JP7306418B2 - Angle detection devices, angle detection systems, parking lock systems, and pedal systems - Google Patents

Description

TECHNICAL FIELD The present invention relates to an angle detection device, an angle detection system , a parking lock system, and a pedal system provided with a magnetic detection element.

2. Description of the Related Art An angle detection device suitable for a throttle opening sensor for detecting the opening of a throttle valve of an internal combustion engine, for example, has been proposed so far (see, for example, Patent Document 1). In the angle detection device of Patent Document 1, changes in magnetic flux generated by rotating magnetic field generating means are detected using a spin-valve giant magnetoresistive element (SV-GMR element).

Also, there is provided a magnetic detection encoder comprising a magnetic detection element for detecting magnetism, a magnet for forming a magnetic field necessary for the operation of the magnetic detection element, and a magnetic shield cover covering the magnetic detection element and the magnet. It has been proposed (see Patent Document 2, for example).

JP 2006-208252 A JP 2015-169439 A

By the way, the angle detection device is required to further improve the angle detection accuracy.

Therefore, it is desired to provide an angle detection device capable of exhibiting high detection accuracy.

An angle detection device as an embodiment of the present invention includes a magnetic detection element, a magnetic field generation member that forms a magnetic field applied to the magnetic detection element, and a magnetic field between the magnetic detection element and the magnetic field generation member in a first direction. a yoke positioned in the The magnetic field generating member , the yoke, and the magnetic detection element are provided relatively rotatable around a rotation axis along the first direction. The yoke has a planar shape curved in an arc along the circumferential direction of a circle centered on the rotation axis on a plane orthogonal to the rotation axis. The yoke includes a portion whose dimension in the first direction increases with increasing distance from the axis of rotation along a plane orthogonal to the axis of rotation.

In the angle detection device as one embodiment of the present invention, the yoke has a planar shape curved in an arc along the circumferential direction of a circle centered on the rotation axis in a plane perpendicular to the rotation axis. along a plane perpendicular to the axis of rotation, the dimension in the first direction increases with increasing distance from the axis of rotation. For this reason, even if there is a deviation in the relative positions of the magnetic detection element, the magnetic field generating member , and the yoke, the magnetic detection element is less likely to affect the detection angle error.

According to the angle detection device as one embodiment of the present invention, high angle detection accuracy can be obtained even when the relative positions of the magnetic detection element, the magnetic field generating member , and the yoke are displaced.

1 is a schematic perspective view showing an example of the overall configuration of an angle detection system according to an embodiment of the invention; FIG. 1B is an exploded perspective view of the angle detection device shown in FIG. 1A; FIG. 1B is a schematic plan view of a magnetic field generation module in the angle detection device shown in FIGS. 1A and 1B; FIG . 1B is a cross-sectional view of the angle detection device shown in FIGS. 1A and 1B; FIG . 1 is a cross-sectional view of an angle detection device as a first reference example; FIG. 5 is a characteristic diagram comparing detected angle errors between the angle detection device according to the embodiment of the present invention shown in FIG. 1A and the angle detection device shown in FIG. 4; FIG. FIG. 11 is an explanatory diagram showing an example of a magnetic flux density distribution of an angle detection device as a second reference example; 6B is a perspective view showing a configuration example of an annular magnet used in the angle detection device of FIG. 6A; FIG. 1B is an explanatory diagram showing an example of a magnetic flux density distribution of the angle detection device according to the embodiment of the invention shown in FIG. 1A; FIG. FIG. 10 is a characteristic diagram showing detected angle errors caused by positional deviation between the magnetic detecting element and the rotating shaft in the angle detecting devices of Experimental Examples 1-1 to 1-5; FIG. 10 is a perspective view schematically showing the appearance of a yoke in the angle detection device of Experimental Example 1-2; FIG. 11 is a perspective view schematically showing the appearance of a yoke in the angle detection device of Experimental Example 1-3; FIG. 10 is a contour diagram schematically showing the magnetic flux density distribution of the magnetic field component in the facing direction of the pair of magnets of the angle detection device of Experimental Example 2-1. FIG. 10 is an explanatory diagram schematically showing a magnetic flux density vector on a plane perpendicular to the rotation axis of the angle detection device of Experimental Example 2-1; FIG. 10 is a contour diagram schematically showing the magnetic flux density distribution of the magnetic field component in the facing direction of the pair of magnets of the angle detection device of Experimental Example 2-2. FIG. 10 is an explanatory diagram schematically showing a magnetic flux density vector on a plane perpendicular to the rotation axis of the angle detection device of Experimental Example 2-2; FIG. 10 is a contour diagram schematically showing the magnetic flux density distribution of the magnetic field component in the facing direction of the pair of magnets of the angle detection device of Experimental Example 2-3. FIG. 10 is an explanatory diagram schematically showing a magnetic flux density vector on a plane perpendicular to the rotation axis of the angle detection device of Experimental Example 2-3; FIG. 10 is a contour diagram schematically showing the magnetic flux density distribution of the magnetic field component in the facing direction of the pair of magnets of the angle detection device of Experimental Example 2-4. FIG. 10 is an explanatory diagram schematically showing a magnetic flux density vector on a plane perpendicular to the rotation axis of the angle detection device of Experimental Example 2-4; FIG. 10 is a contour diagram schematically showing the magnetic flux density distribution of the magnetic field component of the annular magnet of the angle detection device of Experimental Example 2-5. FIG. 10 is an explanatory diagram schematically showing a magnetic flux density vector on a plane perpendicular to the rotation axis of the angle detection device of Experimental Example 2-5; FIG. 12 is a cross-sectional view of the angle detection device of Experimental Example 4-1; 1 is a first schematic diagram of a parking lock system as a first application example to which an angle detection device of the present invention is applied; FIG. FIG. 2 is a second schematic diagram of a parking lock system as a first application example to which the angle detection device of the present invention is applied; 1 is a first schematic diagram of a pedal system as a second application example to which an angle detection device of the present invention is applied; FIG. FIG. 4 is a second schematic diagram of a pedal system as a second application example to which the angle detection device of the present invention is applied;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The description will be given in the following order.
1. one embodiment;2. Experimental example 3. Application example 4. Other variations

<1. one embodiment>
[Configuration of Angle Detection System 100]
First, the configuration of an angle detection system 100 as one embodiment of the present invention will be described with reference to FIGS. 1A to 3. FIG.

