TW201413131A - Brake pad of a disc brake, and disc brake - Google Patents

Abstract

In the case of a brake pad of a disc brake (1) of a motor vehicle, in particular of a utility vehicle, having a pad carrier (7, 9) and having a multi-layer friction pad (6, 8), the multi-layer friction pad (6, 8) has at least one first friction pad layer (61, 81), which adjoins the pad carrier (7, 9), and a second friction pad layer (62, 82), which is remote from the pad carrier (7, 9), wherein the first friction pad layer (61, 81) is composed of a friction material with a greater wear resistance than the second friction pad layer (62, 82). Also described is a disc brake of a motor vehicle, in particular of a utility vehicle.

Description

Brake pad and disc brakes for disc brakes Field of invention

The present invention relates to a brake pad for a disc brake as claimed in the preamble of claim 1, and a motor vehicle, particularly a commercial vehicle, in the preamble of claim 10 brake.

Background of the invention

These brake pads are used for disc brakes of motor vehicles that can be used to carry passengers, and in particular for disc brakes for commercial public vehicles. Herein, the brake pads are substantially composed of a pad carrier and a friction pad fastened thereto, and the friction pad is pressed against a rotating brake disk of one of the disk brakes in a braking program.

In particular, in the case of a disc brake for a compressed air actuated by a heavy-duty vehicle, it may be that in some use cases, the wear of the brake pad of the actuating surface may be significantly different from that of the reaction surface or the rim side. The wear of the brake pad, therefore, due to the shorter service life of the more heavily worn brake pad, the maintenance cost and downtime of the commercial vehicle will increase.

Moreover, there is a risk that the uneven wear of the brake pads listed on both sides of the brake disc is not recognized in time. So a complete A worn brake pad in which the friction pad has been completely worn by the pad carrier and will cause a wheel to lock.

In order to prevent such wheels from locking, it is known that the disc brakes are provided with a wear detecting device. However, this does not eliminate the reduced pad life due to uneven wear and the associated increased maintenance and shutdown costs.

The strongly increased wear of a brake pad may also occur, for example, due to poor cooling conditions, particularly on the rim side of the pad, or due to the accumulation of severe dirt, particularly on the active surface.

In order to prevent the uneven wear, some measures have been taken. The target is that if the brake pads are worn out to a certain extent, the brake pads that are more strongly worn will be restrained in a braking program. The two brake pads can achieve a more uniform final wear condition. However, for this purpose, cumbersome measures must be implemented on the disc brakes and brake pads, which in turn are accompanied by increased costs.

Summary of invention

Accordingly, it is an object of the present invention to provide a brake pad and a disc brake that can be prevented by the extremely uneven wear of the brake pads and that does not require structural modifications to the brakes and brake pads. And can thus be implemented inexpensively.

The object can be achieved by a brake pad having the features of claim 1 of the patent application and by a disc brake having the features of claim 10 of the patent application.

a brake pad having a pad carrier and a multi-layer friction pad In this case, the multi-layer brake pad has at least one first friction pad layer adjacent to the pad carrier plate, and a second friction pad layer away from the pad carrier plate, wherein the first friction pad layer has the same The second friction pad has greater wear resistance.

Therefore, the brake pad according to the present invention has a friction material in the range of its final wear state, which exerts a same clamping force on the brake pad in a braking program, exhibiting a considerable reduction in bamboo wear. Therefore, it is ensured that the brake pad which wears faster and wears, after the wear of the relatively low wear resistance second friction pad, will wear more slowly in the subsequent braking program than the previous brake program, so the brake pad The wear progress during the subsequent braking sequence will be slower relative to a brake pad that has not been fully worn by the second friction pad, so a more uniform wear will be obtained.

Here, the term "abrasion resistance" should be understood to mean the resistance of the friction pad to the mechanical abrasion of the pad material.

The scope of each dependent patent application is an advantageous design variation with respect to the present invention.

