brake for a vehicle

Abstract

The present invention relates to a brake (100) for a vehicle, wherein the brake (100) has a holder (102) that can be mounted fixedly to the vehicle and a floating caliper (106) with a brake actuator (110), wherein a first brake pad (116) of the brake (100) is coupled to the brake actuator (110) and a second brake pad (118) of the brake (100) is coupled to the floating caliper (106), wherein the brake actuator (110) is configured to move the first brake pad (116) in an actuation direction when the brake (100) is actuated until the first brake pad (116) bears against a rotor of the brake (100), then to move the floating caliper (106) with the second brake pad (118) opposite to the actuation direction relative to the holder (102) until the second brake pad (118) also rests against the rotor, and then presses the brake pads (116, 118) against the rotor to generate friction,wherein the brake (100) has a return device (120) supported on the holder (102) and on the floating caliper (106), wherein the return device (120) has an elastic component (122) and an adjustment component (124), wherein the elastic component (122) is configured to be tensioned upon actuation of the brake (100) and to be relaxed after actuation of the brake (100) and to lift the second brake pad (118) from the rotor, wherein the adjustment component (124) has a rotational-translational gear with an electric motor (126) for adjusting the return device (120), wherein the elastic component (122) is supported on a translational part of the gear.

Description

Field of the invention

[0001] The invention relates to a brake for a vehicle. State of the art

[0002] A fixed-caliper brake has brake actuators on both sides of its caliper, which, when actuated, press brake pads from both sides against a brake disc. After actuation, the brake actuators can lift the brake pads from both sides off the brake disc. With hydraulic brake actuators, this can be achieved through the restoring forces of so-called quad rings.

[0003] A floating-caliper brake, on the other hand, has a brake actuator on only one side of its movable floating caliper, which, when actuated, presses one of the two brake pads against the brake disc. When the brake pad contacts the brake disc, the brake actuator moves the floating caliper in the opposite direction until the other brake pad attached to the floating caliper also contacts the brake disc. Only then can the brake actuator build up a contact force to generate friction.

[0004] After braking, the brake actuator can lift one brake pad off the brake disc. The other brake pad remains in contact with the brake disc until it is pushed away due to lateral movement of the brake disc.

[0005] DE 41 19 928 A1 describes a sliding caliper disc brake with a reset device.

[0006] EP 3 296 585 B1 describes a disc brake and a method for operating the disc brake. Disclosure of the invention

[0007] Against this background, the approach presented here presents a brake for a vehicle according to the independent claim. Advantageous further developments and improvements of the approach presented here emerge from the description and are described in the dependent claims. Advantages of the invention

[0008] In the approach presented here, a brake pad mounted on a floating caliper of a floating-caliper brake is lifted from a brake disc by an elastic component after braking. Since the brake pad wears with use, a reference point of the elastic component is adjusted to compensate for wear.

[0009] The approach presented here prevents the brake pad from grinding against the brake disc after braking. This reduces wear on both the brake disc and the brake pad. Furthermore, the brake disc can rotate without friction immediately after braking, thus reducing energy consumption.

[0010] A brake for a vehicle is presented, wherein the brake has a holder that can be mounted fixedly to the vehicle and a floating caliper with a brake actuator, wherein a first brake pad of the brake is coupled to the brake actuator and a second brake pad of the brake is coupled to the floating caliper, wherein the brake actuator is configured to move the first brake pad in an actuation direction upon actuation of the brake until the first brake pad bears against a rotor or a brake disc of the brake, then to move the floating caliper with the second brake pad opposite to the actuation direction relative to the holder until the second brake pad also bears against the rotor, and then to press the brake pads against the rotor to generate friction, wherein the brake has a return device supported on the holder and the floating caliper, wherein the return device has an elastic component and an adjustment component,wherein the elastic component is tensioned or elastically deformed when the brake is applied and is relaxed or returns to an initial shape after the brake is applied and lifts the second brake pad from the rotor, wherein the adjusting component has a rotary-translational gear with an electric motor for adjusting the return device, wherein the elastic component is supported on a translational part of the gear.

[0011] Ideas for embodiments of the present invention can be considered, among other things, to be based on the thoughts and findings described below.

[0012] A floating caliper can be movably mounted on a bracket on a floating guide. The bracket can be attached to a steering knuckle of a vehicle. The bracket can have guides for brake pads and transfer braking forces from the brake pads to the steering knuckle. A wheel hub can be rotatably mounted on the steering knuckle. A brake disc can be attached to the wheel hub, which is encompassed by the floating caliper. A vehicle wheel can be attached to the wheel hub. The wheel hub and brake disc can be referred to as a rotor.

