Electrically actuated operating units, brake boosters, and motor vehicle braking systems

Abstract

An electrically actuated operating unit (106) for a motor vehicle brake includes: a housing body (122) arranged to be displaceable in a braking direction; a recess (150) formed in the housing body (122), wherein the recess (150) is defined at a longitudinal end by a contact shoulder (172); a through opening (158) defined by the contact shoulder (172); and an operating member (124) arranged in the recess (150) and displaceable for operating the motor vehicle brake, the operating member protruding through the through opening (158) of the contact shoulder (172), wherein the operating member (124) is force-transmittingly arranged between the brake pedal and the motor vehicle brake (400). The operating unit (106) further includes: a return spring (126) and a sleeve element (180).

Description

Technical Field

[0001] This disclosure generally relates to electrically actuated operating units for motor vehicle brakes. Specifically, aspects associated with vibrations that undesirably occur during the operation of such operating units are described. Background Technology

[0002] For example, known electrically actuated operating units for motor vehicle braking systems are provided to assist the driver's operating force established via the brake pedal, thereby reducing driver effort. This typically occurs through an electrically actuated actuator that, when actuated, causes adjusting movement of one or more components, using this adjusting movement to increase or generate braking pressure in the master cylinder. Known electrically actuated operating units can also, for example, accumulate necessary braking pressure themselves by actuating the actuator independently of brake pedal operation in automatic driving mode.

[0003] In motor vehicle braking systems with such electrically actuated control units, the brake pedal is typically mechanically connected, or at least capable of being mechanically connected, to a component that moves via an actuator. Consequently, during braking operations, such as in autonomous driving mode, the brake pedal may move toward the vehicle floor. If an obstacle (e.g., an object or the driver's foot) exists in the brake pedal's movement path, that is, between the brake pedal and the vehicle floor, the component connecting the brake pedal to the electrically actuated actuator experiences increased tension. This can damage the component connecting the brake pedal to the moving part and can also cause injury to a trapped foot.

[0004] To prevent this, a dynamic driver foot protection system (dDFP) and / or component protection system (CPF) are typically provided. This component / foot protection system is designed to detect the presence of a foot under the brake pedal during autonomous and / or semi-autonomous braking and switch the pressure buildup to the ESC (Electronic Stability Control) unit to protect the foot and components.

[0005] During the operation of such a system, vibrations frequently occur, making the detection of stuck obstacles more difficult. Therefore, the degree of deformation of the elastic elements arranged in the operating unit can be a measure of whether a stuck obstacle exists. However, the vibrations also cause deformation of the elastic elements. As a result, reliably detecting obstacles under the brake pedal becomes even more difficult. Summary of the Invention

[0006] The purpose of this disclosure is to provide an electrically actuated operating unit for a motor vehicle brake that allows for safe operation. In some embodiments, obstacles beneath the brake pedal can be reliably detected.

[0007] According to a first aspect, an electrically actuated operating unit for a motor vehicle brake is provided, the electrically actuated operating unit having a housing body arranged to be displaceable in a braking direction for operating the motor vehicle brake; a recess formed in the housing body, wherein the recess is defined at a longitudinal end by a contact shoulder; a through opening defined by the contact shoulder; an operating member arranged in the recess and displaceable for operating the motor vehicle brake, the operating member protruding through the through opening of the contact shoulder, wherein the operating member is force-transmittingly arranged between a brake pedal and a motor vehicle brake; a return spring arranged in the recess and configured to move the operating member relative to the housing body away from the contact shoulder; and a sleeve element at least partially circumferentially surrounding a portion of the operating member and held by the return spring to contact the contact shoulder. The sleeve element protrudes into the through opening in such a way that the sleeve element is arranged between the operating member and the inner peripheral surface of the contact shoulder defining the through opening.

[0008] The electrically actuated operating unit can function directly or indirectly, for example, via a transmission device. The transmission device can be functionally located between the electrically actuated motor of the operating unit and the movable housing body.

[0009] The contact shoulder defining the recess can be formed from the housing body. Specifically, the contact shoulder can be formed as a single piece with the housing body. However, the contact shoulder can also be formed from a separate component fixedly connected to the housing body. The through opening defined by the contact shoulder can have any conceivable cross-sectional shape (profile shape). Specifically, the cross-sectional shape can be adapted to the cross-sectional shape of the operating member. In the case of a cylindrical operating member with a circular cross-section, the cross-sectional shape of the through opening can also be, for example, circular.

