Brake with one / two single-sided brake pad discs and optional cooling

Abstract

The invention relates to a disc brake for a vehicle, comprising a brake shoe (1) and a brake disc (3), wherein the brake shoe (1) is arranged on an actuating device (5) for moving the brake shoe (1) towards the brake disc (3) in order to generate a braking torque by friction, characterized in that a brake pad (7) is arranged on the brake disc (3).

Description

[0001] The invention relates to a disc brake for a vehicle and to a vehicle with such a disc brake.

[0002] The heat generated in any mechanical friction brake can lead to overheating of individual components. Above a certain temperature, this process is known as "fading," which results in a significant reduction in the maximum braking torque that can be generated. However, the maximum permissible temperature of a brake fluid is typically reached at significantly lower temperatures. Furthermore, increased wear can occur in the friction components of the mechanical friction brake at significantly higher temperatures.

[0003] Disc brakes are known in the state of the art which have improved air cooling: DE 24 61 159 A1 relates to a cooling system for solid disc brakes with a circumferential brake housing, in which brake rings equipped with brake pads are arranged in a circumferential, externally open, two-part brake housing equipped with radial cooling fins on their outer surfaces, and are fixed in the circumferential direction but axially freely movable and suspended from brake carriers which enclose the brake housing, having openings in the brake housings on the inner circumference of the brake rings which run in an axially parallel or outwardly rising direction and which open into the radial outer ribbing, as well as a one- or two-sided design of the mechanical, hydraulic or pneumatic actuating unit in such a way that they are in contact via projections,so that a free radial flow cross-section is created and, due to the fan effect of the circumferential radial ribbing of the brake housing, cooling air is sucked through the openings from the space outside the brake past the side surfaces of the actuating unit and through the interior of the brake.

[0004] DE 24 59 755 A1 further relates to a twin-disc brake for motor vehicles with a circumferential, externally open brake housing with opposing friction surfaces and brake segments arranged between the friction surfaces, mounted fixedly in the circumferential direction but axially movable, which are suspended from a stationary brake carrier surrounding the brake housing and can be installed and removed without dismantling the brake housing. The brake housing consists of the cylindrical part of the wheel hub and two brake discs fastened by means of a wedge, serrated, involute or splined connection. The brake discs are equipped with projections on their inner circumference, via which the connection to the hub is established. The openings created between the brake disc projections between the hub and the brake discs open into the spaces of the radial ribbing arranged on the outer surface of the brake discs opposite the friction surface.

[0005] DE 26 60 119 C2 also relates to a combined actuating device for a disc brake with a service brake, an auxiliary brake, and a parking brake device, and with an automatic adjustment device for the air gap. Furthermore, a service brake chamber and an auxiliary brake chamber are provided, the latter being delimited by the auxiliary brake piston and an auxiliary brake cylinder. The adjustment device is designed as an expanding device, and an additional piston or cylinder is provided to actuate the expanding device. This additional piston or cylinder is spring-loaded in the direction of travel of the expanding device and, when pressure is applied, can be returned in the opposite direction by an amount that determines the desired air gap. To achieve the parking brake effect, the expanding device can be locked by the additional piston or cylinder when the pressure is released.

[0006] Especially in passenger cars, the space required to accommodate a disc brake can be very limited. This is especially the case in electric vehicles with wheel hub motors. The electric motor is positioned as close as possible to the driven wheel. In such a configuration, a conventional disc brake, including a brake caliper and a brake piston, is often too wide in the axial dimension chain.

[0007] The object of the invention is to provide a disc brake with reduced space requirements in the axial direction.

[0008] The invention is based on the features of the independent claims. Advantageous developments and refinements are the subject of the dependent claims.

[0009] A first aspect of the invention relates to a disc brake for a vehicle, comprising a first brake shoe and a second brake shoe, and a first brake disc and a second brake disc with a respective brake pad, wherein a first brake shoe is arranged on a first actuating device for moving the brake shoe towards the brake disc in order to generate a braking torque by friction, and a second brake shoe is arranged on a second actuating device.

[0010] In the disc brake according to the invention, the respective brake shoe can be moved toward the brake disc by actuating the brake. For this purpose, the respective brake shoe is mounted for appropriate movement, for example, sliding on a guide, and is moved by an arranged actuating device, for example, by hydraulic pressure.

[0011] While conventional brake discs are made of an iron-carbon composite, in particular gray cast iron, a conventional brake shoe has the brake pad, for example a metallic pad, semi-metallic pad, pad made of organic or ceramic material.

[0012] In the disc brake according to the invention, however, the respective brake pad is arranged circumferentially on the respective brake disc. Each brake disc therefore has the brake pad circumferentially on its centrally recessed circular surface, so that the brake shoe, moving axially toward the brake disc, contacts the brake pad rotating with the vehicle wheel, generating friction, which in turn leads to a braking torque.