[0013] A brake actuator can be a hydraulic brake actuator or an electromechanical brake actuator. One side of the brake actuator can be connected to the floating caliper. The other side of the brake actuator can be connected to a first brake pad. The first brake pad can first be applied to a first side of the brake disc, thus supporting the brake actuator against the brake disc. The floating caliper can then be moved, and the second brake pad can be applied to an opposite, second side of the brake disc. The brake disc can then be clamped between the brake pads.

[0014] An elastic component may include an elastomer. The elastic component may include a metallic spring. The elastic component may also include a combination of spring and elastomer. The elastic component may have a preload. The elastic component may be compressed when a force generated by the brake actuator is greater than the preload. The elastic component may be compressed when the floating caliper is moved relative to the holder.

[0015] The elastic component can be supported on the floating caliper. The gearbox can be supported on the bracket. Conversely, the elastic component can be supported on the bracket and the gearbox can be supported on the floating caliper. Different possible arrangements allow for optimal use of the available installation space.

[0016] The gearbox can be a screw drive consisting of a threaded spindle and a nut engaging with the threaded spindle. The nut can be the translational part of the gearbox. Alternatively, the threaded spindle can be the translational part. Different possible designs allow for optimal use of the available installation space.

[0017] The electric motor can drive the threaded spindle. Alternatively, the electric motor can drive the nut. Various possible designs allow for optimal use of the available installation space.

[0018] Four different designs are possible. In a first design, the nut is the translational part and is driven by the electric motor. In a second design, the nut is also the translational part, but the threaded spindle is driven by the electric motor. In a third design, the threaded spindle is the translational part and the nut is driven. In a fourth design, the threaded spindle is the translational part and is driven by the electric motor.

[0019] The lead screw can be self-locking. The lead screw and nut can have a shallow thread pitch. Due to the shallow thread pitch, friction between the nut and the lead screw can be greater than any lateral force caused by the thread pitch. Due to the self-locking, the electric motor can be de-energized and only energized when wear is compensated.

[0020] The reset device may include a maximum force limiting component. The maximum force limiting component may be a predetermined breaking point. The predetermined breaking point may break if a maximum designed load on the maximum force limiting component is exceeded. For example, the predetermined breaking point may be designed as a replaceable shear pin. The maximum force limiting component may also include a bending point. The bending point may be bent if the maximum designed load is exceeded. Alternatively, the maximum force limiting component may be a spring-loaded mechanism that yields when the maximum designed load is exceeded. The mechanism may reset itself when the load decreases. The mechanism can also be reset manually.

[0021] The electric motor used in the reset device can be designed as a stepper motor. The stepper motor can be configured for incremental adjustment or readjustment. The stepper motor enables step-by-step adjustment of the reset device. By using a stepper motor, the reset device can be constructed simply and cost-effectively. Furthermore, the controller used to control the motor can be designed simply.

[0022] It should be noted that some of the possible features and advantages of the invention are described herein with reference to different embodiments. One skilled in the art will recognize that the features may be appropriately combined, adapted, or interchanged to achieve further embodiments of the invention. Short description of the drawing

[0023] Embodiments of the invention are described below with reference to the accompanying drawings, wherein neither the drawings nor the description are to be interpreted as limiting the invention. Fig. 1 shows a representation of a brake according to an embodiment.

[0024] The figure is merely schematic and not to scale. Like reference numerals denote like or equivalent features. Embodiments of the invention

[0025] Fig.1 shows a representation of a brake 100 according to an exemplary embodiment. The brake 100 is a floating caliper brake. The brake has a holder 102 that is attached to a fixed point 104. The fixed point 104 can be arranged, for example, on a steering knuckle of a vehicle's chassis. A floating caliper 106 is mounted on the holder 102 via a floating guide 108 for linear movement in a floating direction. The floating caliper 106 can be referred to as a brake fist because it approximately corresponds to a substantially closed hand, with fingers of the hand grasping a brake disc (not shown here) and a brake actuator 110 arranged on a thumb or palm of the hand. A fixed part 112 of the brake actuator 110 is connected to the floating caliper 106 and is movably mounted on the holder 102 via the floating guide 108. A movable part 114 of the brake actuator 110 is connected to a first brake pad 116 of the brake 100.The movable part 114 is mounted in the fixed part 112, essentially movable in the floating direction. A second brake pad 118 of the brake 100 is arranged on the fingers of the brake fist. The brake disc would be arranged on the vehicle in a gap between the brake pads 116, 118.