The first friction pad layer, in the unworn state, has a pad thickness of, for example, 2 mm to 8 mm, preferably 3 mm to 6 mm. To achieve different wear resistance, the dry lubricant content in the first friction pad layer is greater than the dry lubricant content in the second friction pad layer. Additionally or alternatively, it is also possible that the additive content of the friction coefficient in the first friction pad layer is lower than the additive content of the friction coefficient in the second friction pad layer. The possible dry lubricants here are in particular graphite, lead, bismuth, copper or copper alloys, molybdenum, or tin. Additives that increase friction are, in particular, aluminum, magnesium, cerium, metal oxides and cerates. The coefficient of friction, also known as the friction index or the number of frictions, is Refers to the measurement of the friction between two objects relative to the contact pressure.

In an alternative design variation, a tie layer is provided between the pad carrier and the friction pad, and it partially engages the friction pad and increases wear resistance. There is a thickness corresponding to the first friction pad layer. In this case, the first friction pad layer can be completely replaced by the connecting layer in a design variant or, in another design variant, in the connecting layer.

Here, the connecting layer is preferably in the form of a set of pins, in particular brass pins, which are fixed in the pad carrier and are snapped into the friction pad.

Alternatively, the tie layer is in the form of a sintered, coarse base that can be mechanically coupled to the pad carrier. As previously mentioned, the tie layer may be formed as a sintered base or as a set of pins for engagement in a first friction pad, particularly in accordance with claim 1 of the scope of the patent application.

To prevent uneven wear of the friction pad of one of the other brake pads, in particular due to uneven pressure distribution and due to the supporting force and torsion acting on the brake pad, a tangent or diameter relative to the brake disc The oblique wear in the direction is provided in another preferred design variant to provide the friction pad thickness of the first friction pad partially having the integral friction pad, in particular, parallel to the friction surface of the brake disk. Preferably, it is 20 to 30% of the area of the friction surface of one of the friction pads.

In particular, in order to prevent tangential uneven wear of the brake pad, due to the supporting force of the pad, a tilting torque is generated to act on the brake pad in a circumferential direction, and it causes an increased contact pressure. Applied to, and thus caused, increased wear of the brake pad away from the peripheral end of the brake disc in the direction of rotation, the end being also referred to as the turning-in side of the brake pad, the first friction pad being predetermined One of the brake pads has a larger friction pad thickness in the region of the turn-in side than in a region of the brake pad that is intended to be a turn-out side.

A disc brake according to the invention of a motor vehicle, in particular a commercial vehicle, has a brake caliper that bears against a brake disc and has at least one brake pad preferably attached to the actuation surface of the brake disc And a reaction surface, and which is provided with a pad carrier and a friction pad secured thereto and introduced into a pad, characterized by one or more of the above-described brake pads according to the present invention.

1‧‧‧ disc brakes

2‧‧‧ gap

3,4‧‧‧ brake pads

5‧‧‧Brake clamp

6,8‧‧‧Friction pad

7,9‧‧‧Pushing board

10‧‧‧ cushion

11‧‧‧Buckle holding spring

12‧‧ ‧ offset

61,81‧‧‧First friction pad

62,82‧‧‧Second friction mat

d ₁ ‧‧‧thickness

d ₂ ‧‧‧ overall thickness

HDR‧‧‧ brake disc rotation direction

The embodiments of the present invention will be described in more detail with reference to the accompanying drawings, wherein: FIG. 1 is a perspective view showing a design variation of a disc brake according to the present invention; FIG. 3 to FIG. 5 are various schematic views of the brake pad of FIG. 2 for showing the distribution of the friction pads; FIG. 6 is a brake pad having a connecting layer. BRIEF DESCRIPTION OF THE DRAWINGS Figure 7 is a graph showing the wear performance of a brake pad in accordance with the present invention versus the thickness of the pad of the friction pad.

Detailed description of the preferred embodiment

In the following description of the drawings, expressions such as top, bottom, left, right, front, and rear are merely examples of the disc brakes, brake pads, friction pads, etc., in the respective drawings. Choose a location. These expressions are not to be considered as limiting, that is to say that the terms may vary depending on the results of different working positions or mirror symmetrical configurations.

