Actuator

Abstract

The invention relates to an actuator (10), in particular a parking lock actuator, for indirectly or directly locking a drive part of a motor vehicle, comprising: a base body (12), which has a piston chamber (14) for receiving and guiding a piston (16) mounted in the piston chamber (14) in an axially displaceable manner; a closing body (18) for closing the piston chamber (14) on the axial side; a piston rod (36) which is connected to the piston (16) in an axially displaceable manner and which serves to determine the position of the piston (16) in the piston chamber (14); at least one magnetic element (44) connected to the piston rod (36) in an axially displaceable manner for providing a magnetic field; and at least one sensor unit (52) fixedly arranged on the closure body (18) for detecting a magnetic field of the magnetic element (44), the piston rod (36) having a cavity (14) open in the axial direction for at least partially accommodating the magnetic element (44) in the piston rod (36). In this way, a space-saving and measurement-accurate sensor arrangement in the actuator (10) is achieved.

Description

Technical Field

[0001] The invention relates to an actuator for indirectly or directly locking a drive component of a motor vehicle, in particular a parking lock actuator, and to a motor vehicle component for electrohydraulic actuation of a motor vehicle assembly, by means of which a sensor device for determining the position of a hydraulic piston is implemented which saves structural space and has precise measurement. Background Art

[0002] DE 10 2020 114 933 A1 discloses an actuating actuator for a parking lock, which has a position detector in the form of a magnetic field sensor, which interacts with a permanent magnet integrated into an actuating element along an actuating axis.

[0003] There is a constant need to reduce the installation space requirement of sensor devices in actuators and at the same time to improve the measuring accuracy of the sensor devices. Summary of the invention

[0004] The object of the present invention is to provide measures for realizing a sensor arrangement in an actuator which saves installation space and has precise measurement.

[0005] This object is achieved by an actuator having the features of claim 1 and a motor vehicle component having the features of claim 10. Preferred embodiments of the invention are given in the dependent claims and in the following description, which can each represent an aspect of the invention individually or in combination.

[0006] One embodiment relates to an actuator for indirectly or directly locking a drive component of a motor vehicle, in particular a parking lock actuator, the actuator comprising: a base body having a piston chamber, the piston chamber being used to accommodate and guide a piston supported axially movably in the piston chamber; a closing body for closing the piston chamber on the axial side; a piston rod connected axially movably to the piston, the piston rod being used to determine the position of the piston in the piston chamber; at least one magnetic element connected axially movably to the piston rod, the magnetic element being used to provide a magnetic field; and at least one sensor unit fixedly arranged on the closing body, the at least one sensor unit being used to detect the magnetic field of the magnetic element, wherein the piston rod has a cavity open in the axial direction, the cavity being used to at least partially accommodate the magnetic element in the piston rod.

[0007] The actuator of a motor vehicle component, in particular configured as a parking lock actuator, can be used to indirectly or directly lock a drive component of a motor vehicle. The drive component can be a motor vehicle transmission, preferably a motor vehicle shaft, particularly preferably a drive wheel of a motor vehicle, etc. Here, the indirect or direct locking of the drive component can be performed in particular by the actuator in a form-fitting and / or force-fitting manner. Undesirable movement of the motor vehicle can thus be prevented, in particular from a stationary parking position. It is particularly advantageous here that the locking state of the actuator can be reliably known at any time. The position of the piston in the piston chamber can give an indication of the locking state. The piston that can be axially moved in the piston chamber can be moved in particular by hydraulic pressure loading in the piston chamber. The pressure loading of the piston can preferably be performed only in the activation direction on one side, in which the actuator indirectly or directly unlocks the drive component. The piston can in particular indirectly or directly operate other elements of the actuator, in particular a piston rod, etc., by its axial movement, for locking or unlocking the drive component in a form-fitting and / or force-fitting manner. Here, the piston chamber is closed on the axial side by a closing body. By at least partially placing a magnetic element in the cavity of the piston rod, the piston rod can be used to determine the position of the piston. Here, the sensor unit can detect the magnetic field provided by the magnetic element in the piston rod. Thus, the changing position of the piston rod can be accurately obtained by means of the sensor unit fixedly arranged at the closure body, and the changing position is caused by the axial movement of the piston. Through the changing spatial distance between the magnetic element and the sensor unit, the sensor unit can detect the changing magnetic field strength, thereby also determining the position of the piston in the piston chamber, and thus also determining the locking state of the actuator. By arranging the magnetic element in the cavity of the piston rod, the axial and / or radial structural space required in the actuator can be reduced. Thus, it can be additionally ensured that the magnetic element will not loosen or move from the piston rod during the operation of the actuator. Possible fluctuations in the magnetic field caused by oscillations or vibrations can be better compensated or reduced to an acceptable level by arranging the magnetic element in the piston rod. Therefore, a sensor device that saves structural space and measures accurately in the actuator is realized.

