Magnetic measuring arrangement and corresponding sensor arrangement for motion detection of a moving component

Abstract

Sensor arrangement (30a, 30b, 30c) for motion detection of a moving component (58) comprising a transducer (50), a sensor (40a, 40b, 40c), and a magnetic measuring arrangement for motion detection of the moving component (58) comprising at least one permanent magnet (5, 25) and at least one sensor element (7, 27) for detecting at least one magnetic quantity, wherein the at least one permanent magnet (5, 25) and the at least one sensor element (7, 27) are arranged to be movable at a distance from each other, wherein a movement of the moving component (58) causes a change in the detected at least one magnetic quantity, which can be evaluated to determine an angle of rotation and / or a position of the moving component (58), wherein the magnetic measuring arrangement further comprises at least one shielding element (10, 10a, 10b, 10c, 10d, 10e, 10f, 10g) which is made of a magnetically conductive material and arranged in such a way,that it at least partially encloses the at least one permanent magnet (5, 25) and / or the at least one sensor element (7, 27), characterized in that the measuring transducer (40a, 40b, 40c) has a first housing (42a, 42b, 42c) in which the at least one sensor element (7, 27) is arranged and the measuring transmitter (50) has a second housing (52) in which the at least one permanent magnet (5, 25) is arranged, wherein the second housing (52) has a recess (54) into which the at least one shielding element (10, 10d) is inserted, and wherein the at least one shielding element (10, 10d) is designed as a slotted frame with a larger outer diameter than the recess (54) and is inserted into the recess (54) under tension.

Description

State of the art

[0001] The invention relates to a magnetic measuring arrangement for motion detection of a moving component according to the preamble of independent claim 1.

[0002] German patent application DE 10 2009 055 104 A1 describes a magnetic field sensor arrangement for position detection on translationally movable components. In the described magnetic field sensor arrangement, spatial components of the magnetic field of a magnetic system on the moving component change their direction along the path to be detected, so that their position relative to a stationary sensor can be detected accordingly. The linear component, which is movable in one further degree of freedom, has at least one magnet as part of the magnetic system, to which at least one opposite stationary, magnetic field-sensitive sensor is assigned at a predetermined distance.

[0003] German patent application DE 10 2007 024 867 A1 describes a measuring device for the non-contact detection of a rotation angle. The described measuring device comprises a first body on which a magnet is arranged at a radial distance from an axis of rotation, and a second body with a magnetic field-sensitive element for generating a measurement signal. In this arrangement, the magnetic field-sensitive element and the magnet are tangentially arranged with respect to a circular path of the relative motion during a relative movement between the first and second bodies, wherein the magnet is radially magnetized or polarized in a plane arranged perpendicular to the radial direction relative to the axis of rotation.

[0004] German patent application DE 10 2008 020 153 A1 describes an angle detection device. The described device comprises a rotating element with at least one magnetic north pole region and at least one magnetic south pole region, which are arranged alternately around a center of rotation; a magnetic field detection section with a magnetic plate and detection elements that detect the magnitudes of magnetic components in a direction perpendicular to the magnetic plate; and a computing unit that determines the angle of rotation of the rotating element. The magnetic field detection section is arranged such that the magnetic plate is oriented perpendicular to a first direction in which the magnetic field strength is at its maximum. The magnetic field detection section detects the magnitudes of the magnetic components in the first direction and in a second direction, which corresponds to the direction in which the magnetic north and south pole regions are arranged circumferentially.

[0005] Furthermore, JP 2010 - 139 351 A discloses a generic sensor arrangement for motion detection of a moving component.

[0006] Similar sensor arrangements are also known from JP H11 - 23 213 A, JP S53 - 107 844 U, DE 10 2009 048 389 A1 and US 2011 / 0254543 A1. Disclosure of the invention

[0007] In contrast, the magnetic measuring arrangement according to the invention for motion detection of a moving component with the features of independent claim 1 has the advantage that the influences of external magnetic fields are minimized by means of a shielding element.

[0008] Embodiments of the present invention advantageously enable the shielding element to be easily integrated into an existing design, so that no additional installation volume is required.