In Fig. 1, reference numeral 1 as a whole refers to a motor vehicle, particularly a sliding clamp type disc brake of a commercial vehicle, and a design variation of one of the disc brakes according to the present invention. Here, the disc brake 1 has a brake disc (not shown) which rotates about a rotation axis with the wheel of the motor vehicle when the motor vehicle is moved. Here, HDR refers to the main direction of rotation of the brake disc when the motor vehicle moves in a forward direction. Here, a brake caliper 5 has a pad 10 in which the brake pads 3, 4 are embedded to engage an arc of the brake disc. Here, the brake disc is in a gap between the brake pad 3 disposed on an actuating surface and a reaction surface brake pad 4, and in the case where the disc brake is actuated, the brake pads are 3, 4 will press against the friction surface of the brake disc.

Here, the brake pads 3, 4 are substantially composed of a pad carrier 7, 9 and a friction pad 6, 8. This friction pad is shown in different example design variations in Figures 2 to 6; here, the friction pad indicated by reference numeral 3 in Figures 2 to 6 should not be considered to mean that only the brake is applied. The friction pad of the face is described, but is referred to as a design change of a brake pad, which can be preferably used on both sides of the brake disc, or preferably on the brake application surface, or in the case The reaction surface of the brake disc.

As shown in FIGS. 2 to 6, the multilayer friction pad 6 has at least one first friction pad layer 61 adjacent to the pad carrier plate 7, and a second friction pad layer 62 away from the pad carrier plate 7. Here, the first friction pad layer 61 has greater wear resistance than the second friction pad layer 62, so the friction pad 6 wears more slowly after the second friction pad layer 62 has been completely worn. .

In order to make the different friction pad layers 61, 62 have corresponding wear characteristics, the friction pad layers 61, 62 are not only composed of adhesives and filler materials, such as epoxy resin, elastic materials, coke, etc., and reinforcing fibers such as steel. It is composed of velvet or aromatic polyamide fibers, and there are other additives, etc., which affect the friction characteristics. If an additive with an increased friction coefficient is used, it is preferably aluminum, magnesium, strontium, metal oxide, Or made of tantalate or the like, they will stabilize the friction pad 6, especially at high temperatures.

If using a component that reduces wear, especially from dry lubricants, such as graphite, lead, antimony, copper and copper alloys, or also molybdenum or tin. Therefore, the dry lubricant content in the first friction pad layer 61 is preferably greater than the dry lubrication content in the second friction pad layer. Similarly, it is preferred that the additive content of the friction coefficient in the first friction pad layer 61 is lower than the additive content of the friction coefficient in the second friction pad layer 62.

In order to ensure that the brake pads that wear faster due to environmental conditions have a suitably slowed wear relative to a slower worn brake pad, it has been found that the pad thickness of the first friction pad layer 61 should be better when not worn. It should be in the range of 2 mm to 8 mm, particularly preferably in the range of 3 mm to 6 mm.

Alternatively or in addition to the friction pad having a first friction pad layer as described above, it is also possible to consider that the region of the friction pad layer having the greater wear resistance is formed by a connecting layer, Between the pad carrier 7 and the friction pad 6, which will partially abut the friction pad 6, which will increase the wear resistance, and has a thickness d ₁ corresponding to the first Friction pad. Here, in order to mechanically connect the friction pad 6 to the pad carrier 7, it is preferable to use a pin 12, in particular a brass pin, which is preferably fixed to the pad carrier 7 and The card is in the friction pad 6, as exemplified in FIG.

Alternatively, the tie layer is formed as a sintered, coarse base, and the friction pad 6 is for example cast thereon, wherein the required mechanical strength is ensured by the rough surface of the sintered coarse base. In the brake pad known from the prior art, the sintered coarse base fixed to the pad carrier or the depth of the pin 12 penetrating into the friction pad 6 is small, so that it cannot be effectively utilized. Slow down the wear of the corresponding brake pad. Therefore, the thickness d ₁ of the connecting layer having the sintered coarse bottom or the pin is now larger to correspond to the thickness of the first friction pad layer 61 as described above.

It can also be self-evident that the set of pins 12 or the sintered coarse base can be snapped into a first friction pad layer 61 as previously described.