FIG. 1A is a perspective view showing an example of the overall configuration of the angle detection system 100. FIG. FIG. 1B is an exploded perspective view of an angle detection device 10 (described later) that constitutes the angle detection system 100. FIG. FIG. 2 is a schematic plan view for explaining the mutual positional relationship in a plane orthogonal to the rotation axis J1 (described later) of the magnetic field generation module 2 (described later) of the angle detection system 100. FIG. The term "perpendicular" as used in the present application includes not only the concept of intersecting at 90°, which is a perfect orthogonality, but also the concept of being substantially orthogonal (for example, intersecting at about 90°±5°). Therefore, the schematic plan view shown in FIG. 2 may represent a plane at an angle slightly deviated from 90° with respect to the rotation axis J1. FIG. 2 shows the magnetic field generation module 2 viewed from a sensor chip 11 (described later) of the sensor module 1 (described later). However, in FIG. 2, the outline of the magnetic detection element 41 (described later) included in the sensor module 1, the cross section of the magnetic shield 12 (described later), and the outline of the support 4 (described later) supporting the magnetic field generation module 2 are also shown. It is described with a solid line or a dashed line. FIG. 3 is a cross-sectional view showing a cross section of the angle detection device 10 along the rotation axis J1. However, FIG. 3 also shows the support 4 . The angle detection system 100 is, for example, a device that detects the rotation angle of a rotating member that rotates, and can be applied, for example, as a throttle opening sensor that detects the opening of a throttle valve of an internal combustion engine mounted on an automobile or the like.

As shown in FIG. 1A, the angle detection system 100 comprises, for example, an angle detection device 10, a support 3 and a support 4. As shown in FIG. The angle detection device 10 has, for example, a sensor module 1 and a magnetic field generation module 2 . The sensor module 1 is supported by a support 3, for example, and the magnetic field generating module 2 is supported by a support 4, for example. The magnetic field generation module 2 includes, for example, a magnetic field generation section 20 and a yoke section 30 . The magnetic field generating section 20 has a magnetic field generating member that forms a magnetic field to be detected by the sensor module 1, and is rotatable about the rotation axis J1 with respect to the sensor module 1, for example, in the rotation direction R1. ing. The sensor module 1 has a magnetic detection element as described later. This magnetic detection element detects, for example, the intensity of the magnetic field to be detected formed by the magnetic field generating member, the direction of the magnetic field to be detected, and the like. The yoke portion 30 is arranged in a magnetic field effect region between the magnetic field generating portion 20 and the sensor module 1 in the rotation axis direction and is affected by the magnetic field to be detected, and is rotatably provided integrally with the magnetic field generating portion 20. there is

(Sensor module 1)
The sensor module 1 has, for example, a sensor chip 11, a magnetic shield 12, a terminal portion 13, a holder 14, and a circuit board 15. As shown in FIG. The sensor chip 11 is arranged, for example, on the rotation axis J1. A center position CP of the sensor chip 11 in a plane perpendicular to the rotation axis J1 may be aligned with the rotation axis J1. As shown in FIG. 2, the sensor chip 11 has, for example , a magnetic detection element 41 as the magnetic detection element. The magnetic detection element 41 detects, for example, the strength of the detection target magnetic field formed by the magnetic field generating member. The magnetic detection element 41 is an element capable of detecting the intensity of a magnetic field, such as a Hall element. The magnetic detection element 41 has, for example, a sensitivity axis along a plane perpendicular to the rotation axis J1. That is, when the magnetic detection element 41 is a Hall element, the magnetic detection element 41 can detect the magnetic field strength along the plane perpendicular to the rotation axis J1. The magnetic detection element 41 is preferably located at the center position CP in the plane perpendicular to the rotation axis J1.

The magnetic shield 12 has a first shield portion 121 and a second shield portion 122 as shown in FIG. 3, for example. The first shield portion 121 and the second shield portion 122 are preferably integrated with each other. The magnetic shield 12 may be integrated by collectively forming the first shield portion 121 and the second shield portion 122 . Further, the magnetic shield 12 may be formed by integrating the first shield portion 121 and the second shield portion 122, which are separately formed, with an adhesive or the like. Also, the first shield portion 121 and the second shield portion 122 need only be magnetically connected to each other even if they are not integrated. The first shield portion 121 and the second shield portion 122 may be composed of a soft ferromagnetic material such as Permalloy (NiFe).

The first shield part 121 is provided so as to surround the sensor chip 11 along a plane perpendicular to the direction of the rotation axis J1. The first shield portion 121 has, for example, a substantially cylindrical shape. However, the planar shape of the inner surface and outer surface of the first shield portion 121 is not limited to a circle, and may be an elliptical shape or a polygonal shape. Further, the first shield part 121 may be provided so as to surround part or all of the yoke part 30 and part or all of the magnets 21 and 22 along a plane perpendicular to the rotation axis direction. .

The second shield portion 122 is provided on the side opposite to the magnetic field generation module 2 when viewed from the sensor chip 11 . The second shield portion 122 is, for example, a disk-shaped member extending along a plane perpendicular to the rotation axis J1. A holder 14 is attached to the second shield portion 122 . The holder 14 has a protrusion 14T. The holder 14 is fixed to the second shield portion 122 by press-fitting the protrusion 14T into the opening 12K1 provided in the second shield portion 122 . The terminal portion 13 is erected on the holder 14 and passes through the opening 12K2 provided in the second shield portion 122. As shown in FIG. The terminal portion 13 includes, for example, a main body 131 and leads 132 . The body 131 may be integrated with the holder 14 . A circuit board 15 is attached to the surface of the holder 14 opposite to the second shield portion 122 . The ends of the leads 132 are connected to the circuit board 15 . Furthermore, the sensor chip 11 is provided on the side of the circuit board 15 opposite to the holder 14 . A signal from the sensor chip 11 can be taken out to the outside through the circuit board 15 and the lead 132 . An opening 12K2 may be provided in the first shield portion 121, and the terminal portion 13 may be provided so as to penetrate the opening 12K2 in a direction perpendicular to the rotation axis J1. However, providing the opening 12K in the second shield portion 122 rather than providing the opening 12K2 in the first shield portion 121 can enhance the shielding effect of the magnetic field on the sensor chip 11 by the magnetic shield 12 .

