Patent Application
20180003249
The invention relates to a disk brake for a utility vehicle, and in particular an arrangement for mounting a disk brake caliper.
A brake caliper (also called a sliding caliper) of a disk brake of the generic type is held by fastening elements on a vehicle-side, that is to say stationary, brake carrier.
To this end, guide rods are fastened to the brake carrier, in particular by way of being screwed in. The guide rods are guided on the other side in plain bearings of the brake caliper in such a way that the brake caliper can be displaced axially during a braking operation relative to a brake disk. The brake caliper is held on an axle of the vehicle such that it is secured against rotation.
One of the plain bearings is configured as a locating bearing with a low sliding play and mainly serves for axial guidance of the brake caliper, the bearing play being kept as low as possible.
In contrast, the other plain bearing, as a floating bearing, has a greater bearing play owing to its function, since tolerance compensation and thermally induced expansions are also to be taken into consideration in addition to the axial guidance.
Due to the greater bearing play, rattling noises can be produced during driving operation. In the known disk brake, a sliding bush which consists of plastic, in particular an elastomer, and in which the guide rod is mounted axially displaceably, is used to prevent or damp said rattling noises.
Said sliding bush is held in a bearing bush made from metal, usually from sheet steel, such that it is secured against displacement. The bearing bush is pressed into a bore of the brake caliper and is held in a frictionally locking manner therein as a result, the sliding bush and the bearing bush being constituent parts of a guide bush.
A stop ring is used as a further element of the guide bush in order to limit the insertion when the guide bush is pressed into the bore of the brake caliper. The stop ring bears against a shoulder of the bore of the brake caliper. Moreover, the stop ring protects the sliding bush against damage by limiting the damping travel, thereby avoiding damage of the caliper-side bore as a result of contact of the guide bush.
However, the provision of the guide bush and its assembly can be realized only with considerable complexity, high production costs due to the relatively large number of constituent parts of the guide bush, including the abovementioned metallic bearing bush, the sliding bush made from plastic which is connected to it, and the stop ring.
In order to obtain a press fit for the guide bush and therefore to ensure securing against displacement in the brake caliper, relatively precise machining both of the bearing bush and of the brake caliper-side bore is required.
The abovementioned shoulder of the bore, against which the stop ring bears, can likewise be produced only with corresponding production complexity, that is to say the bore has to be configured as a stepped bore.
The costs of the assembly of the guide bush also do not correspond to the specifications for cost-optimized machining.
The invention is based on the object of developing a disk brake of the generic type in such a way that it is simplified in design terms and its production and assembly becomes simpler and therefore less expensive.
The provision of a guide bush can be dispensed with completely as a result of the invention. Instead, the sliding bush which is required for the typical tasks of a floating bearing is a constituent part of the guide rod, which results in a whole range of advantages. These include first of all the simplified production of the floating bearing, since essentially only the guide rod and the sliding bush, which is held thereon such that it is secured against displacement, have to be produced.
This preferably takes place by way of encapsulation of the guide rod with plastic in order to configure the sliding bush, the guide rod having a circumferential groove in accordance with one embodiment of the invention, the width of which circumferential groove corresponds to the desired width of the sliding bush. The walls which delimit the groove laterally form a stop for securing against displacement, and at the same time serve to prevent crushing of the sliding bush.
According to a further embodiment, grease grooves are provided on the outer side of the sliding bush. The grease grooves preferably run obliquely in a manner known per se and serve to receive grease, in order to make possible a low-friction displacement of the brake caliper on the sliding bush.
On the end side, the grease grooves are delimited, that is to say closed on the end side, by way of at least one circumferential sealing lip. The sealing lip firstly prevents discharge of the grease, and secondly protects the grease grooves against the penetration of dirt.
In addition to the extremely inexpensive production of the floating bearing, which also includes substantially simpler machining of the brake caliper-side bore, in particular since narrow tolerances no longer have to be maintained, the assembly complexity of the floating bearing overall is likewise reduced considerably, that is to say is possible in a very short time. A contribution is made to this, above all, by the fact that the guide rod with an integrated sliding bush merely has to be pushed into the brake caliper-side bore or the brake caliper has to be pushed onto the guide rod which has already been connected to the brake carrier.
All in all, the invention leads to a remarkable cost saving during the production of the disk brake. Here, the functionality, as exists in the case of a disk brake in accordance with the prior art, remains completely preserved.
As a result of the radial projection of the sliding bush with respect to the guide rod, the tasks which are assigned to the floating bearing are met in an unrestricted manner even in the case of the novel floating bearing. They include, in particular, the avoidance of rattling noises, since the sliding bush damps vibrations which occur and prevents the guide rod from coming into contact with the wall of the brake caliper-side bore.
Moreover, production-induced tolerances are also absorbed in the novel configuration by way of the sliding bush, with the result that the guide rod which is fitted with the sliding bush assumes the complete and unrestricted function of a floating bearing.
The width of the sliding bush can be selected freely and is defined merely by the stipulation of a sufficient contact with the wall of the brake caliper-side bore, which contact is in turn defined by a sufficient functionality.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.
The brake caliper 2 is arranged on a stationary brake carrier 1 of the utility vehicle such that it can be displaced axially, in relation to the brake disk.
Two fastening elements are provided which have in each case one guide rod 6 which is connected to the brake carrier 1 and is fastened to the brake carrier 1 by a bolt (not shown). Here, one fastening element is configured as a locating bearing 4 and the other is configured as a floating bearing 5.
In order to mount the guide rod 6, that is to say for axial guidance of the brake caliper 2, the floating bearing 5 has a sliding bush 7 made from a plastic, preferably an elastomer, which is held on the guide rod 6 such that it is secured against displacement according to the invention, as can be seen particularly clearly in
A circumferential groove 12, on the walls of which the sliding bush 7 is supported, is made in the shell of the guide rod 6 in order to secure the sliding bush 7 against axial displacement on the guide rod 6 which otherwise has a stepped bore 11 for receiving said bolt for connection to the brake carrier 1.
It can be seen clearly therein and in
The grease grooves 10 are closed on the end side by way of circumferential sealing lips 8, of which a plurality are integrally formed on each side such that they lie next to one another.
Said sealing lips 8 serve both to prevent a discharge of grease from the grease grooves 10 and to seal the latter in order to avoid penetration of dirt.
As has already been mentioned, the sliding bush 7 is expediently produced by way of encapsulation of the guide rod 6 in the region of the groove 12.
The foregoing disclosure has been set forth merely to illustrate 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 2014 019 112.5 | Dec 2014 | DE | national |
This application is a continuation of PCT International Application No. PCT/EP2015/080154, filed Dec. 17, 2015, which claims priority under 35 U.S.C. §119 from German Patent Application No. 10 2014 019 112.5, filed Dec. 19, 2014, the entire disclosures of which are herein expressly incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2015/080154 | Dec 2015 | US |
| Child | 15625576 | US |