[0010] In some embodiments, the operating member is only partially received in a recess of the housing body and protrudes through a through opening in the contact shoulder. Specifically, the operating member may be received in the housing body in such a way that it is displaceable relative to the housing body in the braking direction and in the opposite direction. The operating member can be displaced in the braking direction, particularly by operation of the brake pedal, and returned to a resting position by the restoring force of a return spring and / or the brake master cylinder. During displacement in the braking direction, the operating member can act directly or indirectly on the pressure piston of the brake master cylinder of the motor vehicle braking system to provide braking pressure. The transmission of force can occur mechanically and / or hydraulically. The brake pedal can be coupled to the operating member via one or more force input members. Specifically, the operating member can be fixedly coupled to the brake pedal in the vehicle, such that the operating member is always coupled to the brake pedal. The operating member may be in the form of an operating lever with a generally circular cross-section.

[0011] The operating component can be further connected to the housing body, such that displacement of the housing body can also cause displacement of the operating component. The operating component can be connected to the housing body, particularly via other components of the operating unit.

[0012] The housing body can be part of the housing of the operating unit or actuator. When the operating unit is electrically actuated, the housing body is displaced in the braking direction relative to the vehicle brake. The housing body can also be directly or indirectly connected to the pressure piston of the brake master cylinder, such that displacement of the housing body causes displacement of the pressure piston and thus causes accumulation of brake pressure. The housing body can be further connected to the operating member, such that displacement of the housing body also causes displacement of the operating member.

[0013] A sleeve element is arranged around a portion of the circumferential surface of the operating member. Thus, the sleeve element can completely surround the operating member, i.e., continuously, or only partially, i.e., having one or more portions surrounding the operating member in the circumferential direction. The sleeve element may have a through opening through which the operating member is guided. In some variations, the sleeve element, the contact shoulder, and the return spring arranged in the recess are such that the sleeve element is held by the return spring to contact the contact shoulder. Specifically, the sleeve element may be held to contact the inner contact surface of the contact shoulder facing the recess. The sleeve element may be at least partially arranged within the recess. The sleeve element or a portion thereof may be arranged between the contact shoulder and the return spring. The sleeve element further protrudes into the through opening, such that the sleeve element is arranged in the region between the inner circumferential surface of the contact shoulder and the operating member. The sleeve element can thus support or stabilize the return spring and / or the operating member relative to the housing body, thereby limiting or preventing movement of those components relative to each other. The sleeve element may be a single piece or multiple pieces.

[0014] The operating member can be arranged to be displaceable relative to the sleeve element. Specifically, when the operating member moves relative to the housing body in the braking direction or in the opposite direction, the sleeve element can remain fixedly anchored in the housing body.

[0015] In one embodiment, the sleeve element may be guided by its inner circumferential surface abutting against or on the outer circumferential surface of the operating member. Very generally, regardless of the form of the sleeve element and the operating member, the sleeve element may be guided by its surface surrounding the operating member abutting against or on the outer surface of the operating member. The sleeve element is therefore preferably loosely abutting against the operating member to allow the operating member to be movable, particularly displaceable, relative to the sleeve element. The sleeve element may abut against the operating member by frictional engagement, such that friction is generated between the two parts when they move relative to each other. In an alternative embodiment, the sleeve element surrounds the operating member at a (small) distance such that the two parts do not contact each other when they move relative to each other.

[0016] In another embodiment, the sleeve element may be guided by resting its outer peripheral surface against or on the inner peripheral surface of the defining through opening of the contact shoulder. The sleeve element can be prevented from being fixedly anchored relative to the housing body. The sleeve element may support the housing body relative to the operating member.

[0017] Similarly, in a variation of another embodiment, the sleeve element can be guided thereon by abutting its outer peripheral surface against the inner sidewall of a defining recess in the housing body. In this variation, the sleeve element can be positioned in a manner that is fixedly anchored relative to the housing body. The sleeve element can support the housing body relative to the operating member.

[0018] In an alternative embodiment of another embodiment, the sleeve element may be arranged at a certain distance, especially a small distance, from the housing body.

