Method for the adjusted attachment of a magnetic sensor device to an actuator

Abstract

Method for the adjusted fastening of a magnetic sensor device to an actuator (100), the magnetic sensor device comprising a sensor module with at least one permanent magnet (112) and a sensor module with a first sensor (114) for measuring the angle of rotation and a second sensor (116) for counting revolutions, the actuator (100) comprising an electric motor with a stator and a rotor (104), characterized in that the following steps are carried out: - Applying a predetermined setting magnetic field to the sensor module, - rotating the adjusting magnetic field and the sensor module relative to each other in a first direction of rotation until a revolution counting range of the second sensor (116) is left, - rotating the adjusting magnetic field and the sensor module relative to each other in a second direction of rotation opposite to the first direction of rotation by a predetermined number of revolutions in order to set the second sensor (116) to a predetermined revolution count value, - Saving an orientation of the setting magnetic field and terminating the application of the setting magnetic field to the sensor module, - mechanical adjustment of the actuator (100) according to the specified revolution count value and - Attaching the encoder module on the rotor side and the sensor module on the stator side.

Description

[0001] The invention relates to a method for the adjusted fastening of a magnetic sensor device to an actuator, the magnetic sensor device comprising a sensor module with at least one permanent magnet and a sensor module with a first sensor for measuring the angle of rotation and a second sensor for counting revolutions, the actuator comprising an electric motor with a stator and a rotor.

[0002] DE 10 2009 034 664 A1 discloses a method for determining the setting position of a motor-driven adjustment element of a motor vehicle by means of a Hall sensor.

[0003] US 2016 / 0041 235 A1 discloses a method for maximizing a target signal and eliminating a bias component for a position sensor.

[0004] US 2012 / 0 181 958 A1 discloses a commutated electric drive and a method for controlling a commutated electric motor.

[0005] From DE 10 2011 014 574 A1 a linear position measuring system is known with a sensor device and with a magnet which is mechanically connected to a piston in order to detect an axial position of the piston, in which the magnet is connected to the piston via a joint.

[0006] From DE 10 2013 222 366 A1 a method is known for determining and / or controlling a position of an electric motor, in particular in a clutch actuation system of a motor vehicle, in which the position of a rotor of the electric motor is picked up by a sensor arranged outside a rotational axis of the electric motor on a stator of the electric motor, wherein the position signal picked up by the sensor is evaluated by an evaluation unit, wherein the position signal is transmitted as a function of a transmission distance between the sensor and the evaluation unit by means of an SPI protocol signal for short transmission distances and / or by means of a PWM signal for longer transmission distances.

[0007] From DE 10 2014 211 146 A1 a piston-cylinder arrangement is known, in particular for a release system in a motor vehicle, with a cylinder designed as a housing, in which a piston is mounted so as to be axially movable, and a switching point sensor is fastened to the housing for measuring the travel of the piston, which is operatively connected to a component arranged on the piston which activates a switching point of the switching point sensor, in which the switching point sensor is designed as a Hall sensor, to which a permanent magnet is assigned for setting a predetermined magnetic flux, and the component which activates the switching point of the Hall sensor is designed to be ferromagnetic, whereby the magnetic flux predetermined by the permanent magnet changes when the piston carrying the ferromagnetic component approaches the Hall sensor.

[0008] From DE 10 2014 225 658 A1 a method is known for sensing a linear and a rotary movement in a switching actuator, preferably a gear actuator, in which a movement of an actuator element is detected by a changing magnetic field, which is detected by a sensor unit, wherein a superimposed rotary and linear movement from the inhomogeneous magnetic field is detected, wherein all three magnetic field components are evaluated from the sensor signal of one sensor unit and information about a direction of rotation and a linear movement of the actuator element is determined therefrom.

[0009] The invention is based on the object of improving a method mentioned above.

[0010] The problem is solved by a method for the adjusted fastening of a magnetic sensor device to an actuator, the magnetic sensor device comprising a transmitter module with at least one permanent magnet and a sensor module with a first sensor for measuring the angle of rotation and a second sensor for counting revolutions, the actuator comprising an electric motor with a stator and a rotor, wherein the following steps are carried out: applying a predetermined setting magnetic field to the sensor module; rotating the setting magnetic field and the sensor module relative to one another in a first direction of rotation until a revolution counting range of the second sensor is left; rotating the setting magnetic field and the sensor module relative to one another in a second direction of rotation opposite to the first direction of rotation by a predetermined number of revolutions in order to set the second sensor to a predetermined revolution count value;Storing an orientation of the adjustment magnetic field and terminating the application of the adjustment magnetic field to the sensor module; mechanically adjusting the actuator according to the specified revolution count; securing the encoder module on the rotor side and the sensor module on the stator side.