(Magnetic field generator 20)
The magnetic field generator 20 has, for example, magnets 21 and 22 as magnetic field generating members. Both magnets 21 and 22 may have a shape that basically has only flat surfaces, such as a substantially cubic shape or a substantially rectangular parallelepiped shape. The magnets 21 and 22 are spaced apart from each other around the rotation axis J1. For example, it is preferable that the distance between the magnet 21 and the rotation axis J1 is equal to the distance between the magnet 22 and the rotation axis J1. Here, the distance between the magnet 21 and the rotation axis J1 and the distance between the magnet 22 and the rotation axis J1 are, for example, as shown in FIG. a distance 21D between the geometric center position P21 and the rotation axis J1, and a distance 22D between the geometric center position P22 of the magnet 22 and the rotation axis J1. The magnetic detection element 41 is preferably arranged at a position coinciding with the position of the rotation axis J1 in the in-plane direction along the plane orthogonal to the rotation axis J1. Also, the materials, shapes and sizes of magnets 21 and 22 are preferably substantially the same. The magnets 21 and 22 are preferably provided at rotationally symmetrical positions with respect to the rotation axis J1 so as to face each other across the rotation axis J1, for example. Moreover, as shown in FIG. 3, the magnets 21 and 22 are both magnetized in the rotation axis direction. Materials constituting the magnets 21 and 22 include, for example, neodymium magnet materials such as NdFeB and rare earth magnet materials such as SmCo.

(Yoke portion 30)
The yoke portion 30 has, for example, a yoke 31 and a yoke 32 that are spaced apart from each other around the rotation axis J1. The yoke 31 and the yoke 32 each have, for example, a planar shape curved in an arc shape along the direction of rotation about the rotation axis J1, ie, the rotation direction R1, in a cross section orthogonal to the rotation axis J1. The central angle of the arc-shaped yokes 31 and 32 viewed from the rotation axis J1 is determined by, for example, a combination of the position of the magnetic detection element 41, the position of the magnet 21, the position of the magnet 22, and the position of the magnetic shield 12. be.

Each of the yokes 31 and 32 includes a portion whose height dimension in the direction of the rotation axis increases as the distance from the rotation axis J1 increases along a plane orthogonal to the rotation axis J1. Specifically, in the yoke 31, for example, the inner end face facing the rotation axis J1 has the smallest height dimension 31H1, and the outer end face opposite to the rotation axis J1 has the largest height dimension 31H2. The yoke 31 has an inclined surface S31. The upper surface S31, which is an inclined surface, is inclined with respect to the rotation axis J1 and is also inclined with respect to a plane orthogonal to the rotation axis J1. Although the upper surface S31 of the yoke 31 is inclined in the examples shown in FIGS. 1B and 3, the lower surface of the yoke 31, that is, the surface facing the magnet 21 may be inclined. However, when the surface of the yoke 31 facing the magnet 21 is an inclined surface, the upper surface of the magnet 21, that is, the surface of the magnet 21 facing the yoke 31 is also an inclined surface along the inclined surface of the yoke 31. I hope it is. In any case, it is preferable that the yoke 31 and the magnet 21 are in close contact with each other so that there is no gap between them. Similarly, in the yoke 32, for example, the inner end face facing the rotation axis J1 has the smallest height dimension 32H1, and the outer end face opposite to the rotation axis J1 has the largest height dimension 32H2. The yoke 32 has an inclined surface S32. The upper surface S32, which is an inclined surface, is inclined with respect to the rotation axis J1 and is also inclined with respect to a plane orthogonal to the rotation axis J1. Although the upper surface S32 of the yoke 32 is an inclined surface in the examples shown in FIGS. 1B and 3, the lower surface of the yoke 32, that is, the surface facing the magnet 22 may be an inclined surface. However, when the surface of the yoke 32 facing the magnet 22 is an inclined surface, the upper surface of the magnet 22, that is, the surface of the magnet 22 facing the yoke 32 is also an inclined surface along the inclined surface of the yoke 32. I hope it is. In any case, it is preferable that the yoke 32 and the magnet 22 are in close contact with each other so that there is no gap between them.

The yoke 31 and the yoke 32 are preferably provided at rotationally symmetrical positions with respect to the rotation axis J1 so as to face each other with the rotation axis J1 interposed therebetween. The yokes 31 and 32 are positioned to overlap the magnets 21 and 22, respectively, in the rotation axis direction, for example. Moreover, as shown in FIG. 3, the yokes 31 and 32 are provided so as to be in contact with the magnets 21 and 22, respectively. Yoke 31 and yoke 32 may be arranged separately from magnet 21 and magnet 22, respectively. However, the yokes 31 and 32 are preferably magnetically connected to the magnets 21 and 22, respectively. Also, for example, the distance between the yoke 31 and the rotation axis J1 is preferably equal to the distance between the yoke 32 and the rotation axis J1. The distance between the yoke 31 and the rotation axis J1 and the distance between the yoke 32 and the rotation axis J1 here refer to the geometrical a distance 31D between the theoretical center position P31 and the rotation axis J1, and a distance 32D between the geometric center position P32 of the yoke 32 and the rotation axis J1. In the magnetic field generating module 2 of this embodiment, the center position P31 of the yoke 31 matches the center position P21 of the magnet 21, and the center position P32 of the yoke 32 matches the center position P22 of the magnet 22. , that is, the case where the distances 21D, 22D, 31D, and 32D all match. Therefore, the magnetic detection element 41 is positioned on the rotation axis J1 in the in-plane direction along the plane perpendicular to the rotation axis J1. Furthermore, the material, shape and size of each of yoke 31 and yoke 32 are preferably substantially the same as each other. Therefore, for example, the height dimension 31H1 and the height dimension 32H1 may be substantially the same, and the height dimension 31H2 and the height dimension 32H2 may be substantially the same. Moreover, the inclination angle of the inclined surface S31 with respect to the rotation axis J1 and the inclination angle of the inclined surface S32 with respect to the rotation axis J1 are preferably substantially the same. Here, the height dimension 21H of the magnet 21 in the rotation axis direction is greater than the height dimension 31H2 of the yoke 31 in the rotation axis direction. Similarly, the height dimension 22H of the magnet 22 in the rotation axis direction is greater than the height dimension 32H2 of the yoke 32 in the rotation axis direction. Examples of materials constituting each of the yokes 31 and 32 include soft magnetic materials such as NiFe.