[0019] In one embodiment, the sleeve element may have a first portion disposed within the recess and a second portion protruding into the through opening. The first and second portions may be single pieces, or alternatively, they may be multiple pieces. The first portion may be held by a return spring to contact a contact shoulder. Specifically, the first portion of the sleeve element may be held to contact the inner contact surface of the contact shoulder facing the recess. The second portion may directly abut the first portion.

[0020] In variations of the embodiment, the first portion may have a larger external dimension than the second portion. If the sleeve element is cylindrical, the first portion may have a larger outer diameter than the second portion. A step may be formed at the transition from the first portion to the second portion, through which the sleeve element rests against the inner surface of the contact shoulder facing the recess.

[0021] According to another embodiment, a sleeve element may be arranged within the housing body, with one end of the sleeve element located outside the recess. In this further embodiment, the sleeve element, or a second portion of the sleeve element, may protrude through the through opening. The second portion may protrude through the entire through opening and enter a cavity in the housing body adjacent to the recess.

[0022] In one embodiment, the connection between the housing body and the operating member can be achieved via a stop element connected to the operating member. The housing body can be configured such that, in the event of movement, such as during autonomous or semi-autonomous braking, the housing body cooperates with the stop element upon reaching a specific position, causing the operating member to move accordingly. The stop element can be connected to the operating member at one end, and the other opposite end extends from the housing body and is connected to a mechanical component of a displacement sensor. As a result, the operating member can be identified, and thus the distance traveled by the brake pedal can be determined.

[0023] In another variant, a resilient intermediate element may be provided. This intermediate element can be provided to limit the tension acting on the operating member during operation of the motor vehicle brake via electrical actuation of the operating unit.

[0024] A resilient intermediate element can be incorporated to reduce the tension or resistance acting on the operating member during vehicle braking, particularly during autonomous operation. The reduced tension or resistance can be a force opposite to the braking direction, especially a holding force. In one embodiment, the resilient intermediate element provides a gradual increase in tension or resistance, the rate of increase being defined by the elastic properties of the intermediate element. The tension or resistance acting on the operating member can be reduced along a defined operating path until the elastic deformation capacity of the intermediate element is exhausted. The resilient intermediate element can be formed of an elastic material, such as, for example, an elastomer or rubber. The resilient element can be formed of a leaf spring (e.g., in the form of a leaf spring) or a coil spring. The resilient intermediate element can also be used as a spring element.

[0025] In variations with an elastic intermediate element, the end of the sleeve element arranged outside the recess can form a stop for the elastic intermediate element. The stop may bear weight when the elastic intermediate element elastically deforms due to a force opposite to the braking direction. The stop can be positioned such that it cooperates with the elastic intermediate element when the elastic deformation capacity of the intermediate element is exhausted (thus posing a risk of damage, for example). When the elastic intermediate element is a leaf spring fastened to the housing body or operating member, the stop can be positioned such that it cooperates with the central region of the leaf spring.

[0026] The resilient intermediate element may, for example, be part of an arrangement that connects the operating member to one or more components of the housing body. Thus, the operating member can be coupled to the housing body via the resilient intermediate element. The operating member can be configured such that, during movement of the housing body in autonomous or semi-autonomous braking, once it reaches a specific position on the housing body, the operating member moves in cooperation with the resilient intermediate element. Therefore, the resilient intermediate element can contact the stop element from the specific position and thus move accordingly.

[0027] According to another aspect, an electromechanical brake booster having an electrically actuated operating unit as described above is provided.

[0028] According to another aspect, a motor vehicle braking system having the aforementioned brake booster is provided. Attached Figure Description

[0029] Further aspects, details, and advantages of this disclosure will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings, in which:

[0030] Figure 1 A braking system for a motor vehicle with a brake booster, the brake booster having an electrically actuated operating unit, is schematically shown; and

[0031] Figure 2 A cross-sectional side view schematically illustrates an embodiment of an electrically actuated operating unit according to the present disclosure, the electrically actuated operating unit having a sleeve element according to one embodiment. Detailed Implementation

[0032] Figure 1 A motor vehicle braking system 1000 with an electrically actuated operating unit is shown. The electrically actuated operating unit is shown here as part of a brake booster. Hereinafter, a description will first be given of... Figure 1 The structure and function of the motor vehicle braking system 1000 (which can therefore also be used in exemplary embodiments).