[0008] The working principle of the actuator, in particular the parking lock actuator, is known, for example, from DE102010053861A1, DE102019119342A1, DE102020114933A1 or DE102021103565A1. The piston chamber of at least one actuator can be divided into a first pressure chamber and a second pressure chamber by a piston, in particular. The piston can have at least one groove for accommodating at least one sealing ring at the outer circumference. The at least one sealing ring can prevent the hydraulic fluid from overflowing from the first pressure chamber into the second pressure chamber. Preferably, only the first pressure chamber is hydraulically loaded. Therefore, the increase in the pressure in the first pressure chamber can cause the piston to move in the direction of the closing body. The second pressure chamber can preferably be formed in the piston chamber without pressure between the piston and the closing body. Therefore, the axial width of the second pressure chamber can be changed by the movement of the piston. The axial movement of the piston in the direction of the first pressure chamber can be limited, in particular, by reducing the cross-section of the piston chamber. As a result, the piston can only move axially in the piston chamber along a predetermined stroke range. The actuator has in particular a safety device for preventing the drive component from being locked by the actuator at a vehicle speed of more than 5 kilometers per hour. This ensures that in the event of a vehicle fault, due to which a pressure drop occurs in the first pressure chamber, the actuator cannot lock the drive component during driving.

[0009] The piston may have a passage in the axial direction, the passage being used to accommodate the first end section of the supporting element extending in the axial direction. Thus, the supporting element may be arranged in the piston at least in sections. The supporting element may have an intermediate section extending on the outer diameter of the first end section in the radial direction, the intermediate section being used to limit the axial mobility of the supporting element in the passage of the piston. The supporting element may have a second end section extending in the axial direction into the cavity of the piston rod. Thus, the piston rod may be indirectly connected to the piston. The piston rod may be arranged at the intermediate section in contact with the side opposite to the piston. Thus, any force transmission from the piston to the piston rod and vice versa can be basically carried out via the intermediate section of the supporting element. The supporting element may in particular indirectly or directly lock the magnetic element in the piston rod in a force-fitting and / or form-fitting manner in the cavity of the piston rod. Thus, it can be ensured that the magnetic element does not move in the piston rod or slip out of the piston rod.

[0010] The piston rod can be designed in particular as a sleeve. Thus, the piston rod can be manufactured cost-effectively by a forming method.

[0011] The magnetic element can be designed as a permanent magnet or the like. Thus, the magnetic element can provide a particularly strong magnetic field. The sensor unit can in particular have a magnetic field sensor. Thus, the position of the piston can be detected simply and quickly by the magnetic element and the sensor unit, so that the locking state of the actuator can also be reliably determined.

[0012] In particular, at least one sensor unit is arranged in a recess on the closing body. The recess can be formed in particular at the end side of the closing body facing away from the piston chamber. As a result, the sensor unit can be arranged on the closing body outside the piston chamber. As a result, simple installation of the sensor unit, easy replaceability, small installation space requirement and high operating duration can be achieved.

[0013] Preferably, the closing body has a channel extending in the axial direction of the piston rod for at least partially passing the piston rod. The piston rod can be moved through the closing body in a form-fitting manner via the channel. This can compensate or prevent possible vibrations or oscillations of the piston rod and thus also possible vibrations or oscillations of the magnetic element.

