Sensor system, decoupling unit and method for detecting an axial position

Abstract

Sensor system (36) for detecting an axial position (x) of an axially displaceable and rotatable rotating component (16) of a decoupling unit (10) of a vehicle, comprising a plastic-bonded permanent magnet element (38) which is at least axially rigidly connected to the rotating component (16) and has permanent magnet means (56) magnetized in the axial direction (40), and a magnetic field sensor (42) for detecting a magnetic field of the permanent magnet element (38).

Description

[0001] The invention relates to a sensor system according to claim 1. Furthermore, the invention relates to a decoupling unit and a method for detecting an axial position.

[0002] There are various designs and technical solutions for all-wheel drive systems in vehicles. Some of them utilize the permanent transmission of torque to the two front and two rear wheels of the vehicle as permanent all-wheel drive. These systems have the advantage of low production costs. However, due to the stricter requirements for reducing CO2 emissions, it is necessary to optimally manage the energy used to move the vehicle. For an all-wheel drive vehicle that does not use the all-wheel drive function the entire time while driving, all-wheel drives without a permanent torque on the front or rear vehicle axle offer advantages in terms of energy efficiency. These systems require corresponding sensors and actuators for the mechanical engagement and disengagement of the all-wheel drive train and therefore have higher development and production costs.

[0003] The object of the present invention is to precisely detect the axial position of a rotating component of a decoupling unit. The sensor system should be designed cost-effectively and in a space-saving manner. Furthermore, the detection should be as reliable as possible, and the sensor system and decoupling unit should be as robust as possible. The energy efficiency of the vehicle should be increased.

[0004] At least one of these objects is achieved by a sensor system having the features of claim 1. This allows the permanent magnet element to be designed cost-effectively and easily attached to the rotating component. The sensor system can be designed more cost-effectively.

[0005] The vehicle can be a hybrid vehicle or an electric vehicle. In a hybrid vehicle, the decoupling unit can influence the torque transfer between the electric motor and the drivetrain, particularly to realize various combinations with the combustion engine. In an electric vehicle, the decoupling unit can influence the torque transfer between the electric motor and the drivetrain, particularly to avoid drag losses in the electric motor and increase efficiency.

[0006] The decoupling unit can be a separating clutch, in particular a Disconnect Clutch Unit (DCU).

[0007] The rotating component can be a claw gear. The rotating component can have a toothing for a positive connection with a connecting component depending on the axial position of the rotating component. The toothing can be a spur toothing. The rotating component can be connected to the connecting component in a first axial position in a torque-transmitting manner. The rotating component can be decoupled from the connecting component in the second axial position, which differs from the first axial position. The rotating component and the connecting component can be rotatable relative to each other.

[0008] The rotating component can be mounted on a shaft for axial displacement. The rotating component can be connected to the shaft in a torque-transmitting manner. The rotating component can be connected to the shaft in a form-fitting, force-fitting, and / or material-locking manner. The rotating component can be constructed primarily of metal. The rotating component can be an injection-molded component. The rotating component can be a steel component. The rotating component can be constructed at least partially of a ferromagnetic material.

[0009] The rotating component can perform a large number of full revolutions around the rotation axis.

[0010] The magnetic field sensor can be a Hall sensor. The magnetic field sensor can detect a magnetic field component of the magnetic field parallel to the axial direction. The magnetic field sensor can detect a magnetic field component of the magnetic field parallel to the axial direction and additionally a radial magnetic field component perpendicular to the axial direction and / or the rotation axis. The magnetic field sensor can detect at least one magnetic field component of the magnetic field perpendicular to the axial direction.

[0011] The permanent magnet element can be formed as a single piece with the rotating component. The permanent magnet element can be overmolded onto the rotating component.

[0012] The permanent magnet element can comprise permanent magnet powder, particularly made of NdFeB and / or hard ferrite, embedded in a plastic base material. The permanent magnet element can be a sintered part, a pressed part (cold-pressed magnetic compound), or an injection-molded part.

[0013] The sensor system may comprise multiple magnetic field sensors and / or multiple permanent magnet elements.

[0014] In a preferred embodiment of the invention, it is advantageous if the magnetic field sensor is arranged at a radial distance from the permanent magnet element. The magnetic field sensor and the permanent magnet element can be spaced apart in the radial direction by, in particular, 1 to 5 mm, preferably 2 to 4 mm, in particular 3 mm.

[0015] In a preferred embodiment of the invention, it is advantageous if the magnetic field sensor is arranged in at least one axial position of the permanent magnet element, axially overlapping the permanent magnet element. This can increase the accuracy of the detection. The magnetic field sensor can be arranged in all axial positions of the permanent magnet element, at least partially, preferably completely, axially overlapping the permanent magnet element.

[0016] In a specific embodiment of the invention, it is advantageous if the permanent magnet element extends circumferentially around the rotating component at least in sections. The permanent magnet element can have an outer circumference with a constant diameter. The permanent magnet element can be rotationally symmetrical. The permanent magnet element and the rotating component can be arranged coaxially.

