Partial disc brake, especially for a vehicle

Abstract

Part-pad disc brake for a motor vehicle, comprising a brake disc with axially directed perforations (6, 6') positioned so that the brake disc is solid in a certain radial area over an entire circular ring without any perforation, and comprising friction linings (2) whose circumferential edge (11) is rounded or swept in the circumferential direction of the brake disc, characterized in that the openings (6, 6') are arranged on the surface of the brake disc swept over by the friction linings (2) in at least two circumferential concentric rings (10, 10'), the openings (6, 6') are elongated holes with an oval or straight outer contour, the elongated holes extending radially outwards in their longitudinal direction, the specific radial region extends in the radial direction between the at least two concentric rings (10, 10') and two points (4, 5) of the circumferential edge (11) of the friction lining (2) which are furthest apart from each other in the circumferential direction of the brake disc, seen in the radial direction of the brake disc, lie at the level of the specific radial area.

Description

[0001] The invention relates to a spot-type disc brake, in particular as a vehicle brake, according to the preamble of the first claim.

[0002] Brake discs with perforated holes in the cylindrical ring-shaped friction surfaces are well known. In the case of solid brake discs, the holes typically extend through the entire thickness of the disc; in the case of internally ventilated brake discs, they may extend only from the friction surface to the inner cavity. The advantages of these perforated holes are improved cooling and faster removal of a moisture film present on the friction surfaces in wet conditions compared to non-perforated brake discs. Furthermore, the cleaning effect of the perforated holes is beneficial for the friction lining applied to the brake pads. Wear particles are at least partially removed through the perforated holes, and the shearing and peeling action of the edges of the perforated holes removes deposits, particularly abrasion, from the friction lining surface.Compared to unperforated brake discs, this results in more consistent friction behavior, even under high loads.

[0003] DE 29 01 349 A1 discloses a metallic brake disc with a reduced tendency to squeal and improved heat dissipation. Openings are formed in the friction surfaces of the brake disc at varying distances from one another in the circumferential direction. The openings extend through the entire thickness of the brake disc and are formed by radially elongated slots or circular holes arranged in radial rows. The openings are located only in the area swept by the friction linings of the brake shoes.

[0004] The German utility model DE 74 41 560 U relates to a disc brake with a perforated brake disc for two-wheeled vehicles. The perforation is intended to prevent any impairment of the braking effect due to water getting onto the brake disc. Rows of holes are arranged within the circular area swept by the friction linings of the brake shoes. The edges of the brake shoes are circular and aligned essentially radially to the center of the brake disc. The perforations of the brake disc and the edges of the brake shoes are aligned relative to one another in such a way that the brake shoe edges do not touch the perforations at the same time and only touch a single point, which is intended to contribute to vibration-free and quiet braking. The figure shows a friction lining whose peripheral edge is rounded in the circumferential direction of the brake disc.

[0005] Further disc brakes are described in DE 10 2009 018 431 A1, DE 34 36 729 A1, DE 25 07 264 A1, EP 2 682 634 A1, JP 2014- 118 997 A and JP S58- 37 330 A.

[0006] The object of the present invention is to provide a spot-type disc brake with a perforated brake disc in which the edges of the recesses in the brake disc do not lead to increased wear of the brake pads.

[0007] The problem is solved by the features of the first claim. A further embodiment of the invention is described in the dependent claim.

[0008] According to the invention, a spot-type disc brake for a motor vehicle, comprising a brake disc with axially directed perforations, which are positioned so that the brake disc is solid in a specific radial region over an entire circular ring without any perforation, and comprising friction linings whose peripheral edge is rounded or swept in the circumferential direction of the brake disc, characterized in that the perforations are arranged in at least two circumferential concentric rings on the surface of the brake disc swept over by the friction linings, the perforations are elongated holes with an oval or straight outer contour, wherein the elongated holes extend radially outwards in their longitudinal direction, the specific radial region extends in the radial direction between the at least two concentric rings, and two points of the peripheral edge of a friction lining that are furthest apart from one another in the circumferential direction of the brake disc,seen in the radial direction of the brake disc, at the level of the specific radial area.