[0011] The magnetic sensor device can be mounted on the actuator in such a way that it is adjusted to enable reliable detection of a rotation angle and reliable counting of revolutions. The magnetic sensor device can be mounted on the actuator in such a way that a detection range of the second sensor and an actuator travel range are correlated with each other. The magnetic sensor device can be mounted on the actuator in such a way that tolerance errors are compensated.

[0012] The method can be carried out using an adjustment device. The adjustment device can have at least one adjustment magnet. The adjustment magnet can be used to apply the predetermined adjustment magnetic field to the sensor module. The adjustment magnet can be placed axially close to the sensor module. The adjustment magnet can be rotatable. The adjustment magnetic field can be rotated relative to the sensor module. The adjustment magnetic field can be rotated while the sensor module is fixed. While the adjustment magnetic field and the sensor module are rotated relative to one another, magnetic field strength information of the first sensor (114) and / or the second sensor can be detected and stored. The adjustment magnet can be removed from the sensor module to stop the adjustment magnetic field being applied to the sensor module.

[0013] The transmitter module and the sensor module can be mounted at a predetermined distance from each other, wherein magnetic field strength information of the first sensor (114) and / or the second sensor is detected and the distance is adjusted taking into account the detected and previously stored magnetic field strength information.

[0014] To secure the encoder module and the sensor module at a predetermined distance from each other, the at least one permanent magnet can be pressed into a predetermined position. The distance between the at least one permanent magnet and the sensor module can be reduced if magnetic field detection produces an excessively weak signal. The distance between the at least one permanent magnet and the sensor module can be increased if magnetic field detection produces an excessively strong signal. Tolerance errors of the sensor module can be compensated.

[0015] A setting measuring device can be used to mechanically adjust the actuator according to the specified revolution count. The adjustment device can comprise a setting measuring device for mechanically adjusting the actuator.

[0016] After attaching the encoder module to the rotor side and the sensor module to the stator side, an actuator mechanism can be completed. The actuator mechanism can include an actuator gear.

[0017] The object underlying the invention is not achieved according to the invention with an actuator having an electric motor and a magnetic sensor device, the electric motor having a stator and a rotor, the magnetic sensor device having a transmitter module with at least one permanent magnet and a sensor module with a first sensor for measuring the angle of rotation and a second sensor for counting revolutions, in which the magnetic sensor device is fastened to the actuator in an adjusted manner according to such a method.

[0018] The actuator can be used to actuate a friction clutch device. The actuator can be used to actuate a master cylinder of a hydrostatic actuation device of a friction clutch device. The hydrostatic actuation device can have a hydraulic path. The hydrostatic actuation device can have a slave cylinder. The slave cylinder can be assigned to the friction clutch device.

[0019] The actuator can be controlled using an electrical control device. The electrical control device can be a control unit. The electrical control device can be a local actuator control unit. The electrical control device can have a computing device. The electrical control device can have a memory device. The electrical control device can have at least one electrical signal input. The electrical control device can have at least one electrical signal output. The electrical control device can be structurally and / or functionally connected to at least one other electrical control device in a signal-conducting manner. A bus system, such as a CAN bus, can serve for the signal-conducting connection.

[0020] The friction clutch device can be arranged in a drive train of a motor vehicle. The drive train can have a prime mover. The prime mover can be an internal combustion engine. The drive train can have a friction clutch device. The drive train can have a transmission. The transmission can be a manual transmission. The drive train can have at least one drivable vehicle wheel.

[0021] The encoder module can be attached to the actuator on the rotor side. The sensor module can be attached to the actuator on the stator side. The encoder module and the sensor module can define a measuring gap for contactless angle measurement and revolution counting.

[0022] The first sensor can have a measuring range of approximately 360°. The first sensor can have at least one Hall element. The first sensor can have a plurality of Hall elements distributed in the circumferential direction of the first sensor. The second sensor can be a GMR sensor (Giant Magneto-Resistance Sensor). A GMR sensor is a sensor based on the giant magneto-resistance effect. A GMR sensor can have a spiral. The spiral can have spiral arms. The spiral can be arranged in a diamond shape. A GMR sensor can have a GMR layer stack. A GMR sensor can have a reference layer and a sensor layer. A magnetization state of the sensor layer can be variable. A GMR sensor can have a domain wall generator. The domain wall generator can be arranged at one end of the spiral. 180° domains can be generated in the domain wall generator.The domains can be injected into the spiral and / or erased again. A magnetization state of the spiral arms can be changed under the influence of a moving magnetic field. A magnetization state of the spiral arms can be changed by rotating a magnetic field and the spiral relative to each other. A number of revolutions can be magnetically stored. A rotational movement can also be detected without an electrical voltage supply. A rotational movement can also be stored without an electrical voltage supply. An electrical resistance value of the spiral can depend on a magnetization state. The first sensor and the second sensor can be arranged on a common circuit board, not according to the invention.