[0033] according to Figure 1 The motor vehicle braking system 1000 includes a brake booster 100, a brake cylinder 200, two brake circuits 300, and four wheel brakes 400 connected to the brake circuits 300. In an exemplary embodiment, the brake cylinder 200 is the master cylinder of the motor vehicle braking system 1000.

[0034] The brake booster 100 includes an electrically actuated electric motor 102, a transmission 104, and an operating unit 106. The brake booster 100 further has a housing 130, in which at least the operating unit 106 is received. The electric motor 102 operates an output gear 108 in the form of a sprocket, which is connected to two output spur gears 112 and 114 via an intermediate gear 110 and optionally other spur gears or transmission components (not shown). The spur gears 112 and 114 are connected to the operating unit 106 of the brake booster 100. The operating unit 106 includes an operating element 120 and a housing body 122 as a force transmission element. The spur gears 112 and 114 engage with the rack portions 116 and 118 of the operating element 120 of the operating unit 106.

[0035] The housing body 122 has a recess (in) Figure 2 (Identified by reference numeral 150 in the accompanying drawings), the operating member 124 of the operating unit 106 is received in the recess and is movable along the longitudinal axis L. The operating member 124 is supported on the contact shoulder of the housing body 122 by a helical spring 126.

[0036] The operating member 124 is hinged to the force input member 128. When the brake booster 100 is mounted on a vehicle (not shown), the force input member 128 protrudes into the passenger compartment. In the vehicle's passenger compartment, the force input member 128 is connected to the brake pedal. The force input member 128 transmits the operating force applied by the driver to the brake pedal to the operating unit 106 of the brake booster 100. Specifically, the force input member 128 transmits the driver's operating force to the operating member 124 of the operating unit 106, which, under the compression of the spring 126, moves towards... Figure 1 The leftward shift in the cylinder allows the driver's applied force to be transmitted to the master cylinder 200.

[0037] The operating unit 106 further includes a rubber-reacting disc 134 on which the force-applying element 136 rests loosely. The reaction disc 134 is received within the housing body 122 and rests against an annular surface 138 of the housing body 122, which extends perpendicular to the longitudinal axis L and forms a contact surface facing the brake master cylinder 200. Through this contact surface 138, the housing body 122 can apply braking force to the reaction disc 134, which transmits this force to the force-applying element 136. The operating member 124 has an end element 140, which, like the contact surface 138, is configured to act on the reaction disc 134 and transmit the operating force applied by the driver to the brake pedal.

[0038] The force-applying element 136 is in the form of a plunger and has a pin-shaped portion. This pin-shaped portion is partially received in the first pressure piston 202 of the brake master cylinder 200 in a force-transmitting manner. In addition to the first pressure piston 202, the brake master cylinder 200 also has another pressure piston 204. These two pressure pistons 202 and 204 define pressure chambers 208 and 210 filled with hydraulic fluid in the housing 206 of the brake master cylinder 200. The pressure chambers 208 and 210 in the brake master cylinder 200 are respectively connected to brake circuits 302 and 304. Through brake circuits 302 and 304, the two wheel brakes 400 can each withstand hydraulic braking pressure to perform braking operations. The brake master cylinder 200 is supplied with brake fluid via an unpressurized container 212.

[0039] The operation of the brake booster 100 and thus the assembly including the brake booster 100 and the brake cylinder 200 can be performed by the driver of the vehicle. The driver operates the brake pedal (not shown), and the operating force applied to the brake pedal by the driver is applied to the operating unit 106 via the force input member 128. As a result of operating the brake pedal, under the compression of the spring 126, the force input member 128 and the operating member 124 rigidly connected to the force input member 128 move to the left, whereby the end element 140 of the operating member 124 penetrates the rubber elastic reaction disc 134.

[0040] Based on the operating force applied by the driver to the brake pedal and / or the pedal travel of the brake pedal, the assistance generated by the electric motor 102 and the transmission 104 can be determined, for example, by a displacement sensor connected to the brake pedal or force input member 128 or by measuring the braking pressure generated by the driver in the master cylinder 200 (which is detected by the sensor and optionally reasonable).