[0013] In contrast to conventional disc brakes, the brake pad rotates with the rotation of the vehicle's wheel, while the brake shoe has no brake pad.

[0014] Each brake disc has a friction surface with its brake pad, so that each brake disc is braked in particular only on one side.

[0015] According to the invention, the disc brake further comprises a first brake disc and a second brake disc with a respective brake pad, wherein a first brake shoe is arranged on a first actuating device and a second brake shoe is arranged on a second actuating device.

[0016] Even when two brake discs are used, each brake disc has a friction lining on its centrally recessed circular surface, at least over one circumference. Furthermore, the actuating devices, which press the first brake shoe and the second brake shoe against the friction lining of the first brake disc and the friction lining of the second brake disc as evenly as possible, are preferably arranged centrally between the two brake discs. If, for example, a wheel hub drive is provided in an electric vehicle, one brake disc can be arranged on the rim, and the other brake disc on a housing of an electric motor of the wheel hub drive.

[0017] According to a further advantageous embodiment, the first actuating device is a first brake piston and the second actuating device is a second brake piston, wherein the first brake piston and the second brake piston are arranged between the brake discs and at the same radius to a wheel axis, but are arranged offset by a rotational circumference around the wheel axis.

[0018] In particular, the offset arrangement of the actuating devices, which are preferably designed as brake pistons, allows for a significant reduction in the axial installation space of the disc brake. The axial space required for installing the disc brake in the area of each wheel of a vehicle is therefore massively reduced.

[0019] According to a further advantageous embodiment, the respective brake shoe has an additional thermal mass.

[0020] The additional thermal mass provides additional thermal inertia and can be geometrically designed and positioned to match the overall wheel package. Advantageously, arranging the additional thermal mass between two brake discs in the area of the brake shoes can reduce the size compared to conventional thermal mass, and the thermal mass can also be geometrically designed with considerable flexibility.

[0021] Further cooling options to reduce the temperature throughout the disc brake can be provided: According to a further advantageous embodiment, the additional thermal mass comprises cooling fins. The cooling fins are preferably made of metal and connected to the additional thermal mass by a metallic heat conductor in order to achieve the highest possible thermal conductivity to the cooling fins.

[0022] According to a further advantageous embodiment, the additional thermal mass has a fluid conduit for conducting cooling fluid through the additional thermal mass or along the additional thermal mass.

[0023] By using cooling fluid, the total thermal mass can be reduced, so that further improvements in driving dynamics can be achieved by reducing the unsprung mass.

[0024] According to a further advantageous embodiment, the fluid conduit has an inlet connection and an outlet connection in order to introduce a mass flow of cooling fluid into the fluid conduit at the inlet connection and to discharge it from the fluid conduit at the outlet connection.

[0025] The cooling fluid can be pumped through the fluid channel automatically due to temperature differences, with appropriate convection occurring, but the cooling fluid can also be actively pumped by a motor-driven pump. The advantage of using a motor is the controllability and adjustability of the mass flow of cooling fluid through the fluid channel.

[0026] According to a further advantageous embodiment, the respective brake pad is guided around a completely closed circumference of a respective brake disc.

[0027] According to this embodiment, at least one annular section of a respective brake disc (i.e., a region between a smaller and a larger circumference, i.e., a region between two radii) is formed entirely from brake pad material. The entire brake disc can also be formed continuously and exclusively as a brake pad, in that it is made entirely from the brake pad material.

[0028] This can advantageously reduce the unsprung masses in the disc brake, which in turn leads to advantages in the driving comfort and driving dynamics of the vehicle.

[0029] According to a further advantageous embodiment, a respective brake disc is completely designed as a brake pad at least along a circumference over its thickness.

[0030] A further aspect of the invention relates to a vehicle with a disc brake as described above and below.

[0031] Advantages and preferred developments of the proposed vehicle result from an analogous and analogous transfer of the statements made above in connection with the proposed disc brake.

[0032] Further advantages, features, and details will become apparent from the following description, in which at least one embodiment is described in detail—possibly with reference to the drawings. Identical, similar, and / or functionally equivalent parts are provided with the same reference numerals.

[0033] They show: Fig. 1: A disc brake according to a first embodiment of the invention. Fig. 2: A disc brake according to a second embodiment of the invention. Fig. 3: A disc brake according to a third embodiment of the invention. Fig. 4: A disc brake according to a fourth embodiment of the invention.

[0034] The representations in the figures are schematic and not to scale.