As described above, in the angle detection device 10, the first shield portion 121 partially or entirely covers the yoke portion 30 and also partially or entirely the magnets 21 and 22 in a plane perpendicular to the rotation axis J1. It is preferable that it is provided so as to surround along. In that case, as shown in FIG. 3, in the angle detection device 10, the distance 121D between the inner surface IS121 of the first shield portion 121 and the rotation axis J1 is longer than the distance 21D2 between the outer surface OS21 of the magnet 21 and the rotation axis J1. getting longer. Also, the distance 121D between the inner surface IS121 of the first shield portion 121 and the rotation axis J1 is longer than the distance 31D2 between the outer surface OS31 of the yoke 31 and the rotation axis J1. Note that FIG. 3 shows a configuration example in which the distance 21D2 and the distance 31D2 match. Similarly, the distance 121D is longer than the distance 22D2 between the outer surface OS22 of the magnet 22 and the rotation axis J1. The distance 121D is longer than the distance 32D2 between the outer surface OS32 of the yoke 32 and the rotation axis J1. Note that FIG. 3 shows a configuration example in which the distance 22D2 and the distance 32D2 match. Furthermore, as shown in FIG. 3, at least a portion of each of the magnets 21 and 22 is provided so as to overlap the first shield portion 121 in a plane direction along a plane perpendicular to the direction of the rotation axis J1. It's good to be

(Support 4)
The support 4 is a member for supporting the magnets 21 and 22 and has, for example, a disk shape. The support 4 has, for example, a mounting hole 4K in its center, and is configured to be attachable to the rotating body with a screw or the like. When the angle detection system 100 is applied as the throttle opening sensor described above, the support 4 is connected to, for example, a rotating shaft of a throttle valve, which is a rotating body, and the support 3 is fixed to, for example, a frame of an internal combustion engine. It will happen. The yokes 31 and 32 are fixed to the magnets 21 and 22, for example. However, the yoke 31 and the yoke 32 may be indirectly fixed to the support 4 without being directly fixed. In any case, the magnetic field generating section 20 and the yoke section 30 are integrally provided with the support 4 so as to be rotatable in the rotational direction R1.

[Operation of Angle Detection System 100]
In the angle detection system 100, when a rotating body (for example, a rotating shaft of a throttle valve) to which the support 4 is attached rotates, the support 4, the magnetic field generating section 20 and the yoke section 30 rotate together in the rotation direction R1. . Along with this, the direction of the detection target magnetic field (magnetic flux) passing through the sensor chip 11 of the sensor module 1 changes periodically. As a result, the magnetic detection element 41 in the sensor chip 11 detects a strong magnetic field (magnetic flux) that varies in a sinusoidal curve according to the rotation angle of the magnetic field generating module 2 . Therefore, the rotation angle of the rotating body to which the magnetic field generating module 2 is fixed can be obtained from the value of the magnetic field (magnetic flux) detected by the magnetic detection element 41 .

[Effects of Angle Detection System 100]
The angle detection device 10 of the angle detection system 100 of the embodiment described above includes a sensor module 1 and a magnetic field generation module 2 . The sensor module 1 has a sensor chip 11 and a magnetic shield 12 . Sensor chip 11 includes a magnetic detection element 41 . The magnetic shield 12 is provided so as to surround the magnetic detection element 41 . The magnetic field generation module 2 has a magnetic field generation section 20 and a yoke section 30 . Magnetic field generator 20 includes magnets 21 and 22 . Yoke portion 30 includes yokes 31 and 32 . Magnets 21 and 22 are adapted to form a magnetic field applied to magnetic detection element 41 . The yokes 31 and 32 are arranged between the magnetic detection element 41 and the magnets 21 and 22 in the rotation axis direction.

As described above, since the angle detection device 10 has the magnetic shield 12, even if the magnetic detection element 41 does not have a magnetic noise canceling function, the angle detection as the first reference example shown in FIG. The angle detection accuracy is improved compared to the case where the component corresponding to the magnetic shield 12 is not provided like the device 110A. That is, according to the angle detection device 10, changes in the relative angle between the sensor module 1 and the magnetic field generation module 2 can be detected with high accuracy. This is because the magnetic shield 12 shields an unnecessary disturbance magnetic field other than the magnetic field generated by the magnetic field generator 20 and reduces the disturbance magnetic field reaching the magnetic detection element 41 . In particular, in angle detection device 10 of the present embodiment, magnetic shield 12 has a structure in which first shield portion 121 and second shield portion 122 are connected. Therefore, the disturbance magnetic field along the in-plane direction perpendicular to the rotation axis J1 can be shielded by the first shield portion 121, and the disturbance magnetic field along the rotation axis direction along the rotation axis J1 can be shielded by the second shield portion 122. can. Therefore, the intensity of the disturbance magnetic field reaching the magnetic detection element 41 can be made extremely small. The opening of the magnetic shield 12 is formed on the side opposite to the second shield portion 122 when viewed from the sensor chip 11. Magnets 21 and 22 for generating a magnetic field to be applied to the magnetic detection element 41 are provided in the opening. ing. Therefore, the influence of the disturbance magnetic field entering from the opening of the magnetic shield 12 and reaching the sensor chip 11 can be sufficiently reduced. FIG. 4 is a cross-sectional view of an angle detection device 110A as a first reference example, and corresponds to FIG. 3 which is a cross-sectional view of the angle detection device 10 of the present embodiment. However, if other measures are taken to reduce the influence of the disturbance magnetic field, such as the magnetic detection element 41 having a magnetic noise canceling function, the magnetic shield 12 may not be provided.

FIG. 5 shows the angle detection device 10 of the present embodiment and the angle detection device as a first reference example when angle detection is performed while applying a disturbance magnetic field of 3000 A/m in a plane perpendicular to the rotation axis J1. It is an example of the result of comparing the detection angle error with the angle detection device 110A (FIG. 4). 5, the horizontal axis represents the rotation angle [deg. ], and the vertical axis indicates the error of the angle detected by the sensor chip 11 [deg. ] is shown. A curve C10 represents the angle error of the angle detection device 10 of the present embodiment, and a curve C110A represents the angle error of the angle detection device 110A of the first reference example. As shown in FIG. 5, in the angle detection device 110A as the first reference example, approximately ±4 [deg. ], the angle detection device 10 of the present embodiment produces an angle error of ±0.5 [deg. ] can be suppressed. Therefore, providing the magnetic shield 12 is extremely effective in reducing the detection angle error due to the disturbance magnetic field.