[0017] In a preferred embodiment of the invention, the permanent magnet element is designed to be annular and closed on its circumference. This allows the axial position to be detected more accurately throughout the rotational movement of the rotating component.

[0018] In a specific embodiment of the invention, it is advantageous if the permanent magnet element is arranged on an outer circumference of the rotating component. The permanent magnet element can be arranged radially outside the toothing of the rotating component.

[0019] In a specific embodiment of the invention, it is advantageous if the permanent magnet element is arranged on a lateral surface of the permanent magnet element. The magnetic field sensor can be arranged radially outside an outer circumference of the permanent magnet element.

[0020] A preferred embodiment of the invention is advantageous in which the permanent magnet element is connected to the rotating component via a radially inner fastening region. The permanent magnet element can be connected to the rotating component in a form-fitting, force-fitting, and / or material-fitting manner. The permanent magnet element can be clipped, pressed, and / or glued to the rotating component. The permanent magnet element can be attached to the rotating component with an undercut.

[0021] Furthermore, within the scope of the invention, a decoupling unit with the features of claim 9 is proposed to solve at least one of the aforementioned problems. This allows the decoupling unit to be designed more cost-effectively.

[0022] The rotating component can be axially displaceable by an actuator element. The actuator element can axially displace a release element. The release element, in turn, can axially displace the rotating component. The axial position of the rotating component can depend on the axial position of the release element. The decoupling unit can engage the vehicle's all-wheel drive as needed.

[0023] The actuator element may comprise an electric motor for providing an actuating force of the release element.

[0024] The decoupling unit can be arranged in a transmission of the vehicle.

[0025] Furthermore, within the scope of the invention, a method for detecting an axial position with the features of claim 10 is proposed to solve at least one of the above-mentioned problems.

[0026] Further advantages and advantageous embodiments of the invention emerge from the description of the figures and the illustrations. Character description

[0027] The invention is described in detail below with reference to the figures. They show in detail: Fig. 1: A spatial view of a decoupling unit with a sensor system in a specific embodiment of the invention. Fig. 2: A front view of a sensor system in another specific embodiment of the invention. Fig. 3: A section of a cross-section of the decoupling unit and the sensor system from Fig. 1. Fig. 4: A spatial view of the permanent magnet element from Fig. 1. Fig. 5: A cross section of a permanent magnet element of a sensor system in another specific embodiment of the invention. Fig. 6: A diagram of a sensor system in another specific embodiment of the invention.

[0028] Fig. Figure 1 shows a three-dimensional view of a decoupling unit with a sensor system, each in a specific embodiment of the invention. The decoupling unit 10 is designed as a separating clutch 12 and comprises an axially displaceable rotating component 16 that can be rotated about a rotational axis 14. The rotating component 16 is designed as a claw gear 18 and has a toothing 20 for a positive connection with a connecting component (not shown here). The toothing 20 is a spur toothing that can be positively connected to a mating toothing of the connecting component.

[0029] The rotating component 16 can assume a first axial position x, in which the toothing 20 positively engages the counter-toothing for torque transmission. In a second axial position deviating from the first axial position x, the rotating component 16 and the connecting component are decoupled from each other and can rotate relative to each other. Torque transmission between the rotating component 16 and the connecting component can be interrupted.

[0030] The axial position x of the rotating component 16 can be switched by an actuator element 24. The actuator element 24 has an actuating shaft 26, which engages with a toothing 28 in a linear toothing 30 on an outer circumference 32 of a release element 34 and, upon rotation of the actuating shaft 26, implements an axial displacement of the release element 34. The release element 34, in turn, is coupled to the rotating component 16 to change the axial position x of the rotating component 16 depending on the axial position of the release element 34.

[0031] The decoupling unit 10 has a sensor system 36 for detecting the axial position x of the rotating component 16. The sensor system 36 comprises a plastic-bonded permanent magnet element 38, which is firmly connected to the rotating component 16 and has permanent magnet means magnetized in the axial direction 40, as well as a magnetic field sensor 42 for detecting a magnetic field of the permanent magnet element 38.

[0032] The magnetic field sensor 42 is designed as a Hall sensor 44 and is arranged radially spaced from the permanent magnet element 38 and axially overlapping the permanent magnet element 38 in at least one axial position x of the permanent magnet element 38. The Hall sensor 44 detects the magnetic field excited by the permanent magnet element 38 with the magnetic field components in all three spatial directions, with less the magnetic field component B z in the z-direction rather than the magnetic field component B xin the x-direction, i.e. parallel to the rotation axis 14 and the magnetic field component B y in the y-direction, i.e. perpendicular to the axis of rotation 14, in order to detect the axial position x of the permanent magnet element 38 and thus of the rotating component 16.