[0009] The core of the invention lies in the use of a shielding element made of a ferromagnetic or magnetically conductive material. The shielding element is arranged such that it at least partially encloses the at least one sensor element that detects a magnetic field and / or the at least one magnet that generates the magnetic field. For example, a shielding element can be provided that encloses both the at least one sensor element and the at least one magnet. Alternatively, a shielding element can be provided that encloses either the at least one sensor element or the at least one magnet. Furthermore, two shielding elements can be provided, wherein a first shielding element encloses the at least one sensor element and a second shielding element encloses the at least one magnet.This allows the generation of the magnetic field by the at least one magnet and / or the detection of the generated magnetic field by the at least one sensor element to be protected from external magnetic field influences, thus increasing the measurement accuracy. Embodiments of the present invention can be used both for measuring the rotation angle of rotating components and for measuring the position of translationally moving components.

[0010] Embodiments of the present invention provide a magnetic measuring arrangement for motion detection of a moving component, comprising at least one permanent magnet and at least one sensor element for detecting at least one magnetic quantity. The at least one permanent magnet and the at least one sensor element are arranged to be movable relative to each other, wherein a movement of the moving component causes a change in the detected at least one magnetic quantity, which can be evaluated to determine a rotation angle and / or a position of the moving component. According to the invention, at least one shielding element is provided, which is made of a magnetically conductive material and is arranged such that it at least partially encloses the at least one permanent magnet and / or the at least one sensor element.To change the detected at least one magnetic quantity, the at least one sensor or the at least one magnet can be connected to the moving component.

[0011] The magnetic measuring arrangement according to the invention is preferably used in a sensor arrangement for motion detection of a moving component, which comprises a measuring transmitter and a measuring transducer.

[0012] The measures and further developments listed in the dependent claims enable advantageous improvements to the magnetic measuring arrangement for motion detection of a moving component specified in independent claim 1.

[0013] In an advantageous embodiment of the magnetic measuring arrangement according to the invention, the at least one shielding element can be designed, for example, as a frame or bracket, or as a hollow body with a round or square cross-section. The at least one shielding element designed as a frame can be closed or have a gap. The frame can be closed, for example, by embossing or welding. The gap can, for example, have a straight, stepped, angled, or serrated contour. The contour of the gap is preferably selected such that the frames cannot become entangled during transport. To adapt to the design requirements of the sensor, the at least one shielding element can also be designed in any other desired geometry. For example, the at least one shielding element can also be designed as a pot or a hood.

[0014] In the embodiment of the sensor arrangement according to the invention, the sensor has a first housing in which the at least one sensor element is arranged. The sensor also has a second housing in which the at least one permanent magnet is arranged. The first housing can be connected to the second housing by means of connecting elements, which are, for example, designed as hollow rivets.

[0015] In a further advantageous embodiment of the sensor arrangement according to the invention, the at least one shielding element can be integrated into the first housing and / or the second housing, or at least partially enclose the first housing and / or the second housing. The at least one shielding element can be adapted to the first housing and / or the second housing and may have at least one recess and / or varying dimensions. The at least one shielding element may have recesses and vary in height and / or thickness to adapt to the housing of the sensor and / or the housing of the transducer. Furthermore, the at least one shielding element can be designed as a shielding hood that partially or completely encloses the first and / or second housing, or as a shielding pot that is integrated into the first and / or second housing.

[0016] In the embodiment of the sensor arrangement according to the invention, the second housing has a recess into which the at least one shielding element is inserted. Here, the at least one shielding element is designed as a slotted frame with a larger outer diameter than the recess and is inserted into the recess under tension.

[0017] In a further advantageous embodiment of the sensor arrangement according to the invention, the movable component can correspond to a pedal or a steering column.