Furthermore, in the angle detection device 10, the magnets 21 and 22 are magnetized along the direction of the rotation axis J1. For this reason, compared to the case where the magnets 21 and 22 are magnetized along the in-plane direction perpendicular to the rotation axis J1, the magnetic flux of the magnetic field formed by the magnets 21 and 22 is reduced to the magnetic shield 12 (of which In particular, it is easy to avoid being absorbed by the first shield portion 121). For example, an angle detection device 110B as a second reference example shown in FIG. 6A has an annular magnet 200 magnetized along an in-plane direction perpendicular to the rotation axis J1 instead of the magnets 21 and 22. there is The composition and volume of the annular magnet 200 are the same as the composition and total volume of the magnets 21 and 22 . FIG. 6A is a diagram schematically showing the magnetic flux density distribution of an angle detection device 110B as a second reference example. Also, FIG. 6B shows an enlarged configuration example of an annular magnet used in the angle detection device of FIG. 6A. An opening 200K is provided in the center of the annular magnet 200 . In the angle detection device 110B of FIG. 6A, part of the magnetic flux of the magnetic field generated by the annular magnet 200 is likely to be absorbed by the magnetic shield 12. As shown in FIG. In FIG. 6A, the level 1 region surrounded by curve Lv1 has the highest magnetic flux density. Hereinafter, the magnetic flux density gradually decreases in the order of the level 2 area surrounded by the curve Lv2, the level 3 area surrounded by the curve Lv3, and the level 4 area surrounded by the curve Lv4. As shown in FIG. 6A, in the angle detection device 110B as the second reference example, almost all of the magnetic shield 12 is a level 1 region. Further, it can be seen that the magnetic flux density of the magnetic field reaching the sensor chip 11 is less than level 4 in the angle detection device 110B.

On the other hand, FIG. 6C schematically represents the magnetic flux density distribution of the angle detection device 10 of this embodiment. As shown in FIG. 6C, in the angle detection device 10 of the present embodiment, the magnets 21 and 22 are magnetized along the direction of the rotation axis J1. 4, and it can be seen that the component of the magnetic field formed by the magnets 21 and 22 that is absorbed by the magnetic shield 12 is suppressed. Further, it can be seen that the magnetic flux density of the magnetic field reaching the sensor chip 11 is level 4 in the angle detection device 10 . Therefore, according to the angle detection device 10 of the present embodiment, it is possible to effectively apply the magnetic field formed by the magnets 21 and 22 to the magnetic detection element 41 . As an example, assuming that the magnets 21 and 22 made of the same material are arranged at the same distance from the sensor chip 11 and the magnetic flux density of the same intensity is applied to the sensor chip 11, as a second reference example In angle detection device 110B, the volume of magnets 21 and 22 is approximately 2.84 times that of angle detection device 10 of the present embodiment. In the angle detection device 10 of the present embodiment, the provision of the magnetic shield 12 causes a reduction in the magnetic flux density of approximately 20%. A decrease in magnetic flux density of 62% occurs.

As described above, according to the angle detection device 10 of the present embodiment, while suppressing a decrease in the effective magnetic flux density at the position where the magnetic detection element 41 for detecting the magnetic field formed by the magnets 21 and 22 is arranged, It can be said that the influence of the magnetic field can be reduced. Furthermore, since the magnets 21 and 22 are magnetized along the rotation axis direction, the magnets 21 and 22 are magnetized in the in-plane direction orthogonal to the rotation axis J1, for example. A magnetic field can be applied to the magnetic sensing element 41 .

Further, the angle detection device 10 of the present embodiment is provided with the yokes 31 and 32 which are rotatably provided integrally with the magnets 21 and 22 . For this reason, the angle detection accuracy is improved as compared with the case where the yoke is not provided, for example.

Further, in the angle detection device 10 of the present embodiment, the yokes 31 and 32 have a planar shape curved in an arc shape along the circumferential direction of a circle centered on the rotation axis J1 on a plane orthogonal to the rotation axis J1. In addition, along a plane orthogonal to the rotation axis J1, the height dimension along the rotation axis J1 increases as the distance from the rotation axis J1 increases. Therefore, even if the sensor chip 11 including the magnetic detection element 41 and the magnets 21 and 22 and the yokes 31 and 32 are displaced from each other, the angular error detected by the magnetic detection element 41 can be corrected. less likely to be affected. This is because the yoke does not have a planar shape curved in an arc along the circumferential direction of a circle centered on the rotation axis J1, or the yoke does not have a planar shape curved along the rotation axis J1 along a plane orthogonal to the rotation axis J1. In the angle detection device 10 of the present embodiment, the spatial region having a constant magnetic flux density exists in the vicinity of the rotation axis J1, compared to the case where the height dimension along the rotation axis J1 increases with increasing distance from the rotation axis J1. Because it spreads.

Further, when the yokes 31 and 32 are arranged at positions overlapping the magnets 21 and 22 in the direction of the rotation axis, respectively, as in the angle detection device 10 of the present embodiment, the yokes 31 and 32 are arranged to overlap the magnets 21 and 22 in the direction of the rotation axis. 21 and 22, the magnetic flux collecting effect of the yokes 31 and 32 is improved, and the intensity distribution of the magnetic field to be detected in the vicinity of the sensor chip 11, that is, the dispersion of the magnetic flux density distribution is reduced. reduced. As a result, angle detection accuracy is further improved.

Further, when the yokes 31 and 32 are arranged to be in contact with the magnets 21 and 22 in the rotation axis direction as in the angle detection device 10 of the present embodiment, the yokes 31 and 32 contact the magnets 21 and 22, respectively. Compared to the case where the yokes 31 and 32 are spaced apart, the magnetic flux collection effect of the yokes 31 and 32 is improved, and variations in the strength distribution of the magnetic field to be detected, that is, the distribution of the magnetic flux density, in the vicinity of the sensor chip 11 are reduced. . As a result, angle detection accuracy is further improved.

Further, like the angle detection device 10 of the present embodiment, the height dimensions 21H and 22H of the magnets 21 and 22 in the rotation axis direction are greater than the height dimensions 31H2 and 32H2 of the yokes 31 and 32 in the rotation axis direction. is also increased, the volume of the magnets 21 and 22 and the volume of the yokes 31 and 32 can be well balanced. Therefore, it is advantageous to effectively supply a magnetic field to be detected with a higher intensity to the sensor chip 11 and to reduce the overall size, particularly in the direction of the rotation axis.

Further, when the magnets 21 and 22 are magnetized in the direction of the rotation axis as in the angle detection device 10 of the present embodiment, the magnetic detection element 41 rotates with respect to the magnetic detection element 41 having the sensitivity axis along the direction of the rotation axis. A magnetic field to be detected along the axial direction can be effectively applied.

Further, according to the angle detection device 10 of the present embodiment, the magnets 21 and 22 are both substantially cubic or substantially rectangular parallelepiped. It is excellent in workability when producing 21 and magnet 22, and is advantageous in terms of mass production, for example.