[0014] Particularly preferably, at least one sensor unit and the channel are at least partially arranged in the same axial region. In particular, at least one sensor unit can be arranged at the closure body spaced apart from the channel in the radial direction. By arranging the sensor unit and the channel in the same axial region, the magnetic element can pass through the sensor unit in the region of the channel in the piston rod, so that the sensor unit can detect the magnetic field of the magnetic element and determine the position of the piston in the piston chamber. By selecting the radial spacing between the sensor unit and the channel, the measurement accuracy of the sensor unit can be set. In the case of a small spacing, the shielding of the magnetic field of the magnetic element by the closure body is smaller. As a result, a smaller magnetic element can be used in the piston rod, thereby also determining the size of the piston rod to be smaller. As a result, the overall structural space of the actuator can be reduced.

[0015] In particular, the magnetic element is locked in the piston rod by means of at least one fastening element in a form-fitting and / or force-fitting manner. The fastening element can in particular be part of the support element. By locking the magnetic element in the piston rod in a form-fitting and / or force-fitting manner, the magnetic element can be prevented from moving in the piston rod. As a result, erroneous measurements for determining the position of the piston in the piston chamber by the sensor unit can be avoided. In particular, only the fastening element can be matched to the cavity of the piston rod. As a result, cost-intensive processing of the magnetic element can be avoided. As a result, the manufacturing costs of the actuator can be reduced, the installation of the magnetic element can be simplified, and the same magnetic element can be inserted into the cavity of piston rods with different diameters and reliably locked in the piston rod by corresponding fastening elements.

[0016] Preferably, at least one fastening element is configured as a disc-shaped or cylindrical extrusion body. In particular, at least one fastening element can be arranged in front of and / or behind the magnetic element in the piston rod. In particular, at least one fastening element can have a spring body that protrudes at least partially in the axial direction and is used to contact the magnetic element on the axial side. The fastening element can be configured in a plastic and / or elastically deformable manner. Thus, by pressing the fastening element axially into the cavity, a shape-fitting and / or force-fitting connection can be performed in the cavity of the piston rod. The disc-shaped embodiment of the fastening element has a relatively small contact surface with the piston rod, whereby the fastening element can be simply and quickly pressed axially into the cavity of the piston rod. The cylindrical embodiment of the fastening element has a larger contact surface with the piston rod than the disc-shaped embodiment of the fastening element, whereby the fastening element will not be skewed when pressed axially and a stronger force-fitting connection between the fastening element and the piston rod is achieved in the cavity. The cylindrical embodiment of the fastening element can have a protrusion protruding in the radial direction. In particular, the cylindrical embodiment of the fastening element has at least two radially protruding and respectively extending circumferentially protruding ridges. Thus, a smaller contact surface between the fastening element and the piston rod can be achieved in the cavity, thereby quickly and easily pressing in the axial direction. The skewing of the fastening element can be avoided by the cylindrical shape. The press-in tolerance, in particular the gap size between the fastening element and the magnetic element, can be compensated by the spring body protruding in the axial direction. In particular, the temperature-related material changes of the components in contact with each other, in particular the piston rod, the magnetic element and the fastening element, can be compensated by the spring body. By the spring body protruding in the axial direction, the fastening element and the magnetic element can also be contacted even when the corresponding contact surfaces are constructed differently and only point-like contact is achieved with each other. The cavity can have different diameters. In particular, the diameter can be larger in the region of the first end section of the piston rod than in the region of the second end section of the piston rod. Thus, the distance for axially pressing in the magnetic element and / or the fastening element can be reduced, thereby also reducing the friction resistance for axially pressing in the magnetic element and / or the fastening element. This facilitates simple and quick pressing in of the magnetic element and / or the fastening element.

[0017] Particularly preferably, the magnetic element is configured as a plastic-bonded magnet. As a result, the magnetic element can be injected into the piston rod in a form-fitting and / or force-fitting manner. As a result, the magnetic element can be matched to the contour of the cavity in the piston rod. Preferably, the piston rod has an opening extending in the axial direction at the end face of the second end section. The opening can have a smaller diameter than the cavity. As a result, the magnetic element can extend through the opening in the axial direction at least in sections and extend out of the cavity. As a result, the magnetic element can be in a form-fitting manner at the second end section against the end face and the contact surface opposite the end face in the hollow profile. This arrangement generally does not require additional fastening means. The required magnetic field strength can therefore be simply and individually set via the amount of magnetic elements introduced into the piston rod.