[0023] The actuator may have an actuator housing. The stator may be fixed to the housing. The rotor may be rotatably mounted in the housing. The actuator may have an actuator gear. The actuator gear may be used to convert a rotary motion into a linear motion. The gear may be a helical gear. The gear may have a threaded spindle. The gear may have a spindle nut. The threaded spindle may be connected to the rotor in a rotationally fixed manner. The spindle nut may be connectable to a master cylinder to transmit axial motion.

[0024] In summary, and in other words, the invention thus provides, among other things, a method for commissioning and calibrating a multiturn sensor. This method can be used to eliminate B-field tolerance susceptibility. Multiturn sensor information can be compared with a displacement axis to be measured.

[0025] A procedure can refer to a (displacement) measuring system that includes a magnetic 360° angle sensor capable of detecting the strength of a B-field in all three spatial directions. A multiturn sensor can also be included, which is capable of outputting complete revolutions of the displacement axis through a GMR effect caused by magnetic domain transitions, with this information remaining even after a power loss. Both sensors can detect the angular position of a sensor magnet by the orientation of its B-field relative to these sensors. A device in which the displacement sensor is used can consist of a circuit board containing the sensors and a mechanical part whose spindle rotation or stroke information is to be recorded. When both modules are initially assembled, the sensor is to be calibrated once with the displacement information of a mechanical component.The travel axis should be smaller than the sensor's coverage area to prevent any misalignment between the sensor and the travel distance (total angle of rotation) of the mechanism during operation. This would occur if the total detection angle of the multiturn sensor were exceeded. Depending on how many revolutions the sensor travels in one direction of rotation, a subsequent reversal of the direction of rotation would interpret the point from the reversal as the new zero point, thus misaligning the original calibration of the travel axis. This would result in misalignment during operation of the device, which would be incorrectly interpreted by the sensor with regard to the total travel (a travel that is too small or too large than actually present).

[0026] The sensor and mechanics can be calibrated / designed to each other as follows: - A device-bound sensor adjustment magnet of known magnetic strength can be placed against both sensors against a defined, known axial dimension corresponding to a design. - The sensor can be rotated in one direction by a rotation number that is greater than the total rotation angle detection range of the multiturn sensor. - The direction of rotation can be reversed and it can be driven to a specific number of revolutions. - During this adjustment process, magnetic field strength information from the angle of rotation sensor and / or the multiturn sensor can be read out and saved. - The magnet can be moved axially away from the sensor, whereby the magnetic field orientation can be noted / recorded according to the last set angle. - A stored total number of revolutions of the sensor can be transferred to a mechanical travel axis that is not yet attached to the sensor at this time. - An external position measuring system can be used for this purpose, which can record the position of the mechanics. - The mechanism can now be adjusted so that the external position measuring system corresponds to the speed of the sensor. - The device's sensor magnet can now be pressed to a calculated axial distance from the sensor. The stored information from the single-turn sensor can be used for this purpose, and the magnetic field strength of the sensor being pressed in can also be recorded. If the detected magnetic field was too weak, the distance to the sensor can be reduced according to a nominal design; if not, the distance can be increased. Using the stored information from the single-turn sensor, any axial tolerance of the sensor module that might otherwise be undetectable can also be taken into account for this adjustment. - The mechanism is now attached to the sensor, ensuring that the angle of rotation of the sensor corresponds to that of the original adjustment sensor.

[0027] The invention enables the adjusted attachment of a magnetic sensor device to an actuator. Commissioning is enabled. Initial assembly of a magnetic sensor device and an actuator is enabled. Alignment of a magnetic sensor device with the path information of a mechanism is enabled. Unintentional adjustment during operation is prevented. Misinterpretation of an actuator movement is prevented. Proper detection of a rotation angle and proper revolution counting are ensured.

[0028] Exemplary embodiments of the invention are described in more detail below with reference to the figures. Further features and advantages will become apparent from this description. Specific features of these exemplary embodiments may represent general features of the invention. Features of these exemplary embodiments combined with other features may also represent individual features of the invention. Fig. 1 shows schematically and by way of example an actuator with an electric motor and an actuator gear as well as a magnetic sensor device with a transmitter module and a sensor module attached to the actuator in an adjusted manner.