Further, when the magnetic field generator 20 has a pair of magnets 21 and 22 spaced apart from each other around the rotation axis J1 as in the angle detection device 10 of the present embodiment, magnetic field generation Compared to the case where the portion 20 has only one magnet, the total volume of the magnets 21 and 22 can be reduced without impairing the angle detection accuracy, and the weight can be reduced.

Further, in the angle detection device 10 of the present embodiment, if the material, shape and size of the magnet 21 and the material, shape and size of the magnet 22 are made substantially the same, compared to the case where they are different. Therefore, the angle detection accuracy can be further improved. Furthermore, by matching the distance 21D and the distance 22D, the angle detection accuracy can be further improved compared to the case where the distance 21D and the distance 22D are different. This is because variations in the detection target magnetic field applied to the sensor module 1 due to the rotation angle of the magnetic field generation module 2 are reduced.

Further, as in the angle detection device 10 of the present embodiment, when the yokes 31 and 32 have a planar shape curved in an arc shape along the rotation direction R1 on a plane orthogonal to the rotation axis J1, the yoke Angle detection accuracy can be further improved compared to the case where 31 and 32 have, for example, a planar shape extending linearly. This is because variations in the detection target magnetic field applied to the sensor module 1 due to the rotation angle of the magnetic field generation module 2 are reduced.

Further, when the yoke portion 30 has the yoke 31 and the yoke 32 which are spaced apart from each other around the rotation axis J1, for example, the yoke 31 and the yoke 32 are connected to form one circular ring. By comparison, weight reduction can be achieved.

Further, if the yokes 31 and 32 are provided at rotationally symmetrical positions with respect to the rotation axis J1, the angle detection accuracy can be further improved compared to the case where they are not at rotationally symmetrical positions. can. Furthermore, by matching the distance 31D and the distance 32D, the angle detection accuracy can be further improved compared to the case where the distance 31D and the distance 32D are different. This is because all of these reduce variations in the detection target magnetic field applied to the sensor module 1 due to the rotation angle of the magnetic field generation module 2 .

<2. Experimental example>
Next, the relationship between the shape of the yokes 31 and 32 and the detected angle error was examined for the angle detection device 10 of the embodiment shown in FIG.

(Experimental example 1-1)
Regarding the angle detection device 10 of the above embodiment, detection when the center position CP of the magnetic detection element 41 in the plane perpendicular to the rotation axis J1 deviates from the position of the rotation axis J1 within a range of 0 mm to 1.0 mm Angular error was investigated. The result is shown by curve C1-1 in FIG. Here, the error of the rotation angle of the magnetic field generation module 2 detected by the sensor module 1 when the magnetic field generation module 2 is rotated without applying an external magnetic field other than the magnetic field formed by the magnets 21 and 22 is simulated. obtained by The magnets 21 and 22 are neodymium magnets (rare earth magnets containing neodymium, iron, and boron as main components ) , and the dimensions of each of the magnets 21 and 22 are 6.0 mm x 2.5 mm x 5.0 mm. 21D and distance 22D were 4.75 mm. The material of each of the arc-shaped yokes 31 and 32 is SPCC (common steel), the central angle of each of the yokes 31 and 32 is 90°, and the height dimensions 31H1 and 32H1 of the yokes 31 and 32 are 0.5 mm. , and height dimensions 31H2 and 32H2 of the yokes 31 and 32 are set to 2.5 mm, respectively. Furthermore, the distance between the yokes 31 and 32 and the magnetic detection element 41 in the rotation axis direction was set to 1 mm.

(Experimental example 1-2)
Except that instead of the yoke portion 30 including the yokes 31 and 32, the yoke portion 30A including the yokes 31A and 32A shown in FIG. The error was obtained by simulation. The result is shown by curve C1-2 in FIG. The yokes 31A and 32A are soft ferromagnetic bodies having a planar shape forming a part of an annular member and having a substantially constant height dimension in the rotation axis direction. The composition and volume of the yokes 31A and 32A were the same as those of the yokes 31 and 32. FIG.

(Experimental example 1-3)
Except that instead of the yoke portion 30 including the yokes 31 and 32, the yoke portion 30B including the yokes 31B and 32B shown in FIG. The error was obtained by simulation. The result is shown by curve C1-3 in FIG. The yokes 31B and 32B are substantially triangular prism-shaped soft ferromagnetic bodies that have inclined surfaces S31B and S32B but extend linearly without bending in the in-plane direction perpendicular to the rotation axis J1. The composition and volume of the yokes 31B and 32B were the same as those of the yokes 31 and 32. FIG.

(Experimental example 1-4)
The rotation angle error was obtained by simulation in the same manner as in Experimental Example 1-1, except that the yokes 31 and 32 were not used. The results are shown by curves C1-4 in FIG.

(Experimental example 1-5)
Except for using an annular magnet 200 magnetized in the in-plane direction orthogonal to the rotation axis J1 as shown in FIG. The rotation angle error was obtained by simulation in the same manner as in Example 1-1. The result is shown by curve C1-5 in FIG.

As shown in FIG. 7, in each experimental example, it was confirmed that the detected angle error increased as the amount of misalignment [mm] of the center position CP with respect to the position of the rotation axis J1 increased. However, in Experimental Example 1-1 corresponding to the angle detection device 10 of the present embodiment, it was confirmed that the detection angle error was sufficiently reduced as compared with the other Experimental Examples 1-2 to 1-5. rice field.

(Experimental example 2-1)
Next, regarding the angle detection device 10 of FIG. 3 described in the above embodiment, among the magnetic fields generated by the magnets 21 and 22, the magnetic field in the horizontal direction of the paper surface of FIG . The magnetic flux density distribution of the component was obtained by simulation. The magnetic detection element 41 detects the strength of the magnetic field in the direction in which the magnets 21 and 22 face each other. FIG. 9A is a contour diagram schematically showing the magnetic flux density distribution of the magnetic field component in the facing direction of the magnets 21 and 22 of the angle detection device 10 as Experimental Example 2-1. Note that FIG. 9A shows the magnetic flux density distribution for the spatial region between the magnet 21 and the yoke 31 and the magnet 22 and the yoke 32, and the magnetic flux density distribution for other spatial regions is omitted. FIG. 9B is an explanatory diagram schematically showing the vector of the magnetic flux density in the vicinity of the sensor chip 11 along the plane perpendicular to the rotation axis J1 for the angle detection device 10 as Experimental Example 2-1. . 9A and 9B, the direction in which the magnet 21 and the yoke 31 face the magnet 22 and the yoke 32 is defined as the X-axis direction, and the direction of the rotation axis J1 is defined as the Z-axis direction. The orthogonal direction is defined as the Y-axis direction.