[0041] Alternatively, a deceleration request can be initiated by a system designed for autonomous or semi-autonomous driving, and thus a force can be applied to the master brake cylinder 200 via the operating unit 106. In this case, there is no "brake assist" in the conventional sense, as the driver is not applying any operating force.

[0042] Assist (when the brake pedal is normally operated) or total operating force (in automatic or semi-automatic driving mode) is generated or converted by the electric motor 102 and the transmission 104, and transmitted to the operating element 120 of the operating unit 106. The rack portions 116 and 118 of the operating element 120 are driven via spur gears 112 and 114 of the transmission 104. The operating element 120 rests its end face against the contact shoulder 142 of the housing body 122. As a result, when the brake booster 100 is in operation, the operating element 120 can cause the housing body 122 to move along... Figure 1The longitudinal axis L in the brake booster 100 moves to the left. When the driver operates the brake booster 100, the housing body 122 acts on the rubber elastic reaction disc 134 via the contact surface 138 and the end face of the end element 140 of the operating member 124. The resultant force of the operating force generated by the driver (if present) and the assistance generated by the electric motor 102 and the transmission device 106 (or the operating force in the case of autonomous or semi-autonomous braking) is transmitted to the pressure piston 202 by the reaction disc 134 and the force application element 136 located thereon. The spring 144 arranged between the housing 130 and the housing body 122 of the brake booster 100 is thus compressed, causing the pressure piston 202 of the master cylinder 200 to move to the left along the longitudinal axis L, thereby causing the second pressure piston 204 to also move to the left. In this way, hydraulic braking pressure is generated in the pressure chambers 208 and 210. The braking pressure generated in pressure chambers 208 and 210 is transmitted to wheel brake 400 via brake circuits 302 and 304 for braking operation.

[0043] After braking operation Figure 1 The operating unit 106 is propelled along the path by the restoring force of the spring 144 and the hydraulic pressure in the pressure chambers 208 and 210. Figure 1 The longitudinal axis L in the middle moves back to the right again.

[0044] Figure 2 The operating unit 106 according to this disclosure is shown in an enlarged view. Therefore, Figure 2 operation unit 106 and Figure 1 The components of the operation unit 106 have the same reference numerals corresponding to the components in the accompanying drawings. For example... Figure 1 As shown in the diagram of the operation unit 106, Figure 2 The operation unit 106 can have the same arrangement and function.

[0045] exist Figure 2 In the figure, a recess in the housing body 122 that partially receives the operating member 124 is identified by reference numeral 150. The recess 150 is here in the form of a cylindrical recess, but may also have any other conceivable shape, such as a parallelepiped. The recess 150 is defined circumferentially (or along the long side) by inner walls 156 (or multiple inner walls in the case of a parallelepiped). At one longitudinal end, Figure 2 At the left longitudinal end, the recess 150 is defined by the contact shoulder 172, through which the spring 126 passes. Figure 2The left end of the spring 126 is supported on the contact shoulder 172. Here, the spring 126 is indirectly supported on the contact shoulder 172, as will be explained in more detail below. A through opening 158 is provided in the housing body 122, which is defined circumferentially by the contact shoulder 172. The operating member 124 is arranged to protrude through the through opening 158 in a displaceable manner.

[0046] In addition, Figure 2 In the longitudinal section, it can be seen that the housing body 122 is in the form of a hollow body. A hollow region 152 forms another recess. The hollow region 152 is separated from the recess 150 by a contact shoulder 172. A through opening 158 thus connects the hollow region 152 to the recess 150. A stop element 154 is received in the hollow region 152, which extends transversely to the operating direction of the operating member 124 and is rigidly connected to the operating member 124 at a first end. At the opposite second end, the stop element 154 protrudes outward through a window formed in the housing body 122 to mechanically connect to a corresponding element of a displacement sensor arranged in the housing body. As a result, the movement of the operating member 124 can be quantitatively determined by the displacement sensor.

