JPH0159460B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a lining wear warning device that emits an alarm when the lining of a brake pad used for braking an automobile is worn to the permissible limit, and alerts the user to the need to replace the pad. .

Conventionally, for example, a leaf spring called a pad grip is installed between the support and the backing of a pad that slides while being guided by the support of a disc brake to eliminate rattling between the two. Lining abrasion warning devices are widely used in which, when worn to the limit, the tip of the leaf spring comes into contact with the disk, vibrates finely as the disk rotates, and generates an alarm.

The structure and operation of the disc brake will be explained with reference to FIGS. 1 and 2 showing a conventional example. A disc brake is a left and right guide of a support 2 that is fixed to the vehicle body by screwing bolts (not shown) into screw holes 1 and 1. The protrusions 4a, 4a formed in the grooves 3, 3 on both sides of the backing metal 4 of the pad are freely slidable in the direction perpendicular to the plane of the paper, and the rotor 5 rotates in the direction of the arrow in conjunction with the wheels.
Two pads located on both sides of the rotor are pressed against the rotor 5 by a caliper and a cylinder piston to create a frictional effect, and the wheels are braked via the rotor 5. In such a disc brake, the back plate 4 of the pad has its protrusions 4a, 4a as described above.
Since the protrusions 4a fit loosely and slidably with the guide grooves 3 of the support, if left as they are, the protrusions 4a will rattle within the guide grooves 3 due to vibrations of the vehicle body, shocks during braking, etc., resulting in noise. occurs. In order to prevent such noise generation, the leaf spring 6 has a guide groove 3 and a protrusion 4.
For example, as shown in Fig. 2, both ends of the C-shaped base 6a are bent sideways at almost right angles to form pieces 6b and 6c, respectively, and one piece 6c is made with a hole. The short rod-shaped protrusion 4b formed on the back metal 4 of the pad is fitted into the hole, and the protrusion 4b is caulked to fix the piece 6c to the back metal 4, and the tip 6d of the other piece 6b prevents wear of the lining 7 of the pad. Formed to a length that freely protrudes to the position of the maximum allowable thickness l,
The other piece 6b presses against the side surface of the guide groove 3 of the support.

The leaf spring 6 configured and installed in this way prevents rattling between the protrusion 4a of the back metal and the guide groove 3 of the support, and also prevents the lining 7 of the pad from being worn to the maximum allowable limit ( When the thickness reaches l), the tip 6d of the spring 6 comes into contact with the side surface of the rotor 5, and as the rotor 5 rotates, the leaf spring 6
The entire unit vibrates finely and generates a warning sound to alert drivers and others that the lining is worn out.

However, in the conventional lining wear warning device constructed and operated as described above, the leaf spring 6
Even when the tip 6d of the rotor 5 comes into contact with the side surface of the rotor 5, it does not generate a sufficiently loud warning sound, and the passenger often misses the warning sound, and the low rigidity makes it easy to break. It was hot.

The lining wear warning device of the present invention eliminates the above-mentioned drawbacks.

The present invention will be explained below with reference to drawings showing examples.

FIG. 3 shows a first embodiment of the invention. The two leaf springs 6, 6, which have the same structure as the above-mentioned conventional leaf spring, are almost the same type and differ in size by the thickness of the plate.
The pieces 6b, 6b on the side having the tip 6d are overlapped closely with each other, and the ends of the other overlapping pieces 6c, 6c are connected by the short rod-shaped protrusion 4b of the back metal 4 of the pad. It is caulked to the back side of the back metal 4. The tips 6d, 6d of each leaf spring 6, 6 are the maximum allowable wear thickness l of the lining 7, as in the past.
It protrudes freely up to the surface. Therefore, when the lining 7 wears down to the allowable limit, the tips 6d, 6d of the two leaf springs 6, 6 contact the side surface of the rotor 5 at the same time, and since both tips 6d, 6d are separated from each other, each leaf spring 6 and 6 vibrate independently. Therefore, a large chattering sound is generated at the contact portion between the leaf springs 6, 6, and the occupant can be reliably informed of the time to replace the pads. Further, since the two leaf springs 6, 6 support each other, the overall strength is improved and failures due to breakage are reduced.

In the above embodiment, a disc brake is equipped with a wear warning device, and the leaf spring 6 is also used as a pad grip to prevent rattling between the pad and the support. The wear warning device of the invention is not limited to disc brakes,
It can also be installed on drum brakes. That is,
As shown in FIG. 4, two leaf springs 6, 6 with one end bent into a U-shape are stacked on top of each other with only the pieces 6b, 6b separated, and fixed to the back metal 4 with a rivet 8, and each piece is The tips 6d, 6d of the linings 6b, 6b are located on the surface of the lining 7, which has the maximum allowable wear thickness l. The operation and effect of the lining wear warning device in this embodiment are also the same as in the first embodiment. Also, in any of the examples, the leaf spring 6 has two
It can be more than one.

[Brief explanation of drawings]

Fig. 1 is a side view of a disc brake equipped with a lining wear warning device, Fig. 2 is an enlarged sectional view taken along line A-A of Fig. 1 showing a conventional wear warning device, and Fig. 3
This figure is a sectional view similar to FIG. 2 showing a first embodiment of the present invention, and FIG. 4 is a partial side view of a drum brake shoe showing a second embodiment of the invention. 1: Screw hole, 2: Support, 3: Guide groove, 4:
Back metal, 4a: protrusion, 4b: protrusion, 5: rotor,
6: Leaf spring, 6a: Base, 6b, 6c: Piece, 6
d: Tip, 7: Lining, 8: Rivet.

Claims (1)

[Claims] 1. Both ends of a c-shaped base 6a made of elastic material are bent to the same side to form two pieces 6b and 6c, one piece 6c is fixed to the back metal 4 of the pad, and the other piece 6b is fixed to the back metal 4 of the pad. 2 of the leaf springs 6 whose tips 6d freely protrude to the surface of the lining 7 having the maximum allowable wear thickness;
The other pieces 6b are separated from each other in a parallel state, and the c-shaped bases 6a and the one piece 6c are separated.
The lining wear warning device is constructed by fixing the pads to the back metal 4 of the pad by the one piece 6c in a state where the pads are stacked on top of each other.