[0035] Fig. Figure 1 shows a disc brake for a vehicle in section, looking into a rotational plane. The dash-dot-dash line on the underside of the Fig. 1 symbolizes a wheel axle. Shown in section are a left brake disc 3 and a right brake disc 3, on the inside of which brake pads 7 are applied. The brake discs 3 move with the rotation of a wheel, which can be braked by the disc brake. Furthermore, two actuating devices 5 are provided on a housing. These actuating devices 5 are designed as brake pistons or, when the disc brake is actuated, serve to move the brake shoes 1 in the opposite direction, i.e. away from each other against a common spring force in the direction of the brake pads 7 of the respective brake disc 3, so that the respective rotating brake pad 7 rubs against a respective end of a brake piston and thereby exerts a braking torque on the wheel of the vehicle. When the actuation of the disc brake is withdrawn, the spring force ensures that the brake shoes 1 move away from the brake discs 3 again.The mobility of the brake shoes 1 can be achieved by a linear guide so that both brake shoes 1 can move away from each other in a translational manner when the disc brake is actuated and can move towards the brake discs 3. A bearing can also be provided around a common pivot point in order to keep the brake shoes 1 movable relative to the brake discs 3. In order to save axial installation space, the first brake piston and the second brake piston are not only arranged between the brake discs 3 and at the same radius to a wheel axis, but are also arranged offset by a rotational circumference around the wheel axis, i.e. in . Fig. 1 is offset into the plane of the drawing. A thermal mass 9 is also provided to introduce additional thermal inertia into the disc brake. The additional thermal mass 9 is connected to both brake shoes 1 with good thermal conductivity, allowing heat generated by friction to be dissipated from the disc brake into the vehicle's surroundings.

[0036] Fig. 2 shows a variant of the disc brake of the Fig. 1. Here, the additional thermal mass 9 has a fluid conduit 11 for conducting cooling fluid through the additional thermal mass 9. The fluid conduit 11, in turn, has an inlet connection and an outlet connection for introducing a mass flow of cooling fluid into the fluid conduit 11 at the inlet connection and discharging it from the fluid conduit 11 at the outlet connection. The cooling fluid heated in the additional thermal mass 9 can be fed to a heat exchanger outside the disc brake in order to release the absorbed heat again, for example through airflow.

[0037] Fig. 3 shows a variant of the disc brake of the Fig. 1. While according to the concept of Fig. 1 the respective brake pad 7 is arranged on a respective inner end face of the brake discs 3, in the variant of the Fig. 3 the respective complete brake disc 3 is made of the material of the brake pad 7, so that the respective brake disc 3 and its brake pad 7 each form a unit.

[0038] Fig. In contrast, Figure 4 shows a simplified embodiment of a disc brake in which only a single actuating device 5 is provided to guide a single brake shoe 1, when the disc brake is actuated, to exactly one brake disc 3, which is itself designed as a brake pad 7. Alternatively, a brake disc 3 coated with a brake pad 7 can be used.

[0039] Although the invention has been illustrated and explained in detail by preferred embodiments, the invention is not limited by the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention. It is therefore clear that numerous variations exist. It is also clear that exemplary embodiments are truly only examples and should not be construed as limiting the scope, possible applications, or configuration of the invention in any way.Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, whereby the person skilled in the art, with knowledge of the disclosed inventive concept, can make various changes, for example with regard to the function or arrangement of individual elements mentioned in an exemplary embodiment, without departing from the scope of protection defined by the claims and their legal equivalents, such as further explanations in the description. List of reference symbols 1 brake shoe 3 brake disc 5 Actuating device 7 Brake pad 9 additional thermal mass

Claims

[1] Disc brake for a vehicle, comprising a first brake shoe (1) and a second brake shoe (1), and a first brake disc (3) and a second brake disc (3) with a respective brake pad (7), wherein a first brake shoe (1) is arranged on a first actuating device (5) for moving the brake shoe (1) towards the brake disc (3) in order to generate a braking torque by friction, and a second brake shoe (1) is arranged on a second actuating device (5). [2] Disc brake according to claim 1, wherein the first actuating device (5) is a first brake piston and the second actuating device (5) is a second brake piston, wherein the first brake piston and the second brake piston are arranged between the brake discs (3) and at the same radius to a wheel axis, but are arranged offset by a rotational circumference around the wheel axis. [3] Disc brake according to one of the preceding claims, wherein the respective brake shoe (1) has an additional thermal mass (9). [4] Disc brake according to claim 3, wherein the additional thermal mass (9) has cooling fins. [5] Disc brake according to one of claims 3 to 4, wherein the additional thermal mass (9) has a fluid conduit (11) for conducting cooling fluid through the additional thermal mass (9) or along the additional thermal mass (9). [6] Disc brake according to claim 5, wherein the fluid conduit (11) has an inlet port and an outlet port for introducing a mass flow of cooling fluid into the fluid conduit (11) at the inlet port and for discharging it from the fluid conduit (11) at the outlet port. [7] Disc brake according to one of the preceding claims, wherein the respective brake pad (7) is guided around a completely closed circumference of a respective brake disc (3). [8] Disc brake according to one of the preceding claims, wherein a respective brake disc (3) is formed entirely as a brake pad (7) at least along a circumference over its thickness. [9] Vehicle with a disc brake according to one of the preceding claims.

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