Electromechanical brake with parking braking function

Abstract

The invention relates to an electromechanical brake (10) for a motor vehicle. The electromechanical brake (10) comprises an electric motor (14) arranged on a caliper housing (18). The electric motor (14) drives the at least one spindle drive unit (30) to rotate via the transmission unit (22) such that the spindle drive unit (30) axially adjusts the brake regulator (62) for braking. According to the invention, a blocking wheel (34) is arranged on a rotationally driven element (50) of the spindle drive unit (30), which blocking wheel interacts with a blocking element (38) when the blocking element (38) is actuated such that the axial adjustment of the brake actuator (62) is blocked.

Description

Technical Field

[0001] This invention relates to an electromechanical brake for a motor vehicle. Furthermore, this invention relates to a motor vehicle having such an electromechanical brake. Background Technology

[0002] Typically, service brakes are brakes that use brake fluid to press the brake piston and brake pads against the brake disc to stop the vehicle. Parking brakes, on the other hand, are constructed as electromechanical brakes. With the increasing electrification of assemblies in motor vehicles, service brakes should also be constructed as electromechanical brakes, thereby eliminating the need for brake fluid and the associated complex valve and piping structures. Such electromechanical brakes can also significantly reduce maintenance costs.

[0003] Document EP 0 944 781 B1 discloses an electromechanically operable brake that presses brake pads against a brake disc for braking. This brake includes a lead screw drive unit having a lead screw and a lead screw nut, wherein the lead screw is connected to the brake pads. The lead screw nut is securely connected to a sleeve surrounding the lead screw nut from the outside. The sleeve is rotatably arranged in a brake caliper via bearings. A permanent magnet is arranged in the sleeve, thus forming the rotor of an electric motor. The sleeve is surrounded by a stator, through which the rotor can be driven. By corresponding rotation of the lead screw nut, the brake pads can move axially to apply braking force. Summary of the Invention

[0004] The purpose of this invention is to provide an electromechanical brake for motor vehicles in which a parking brake can be integrated in a space-saving and weight-saving manner.

[0005] This objective is achieved by an electromechanical brake having the subject matter of claim 1. Preferred embodiments are derived from the dependent claims.

[0006] This invention provides an electromechanical brake for a motor vehicle. The electromechanical brake includes an electric motor disposed on a brake caliper housing. The electric motor drives at least one lead screw drive unit to rotate via a transmission unit, causing the lead screw drive unit to axially adjust a brake adjuster for braking. A stop wheel is arranged on the driven rotating element of the lead screw drive unit; when the stop element is actuated, the stop wheel interacts with the stop element, thereby blocking the axial adjustment of the brake adjuster.

[0007] A lead screw drive unit is understood as a structural unit comprising at least one lead screw nut and a lead screw, through which rotational motion can be converted into translational motion. A brake adjuster is understood as part of an electromechanical brake that transmits braking force from the lead screw drive unit to the brake pads. The driven rotating element of the lead screw drive unit is an element that performs only rotational motion. This rotational motion can generate translational motion of the lead screw drive unit. Advantageously, the driven rotating element is the lead screw of the lead screw drive unit.

[0008] The stop wheel has a wheel-shaped construction, wherein its axis of rotation is coaxial with the axis of rotation of the driven rotating element. The stop wheel is configured to act in conjunction with the stop element in a blocking manner. Accordingly, a parking brake is formed by the stop wheel and the stop element, which can hold the brake adjuster in the braking position. Therefore, this parking brake can be formed using only the stop wheel and the stop element. The stop wheel and the stop element can be arranged in the brake caliper housing in a space-saving and weight-saving manner. Therefore, a parking brake can be easily formed using the stop wheel and the stop element.

[0009] In a preferred embodiment of the invention, the blocking wheel is formed by the worm gear of the transmission unit. Therefore, the worm gear has both a driving function and a locking function. Thus, a separate blocking wheel can be eliminated. Consequently, the number of parts and weight of the electromechanical brake can be kept low.

[0010] In another preferred embodiment of the invention, the blocking wheel is formed by gears arranged on the worm gear. Therefore, the worm gear and the blocking wheel are a single piece. Thus, the blocking wheel does not require a separate component. This allows for a lower number of components in the electromechanical brake. By constructing the worm gear and the blocking wheel separately, they can be better adapted to their respective requirements. Accordingly, for example, the teeth of the blocking wheel can be configured such that they optimally block the axial movement of the brake adjuster.