[0018] Exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description. In the drawings, identical reference numerals denote components or elements that perform the same or analogous functions. Brief description of the drawings Fig. Figure 1 shows a schematic sectional view of a first embodiment of a magnetic measuring arrangement according to the invention for motion detection of a moving component. Fig. Figure 2 shows a schematic sectional view of a second embodiment of a magnetic measuring arrangement according to the invention for motion detection of a moving component. Fig. Figure 3 shows a schematic sectional view of a third embodiment of a magnetic measuring arrangement according to the invention for motion detection of a moving component. Fig. Figure 4 shows a schematic sectional view of a fourth embodiment of a magnetic measuring arrangement according to the invention for motion detection of a moving component. Fig. Figure 5 shows a schematic sectional view of a fifth embodiment of a magnetic measuring arrangement according to the invention for motion detection of a moving component. Fig. Figure 6 shows a schematic sectional view of a sixth embodiment of a magnetic measuring arrangement according to the invention for motion detection of a moving component. Fig. Figure 7 shows a schematic perspective view of a first embodiment of a shielding element for a magnetic measuring arrangement according to the invention for motion detection of a moving component. Fig. Figure 8 shows a schematic perspective view of a second embodiment of a shielding element for a magnetic measuring arrangement according to the invention for motion detection of a moving component. Fig. Figure 9 shows a schematic perspective view of a third embodiment of a shielding element for a magnetic measuring arrangement according to the invention for motion detection of a moving component. Fig. Figure 10 shows a schematic representation of a fourth embodiment of a shielding element for a magnetic measuring arrangement according to the invention for motion detection of a moving component. Fig. Figure 11 shows a schematic representation of a fifth embodiment of a shielding element for a magnetic measuring arrangement according to the invention for motion detection of a moving component. Fig. Figure 12 shows a schematic perspective view of a first embodiment of a sensor arrangement according to the invention for motion detection of a moving component in a pre-assembled state. Fig. Figure 13 shows a schematic perspective view of the first embodiment of a sensor arrangement according to the invention for motion detection of a moving component in a partially assembled state. Fig. Figure 14 shows a schematic sectional view of the first embodiment of a sensor arrangement according to the invention for detecting the motion of a moving component in an assembled state. Fig. Figure 15 shows a schematic perspective view of a second embodiment of a sensor arrangement according to the invention for motion detection of a moving component in an assembled state. Fig. Figure 16 shows a schematic sectional view of the third embodiment of a sensor arrangement according to the invention for detecting the motion of a moving component in an assembled state. Embodiments of the invention

[0019] To detect the angle of a rotating shaft, it is known in the art to detect the rotational movement of a magnet positioned centrally on the shaft. For this purpose, the rotation of the magnetic vector around the axis of rotation is detected using appropriately sensitive magnetic sensors, such as AMR and / or GMR sensors, Hall sensors, Hall sensors with integrated magnetic field concentrators, etc. The detection of the rotating magnetic vector is essential for the sensor element used. For example, if a magnet is designed as a round magnet and rotates in front of the sensor element, the magnetic vector also rotates. This rotational movement is detected by a sensor element positioned in front of the magnet, which is part of an ASIC (application-specific integrated circuit) and detects the magnetic vector parallel to the magnet surface.In two-dimensional or three-dimensional Hall sensors, this is achieved through indirect angle detection via an arctangent function of the directed magnetic flux densities. Such a Hall sensor can unambiguously detect the angular position of the round magnet over 360°. AMR sensors enable direct angle detection and, by their very nature, directly measure the angle of the magnetic vector. Devices for angle and displacement detection can be used in vehicles in various actuation systems for vehicle braking systems, for headlight range adjustment, for measuring the angular position of shafts, and especially for driver braking request detection at the brake pedal or driver acceleration request detection at the accelerator pedal. The magnetic flux density can be affected by external magnetic fields, such as those generated by current-carrying conductors, which can lead to signal deviations.

[0020] To detect the position of a translationally moving slide, the translational movement of at least one magnet coupled to the slide can be detected. For this purpose, the rotation of the magnetic vector along the at least one magnet is detected using appropriately sensitive magnetic sensors, such as AMR and / or GMR sensors, Hall sensors, Hall sensors with integrated magnetic field concentrators, or other 2D or 3D Hall or AMR sensors. The detection of the rotating magnetic vector is essential for the sensor element. For example, a translationally moving bar magnet can be used. As the bar magnet moves, the orientation of the magnetic field vectors changes relative to a fixed point. This change in orientation of the magnetic field vectors can be detected and evaluated by the at least one sensor element.This is achieved in a 2D or 3D Hall sensor element via arctangent calculation of the magnetic flux density or indirect angle detection via inplanar magnetic field components. Such a Hall sensor can unambiguously detect the angular position of the round magnet over a 360° range.