[0047] The first end of the stop element 154 can be coupled to the operating member 124 in any possible manner. The stop element 154 can, for example, engage in a correspondingly shaped opening in the operating member 124, the stop element 154 can be guided through a through opening in the actuating member 124, or the stop element 154 can, for example, be formed at the first end such that the stop element circumferentially surrounds the operating member 124. Here, the stop element 154 has a forked attachment portion that allows the stop element 154 to be attached to the operating member transversely to the longitudinal axis of the operating member 124, wherein opposing forks engage in circumferentially recessed recesses in the operating member 124. In the example shown here, the stop element 154 has a “double L” shape in the sectional view, but it can also have any other suitable shape.

[0048] In the region of the stop element 154, the leaf spring 160 is radially fastened to the operating member 124 on the outer side. For example... Figure 2 As can be seen, the leaf spring 160 rests centrally against the stop element 154. The surface of the stop shoulder 172 facing the leaf spring and the surface of the leaf spring 160 facing the stop shoulder 172 each form a connecting surface, through which the housing body 122 can be mechanically connected to the operating member 124. For example, in the case of autonomous operation of the brake booster 100, this connection can occur during the movement of the housing body 122 in the braking direction.

[0049] Such as about Figure 1As described, the torque generated by the electric motor 102 is transmitted via the transmission 104 to the operating element 120 of the operating unit 106, and from there to the housing body 122 via the contact shoulder 142. In the case of autonomous or semi-autonomous operation of the brake booster 100 (which thus functions as a (single) operating force generator), due to the connection between the housing body 122 and the operating member 124 (via a stop element 154 connected to the operating member 124 and a leaf spring 160 arranged between the housing body 122 and the stop element 154), the operating member 124 moves in the braking direction independently of the driver's operation of the brake pedal. Since the operating member 124 is connected to the brake pedal via the force input member 128, the brake pedal also moves in the direction toward the vehicle floor.

[0050] If an obstacle (e.g., a foot) exists in the adjustment path of the brake pedal, that is, between the brake pedal and the vehicle floor, a holding force (resistance) opposite to the braking direction acts on the brake pedal and the connecting parts between the brake pedal and the components of the operating unit 106 that are moved by the electric motor 102. Specifically, the holding force acting in the pulling direction (opposite to the braking direction) acts on the operating member 124 and the force input member 128, which can lead to damage to components of the operating unit 106 and the obstacle (e.g., foot injury).

[0051] Leaf spring 160 serves as an elastic damping element and elastically deforms in the opposite direction of braking under this retaining force. The elastic deformation causes a reduction (at least an initial reduction) in the retaining force acting on the component and the force acting on the stuck obstacle when the obstacle is stuck.

[0052] The degree of deformation of the elastic intermediate element (here, leaf spring 160) can be used as a measure of detecting a stuck obstacle. Therefore, the degree of deformation of the elastic intermediate element 160 is directly related to the difference between the movement of the operating member 124 detected (e.g., by a displacement sensor) and the movement of the motor drive and the housing body 122 detected (e.g., by a motor position sensor). However, the elastic intermediate element 160 can also deform due to other forces, for example, attributable to the spring 126. These “additional” deformations of the intermediate element 160 mask the deformation caused by “sticking,” leading to uncertainty and inaccuracy in detecting stuck obstacles. Furthermore, due to the limited deformability of the elastic intermediate element 160, these “additional deformations” in some cases reduce the deformation path available for reducing retention / tension.

[0053] When determining the difference between the movement of the operating member 124 detected (e.g., by a sensor) and the movement of the motor driver and thus the displacement housing body 122 detected (e.g., by a motor position sensor), it is typically also necessary to know the free travel (or hysteresis) between the housing body 122 and the operating member 124. This is the distance the housing body 122 moves before the leaf spring 160 contacts the contact shoulder 172, and thus the operating member 124 and therefore the pedal also move accordingly. This free travel must be taken into account when determining the movement difference and is well known. However, during operation, it can happen that the determined free travel differs from the actual free travel due to the bending of the leaf spring 160. This effect can also lead to uncertainty and inaccuracy in detecting stuck obstacles. These problems occur in Figure 2 The following is a solution in an exemplary embodiment.

[0054] According to this disclosure, the operating unit 106 has a sleeve element 180. The sleeve element 180 is partially disposed within a recess 150 and protrudes into a through opening 158. The sleeve element 180 thus has a first portion 180A disposed within the recess 150 and a second portion 180B protruding into the through opening 158. In the exemplary embodiment shown herein, the second portion 180B protrudes through the through opening 158 into another recess 152.