[0011] Preferably, the stop wheel is arranged as a separate component on the driven rotating element relative to the worm gear of the transmission unit. This stop wheel is thus set up independently of the worm gear. By providing a separate stop wheel, it can be arranged independently of the worm gear on the driven rotating element. The stop wheel and the stop element can be arranged according to the available space within the brake caliper housing. The stop wheel can also be made of a different material than the worm gear. Therefore, the stop wheel can be better adapted to requirements.

[0012] In an advantageous improvement, the blocking element is a pin-shaped structure that engages with the gap in the blocking wheel. The advantage of constructing the blocking element as a pin is that it can be constructed in a space-saving manner. Furthermore, this pin-shaped blocking element can be operated by a magnetic actuator. Thus, a space-saving blocking element can be provided in a convenient and economical manner.

[0013] A particular advantage is that this magnetic actuator is constructed as a bistable magnetic actuator. Therefore, the pin-shaped blocking element can be stably held in both the parking and driving positions. Thus, even when the vehicle is parked, the blocking element can hold the vehicle in the parking position without any additional power supply. Similarly, in the event of a magnetic actuator failure, the bistable magnetic actuator prevents the parking brake from being accidentally engaged during driving.

[0014] Preferably, the blocking element is configured as a rotatable pawl that works in conjunction with the blocking wheel. This rotatable pawl can also be arranged in the brake caliper housing in a space-saving manner. Compared to a pin-shaped implementation, the axial length of this blocking element can be reduced.

[0015] In another advantageous embodiment, the blocking element is controlled by the controller of the electromechanical brake. Therefore, the controller controls both the electric motor and the blocking element. This allows for better coordination between the control of the electric motor for the braking process and the control of the blocking element for engaging the parking brake. Furthermore, a separate controller is not required for the control of the blocking element.

[0016] According to a suitable embodiment, a torsional vibration damper is provided between the driven rotating part of the lead screw drive unit and the stop wheel, or between the worm gear and the stop wheel. This torsional vibration damper can be constructed according to various embodiments known from the prior art. The torsional vibration damper can reduce torsional vibration between the worm and the stop wheel, or between the driven rotating element and the stop wheel.

[0017] The present invention also provides a motor vehicle having such an electromechanical brake. This motor vehicle has the advantages and features described above. Attached Figure Description

[0018] Embodiments of the present invention are shown in the accompanying drawings and explained in more detail in the following description. The drawings show:

[0019] Figure 1 An external perspective view of an electromechanical brake according to an embodiment of the present invention is shown.

[0020] Figure 2 Cross-sectional views of a lead screw drive unit with a blocking wheel and a blocking element according to two embodiments of the present invention are shown.

[0021] Figure 3 A cross-sectional view of a lead screw drive unit with a second embodiment having a blocking wheel is shown.

[0022] Figure 4 A cross-sectional view of a lead screw drive unit with a stop wheel according to a third embodiment is shown.

[0023] Figure 5 It shows Figure 4 The diagram of the torsional vibration damper in the image, and

[0024] Figure 6 A cross-sectional view of a lead screw drive unit with a fourth embodiment having a stop wheel is shown. Detailed Implementation

[0025] Figure 1 An external perspective view of an electromechanical brake 10 according to an embodiment of the present invention is shown. The electromechanical brake 10 includes an electric motor 14 disposed on a brake caliper housing 18. The electric motor 14 drives a transmission unit 22 disposed in the brake caliper housing 18. Furthermore, a controller 26 is disposed on the brake caliper housing 18, through which the electric motor 14 can be controlled.

[0026] Figure 2 Cross-sectional views of a screw drive unit 30 according to two embodiments of the present invention, having a blocking wheel 34 and a blocking element 38, are shown. In this embodiment, the transmission unit 22 is configured as a worm gear transmission device. The worm 42, driven by the electric motor 14, drives the worm wheel 46, which is fixed to the screw 50 of the screw drive unit 30 in a non-rotatable manner. In the embodiment shown here, the screw drive unit 30 is configured as a ball screw driver. Therefore, balls 58 are arranged between the screw 50 and the screw nut 54, which can reduce friction within the screw drive unit 30.

[0027] The brake adjuster 62 can be axially adjusted to apply braking force via a lead screw nut 54 arranged in an axially movable manner within the brake caliper housing 18. The brake adjuster 62 is located at the axial end of the lead screw nut 54. To withstand the braking force, a bearing assembly 66 is also provided in the brake caliper housing 18, through which the braking force is transferred from the lead screw 50 into the brake caliper housing 18. A stop wheel 34 configured as a gear is also arranged on the lead screw 50. In one embodiment, the stop wheel 34 interacts with a pin-shaped stop element 38, thereby preventing axial adjustment of the brake adjuster 62. Correspondingly, the pin-shaped stop element 38 can move axially along the pin axis 70.