[0018] In particular, the closing body has a recess extending in the axial direction of the piston rod, which is used to support the spring element with a restoring force acting in the opposite direction of the movement of the piston. Particularly preferably, the piston rod at least partially extends through the spring element in the axial direction. In particular, the spring element can be abutted on the axial side at the first end section of the piston rod extending in the radial direction. Particularly preferably, the spring element can be abutted on the axial side at the support surface extending in the radial direction in the recess of the closing body. The spring element is supported at the closing body with a restoring force acting in the opposite direction of the movement of the piston to indirectly load the piston in the opposite direction of the activation direction of the piston by the restoring force of the spring element, in which the actuator indirectly or directly unlocks the drive component. It is therefore ensured that after the pressure in the first pressure chamber drops, the piston is pushed back by the restoring force of the loading spring element and the piston rod is moved into the actuator at the same time. The spring element is particularly configured as a helical spring. Particularly preferably, the spring element is configured as a compression spring. As a result, the spring element can always provide sufficient restoring force in the event of a break, so that the piston moves back to the initial position, thereby causing the locking of the drive component. The closing body can have, in particular, a cylindrical recess extending in the axial direction for receiving and supporting the spring element. The diameter of the cylindrical recess can, in particular, be designed to be smaller than the diameter of the piston chamber.

[0019] Particularly preferably, at least 50% of the spring element is arranged in the closing body. In particular, at least 40% of the piston rod is arranged in the closing body. In the assembled state, at least 50% of the length of the spring element can be arranged in the closing body. In the assembled state, at least 40% of the length of the piston rod can be arranged in the closing body. As a result, the piston chamber and thus the entire base body of the actuator can be constructed smaller and the spring element and / or the piston rod can be reliably supported in the closing body. Therefore, the piston chamber only extends the length of the required stroke range in the axial direction, which is necessary for the successful locking or unlocking of the drive component. This can not only reduce the manufacturing cost of the base body but also reduce the structural space requirement of the actuator. The piston rod can extend through the spring element in particular in the cylindrical recess of the closing body. The structural space requirement of the actuator can be additionally reduced by the arrangement.

[0020] Preferably, the piston can be axially moved along a stroke range arranged in the piston chamber, wherein the closing body limits the axial movement of the piston in one direction. As a result, the wall of the closing body can be used as a stop for the piston. The closing body can in particular have at least one projection extending into the piston chamber for limiting the axial movement of the piston along the stroke range. The at least one projection can preferably be annularly configured and extend along the wall of the piston chamber. As a result, the at least one projection can additionally serve as a centering aid for the closing body at the base. In this way, the assembly of the closing body at the base is simplified.

[0021] A further embodiment relates to a motor vehicle component for electrohydraulic actuation of a motor vehicle assembly, which has at least one actuator, in particular a parking lock actuator, for indirectly or directly locking a drive component according to the features of the description.

[0022] The motor vehicle component can be arranged in the motor vehicle indirectly or directly at the motor vehicle assembly, in particular at the motor vehicle clutch and / or the motor vehicle transmission. In addition to at least one actuator, the motor vehicle component also has at least one valve unit, which is used to indirectly or directly operate the motor vehicle clutch. At least one valve unit of the motor vehicle component can preferably indirectly or directly operate a motor vehicle clutch, which is especially configured as a claw clutch, a double clutch, etc., so that the drive shaft of the motor vehicle engine, which is especially configured as an internal combustion engine or an electric motor, can be connected to at least one transmission input shaft or a motor vehicle shaft, especially a wheel shaft, of the motor vehicle transmission. This connection can be carried out via at least one sub-clutch or claw clutch. As a result, the torque can be reliably transmitted from the drive shaft of the motor vehicle engine to at least one transmission input shaft or a motor vehicle shaft of the motor vehicle transmission. In particular, the front axle of the motor vehicle can be indirectly or directly decoupled from the drive shaft of the motor vehicle engine by means of a motor vehicle clutch, in particular a claw clutch. The joint arrangement of at least one valve unit and at least one actuator realizes a motor vehicle component that saves structural space, and the motor vehicle component is configured to operate multiple motor vehicle assemblies. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is explained below by way of example based on preferred embodiments with reference to the accompanying drawings, wherein the features shown below may represent an aspect of the present invention both individually and in combination. The accompanying drawings show:

[0024] Figure 1 : A side sectional view showing a first embodiment of the actuator,

[0025] Figure 2 : A side cross-sectional view showing the piston rod of the actuator,