[0055] The sleeve element 180 has a shape adapted to match the shape of the recess 150 and / or the operating member 124 and / or the through opening. The sleeve element 180 completely or at least partially circumferentially surrounds a portion of the operating member 124. That is, the sleeve element 180 may have a hollow region in the circumferential direction. According to this disclosure, for example, a first portion 180A may completely surround the operating member 124, while a second portion 180B may only partially surround the operating member 124, or vice versa. Alternatively, the sleeve element 180 may be configured such that both the first portion 180A and the second portion 180B completely or only partially surround the operating member 124.

[0056] In this example, the sleeve element 180 is annular. The sleeve element has a central opening through which the actuating member 124 is guided. The first portion 180A has a larger outer diameter than the second portion 180B. As a result, the first portion 180A defines a contact surface that cooperates with the contact shoulder 172. Therefore, the sleeve element 180 (more precisely, the first portion 180A of the sleeve element 180) is arranged between a longitudinal end of the helical spring 126 and the contact shoulder 172. The helical spring 126 holds the sleeve element 180 in contact with the contact shoulder 172. The helical spring 126 is supported by its second longitudinal end on the collar 162 of the actuating member 126.

[0057] The second portion 180B has a smaller outer diameter than the first portion 180A, so it can protrude into or through the through opening 158. Therefore, the second portion 180B is arranged between the operating member 124 and the inner circumferential surface of the contact shoulder 172 defining the through opening 158. The sleeve element 180 is arranged in a separate recess 152, forming a stop for the leaf spring 160 when the leaf spring bends due to tension (resistance) in the event of jamming an obstacle. This will be discussed in more detail below.

[0058] The sleeve element 180 and the operating element 124 are configured and arranged relative to each other in such a way that the operating element 124 is movable (optionally guided) relative to and through the sleeve element 180, more precisely, displaceable. This can be achieved by arranging the operating element 124 and the sleeve element 180 at a small distance from each other. However, this can also be achieved by having the sleeve element 180 rest against the operating element 124, thereby enabling guided movements with low friction.

[0059] The sleeve element 180 can rest against the housing body 122 relative to the housing body 122. The arrangement of the sleeve element 180 against the housing body 122 achieves positioning of the sleeve element 180 relative to the housing body 122 (which is more or less larger). As a result, the spring 126 can be fixedly "closed" in the recess 150 by the sleeve element 180, thus preventing large vibrations of the spring 126.

[0060] Therefore, ideally, the sleeve element 180 has two effects: the spring 126 is fixedly arranged in the recess 126 such that the sleeve element 180 is free from vibrations or undesirable vibrations that would cause the elastic element 160 to bend, and if undesirable vibrations do occur, they are not transmitted or at least transmitted in a damped manner to the housing body 122. This can be achieved by deformation and / or displacement of the sleeve element 180 and / or by the application of frictional forces.

[0061] Furthermore, when the leaf spring bends and resistance acts on the operating member 124, the bending of the leaf spring 160 is limited by the free end of the sleeve element 180, which serves as a stop. Specifically, the leaf spring 160 then rests against the free end of the sleeve element through its middle portion. This state also has the effect of preventing or reducing vibration of the system, such that, for example, the spring 126 cannot vibrate or at least can vibrate relative to the housing body 122 to a reduced degree.

[0062] The sleeve element 180 may be formed of a metallic material. The sleeve element 180 may also be formed of a. The sleeve element 180 may constitute a closing element for the spring 126 and / or a damping element for the vibration of the spring 126 and the system as a whole.

[0063] In addition to the sleeve element 180, the operating unit 106 may also have a separately formed damping element that dampens undesirable system vibrations, especially in the case of autonomous or semi-autonomous braking. For example, this could be an O-ring arranged between the operating member 124 and the housing body 122. Figure 2 In an exemplary embodiment, an O-ring or damping element can therefore very typically be arranged in a circumferential groove in the first portion 180A of the sleeve element 180 formed between the housing body 122 and the operating member 124. Furthermore, the damping element can be, for example, in the form of a friction sleeve arranged between the sleeve element 180 and / or the operating member 126 and / or between the sleeve element 180 and / or the housing body 124. The frictional force acting between elements 180, 124 or 180, 122 can thus reduce undesirable vibrations in the system. The friction between the two elements 180, 124 or 180, 122 in this contact area can serve a damping purpose. The friction sleeve is then fixedly connected to the sleeve element 180.

