Disc brake for a commercial vehicle

Abstract

The invention relates to a disc brake for a commercial vehicle, comprising: a brake caliper (1) which extends over a brake disc (2); brake pads (3) which contact the brake disc (2) in a functional position; a brake application device (5) by means of which one of the brake pads (3) can be pressed against the brake disc (2) via at least one actuation spindle (10); an adjustment device (8) which is connected to the actuation spindle (10) for conjoint rotation and by means of which a wear-induced change in the clearance between the brake pad (3) and the brake disc (2) can substantially be compensated for; a closure lid (13) which covers the adjustment device (8) and is secured to the brake caliper (1); and a Hall sensor (17) which corresponds with a planetary gearing connected to the actuation spindle (10), the planetary gearing comprising a sun gear (14), planetary gears (16) engaging therewith, a drive element (15) and a driver gear (21), wherein at least the sun gear (14) and the drive element (15) are formed as a prefabricated assembly.

Description

[0001] DESCRIPTION

[0002] Disc brakes for a commercial vehicle

[0003] The invention relates to a disc brake for a commercial vehicle according to the preamble of claim 1.

[0004] In order to keep the clearance between the brake disc and the clamping-side brake pad constant when the brake is unloaded, i.e., in the non-functional position of the brake pad, i.e., to compensate for a wear stroke caused by the removal of a friction layer of the brake pad during braking, disc brakes are known which have at least on the clamping side an adjusting device having two adjusting spindles that are rotatable synchronously via a common drive chain and thus axially displaceable.

[0005] Devices are used to detect brake pad wear, consisting of a reduction gear connected to one of the two adjusting spindles and an associated pad wear sensor.

[0006] This adjusting device is integrated into a brake piston that is rotatably mounted in a bridge. The adjusting device rotates the piston to compensate for pad and / or disc wear. The rotation of the threaded spindle is used as an input parameter for indirect pad wear detection.

[0007] To protect against environmental influences, the adjusting device is covered by a cover which is held on the outside of the brake caliper and which also serves to protect the brake mechanism located in the brake caliper.

[0008] From DE 102017 128594 A1 a disc brake of the generic type is known in which the reduction gear is designed as a planetary gear and the pad wear sensor is designed as a Hall sensor.

[0009] The Hall sensor converts a measured rotation angle into an electrical output signal, continuously monitoring pad and brake disc wear across its entire wear range. In every possible operating and maintenance condition of an installed brake, the Hall sensor should correlate the wear state, i.e., the angular position of the input terminal, to a single, precise signal value.

[0010] Depending on the capacity of an electronic diagnostic control unit, the signal can be used for continuous wear monitoring with wear indicator, monitoring of brake function by comparing the plausibility of different brakes, simplifying maintenance, and comparing wear between multiple axles of the commercial vehicle.

[0011] In normal ferry operation, the Hall sensor is only briefly switched on after each brake application; however, when resetting the disc brake to replace worn brake pads, the Hall sensor is not switched on.

[0012] A disadvantage of the known disc brake, namely the aforementioned DE 102017 128594 A1, is the relatively large space requirement in the axial and radial direction, especially due to a magnetic plate that is part of the Hall sensor.

[0013] Furthermore, the sun gear of the planetary gear, which corresponds to the planet gears of the planetary gear, and a drive element are specified as separate parts, which not only makes assembly more difficult but also results in relatively high manufacturing costs.

[0014] The invention is based on the objective of further developing a disc brake of the generic type in such a way that, in particular, the adjusting device of the disc brake can be manufactured more easily and therefore more cost-effectively, and its usability is improved.

[0015] This problem is solved by a disc brake having the features of claim 1.

[0016] This design measure offers a number of advantages over the prior art. For example, the required installation space for the adjustment mechanism is significantly reduced, which meets the ongoing demand for minimizing installation space.

[0017] The reduced number of components resulting from the invention simplifies brake assembly, with an integrated drive element holding the entire assembly together as a unit, thus enabling pre-assembly of this unit.

[0018] Furthermore, the design according to the invention offers tolerance compensation with respect to angular errors. This tolerance compensation is achieved by the drive element between the components of the disc brake and the sensor in both axial and radial directions.

[0019] The aforementioned minimization of installation space, which concerns a receiving chamber for the cover, also allows for the integration of the Hall sensor. The drive element acts as a fixation for the entire assembly, which, as mentioned, is supplied as a single unit.

[0020] Further advantageous embodiments of the invention are characterized in the dependent claims.

[0021] An embodiment of the invention is described below with reference to the accompanying drawings.

[0022] They show:

[0023] Fig. 1 shows a disc brake of the type in a partially cutaway top view,

[0024] Fig. 2 shows a partially cutaway front view of the disc brake, seen in the direction of arrow X in Figure 1.