[0026] Figure 3 : a perspective cutaway view showing the fastening element within the piston rod, and

[0027] Figure 4 : A side cross-sectional view showing the magnetic element within the piston rod. DETAILED DESCRIPTION

[0028] exist Figure 1The actuator 10 shown in the figure can be used to indirectly or directly lock a drive component of a motor vehicle. For this purpose, the actuator 10 has a base body 12, which has a piston chamber 14, which is used to accommodate a piston 16 that can be axially displaced in the piston chamber 14. The piston chamber 14 is closed on the axial side by a closing body 18. Here, the closing body 18 can limit the axial movement of the piston 16 in the piston chamber. Here, the piston chamber 14 is divided into a first pressure chamber 20 and a second pressure chamber 22 by the piston 16. For this purpose, the piston 16 has at least one groove 24 for accommodating at least one seal 26 at the outer circumference. The increase in pressure in the first pressure chamber 20 can cause the piston 16 to shift in the direction of the closing body 18. The second pressure chamber 22 can be formed in the piston chamber 14 without pressure between the piston 16 and the closing body 18. The axial movement of the piston 14 in the direction of the first pressure chamber 20 is limited by the reduction of the cross section of the piston chamber 14. Therefore, the piston 16 can only move axially in the piston chamber 14 along a predetermined stroke range 28. The closing body 18 has a cylindrical recess 30 extending in the axial direction, which serves to support a spring element 32, and a cylindrical channel 34 extending through the closing body 18 in the axial direction, which serves to support a piston rod 36. The piston rod 36 is connected to the piston 16 in a movable and fixed manner via the support element 38. The piston rod 36 has a first end section 40 extending in the radial direction, which serves to support the support element 38 and the spring element 32, wherein the spring element 32 acts on the piston rod 36 with a restoring force opposite to the displacement direction of the piston 16. The piston rod 36 has a cavity 42 open in the axial direction, which serves to accommodate a magnetic element 44 in the piston rod 36. The magnetic element 44 can be locked in the piston rod 36 by a fastening element 46 in a form-fitting and / or force-fitting manner. The fastening element 46 also has two radially protruding ridges 48, which each extend along the circumference of the fastening element 46. As a result, a smaller contact surface between the fastening element 46 and the piston rod 36 can be achieved in the cavity 42, so that the axial pressing of the fastening element 46 can be carried out quickly and easily. The cylindrical shape can avoid the skewing of the fastening element 46 in the cavity 42. The closing body has a recess 50 for accommodating a sensor unit 52, which is arranged at the end side of the closing body 18 facing away from the piston chamber 14. The sensor unit 52 and the channel 34 can be arranged at least partially in the same axial region and spaced apart from each other in the radial direction. By arranging the sensor unit 52 and the channel 34 in the same axial region, the magnetic element 44 can pass through the sensor unit 52 in the piston rod 36 in the region of the channel 34, so that the sensor unit 52 can detect the magnetic field of the magnetic element 44 and determine the position of the piston 16 in the piston chamber 14. By selecting the radial spacing between the sensor unit 52 and the channel 34, the measurement accuracy of the sensor unit 52 can be set.This results in a sensor arrangement in the actuator 10 that saves installation space and measures with high precision.

[0029] exist Figure 2 The piston rod 36 shown in FIG. 4 has a cavity 42 with two different diameters. The magnetic element 44 is arranged in a second end section 54 of the piston rod 36 supported in the channel 34 and is locked in the piston rod 36 by a disc-shaped fastening element 46. The transition formed at the piston rod 36 by two different diameters can be formed as an axial stop 56 to limit the axial movement of the piston rod 36, and the axial movement of the axial stop is limited by a bearing surface 58 of the closure body 18 extending in the radial direction.

[0030] exist Figure 3 The fastening element 46 shown in the figure has a spring body 60 protruding at least partially in the axial direction for contacting the magnetic element 44 on the axial side. By means of the spring body 60 protruding in the axial direction, press-fit tolerances, in particular the gap size between the fastening element 46 and the magnetic element 44, can be compensated.

[0031] exist Figure 4 The magnetic element 44 shown in FIG. 1 is locked in a form-fitting manner in the piston rod 36 in the region of the second end section 54 at an opening 62 extending in the axial direction. This embodiment is particularly suitable for magnetic elements 44 bonded with plastic, which are injected directly into the cavity 42. This arrangement does not require additional fastening means.