In order to prevent uneven wear of one of the brake pads, for example, a tangential or radial direction of oblique wear relative to the brake disc, the first friction pad layer 61 is preferably a friction pad thickness corresponding to the The friction pad thickness D _{G of the} overall friction pad. For example, as shown in FIG. 4, the first friction pad layer 61 may be at the end E of one of the brake pads 3, preferably on an area of 20 to 30% of the surface of the overall friction pad (parallel to the The friction surface of the brake disc can be applied beyond the thickness of the full friction pad. In the case of such designed brake pads, additional measures would be required to prevent the brake pads 3, 4 from being flipped over a brake disc 1, as an adverse effect would result if improperly installed.

Figure 5 shows a further design variant of the brake pad 3 according to the invention, wherein the first friction pad layer 61 is designed to be radially offset relative to the friction pad thickness D ₁ of the brake disk to offset this The radial brake pads 3 are unevenly worn in the radial direction.

Figure 7 again shows, in a diagram, the wear performance of a brake pad in accordance with the present invention. It can clearly see the increased wear of the brake pad in the region of the second friction pad layer 62, which wear is reduced in the range of a final wear state, when the brake pad has the first friction pad The layer 61 ensures a longer service life than if the brake pad has a friction pad that has consistent wear resistance.

Since the uneven wear in the mat can be prevented, as shown in Figs. 4 and 5, a more increased service life of the brake pads 3, 4 thus designed can be obtained. Here, the brake pads 3, 4 can also be used in combination with the other measures described above to homogenize the wear of the brake pads 3, 4 of the brake application surface and the reaction surface.

3‧‧‧ brake pads

6‧‧‧Friction pad

7‧‧‧Pushing board

11‧‧‧Buckle holding spring

12‧‧ ‧ offset

61‧‧‧First friction pad

62‧‧‧Second friction pad

Claims (11)

A brake pad for a motor vehicle, in particular a commercial vehicle, having a pad carrier and having a plurality of friction pads, characterized in that the multilayer friction pad has at least one first friction pad adjacent to the pad carrier And a second friction pad layer is away from the pad carrier, wherein the first friction pad layer has greater wear resistance than the second friction pad layer. A brake pad according to claim 1, characterized in that the first friction pad layer has a pad thickness of from 2 mm to 8 mm, preferably from 3 mm to 6 mm, in an unworn state. A brake pad according to claim 1 or 2, characterized in that the content of the dry lubricant in the first friction pad layer is greater than the content of the dry lubricant in the second friction pad layer. A brake pad according to claim 1 or 2, characterized in that the additive content of the friction coefficient in the first friction pad layer is lower than the additive content of the friction coefficient in the second friction pad layer. A brake pad according to any one of the above claims or according to the preceding part of claim 1, characterized in that a connection layer is provided between the pad carrier and the friction pad, and the portion is partially connected thereto. In the friction pad, the wear resistance is increased, and has a thickness corresponding to the first friction pad layer. A brake pad according to claim 5, characterized in that the connecting layer is in the form of a sintered coarse base or a set of pins, in particular a brass pin, which is fixed to the pad carrier and will bear against the friction pad. in. A brake pad according to any one of the preceding claims, characterized in that the first friction pad layer partially has a friction pad thickness of the integral friction pad. A brake pad according to claim 7, characterized in that the first friction pad has a friction pad thickness of the integral friction pad on 20% to 30% of the friction surface of the friction pad. A brake pad according to any one of the preceding claims, wherein the first friction pad has a predetermined area as a turn-out side in a region intended to be a turning-in side of the brake pad Greater friction pad thickness in the area. A motor vehicle, in particular a disc brake for a commercial vehicle, having a brake caliper that is coupled to a brake disc and having at least one brake pad tying a pad carrier and a friction pad secured thereto It is introduced into a mat, characterized in that the brake mat is designed according to one or more of the above claims. A disc brake according to claim 10, wherein on the brake application surface and the back surface of the brake disc, in each case there is at least one brake pad having a pad carrier and at least one friction pad parallel to the brake pad One of the rotating shafts of the brake disc is displaceably guided, characterized in that at least one of the brake pads is designed according to one or more of the above claims 1 to 9.