[0029] The actuator 100 is used to actuate a master cylinder of a hydrostatic actuation device of a friction clutch device of a motor vehicle. The actuator 100 has a housing 102. The electric motor has a stator and a rotor 104. The stator is fixed to the housing. The rotor 104 is rotatably mounted in the housing 102. The actuator 100 has a spindle drive with a spindle nut 106 and a spindle rod 108. The spindle drive serves to convert a rotary movement of the rotor 104 into a linear movement of the spindle rod 108. The spindle rod 108 is connected to a piston 110 of the master cylinder (not shown in detail here) in such a way that it transmits axial movement.

[0030] The encoder module of the magnetic sensor device has permanent magnets 112 and is fixedly mounted on the rotor 104 of the electric motor. In this case, the permanent magnets 112 are pressed in. The sensor module of the magnetic sensor device is fixed to the housing. The sensor module has a first sensor 114 for measuring the angle of rotation and a second sensor 116 for counting revolutions. The first sensor 114 has Hall elements and can detect angles of rotation up to 360° as well as the strength of a B field. The second sensor 116 is a GMR sensor with a counting function. The sensors 114, 116 are arranged on a common circuit board 118.

[0031] To adjust the magnetic sensor device to the actuator 100, the sensor module is first subjected to a predetermined magnetic field using an adjustment magnet, and the adjustment magnet is rotated relative to the sensor module until it leaves a revolution counting range of the second sensor 116. Subsequently, the adjustment magnet is rotated relative to the sensor module in an opposite direction to adjust the second sensor 116 to a predetermined revolution count value. During the rotation of the adjustment magnet, magnetic field strength information from the second sensor 116 is recorded and stored.

[0032] Subsequently, an orientation of the adjustment magnetic field is stored, and the adjustment magnet is removed. Next, the actuator 100 is adjusted according to the specified revolution count, the permanent magnets 112 are pressed onto the rotor 104, and the sensor module is fixedly mounted on the housing. The encoder module and the sensor module are mounted at a predetermined distance a from each other, with magnetic field strength information from the second sensor 116 being acquired, and the distance a being adjusted taking into account the acquired and previously stored magnetic field strength information.

[0033] The magnetic sensor device is thus attached to the actuator 100 in such a way that an actuator travel 120 lies within a measuring range 122 of the second sensor 116 and the measuring range 122 is not left even in the end positions 124, 126 of the actuator 100. List of reference symbols 100 actuator 102 housings 104 Rotor 106 spindle nut 108 spindle rod 110 pistons 112 Permanent magnet 114 first sensor 116 second sensor 118 circuit board 120 actuator travel 122 measuring range 124 End position

Claims

[1] Method for the adjusted fastening of a magnetic sensor device to an actuator (100), the magnetic sensor device comprising a sensor module with at least one permanent magnet (112) and a sensor module with a first sensor (114) for measuring the angle of rotation and a second sensor (116) for counting revolutions, the actuator (100) comprising an electric motor with a stator and a rotor (104), characterized by that the following steps are carried out: - Applying a predetermined setting magnetic field to the sensor module, - rotating the adjusting magnetic field and the sensor module relative to each other in a first direction of rotation until a revolution counting range of the second sensor (116) is left, - rotating the adjusting magnetic field and the sensor module relative to each other in a second direction of rotation opposite to the first direction of rotation by a predetermined number of revolutions in order to set the second sensor (116) to a predetermined revolution count value, - Saving an orientation of the setting magnetic field and terminating the application of the setting magnetic field to the sensor module, - mechanical adjustment of the actuator (100) according to the specified revolution count value and - Attaching the encoder module on the rotor side and the sensor module on the stator side. [2] Method according to claim 1, characterized by that during a rotation of the adjusting magnetic field and the sensor module relative to each other, magnetic field strength information of the first sensor (114) and / or the second sensor (116) is detected and stored. [3] Method according to claim 2, characterized bythat the transmitter module and the sensor module are fastened at a predetermined distance from one another, wherein magnetic field strength information of the first sensor (114) and / or the second sensor (116) is detected and the distance is adjusted taking into account the detected and previously stored magnetic field strength information. [4] Method according to claim 3, characterized by that for fastening the encoder module and the sensor module at a predetermined distance from one another, the at least one permanent magnet (112) is pressed into a predetermined position. [5] Method according to at least one of the preceding claims, characterized by that a setting measuring device is used for mechanically adjusting the actuator (100) according to the predetermined revolution count value. [6] Method according to at least one of the preceding claims, characterized bythat after the encoder module has been attached to the rotor side and the sensor module has been attached to the stator side, an actuator mechanism is completed.

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