 34 into an upper part. to form. The two strands of the electrical conductor 26 pass along the inside of the protective layer 34 and under the extension 56 and then through the hollow rehet 18, after which the two strands 5 are matched in the usual manner by plug connectors. The circuit is connected to a circuit (not shown). The protective seal (34) with its extension 56 has a disk-like sloped upper edge, slopes outward from the center of the brake pad 10, adapts to the space requirements of the restraining spring 20, is actually a little more inclined than shown in FIG. 1 when installing the brake pad.

In the variant shown in FIGS. 4 and 5, the extension 56 projects beyond the central plane 42 and extends downwardly like a hook. This configuration of the extension 56 prevents the two strands of the electrical conductor 26 passing upwardly from looping into inadvertent contact with a component of the brake moving relative to the brake spring 20, such as the restraining spring 20. It also makes it more certain that it does not form. This contact can damage the loop over time.

[Brief explanation of the drawing]

Fig. 1 is a side view of the brake section of a disc brake including an alarm device, and the alarm device is partially shown in a cross section parallel to the brake disc when viewed from the corresponding disc brake. Figure 3 is an enlarged view of the alarm device in the direction of the arrow in Figure 1, Figure 3 is a vertical sectional view taken along the line 2 in Figure 2, and Figure 4 is a portion corresponding to Figure 2 of a modified example of the alarm device. 5 is a partial view corresponding to FIG. 3 of a modified example. 10.Brake pad, 22.Friction lining, 24.Alarm device, 26.Electric conductor, 28.
Plaque, 30...Shaft, 32, Head, 34...Protective shield, 40...
Vertical groove, 42... center plane.

Claims (1)

[Claims] 1. An alarm device for instructing wear of a friction lining of a brake pad of a disc brake, in particular, a shaft having an electrical conductor (c) and a vertical groove for accommodating the electrical conductor (a). In an alarm device comprising a plug having a spatula l'c3B through which an electrical conductor passes, a protective girdle is provided in the plug extending upwardly from its head and having a longitudinal groove ( 4G. 2. In the alarm device according to claim 1, the protective shield has an upper edge (58) having a desk-like slope. ). 3. In the alarm device according to claim 1 or 2, the protective shield is spaced above the head G3 and connected to the shaft. A device characterized by having an extension (56) projecting in the direction toward the common central plane (421) of the vertical groove (41). 4. In the alarm device according to claim 3, the extension @) A device characterized by extending beyond the center plane (44) and extending downward like a hook. 5. Any one of claims 1 to 4.
2. The alarm device according to paragraph 1, wherein the flute is located along two opposing surface lines of the shirt and at its ends (4
4) In a device in which the electrical conductor (a) runs in a U-shape around the end of the shaft (7), the head ″′ (
A device characterized in that 32 comprises a slotted tab on either side, thereby forming an extension of the longitudinal groove (40), in which the electrical conductor (c) is located. 6. The alarm device according to claim 5, characterized in that the vertical groove (40) becomes deeper toward the end (44) of the shaft (30). Any 1 from paragraph 1 to paragraph 6
In the alarm device described in paragraph 1, the protective shield'' (3
4) faces the opposite side to the central plane (42) of the shirt f30), and is closer to the central plane (421) than the outer surface 50) of the head G2
A device characterized by being located far away from the