(Experimental example 2-2)
Next, regarding the angle detection device 10A having substantially the same configuration as the configuration of the angle detection device 10 shown in FIG. The same evaluation was performed under the same conditions as in Experimental Example 2-1 above. FIG. 10A is a contour diagram schematically showing the magnetic flux density distribution of the magnetic field component in the facing direction of the magnets 21 and 22 of the angle detection device 10A as Experimental Example 2-2. Note that FIG. 10A shows the magnetic flux density distribution for the spatial region between the magnet 21 and the yoke 31A and the magnet 22 and the yoke 32A, and the magnetic flux density distribution for other spatial regions is omitted. . FIG. 10B is an explanatory diagram schematically showing the vector of the magnetic flux density in the vicinity of the sensor chip 11 along the plane perpendicular to the rotation axis J1 for the angle detection device 10A as Experimental Example 2-2. . 10A and 10B, the direction in which the magnet 21 and the yoke 31A and the magnet 22 and the yoke 32A face each other is defined as the X-axis direction, and the direction of the rotation axis J1 is defined as the Z-axis direction. The direction orthogonal to the direction is defined as the Y-axis direction.

(Experimental example 2-3)
Next, regarding the angle detection device 10B having substantially the same configuration as the configuration of the angle detection device 10 shown in FIG. The same evaluation was performed under the same conditions as in Experimental Example 2-1 above. FIG. 11A is a contour diagram schematically showing the magnetic flux density distribution of the magnetic field component in the facing direction of the magnets 21 and 22 of the angle detection device 10B as Experimental Example 2-3. Note that FIG. 11A shows the magnetic flux density distribution for the spatial region between the magnet 21 and yoke 31B and the magnet 22 and yoke 32B, and the magnetic flux density distribution for other spatial regions is omitted. FIG. 11B is an explanatory diagram schematically showing the vector of the magnetic flux density in the vicinity of the sensor chip 11 along the plane perpendicular to the rotation axis J1 for the angle detection device 10B as Experimental Example 2-3. . 11A and 11B, the direction in which the magnet 21 and the yoke 31B and the magnet 22 and the yoke 32B face each other is defined as the X-axis direction, and the direction of the rotation axis J1 is defined as the Z-axis direction. The direction orthogonal to the direction is defined as the Y-axis direction.

(Experimental example 2-4)
Next, an angle detection device 10C having substantially the same configuration as the configuration of the angle detection device 10 shown in FIG. Similar evaluation was performed under the conditions of FIG. 12A is a contour diagram schematically showing the magnetic flux density distribution of the magnetic field component in the facing direction of the magnets 21 and 22 of the angle detection device 10C as Experimental Example 2-4. Note that FIG. 12A shows the magnetic flux density distribution for the spatial region between the magnets 21 and 22, and the magnetic flux density distribution for other spatial regions is omitted. FIG. 12B is an explanatory diagram schematically showing the vector of the magnetic flux density in the vicinity of the sensor chip 11 along the plane orthogonal to the rotation axis J1 for the angle detection device 10C as Experimental Example 2-4. . 12A and 12B, the direction in which the magnets 21 and 22 face each other is the X-axis direction, the direction of the rotation axis J1 is the Z-axis direction, and the direction perpendicular to the X-axis direction and the Z-axis direction is the Y-axis direction. direction.

(Experimental example 2-5)
Next, the configuration is substantially the same as the configuration of the angle detection device 10 shown in FIG. 3, etc., except that the annular magnet 200 shown in FIG. The same evaluation was performed for the angle detection device 110B having the configuration under the same conditions as in Experimental Example 2-1. FIG. 13A is a contour diagram schematically showing the magnetic flux density distribution of the magnetic field component in the radial direction of the annular magnet 200 of the angle detection device 110B as Experimental Example 2-5. Note that FIG. 13A shows the magnetic flux density distribution for the spatial region near the opening 200K of the annular magnet 200, and the magnetic flux density distribution for other spatial regions is omitted. FIG. 13B is an explanatory diagram schematically showing the vector of the magnetic flux density in the vicinity of the sensor chip 11 along the plane perpendicular to the rotation axis J1 for the angle detection device 110B as Experimental Example 2-5. . 13A and 13B, the radial direction of the annular magnet 200 is the X-axis direction, the direction of the rotation axis J1 is the Z-axis direction, and the direction orthogonal to the X-axis direction and the Z-axis direction is the Y-axis direction.

As shown in FIGS. 9A to 13B, in Experimental Example 2-1 (FIGS. 9A and 9B), compared with other Experimental Examples 2-2 to 2-5, the magnetic field in the facing direction of magnet 21 and magnet 22 For each component, it was confirmed that a wider region with substantially the same magnetic flux density was secured in the vicinity of the sensor chip 11 . From a comparison of FIG. 9B with FIGS. 10B, 11B, 12B, and 13B, in Experimental Example 2-1 (FIG. 9B), in comparison with other Experimental Examples 2-2 to 2-5, in the vicinity of the sensor chip 11 The directions of the magnetic flux density vectors of are aligned in the X-axis direction. Therefore, even if the center position CP of the sensor chip 11 is slightly deviated from the positions of the magnets 21 and 22 and the positions of the yokes 31 and 32, in Experimental Example 2-1 (FIG. 9B), the other Experimental Example 2-2 It was found that the error of the angle detected by the sensor chip 11 was suppressed to a smaller value compared to 2-5.

Further, in Experimental Example 2-1 (FIG. 9A), the sensor chip 11 is included in the level 4 area surrounded by the curve Lv4. Therefore, compared with other experimental examples 2-2 to 2-5 (FIGS. 10B, 11B, 12B, and 13B), it can be seen that the magnetic field formed by the magnets 21 and 22 is effectively applied to the sensor chip 11. It could be confirmed. In addition, in FIGS. 9A, 10A, 11A, 12A, and 13A, the level 1 region surrounded by the curve Lv1 has the highest magnetic flux density. Hereinafter, the magnetic flux density gradually decreases in the order of the level 2 area surrounded by the curve Lv2, the level 3 area surrounded by the curve Lv3, and the level 4 area surrounded by the curve Lv4. 9A, 10A, 11A, 12A, and 13A, the values of magnetic flux densities respectively meant by level 1 (Lv1) to level 4 (Lv4) are common in all of FIGS. 9A, 10A, 11A, 12A, and 13A are doing.