[0021] As from Fig. As can be seen in Figures 1 to 6, the illustrated embodiments of a magnetic measuring arrangement 1a, 1b, 1c, 1d, 20a, 20b according to the invention for detecting the motion of a moving component comprise at least one permanent magnet 5, 25 with a magnetic north pole region N and a magnetic south pole region S and at least one sensor element 7, 27 for detecting at least one magnetic quantity. The at least one permanent magnet 5, 25 and the at least one sensor element 7, 27 are arranged to be movable at a distance from each other, wherein a movement of the moving component causes a change in the detected at least one magnetic quantity, which can be evaluated to determine an angle of rotation and / or a position of the moving component.According to the invention, at least one shielding element 10, 10a, 10b, 10c, 10d, 10e, 10f, 10g is provided, which is made of a magnetically conductive material and is arranged in such a way that it at least partially encloses the at least one permanent magnet 5, 25 and / or the at least one sensor element 7, 27.

[0022] As from Fig. As can be seen from Figures 1 to 6, the at least one shielding element 10, 10a, 10b, 10c, 10d, 10e, 10f, 10g is arranged such that a vertical axis or longitudinal axis of the at least one shielding element 10, 10a, 10b, 10c, 10d, 10e, 10f, 10g is preferably perpendicular to a sensitive plane, which for example consists of a flux density B x along an x-direction and from a flux density B y is spanned along a y-direction.

[0023] In the Fig. In the embodiments shown in Figures 1 to 4, the magnetic measuring arrangement 1a, 1b, 1c, 1d according to the invention is used to detect the angle of rotation of a non-visible component rotating about a rotational axis 3, with which the at least one permanent magnet 5 is coupled. In an alternative embodiment not shown, the sensor element 7 is connected to the rotating non-visible component and the at least one permanent magnet 5 is arranged in a fixed position.

[0024] In the Fig. 5 and Fig. In the embodiments shown in Figure 6, the magnetic measuring arrangement 20a, 20b according to the invention is used to detect the position of a non-visible component moving translationally along a direction of movement 9, with which the at least one permanent magnet 25 is coupled. In an alternative embodiment not shown, the sensor element 27 is connected to the translationally moving non-visible component and the at least one permanent magnet 25 is arranged in a fixed position.

[0025] As from Fig. As can be seen further in Figure 1, the shielding element 10 in the illustrated first embodiment is designed as a frame 10a open at the top and bottom or as a hollow body with a round or square cross-section, which encloses both the sensor element 7 and the permanent magnet 5.

[0026] As from Fig. As can be seen further in Figure 2, the shielding element 10 in the second embodiment shown is designed as a pot 10b or hollow body open at the bottom with a round or square cross-section, which encloses both the sensor element 7 and the permanent magnet 5.

[0027] As from Fig. As can be seen further in Figure 3, the shielding element 10 in the third embodiment shown is designed as a frame 10c open at the top and bottom with a round or square cross-section, which only encloses the sensor element 7.

[0028] As from Fig. As can be seen further in Figure 4, the shielding element 10 in the fourth embodiment shown is designed as a frame 10d open at the top and bottom with a round or square cross-section, which only encloses the permanent magnet 5.

[0029] As from Fig. As can be seen further in Figure 5, the shielding element 10 in the fifth embodiment shown is designed as a bottom-open pot 10e or bracket with a square cross-section, which completely encloses the sensor element 27 and partially encloses the permanent magnet 25.

[0030] As from Fig. As can be seen further in Figure 6, the shielding element 10 in the fifth embodiment shown is designed as a ring or a hollow body open at the front and rear with a square cross-section, which encloses the sensor element 27 and the permanent magnet 25.

[0031] As from Fig. As can be seen from Figures 7 to 11, in the illustrated embodiments the shielding elements 10, designed as frames, each comprise a base body 12a, 12b, 12c, 12d, 12e with a gap 14a, 14b, 14c, 14d, 14e.