[0009] Advantageously, axially directed perforations in the brake disc increase the surface area and thus optimize cooling without increasing wear on the brake disc or brake pads. A so-called neutral line—that is, an area of ​​a certain radial width across the entire circumference of the brake disc that is not intersected by perforation edges, where rounded or swept-back brake pads begin their braking engagement, viewed in the radial direction—can significantly reduce wear, especially due to shearing at the friction pad tip.

[0010] Preferred embodiments of the invention are characterized in that the perforations are arranged on the surface of the brake disc swept by the brake pads in at least two circumferential concentric rows or rings with a rotationally symmetrical pattern. The perforations can, for example, be elongated holes with an oval or straight outer contour to maximize the surface area. The neutral line and the tips of the brake pad sweep are then located between the two rows or rings with perforations. Generally, friction lining wear is reduced there, i.e., in the center line of the friction lining, which represents the largest area without potential contact with perforations.

[0011] The perforations can be cost-effectively integrated into a corresponding casting process or can be created in a single manufacturing step by drilling. To achieve the maximum number of perforations and thus the largest possible surface area, the number of perforations for each row is advantageously defined as follows: For a first row, n*(1+i) perforations apply, a next second row located further out in the radial direction then has n*(1+i+1) perforations and a ring of perforations located in the k-th row then has a number of n*(k+i) perforations, with n being the number of repetitions of a pattern,

[0012] i is the number of perforations of the pattern in the first ring (in the figure i=2).

[0013] A preferred embodiment of the present invention for a spot-type disc brake is shown schematically in the accompanying drawing, limited to the essentials. The sole figure shows a quarter-circle partial view of a brake disc according to the invention in the area of ​​a friction lining.

[0014] The figure shows a quarter-circle section 3 of a brake disc of a spot-type disc brake with axially directed openings 6, 6' in a friction disc 1 and with a friction lining 2, the circumferential edge 11 of which is arrowed in the circumferential direction of the brake disc and has two arrowheads 4, 5.

[0015] A geometrically regularly repeating pattern of perforations 6, 6' in the friction disc 1 of the brake disc for motor vehicles in the circumferential direction of the brake disc over a circular ring surface of the friction disc 1 is represented by two dashed lines 7, 8 running radially on the friction disc 1 between them, while a neutral line 9 without edges of perforations 6, 6', shown in dash-dotted lines, on which the tips 4, 5 of the sweeps of the brake pads 2 are located, runs between two concentric rings 10, 10' with perforations 6, 6'. The perforations 6, 6' thus run in concentric rings 10, 10' with a rotationally symmetrical pattern such that the brake disc is solid in a certain radial region around the neutral line 9 over an entire circular ring without any perforations.In this specific radial area around the neutral line 9, the two arrowheads 4, 5 are located as the two points of the circumferential edge 11 of the friction lining 2 that are furthest apart from each other in the circumferential direction of the brake disc.

[0016] The openings 6, 6' are designed as elongated holes with a straight outer contour.

[0017] Alternatively, the friction lining 2 can also be rounded instead of the arrowhead. It then has no arrowheads 4, 5, but instead a radius, advantageously extending between its outer peripheral edge 11' and its inner peripheral edge 11''.

[0018] According to the prior art, the brake disc can be fixed via its inner peripheral edge 12 to a wheel flange (not shown) of a wheel suspension of a motor vehicle (also not shown).

Claims

[1] Part-pad disc brake for a motor vehicle, comprising a brake disc with axially directed perforations (6, 6') which are positioned so that the brake disc is solid in a certain radial area over an entire circular ring without any perforation, and comprising friction linings (2) whose circumferential edge (11) is rounded or swept in the circumferential direction of the brake disc, characterized by , that the openings (6, 6') are arranged on the surface of the brake disc swept over by the friction linings (2) in at least two circumferential concentric rings (10, 10'), the openings (6, 6') are elongated holes with an oval or straight outer contour, the elongated holes extending radially outwards in their longitudinal direction, the specific radial region extends in the radial direction between the at least two concentric rings (10, 10') and two points (4, 5) of the circumferential edge (11) of the friction lining (2) which are furthest apart from each other in the circumferential direction of the brake disc, seen in the radial direction of the brake disc, lie at the level of the specific radial area. [2] Part-pad disc brake according to claim 1, characterized by that the rings (10, 10') form a rotationally symmetrical pattern.

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