[0026] During braking, the brake actuator 110 is actuated and the movable part 114 moves out of the fixed part 112. The first brake pad 116 is moved by the movable part 114 toward the second brake pad 118 until the first brake pad 116 rests against the brake disc. The brake actuator 110 is thus supported on the brake disc and the fixed part 112 begins to move away from the brake disc. In doing so, the fixed part 112 takes the floating caliper 106 with the second brake pad and moves it along the floating guide 108 relative to the holder 102, whereby the second brake pad 118 is also applied to the brake disc. Only when both brake pads 116, 118 are in contact with the opposite sides of the brake disc can the brake actuator 110 build up a contact force and thus decelerate the brake disc.

[0027] When braking is stopped, the movable part 114 is moved back into the fixed part 112 of the brake actuator 110 and thus the first brake pad 116 is lifted from the brake disc.

[0028] In the approach presented here, a return device 120 is arranged between the holder 102 and the floating caliper 106. The return device 120 is designed to move the floating caliper 106 and the second brake pad 118 connected thereto away from the brake disc after the brake 100 has been actuated. For this purpose, the return device 120 has an elastic component 122. The elastic component 122 is elastically deformed when the brake actuator 110 moves the floating caliper 106 along the floating guide 108. Due to the deformation, the elastic component 122 stores a spring force. When the brake actuator 110 is deactivated, the elastic component 122 relaxes and returns to its original shape. In doing so, the elastic component 122 moves the floating caliper 106 along the floating guide 108 relative to the holder 102. This also lifts the second brake pad 118 off the brake disc.

[0029] The return device 120 further includes an adjustment component 124. The elastic component 122 is supported on the adjustment component 124. Here, the elastic component 122 is a compression spring and rests against the floating caliper 104. The adjustment component 124 is attached to the holder 102.

[0030] The adjustment component is designed as a rotational-translational gear and is driven by an electric motor 126. Here, the electric motor 126 acts on a threaded spindle 128, on which a linearly movable nut 130 is arranged. The elastic component 122 rests against the nut 130. When the threaded spindle 128 is rotated, the position of the nut 130 changes, and thus a reference point of the elastic component 122 changes. When the second brake pad 118 becomes worn, wear on the second brake pad 118 can be compensated for.

[0031] In one embodiment, the threaded spindle 128 is self-locking. The position of the nut 130 therefore does not change without the electric motor 126 being activated. The electric motor 126 is then activated only for adjustment.

[0032] In the following, possible embodiments of the invention are summarized again or presented with slightly different wording.

[0033] A brake that resets on both sides is presented.

[0034] So-called floating-caliper brakes can be used with hydraulic brakes as well as with electromechanical brakes. The floating-caliper brake is mounted on the wheel and grips the brake disc.

[0035] To ensure that the reaction force of the actuation from one side can also be used for braking, the actuation is supported by the so-called fist and fingers on the second pad (rim side). This fist is mounted in a floating manner on the brake bracket. The floating guide is designed to be easily movable. This means that the pads wear evenly on both sides. The brake pads are supported in the brake bracket so that neither the piston nor the finger side has to absorb lateral forces (the braking force).

[0036] There are also drum brakes, which also work with two brake pads.

[0037] The principle for all brakes is to minimize any braking torque when the brake is not applied. For a disc brake, this means that both brake pads lift off the disc. On the piston side, this is supported by a quad ring, so the piston retracts even with a hydraulic brake; with an electromechanical brake, this can be achieved by the motor. The floating side is pushed away by the brake disc. The so-called air gap should be the same on both sides to minimize the free travel for the next application.

[0038] With a drum brake, the pads should be kept centered to minimize free play.

[0039] The approach presented here ensures that the brake pad (on the rim side of the brake) releases correctly from the brake disc when the brake is not applied. Similarly, with a floating drum brake, both brake pads can be safely lifted from the drum. The floating pad (on the finger side) can also be cleanly removed from the disc or brake drum.

[0040] Here, a motor, a rotation-translation conversion and a suitable spring ensure that the floating side moves away from the brake disc when not actuated, so that both pads are almost the same distance away from the brake disc / brake drum.

[0041] The approach presented here can be used for both hydraulic brakes and electromechanical brakes.

[0042] The motor can move the brake yoke, but thanks to the spring positioned between them, it is not subjected to excessive forces during braking. The spring is tensioned at higher forces and will push or pull the brake yoke away at lower forces. This can be retrofitted to any brake. The components used can be cost-effective because only low forces and low dynamics are required.

