Patent Application
20080271963
The present invention relates to a disc brake and, in particular, a disc brake for a commercial vehicle.
Such a disc brake is known, for example, from DE 199 07 958 A1. DE 199 07 958 A1 shows and describes a brake pad, which consists of a friction lining and a lining carrier plate, which bears on its lining carrier plate side against a pressure plate. The pressure plate is displaceably mounted in a brake caliper. A brake application device is used to press the brake pad against the brake disc.
Since the structural space available in the brake caliper for accommodating the brake pads is relatively small, the lining carrier plate is made to be relatively thin. As a result, problems arise with respect to supporting the loads which occur during braking. For these reasons, it is also problematic to couple the lining carrier plate to the pressure plate.
In addition, incorrect fitting may occur with the known structures because the brake lining may be fitted in a reversed position, i.e., one rotated by 180°, without this being noticed, so that the friction lining is then adjacent the pressure plate and not directed toward the brake disc, as is required.
Moreover, known disc brakes even permit the brake lining to be replaced by other makes that may not be approved for the vehicle or the particular disc brake in question.
This can, of course, restrict the operational safety of the disc brake, which is unacceptable in principle, especially since disc brakes are among the components in a vehicle which are particularly important from a safety point of view.
Although it has already been attempted to code brake pads, such coding is not suitable for performing functional tasks. In addition, the known coding can be removed by simple mechanical working, for example using a hammer and chisel, which means that uncoded brake pads can easily be used by unauthorized manufacturers.
A further criterion with regard to the requisite operational safety is the quality of the friction lining whose identification has, until now, been stamped onto the outside of the lining carrier plate in color or engraved with a stamping tool by a needle stamping method.
After a certain time, however, the corrosion and temperatures which occur during operation destroy these identifications to the point that they can no longer be seen. In the event of damage, therefore, it is frequently not possible to determine whether use was made of a correct brake pad or not.
The present invention is based on the object of further developing a disc brake such that the operational safety is improved with little design and manufacturing complexity.
This object is achieved by providing a disc brake, in particular for a commercial vehicle, having a brake caliper which straddles a brake disc and having brake pads, which are arranged in the brake caliper on both sides with the brake disc. Each brake pad includes a friction lining and a lining carrier plate. Each lining carrier plate bears against a pressure plate, which is supported in the brake caliper, or a supporting surface on the brake caliper side. At least one of the lining carrier plates and the associated pressure plate, or supporting surface, are provided on their mutually facing bearing surfaces of mutually corresponding form-fitting structures, which are formed in the manner of a coding, for transferring loads which occur during braking.
The invention achieves essentially two major advantages. By designing the mutually corresponding form-fitting structures on the lining carrier plate, on the one hand, and the pressure plate or a supporting surface of the brake caliper, on the other hand, only that brake pad which is intended for this use can be fitted. It is ensured that the brake pad can be placed against the pressure plate or the supporting surface only with its lining carrier side and not, as described, with its friction lining surface. In addition, no other product can be used, since the form-fitting structures are designed in such a way that the use of another brake pad which does not have these form-fitting means cannot be used.
In this case, the form-fitting structures can be designed individually, for example in the form of a workpiece identification, a logo, or the like. In this case, the brake pads can be used only in vehicles of a single provider. It is then also possible to permanently engrave the means of identifying the quality of friction lining used.
The coding also permits the prior determination of the brake pads for a specific installation site. It is thus possible to exactly allocate brake pads with different coefficients of friction of the friction linings, as are required for an inner pad and an outer pad, in order, for example, to take into account the different cracking behavior of a brake disc. Interchanging of the two brake pads can therefore be excluded.
The pressure plates are preferably produced from stainless (or almost stainless) material and are designed to have high fatigue strength for the service life of a disc brake.
In addition to the precise and reliable allocation of the brake pad to a particular pressure plate or supporting surface, the loads occurring during braking can be transferred by the form-fitting structures from the brake lining to the pressure plate and, therefore, to the brake caliper in an unrestricted fashion, it being possible to tangentially, radially and, if required, also laterally, support the forces that occur.
The coding or the form-fitting structures can be configured in a simple manner such that a requisite overlap length can be produced in all functionally relevant directions.
In addition, the form-fitting structures can be designed to be mechanically extremely robust and can be subjected to high temperatures through suitable material selection.
The pressure plate can be of one-part or two-part design, wherein, in the case of a two-part design, it is formed from a die sheet, which is provided with the coding and is cast into a carrier plate, for example. In this case, the form-fitting structures on the pressure plate side are formed by recesses which are produced by material-removing machining or punching.
In the case of a one-part design, the pressure plate can be forged or cast, wherein the form-fitting structures are, preferably, designed as depressions into which corresponding form-fitting structures of the lining carrier plate, which are designed as elevations, engage with an accurate fit. By means of cold or hot calibration following the casting, material-removing machining (milling, counter-sinking, drilling), or forging, it is possible to produce corresponding accuracy of the form-fitting structures. Particularly simple fashioning of the form-fitting structures in the pressure plate arises as a result of indentations in different patterns, to which the form-fitting structures of the lining carrier plate are matched.
Further advantageous embodiments of the invention are described and claimed herein.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description when considered in conjunction with the accompanying drawings.
During braking, the application device 5 is used to press brake pads 3, which are arranged in the brake caliper 1, against both sides of the brake disc 2.
As shown in
Furthermore, each brake pad 3 is supported in the present exemplary embodiment on a pressure plate 4, which is coupled to the brake caliper 1.
According to the invention, the pressure plate 4 and the lining carrier plate 7 have, on their mutually facing bearing surfaces, form-fitting structures 8, 9. These structures 8, 9 are formed in the manner of a coding and serve to transfer the loads which occur during braking.
For this purpose, the form-fitting structure of the brake pad 3 has an elevated form and the associated form-fitting structure 9 of the pressure plate 4 has a depressed form into which the form-fitting structure 8 engages with a substantially accurate fit.
In the exemplary embodiment shown in
In principle,
The exemplary embodiment corresponding to
In
In the same way as in the exemplary embodiment in accordance with
It goes without saying that other designs of the form-fitting structures 8, 9 are also contemplated. It is important that together they form a coding and absorb the radial, tangential, and/or lateral forces which occur during braking.
The foregoing disclosure has been set forth merely to illustrate one or more embodiments of the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2005 050 581.3 | Oct 2005 | DE | national |
This application is a continuation of PCT International Application No. PCT/EP2006/010141, filed on Oct. 20, 2006, which claims priority under 35 U.S.C. §119 to German Application No. 10 2005 050 581.3, filed Oct. 21, 2005, the entire disclosures of which are expressly incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2006/010141 | Oct 2006 | US |
| Child | 12106577 | US |