[0033] Fig. Figure 2 shows a front view of a sensor system in another specific embodiment of the invention. The magnetic field sensor 42 can be arranged in the radial direction, in which the magnetic field component B y in the radial direction 46. The magnetic field sensor 42' can also be offset from the radial direction 46' of the permanent magnet element 38, in which the magnetic field component B' y angled to the radial direction 46'.

[0034] Fig. 3 shows a section of a cross-section of the decoupling unit and the sensor system from Fig. 1. The permanent magnet element 38 is designed as a closed ring on the circumference and extends completely around the circumference of the rotating component 16. The permanent magnet element 38 is designed as a magnetic ring 48, in particular as a sensor ring, which is arranged on an outer circumference 32 of the rotating component 16. The rotating component 16 has a lateral surface 50 on which the permanent magnet element 38 is arranged.

[0035] The permanent magnet element 38 has a radially inner fastening region 52, via which the permanent magnet element 38 is firmly connected to the rotating component 16, i.e., axially and rotationally fixed. A stepped shoulder 54 on the permanent magnet element 38 ensures axial alignment with the rotating component 16.

[0036] The release element 34 can be axially preloaded relative to the rotary component 16 by a spring element not shown here, in particular a corrugated spring.

[0037] Fig. 4 shows a spatial view of the permanent magnet element from Fig. 1. The permanent magnet element 38 is designed as a circumferentially closed magnetic ring 48.

[0038] Fig. Figure 5 shows a cross-section of a permanent magnet element of a sensor system in another specific embodiment of the invention. The permanent magnet element 38 has permanent magnet means 56 magnetized in the axial direction 40. These comprise, for example, permanent magnet powder embedded in a plastic base material, which is magnetized in the axial direction 40.

[0039] The magnetic field sensor 42 is spaced apart in the radial direction 46, for example with a radial distance 58 of 3 mm, from the permanent magnet element 38 and arranged axially overlapping the permanent magnet element 38.

[0040] Fig.Figure 6 shows a diagram of a sensor system in another specific embodiment of the invention. The diagram shows the magnetic field components B detected by the magnetic field sensor when the axial position x of the permanent magnet element and thus of the rotating component changes. x , B y , B z as a function of the axial position x of the permanent magnet element. Furthermore, the function arctan(BxBy) which is used to detect the axial position x of the rotating component depending on the magnetic field component B x , B y This represents a linear function over the axial position, allowing the axial position x to be determined precisely. List of reference symbols 10 Decoupling unit 12 Separating clutch 14 axis of rotation 16 Rotating component 18 Claw wheel 20 Gearing 24 Actuator element 26 Actuating shaft 28 Gearing 30 Linear gearing 32 outer circumference 34 release element 36 Sensor system 38 Permanent magnet element 40 axial direction 42 Magnetic field sensor 44 Hall sensor 46 radial direction 48 magnetic ring 50 lateral surface 52 Mounting area 54 paragraph 56 permanent magnet means 58 Radial distance B x Magnetic field component B y Magnetic field component B z Magnetic field component x axial position

Claims

[1] Sensor system (36) for detecting an axial position (x) of an axially displaceable rotary component (16) of a decoupling unit (10) of a vehicle, said rotary component being rotatable about a rotational axis (14), comprising a plastic-bonded permanent magnet element (38) which is at least axially fixedly connected to the rotating component (16) and has permanent magnet means (56) magnetized in the axial direction (40), a magnetic field sensor (42) for detecting a magnetic field of the permanent magnet element (38). [2] Sensor system (36) according to claim 1, characterized by that the magnetic field sensor (42) is arranged at a distance from the permanent magnet element (38) in the radial direction (46). [3] Sensor system (36) according to claim 1 or 2, characterized by that the magnetic field sensor (42) is arranged in at least one axial position (x) of the permanent magnet element (38) axially overlapping the permanent magnet element (38). [4] Sensor system (36) according to one of the preceding claims, characterized by that the permanent magnet element (38) extends circumferentially at least in sections around the rotating component (16). [5] Sensor system (36) according to one of the preceding claims, characterized by that the permanent magnet element (38) is designed to be ring-shaped and closed on the circumference. [6] Sensor system (36) according to one of the preceding claims, characterized by that the permanent magnet element (38) is arranged on an outer circumference (32) of the rotating component (16). [7] Sensor system (36) according to one of the preceding claims, characterized by that the permanent magnet element (38) is arranged on a lateral surface (50) of the permanent magnet element (38). [8] Sensor system (36) according to one of the preceding claims, characterized by that the permanent magnet element (38) is connected to the rotating component (16) by a radially inner fastening region (52). [9] Decoupling unit (10) comprising an axially displaceable rotating component (16) rotatable about a rotation axis (14) and a sensor system (36) according to one of the preceding claims. [10] Method for detecting an axial position (x) of an axially displaceable rotary component (16) of a decoupling unit (10) according to claim 9, said rotary component being rotatable about a rotational axis (14), with a sensor system (36) according to one of claims 1 to 8.

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