[0028] exist Figure 2A second embodiment of the blocking element 38 is also shown in the figure. This second embodiment is shown to the left of the center line 74 in the figure. In this embodiment, the blocking element 38 is configured as a rotatable pawl that engages with the teeth 78 of the blocking wheel 38 by rotation. Accordingly, the blocking element 38 can also block the axial adjustment of the brake adjuster 62.

[0029] Figure 3 A cross-sectional view of a lead screw drive unit 30 with a stop wheel 34 according to a second embodiment is shown. Figure 2 In contrast, the blocking wheel 34 is not arranged on the side of the worm gear 46 facing the brake adjuster 62, but rather on the side of the worm gear 46 opposite to the brake adjuster 62. Furthermore, the blocking wheel 34 is constructed as a component of the worm gear 46. Therefore, the worm gear 46 and the blocking wheel 34 form a single component. This reduces the number of parts and the additional manufacturing workload.

[0030] Figure 4 A cross-sectional view of a lead screw drive unit 30 with a stop wheel 34 according to a third embodiment is shown. This embodiment is compared here with... Figure 3 The embodiments are similar. However, in this embodiment, the blocking wheel 34 is configured as a separate part from the worm gear 46. Furthermore, a torsional vibration damper 82 is arranged between the worm gear 46 and the blocking wheel 34, which reduces torsional vibration between them. Accordingly, the worm gear 46 and the blocking wheel 34 can rotate relative to each other within a limited range.

[0031] Figure 5 It shows Figure 4 One embodiment of the torsional vibration damper 82 used in this device. In this torsional vibration damper 82, an arc spring 94 is arranged between the worm gear protrusion 86 and the blocking wheel protrusion 90, and the torsional vibration between the worm gear 46 and the blocking wheel 34 is damped by the arc spring.

[0032] Figure 6 A cross-sectional view of a lead screw drive unit 30 with a fourth embodiment having a stopper wheel 34 is shown. This embodiment differs from previous embodiments in that a separate stopper wheel 34 is not provided. Instead, the stopper wheel 34 is formed by a worm gear 46. Therefore, the worm gear 46 fulfills two different functions. By using the worm gear 46 in this manner, weight and space previously used for a separate stopper wheel 34 can be saved.

Claims

1. Electromechanical brake (10) for a motor vehicle, comprising an electric motor (14) arranged on a brake caliper housing (18), wherein The electric motor (14) drives at least one lead screw drive unit (30) to rotate via the transmission unit (22), causing the lead screw drive unit (30) to axially adjust the brake adjuster (62) for braking. Its features are, A stop wheel (34) is arranged on the driven rotating element (50) of the lead screw drive unit (30). When the stop element (38) is operated, the stop wheel interacts with the stop element, thereby blocking the axial adjustment of the brake adjuster (62).

2. The electromechanical brake (10) according to claim 1, characterized in that The blocking wheel (34) is formed by the worm gear (46) of the transmission unit (22).

3. The electromechanical brake (10) according to claim 1, characterized in that The blocking wheel (34) is formed by a gear arranged on the worm gear (46).

4. The electromechanical brake (10) according to claim 1, characterized in that The blocking wheel (34) is arranged as a separate part on the driven rotating element (50) relative to the worm gear (46) of the transmission unit (22).

5. Electromechanical brake (10) according to any one of the preceding claims, characterized in that The blocking element (38) has a pin-shaped structure and engages in the gap of the blocking wheel (34).

6. The electromechanical brake (10) according to any one of claims 1 to 4, characterized in that, The blocking element (38) is configured as a rotatable pawl that works in conjunction with the blocking wheel (34).

7. The electromechanical brake (10) according to any one of the preceding claims, characterized in that, The blocking element (38) is controlled by the controller (26) of the electromechanical brake (10).

8. The electromechanical brake (10) according to any one of the preceding claims, characterized in that, A torsional vibration damper (82) is arranged between the driven rotating element (50) of the lead screw drive unit (30) and the blocking wheel (34), or between the worm gear (46) and the blocking wheel (34).

9. A motor vehicle, said motor vehicle comprising an electromechanical brake (10) according to any one of the preceding claims.

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