[0064] The solutions disclosed herein are particularly suitable for electronically controlled operating units that provide a direct mechanical connection between the brake pedal and the electromechanical drive components of a specific operating unit, wherein the brake pedal can therefore move in conjunction with autonomous or semi-automatic braking. In solutions known in the prior art, vibrations occurring during autonomous braking when a stuck obstacle is present make the detection of the stuck obstacle more difficult. Using the disclosed damping element, such vibrations can be largely prevented or at least reduced, and thus the stuck obstacle can be reliably detected. When a stuck obstacle is detected, additional brake pressure accumulation can be switched to another unit, such as the hydraulic pump of the electronic stability control (ESC) system, and the electric motor 102 can cause the operating unit 106 to move in the opposite direction of braking to reduce the sticking force.

Claims

1. An electrically actuated operating unit (106) for a motor vehicle brake (400), comprising: The housing body (122) is arranged to be displaceable in the braking direction by an electric motor (102) for operating the motor vehicle brake (400); A recess (150) is formed in the housing body (122), wherein, The recess (150) is defined at one longitudinal end by a contact shoulder (172); A through opening (158), the through opening being defined by the contact shoulder (172); An operating member (124) is disposed in the recess (150) and is displaceable for operating the motor vehicle brake (400), and the operating member protrudes through a through opening (158) of the contact shoulder (172), wherein the operating member (124) is disposed between the brake pedal and the motor vehicle brake (400) in a force-transmitting manner. An elastic intermediate element (160) limits the tension acting on the operating member (124) by the electric actuation of the operating unit (106) during operation of the motor vehicle brake (400); A return spring (126) is disposed in the recess (150) and configured to move the operating member (124) relative to the housing body (122) away from the contact shoulder (172), and the electrically actuated operating unit has A sleeve element (180) at least partially surrounds a portion of the operating member (124) and is held by the return spring (126) to contact the contact shoulder (172), wherein the sleeve element (180) protrudes into the through opening (158) such that the sleeve element is disposed between the operating member (124) and the inner circumferential surface of the contact shoulder (172) defining the through opening (158), wherein the end of the sleeve element (180) disposed outside the recess (150) forms a stop for the elastic intermediate element (160) to limit the deformation of the elastic intermediate element.

2. The operating unit (106) as described in claim 1, wherein, The operating member (124) is arranged to be displaceable relative to the sleeve element (180).

3. The operating unit (106) as described in claim 1 or 2, wherein, The sleeve element (180) is guided by its inner circumferential surface against or on the outer circumferential surface of the operating member (124).

4. The operating unit (106) as described in claim 1 or 2, wherein, The sleeve element (180) is guided by its outer peripheral surface against or on the inner peripheral surface of the contact shoulder (172) that defines the through opening (158).

5. The operating unit (106) as described in claim 1 or 2, wherein, The sleeve element (180) is guided by its outer peripheral surface against or on the inner wall (156) of the housing body (122) that defines the recess (150).

6. The operating unit (106) as described in claim 1 or 2, wherein, The sleeve element (180) has a first portion (180A) disposed inside the recess (150) and a second portion (180B) protruding into the through opening (158).

7. The operating unit (106) as claimed in claim 6, wherein, The first part (180A) has a larger external dimension than the second part (180B).

8. The operating unit (106) as described in claim 1 or 2, wherein, The sleeve element (180) is arranged in the housing body (122), and one end of the sleeve element is located outside the recess (150).

9. The operating unit (106) as described in claim 1 or 2, wherein, The housing body (122) can be connected to the operating member (124) via a stop element (154) connected to the operating member (124).

10. The operating unit (106) as claimed in claim 1, wherein, The elastic intermediate element (160) is a leaf spring installed in the housing body (122).

11. The operating unit (106) as claimed in claim 1, wherein, The operating component (124) can be connected to the housing body (122) via the elastic intermediate element (160).

12. An electromechanical brake booster (100) having an electrically actuated operating unit (106) as described in any one of claims 1 to 11.

13. A motor vehicle braking system (1000) having an electromechanical brake booster (100) as described in claim 12.

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