[0025] Fig. 1 shows a disc brake for a commercial vehicle, with a brake caliper 1 overlapping a vehicle-side brake disc 2, which is axially displaceable on a brake carrier 4 by means of guide arms 12, with respect to the brake disc 2.

[0026] A clamping device 5 is arranged in the brake caliper 1, with a brake lever 7 which acts on a bridge 6 in the event of braking and is supported on a pivot bearing.

[0027] In the example, two adjusting spindles 10, arranged parallel and spaced apart from each other and provided with an external thread, are screwed into the bridge 6. Each spindle carries a pressure piece 11 at its end facing the brake disc 2. During braking, the pressure pieces 11 are pressed against an associated brake pad 3 via the pivotable brake lever 7 and the bridge 6, as is an opposing, reaction-side brake pad 3.

[0028] To compensate for a changing clearance, i.e. the distance between the brake pad 3 and the brake disc 2, an adjusting device 8 is provided, with which, when the brake is actuated, the adjusting spindles 10, which engage with their external thread in an internal thread of the bridge 6, can be rotated in the direction of the brake disc 2.

[0029] To synchronize the adjustment, the adjusting device 8 has a traction drive 9 with a traction element in the form of a chain. To protect the traction drive 9 and the adjusting device 8, a cover 13 is provided that conceals them from the environment and is attached to the brake caliper 1, for example by screws.

[0030] Figure 2 shows the adjusting device 8 in an exploded view. A reduction gear in the form of a planetary gear can be seen, comprising a sun gear 14 and a drive element 15 with external teeth, which, in its assembled position, engages a drive shaft 19 of the adjusting spindle 10. Furthermore, the planetary gear has planet gears 16 that mesh with the sun gear 14.

[0031] According to the invention, the sun gear 14 and the drive element 15 are designed as a prefabricated unit, in particular as a single piece. It is also conceivable to prefabricate the drive element 25 and the sun gear 14 as a unit and join them together by means of a form-fit or material-fit connection.

[0032] On the side opposite the drive element 15, associated with the sun gear 14, a Hall sensor 17 is provided, with a magnet 18 having a central opening 20 into which the sun gear 14 is partially inserted. A drive gear 21, which is also part of the prefabricated assembly, is provided between the sun gear 14 and the drive element 15. (Reference numeral list)

[0033] 1 brake caliper

[0034] 2 brake discs

[0035] 3 brake pads

[0036] 4 brake carriers

[0037] 5 Tensioning device 6 Bridge

[0038] 7 brake levers

[0039] 8 Adjustment device 9 Traction drive

[0040] 10 adjusting spindles

[0041] 11 Printed piece

[0042] 12 Guide bar

[0043] 13 Cover 14 Sun wheel

[0044] 15 Drive element 16 Planetary gear

[0045] 17 Hall sensor

[0046] 18 Magnet

[0047] 19 Drive shaft

[0048] 20 Center opening

[0049] 21 Drive wheel

Claims

Claims 1. Disc brake for a commercial vehicle, comprising a brake caliper (1) extending over a brake disc (2), brake pads (3) contacting the brake disc (2) in the operating position, a clamping device (5) with which one of the brake pads (3) can be pressed against the brake disc (2) via at least one adjusting spindle (10), an adjusting device (8) connected to the adjusting spindle (10) in a twisted manner, with which a wear-related change in the clearance between the brake pad (3) and the brake disc (2) can be substantially compensated, a cover (13) attached to the brake caliper (1) covering the adjusting device (8), and a Hall sensor (17) corresponding to a planetary gear connected to the adjusting spindle (10) as a pad wear sensor, wherein the planetary gear comprises a sun gear (14), planet gears (16) meshing with it, a drive element (15), and a drive gear (21). characterized by the fact that at least the sun wheel (14) and the drive element (15) are designed as a prefabricated assembly.

2. Disc brake according to claim 1 , characterized by the fact that the drive wheel (21) is part of the assembly.

3. Disc brake according to claim 1 or 2, characterized by the fact that the component unit is formed in one piece.

4. Disc brake according to one of the preceding claims, characterized by the fact that the sun wheel (14) and the drive element (15) are connected to each other by a form-fit or material-fit connection.

5. Disc brake according to one of the preceding claims, characterized by the fact that the Hall sensor (17) is arranged on the side associated with the sun gear (14).

6. Disc brake according to one of the preceding claims, characterized in that a magnet (18) of the Hall sensor (17) has a central opening (20) into which the sun wheel (14) is partially inserted.

7. Disc brake according to one of the preceding claims, characterized by the fact that the drive wheel (21) is arranged between the sun wheel (14) and the drive element (15).

8. Disc brake according to one of the preceding claims, characterized by the fact that the drive wheel (21) is part of the one-piece design of the assembly.

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