[0032] Reference numerals list

[0033] 10Actuator

[0034] 12 Matrix

[0035] 14 piston chamber

[0036] 16 Piston

[0037] 18 closed body

[0038] 20First pressure chamber

[0039] 22 Second pressure chamber

[0040] 24 slots

[0041] 26 Seals

[0042] 28 travel range

[0043] 30 recesses

[0044] 32 Spring elements

[0045] 34 channels

[0046] 36 piston rod

[0047] 38 Support element

[0048] 40 first end section

[0049] 42 Cavity

[0050] 44Magnetic components

[0051] 46 Fastening elements

[0052] 48 ridge

[0053] 50 blank space

[0054] 52 sensor units

[0055] 54 second end section

[0056] 56 stopper

[0057] 58 Support surface

[0058] 60 Spring Body

[0059] 62 opening.

Claims

1. An actuator for indirectly or directly locking a drive component of a motor vehicle, in particular a parking lock actuator, the actuator comprising: A base body (12) having a piston chamber (14) for accommodating and guiding a piston (16) supported in the piston chamber (14) in an axially movably manner; A closing body (18) for closing the piston chamber (14) on the axial side; a piston rod (36) axially movably connected to the piston (16), the piston rod being used to determine the position of the piston (16) in the piston chamber (14); at least one magnetic element (44) connected to the piston rod (36) in an axially movably manner, the magnetic element being used to provide a magnetic field; and at least one sensor unit (52) fixedly arranged at the closure body (18), the at least one sensor unit being used to detect the magnetic field of the magnetic element (44), The piston rod (36) has a cavity (42) which is open in the axial direction, and the cavity is used to at least partially accommodate the magnetic element (44) in the piston rod (36).

2. The actuator according to claim 1, wherein the at least one sensor unit (52) is arranged in a recess (50) in the closure body (18), In particular, the recess (50) is formed at the end side of the closure body (18) facing away from the piston chamber (14).

3. The actuator according to claim 1 or 2, wherein the closing body (18) has a channel (34) extending in the axial direction of the piston rod (36) for at least partially passing the piston rod (36).

4. The actuator according to claim 3, wherein the at least one sensor unit (52) and the channel (34) are arranged at least partially in the same axial region, In particular, the at least one sensor unit (52) is arranged on the closing body (18) at a distance from the channel (34) in a radial direction.

5. The actuator according to any one of claims 1 to 4, wherein the magnetic element (44) is locked in the piston rod (36) by means of at least one fastening element (46) in a form-fitting and / or force-fitting manner.

6. The actuator according to any one of claims 1 to 5, wherein the at least one fastening element (46) is designed as a disk-shaped or cylindrical extrusion body, In particular, at least one fastening element (46) is arranged in the piston rod (36) in front of and / or behind the magnetic element (44). In particular, the at least one fastening element (46) has a spring body (60) which protrudes at least partially in the axial direction for contacting the magnetic element (44) on the axial side.

7. The actuator according to claim 1 , wherein the magnetic element ( 44 ) is designed as a plastic-bonded magnet. In particular, the magnetic element (44) can be injected into the piston rod (36) in a form-fitting and / or force-fitting manner.

8. The actuator according to claim 1 , wherein the closing body ( 18 ) has a recess ( 30 ) extending in the axial direction of the piston rod ( 36 ) and is used to support a spring element ( 32 ) with a restoring force acting opposite to the displacement direction of the piston ( 16 ), In particular, the piston rod (36) extends at least partially in the axial direction through the spring element (32). In particular, the spring element (32) bears axially against a first end section (40) of the piston rod (36) extending in the radial direction. In particular, the spring element (32) bears axially against a bearing surface (58) extending in the radial direction in a recess (30) of the closing body (18).

9. The actuator according to any one of claims 1 to 8, wherein the piston is axially movable along a stroke range (28) provided in the piston chamber (14), wherein the closing body (18) limits the axial movement of the piston (16) in one direction.

10. A motor vehicle component for electrohydraulic actuation of a motor vehicle assembly, the motor vehicle component having at least one actuator (10) according to any one of claims 1 to 9 for indirectly or directly locking a drive component, in particular a parking lock actuator.

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