[0043] The brake bracket is firmly connected to the steering knuckle (not shown here). The brake bracket supports the brake pads. The brake bracket and the floating guide together ensure that the brake disc can move transversely to the brake disc. It doesn't matter where the floating guide inserts—whether into the brake bracket or the brake disc.

[0044] Additionally, a motor is attached to the brake holder, driving a rotation / translation converter (such as a spindle). This spindle can compress a spring connected to the opposite side of the fist (referred to here as the adjustment module). The spindle of the adjustment module is ideally self-locking. This adjustment module could also be constructed in reverse, with the motor attached to the fist and the spring attached to the brake holder.

[0045] Boundary conditions apply to the spring. Its active length is longer than the maximum displacement of the fist toward the brake holder during braking, but it may also be longer. sSpring > sMaxSlide.

[0046] Ideally, the spring force is designed with a defined preload force (FSpring) and a minimal displacement-dependent change (cSpring). Of course, this is also possible with a spring that has a higher displacement-dependent change.

[0047] The spring force is at least large enough to move the floating caliper in the guide. Optionally, the spring can also do this when lateral forces act on the caliper (cornering). FSpring > Fslide.

[0048] The spring force is selected so that it can be easily compressed during braking, thus imposing a negligible force on the brake caliper. FSpring << Fzuspann.

[0049] When the brake caliper is not actuated, the piston (whether hydraulic or electromechanical) can retract the piston-side brake pad from the disc (or clear the path). At the same time, the motor of the adjustment module can set a target position for the finger-side pad. In the case of an electromechanical brake, the piston-side pad can travel approximately twice the distance of the finger-side pad, ensuring the same clearance on both sides.

[0050] Pad wear changes the position set by the adjustment module's motor. This motor can be controlled via a separate control unit or, in the case of an EMB, via the existing control unit.

[0051] The coupling of the spring or the motor can be done in such a way that in the event of a fault (forces too high) the adjustment module breaks off and is thus deactivated.

[0052] The adjustment module can be mounted modularly to a saddle. The motor of the adjustment module can be implemented as a stepper motor.

[0053] Finally, it should be noted that terms such as "comprising," "having," etc., do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a plurality. Reference signs in the claims are not to be considered limiting. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 41 19 928 A1

[0005] EP 3 296 585 B1

[0006]

Claims

[1] Brake (100) for a vehicle, wherein the brake (100) has a holder (102) that can be mounted fixedly to the vehicle and a floating caliper (106) with a brake actuator (110), wherein a first brake pad (116) of the brake (100) is coupled to the brake actuator (110) and a second brake pad (118) of the brake (100) is coupled to the floating caliper (106), wherein the brake actuator (110) is configured to move the first brake pad (116) in an actuation direction when the brake (100) is actuated until the first brake pad (116) bears against a rotor of the brake (100), then to move the floating caliper (106) with the second brake pad (118) opposite to the actuation direction relative to the holder (102) until the second brake pad (118) also bears against the rotor and then press the brake pads (116, 118) against the rotor to generate friction, wherein the brake (100) has a return device (120) supported on the holder (102) and the floating caliper (106),wherein the return device (120) comprises an elastic component (122) and an adjustment component (124), wherein the elastic component (122) is configured to be tensioned upon actuation of the brake (100) and to be relaxed after actuation of the brake (100) and to lift the second brake pad (118) from the rotor, wherein the adjustment component (124) comprises a rotationally translational gear with an electric motor (126) for adjusting the return device (120), wherein the elastic component (122) is supported on a translational part of the gear. [2] Brake (100) according to claim 1, wherein the elastic component (122) is supported on the floating caliper (106) and the gear is supported on the holder (102). [3] Brake (100) according to claim 1, wherein the elastic component (122) is supported on the holder (102) and the gear is supported on the floating caliper (106). [4] Brake (100) according to one of the preceding claims, wherein the gear is a screw drive with a threaded spindle (128) and a nut (130) engaging in the threaded spindle (128). [5] Brake (100) according to claim 4, wherein the nut (130) is the translational part. [6] Brake (100) according to claim 4, wherein the threaded spindle (128) is the translational part. [7] Brake (100) according to one of claims 4 to 6, wherein the electric motor (126) drives the threaded spindle (128). [8] Brake (100) according to one of claims 4 to 6, wherein the electric motor (126) drives the nut (130). [9] Brake (100) according to one of claims 4 to 8, wherein the threaded spindle (128) is self-locking. [10] Brake (100) according to one of the preceding claims, wherein the return device (120) has a maximum force limiting component. [11] Brake (100) according to one of the preceding claims, wherein the electric motor is designed as a stepper motor.

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