[0032] As from Fig. As can be seen further in Figure 7, the base body 12a of the depicted shielding element 10 has a round cross-section and a gap 14a with a stepped contour.

[0033] As from Fig. As can be seen further in Figure 8, the base body 12b of the depicted shielding element 10 has a square cross-section and a gap 14b with a slanted contour.

[0034] As from Fig. As can be seen further in Figure 9, the base body 12c of the depicted shielding element 10 has a rectangular cross-section and a gap 14c with an oblique contour. In addition, two sides of the base body 12c have different heights, and recesses 16 are provided in two other sides of the base body 12c.

[0035] As from Fig. As can be seen further in Figure 10, the basic body 12d of the depicted shielding element 10 has a square or round cross-section and a gap 14d with a straight contour.

[0036] As from Fig. As can be seen further in Figure 11, the base body 12e of the depicted shielding element 10 has a square or round cross-section and a gap 14e with a jagged contour.

[0037] As from Fig. As can be seen from Figures 12 to 16, the illustrated embodiments of a sensor arrangement 30a, 30b, 30c according to the invention for motion detection of a moving component 58 each comprise a measuring transmitter 50 and a measuring transducer 40a, 40b, 40c. Fig. As can be seen further in Figures 12 to 16, the measuring transducer 40a, 40b, 40c has a first housing 42a, 42b, 42c in which the at least one sensor element 7 is arranged. The measuring transmitter 50 has a second housing 52 in which the at least one permanent magnet 5 is arranged. Furthermore, the first housing 42a, 42b, 42c is connected to the second housing 52 by means of connecting elements 44, for example, hollow rivets. To fasten the sensor assembly 30a, 30b, 30c in the vehicle, screws can be passed through the hollow rivets and tightened in corresponding receptacles.

[0038] As from Fig. As can be seen further in Figures 12 to 16, the illustrated embodiments of the sensor arrangement 30a, 30b, 30c according to the invention are used to detect a rotary movement of an actuating lever 58, which is coupled to a pedal (not shown) in order to detect a driver request at the brake pedal or accelerator pedal. Fig. As can be seen further in Figures 12 to 16, the measuring transmitter 50 is identical in the illustrated embodiments. Here, a shaft connected to the at least one permanent magnet 5 is rotated by the actuating lever 5 against the force of a return spring 59 by the pedal (not shown). Above the permanent magnet 5, at a defined distance representing a magnetic air gap, is the at least one sensor element 7, which is preferably implemented as an ASIC (application-specific integrated circuit). The at least one sensor element 7 detects at least one magnetic quantity that changes due to the rotational movement of the at least one permanent magnet 5. This allows the at least one sensor element 7 to supply a signal to a downstream evaluation circuit of the ASIC, which can be converted into the absolute rotation angle experienced by the actuating lever 5.

[0039] As from Fig. As can be seen further in Figures 12 to 16, the housing 52 of the sensor 50 has a recess 54 into which a shielding element 10, 10d, designed as a slotted frame 10d with a round cross-section, is inserted. Advantageously, the shielding element 10, 10d has a larger outer diameter than the recess 54 and is inserted and positioned under tension in the recess 54. Additionally, a seal 56 is arranged in the recess 54, bearing against the inside of the shielding element 10, 10d.

[0040] As from Fig. As can be seen further in Figures 12 to 14, the illustrated first embodiment of the sensor arrangement 30a according to the invention has only one shielding element 10, 10d, which is arranged in the second housing 52 of the measuring transmitter 50 in such a way that it surrounds the at least one permanent magnet 5.

[0041] As from Fig. As can be seen further in Figure 15, the illustrated second embodiment of the sensor arrangement 30b according to the invention has, in addition to the shielding element 10, 10d arranged in the second housing 52 of the measuring transmitter 50, a further shielding element 10 designed as a hood 10g, which partially encloses the first housing 42b of the measuring transducer 40b and thus the at least one sensor element 7.

[0042] As from Fig. As can be seen further in Figure 16, the illustrated third embodiment of the sensor arrangement 30c according to the invention has, in addition to the shielding element 10, 10d arranged in the second housing 52 of the measuring transmitter 50, a further shielding element 10 designed as a pot 10b, which is integrated into the first housing 42c of the measuring transducer 40c and which encloses at least one sensor element 7.

[0043] Embodiments of the present invention enable, through the at least one shielding element, a minimization of the influence of external magnetic fields and a simple integration of the shielding element into the existing housing design, so that no additional installation volume is required.

Claims

[1] Sensor arrangement (30a, 30b, 30c) for motion detection of a moving component (58) comprising a transducer (50), a sensor (40a, 40b, 40c) and a magnetic measuring arrangement for motion detection of the moving component (58) comprising at least one permanent magnet (5, 25) and at least one sensor element (7, 27) for detecting at least one magnetic quantity, wherein the at least one permanent magnet (5, 25) and the at least one sensor element (7, 27) are arranged to be movable relative to each other, wherein a movement of the moving component (58) causes a change in the detected at least one magnetic quantity, which can be evaluated to determine an angle of rotation and / or a position of the moving component (58), wherein the magnetic measuring arrangement further comprises at least one shielding element (10, 10a, 10b, 10c, 10d, 10e, 10f, 10g) which is made of a magnetically conductive material and arranged in such a way,that it at least partially encloses the at least one permanent magnet (5, 25) and / or the at least one sensor element (7, 27), , characterized by , that the sensor (40a, 40b, 40c) has a first housing (42a, 42b, 42c) in which the at least one sensor element (7, 27) is arranged and the transmitter (50) has a second housing (52) in which the at least one permanent magnet (5, 25) is arranged, wherein the second housing (52) has a recess (54) in which the at least one shielding element (10, 10d) is inserted, and wherein the at least one shielding element (10, 10d) is designed as a slotted frame with a larger outer diameter than the recess (54) and is inserted into the recess (54) under tension. [2] Sensor arrangement (30a, 30b, 30c) according to claim 1, characterized by, that the at least one shielding element (10, 10d) is designed with a gap (14a, 14b, 14c, 14d, 14e) wherein the gap (14a, 14b, 14c, 14d, 14e) has a straight or stepped or oblique or jagged contour. [3] Sensor arrangement (30a, 30b, 30c) according to claim 1 or 2, characterized by , that the at least one shielding element (10, 10d) has a round cross-section. [4] Sensor arrangement (30a, 30b, 30c) according to any one of the preceding claims, characterized by , that the at least one shielding element (10, 10d) in the second housing (52) is arranged such that it surrounds the at least one permanent magnet (5). [5] Sensor arrangement (30a, 30b, 30c) according to any one of the preceding claims, characterized by , that the at least one shielding element (10, 10d) is arranged in the recess (54) such that an outer surface of the shielding element (10, 10d) contacts the second housing (52). [6] Sensor arrangement (30a, 30b, 30c) according to any one of the preceding claims, characterized by a seal (56) which is arranged in the recess (54) such that it rests against an inner side of the at least one shielding element (10, 10d). [7] Sensor arrangement (30a, 30b, 30c) according to any one of the preceding claims, characterized by , that the first housing (42a, 42b, 42c) is connected to the second housing (52) via connecting elements (44). [8] Sensor arrangement (30a, 30b, 30c) according to any one of the preceding claims, characterized by , that the at least one shielding element (10, 10d) is adapted to the second housing (52) and has at least one recess (16) and / or varying dimensions. [9] Sensor arrangement (30a) according to one of the preceding claims, characterized by , that a single shielding element (10, 10d) is provided. [10] Sensor arrangement (30b) according to any one of claims 1 to 8, characterized bya single shielding element (10, 10d) arranged in the second housing (52) and at least one further shielding element (10g) which is designed as a hood and which partially encloses the first housing (42b) and the at least one sensor element (7). [11] Sensor arrangement (30c) according to any one of claims 1 to 8, characterized by a single shielding element (10, 10d) arranged in the second housing (52) and at least one further shielding element (10b) which is designed as a pot and which is integrated into the first housing (42c) and which encloses at least one sensor element (7).

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