In Experimental Example 2-3 (FIG. 11A), the peripheral region of the sensor chip 11 is included in the level 4 region surrounded by the curve Lv4, but the central region of the sensor chip 11 has a lower magnetic flux density than level 4. included in This is because in Experimental Example 2-3 (FIG. 11A), the magnetic flux density tends to decrease slightly in the vicinity of the midpoint between the magnets 21 and 22 . Therefore, it was confirmed that, in comparison with Experimental Example 2-1 (FIG. 9A), in Experimental Example 2-3 (FIG. 11A), the detection angle error tends to increase as the amount of misalignment of the center position CP increases.

In addition, in Experimental Example 2-4 (FIG. 12A), the sensor chip 11 is included in a region with a magnetic flux density lower than Level 4. FIG. Furthermore, in Experimental Example 2-4 (FIG. 12A), it was confirmed that the magnetic flux density distribution in the spatial region between the magnets 21 and 22 has a relatively large variation.

Further, in Experimental Example 2-5 (FIG. 13A), the sensor chip 11 is included in a region with a magnetic flux density lower than level 4. FIG. Furthermore, in Experimental Example 2-5 (FIG. 13A), it was confirmed that the flatness of the magnetic flux density distribution in the spatial region between the magnets 21 and 22 was not sufficiently obtained.

As described above, in Experimental Example 2-1 (FIG. 9A) corresponding to the angle detection device 10 of the present embodiment, the yokes 31 and 32 are arranged on a plane perpendicular to the rotation axis J1. In addition to having a planar shape curved in an arc shape along the circumferential direction of the rotation axis J1, along a plane perpendicular to the rotation axis J1, the height dimension along the rotation axis J1 increases as the distance from the rotation axis J1 increases. there is Therefore, even if the position of the sensor chip 11 deviates from the positions of the magnets 21 and 22 and the positions of the yokes 31 and 32, it has been found that the angle detection error by the sensor chip 11 can be kept low. Furthermore, by having the yokes 31 and 32 having the shapes described above, the magnetic field formed by the magnets 21 and 22 is efficiently applied to the sensor chip 11, which contributes to the miniaturization and weight reduction of the magnets 21 and 22. I was able to confirm that.

(Experimental example 3-1)
Next, regarding the angle detection device 10 of FIG. 3 described in the above embodiment, apart from the magnetic fields generated by the magnets 21 and 22, FIG. A disturbance magnetic field of 25 mT was applied in the direction and its influence was investigated. Specifically, the increment ΔBy [mT] of the magnetic field in the direction of the disturbance magnetic field applied to the sensor chip 11 and the detection angle error ΔAE [deg. ] was examined. Table 1 shows the results.

(Experimental example 3-2)
An angle detection device 10A (FIG. 10A) having substantially the same configuration as the configuration of the angle detection device 10 shown in FIG. , the same evaluation was performed under the same conditions as in Experimental Example 3-1 above. The results are also shown in Table 1.

(Experimental example 3-3)
Regarding the angle detection device 10B (FIG. 11A) having substantially the same configuration as the configuration of the angle detection device 10 shown in FIG. , the same evaluation was performed under the same conditions as in Experimental Example 3-1 above. The results are also shown in Table 1.

(Experimental example 3-4)
An angle detection device 10C (FIG. 12A) having substantially the same configuration as the configuration of the angle detection device 10 shown in FIG. Similar evaluations were performed under similar conditions. The results are also shown in Table 1.

(Experimental example 4-1)
The configuration is substantially the same as the configuration of the angle detection device 10 shown in FIG. The same evaluation was performed under the same conditions as in Experimental Example 3-1 above for the angle detection device 10D (FIG. 14). The results are also shown in Table 1.

(Experimental example 5-1)
An angle detection device having substantially the same configuration as the angle detection device 10 (FIG. 9A) except that it does not have the magnetic shield 12 was tested under the same conditions as in Experimental Example 3-1. An evaluation was carried out. The results are also shown in Table 1.

(Experimental example 5-2)
An angle detection device having substantially the same configuration as the angle detection device 10A (FIG. 10A) except for not having the magnetic shield 12 was evaluated under the same conditions as in Experimental Example 3-1. carried out. The results are also shown in Table 1.

(Experimental example 5-3)
An angle detection device having substantially the same configuration as the angle detection device 10B (FIG. 11A), except for not having the magnetic shield 12, was evaluated under the same conditions as in Experimental Example 3-1. carried out. The results are also shown in Table 1.

(Experimental example 5-4)
Except for not having the yokes 31 and 32 and the magnetic shield 12, the angle detection device having substantially the same configuration as the angle detection device 10 shown in FIG. Similar evaluation was performed under the conditions of The results are also shown in Table 1.

As shown in Table 1, the magnetic field increment ΔBy [mT] in the direction of the disturbance magnetic field applied to the sensor chip 11 and the detection angle error ΔAE [deg. ] can be reduced most. Further, from a comparison between Experimental Examples 3-1 to 3-4 and Experimental Examples 5-1 to 5-4, regardless of the presence or absence of the yoke, and regardless of the shape of the yoke, the magnetic shield provided the sensor chip. 11, and the detection angle error ΔAE [deg. ] can be effectively reduced. Furthermore, even with the cylindrical magnetic shield 12A, the magnetic field increment ΔBy [mT] in the direction of the disturbance magnetic field applied to the sensor chip 11 and the detection angle error ΔAE [deg. ] can be sufficiently reduced.

<3. Application example>
(First application example)
15A and 15B are schematic diagrams showing a park lock system 210 having the angle detection system 100 described in the above embodiments. The park lock system 210 is a mechanism that is mounted on a vehicle such as an automobile, for example, and prevents the vehicle from moving by setting the shift lever to a parking mode when the driver parks the vehicle in a parking lot or the like. FIG. 15A represents an unlocked state in which it is not locked, and FIG. 15B represents a locked state. Park lock system 210 includes, for example, motor 202 provided inside housing 201 , shaft 203 , lever 204 , rod 205 , engagement portion 206 and parking gear 208 having gear teeth 207 . The shaft 203 extends, for example, in a direction perpendicular to the plane of the drawing, and is rotatable by a motor 202 . An end portion of the shaft 203 is provided with the angle detection system 100 of the embodiment described above to detect the rotation angle of the shaft 203 . A base end of a lever 204 extending parallel to the plane of the paper is fixed to a shaft 203 and driven by a motor 202 to rotate along the plane of the paper. A proximal end of a rod 205 is attached to the distal end of the lever 204, and the rotation of the lever 204 causes the rod 205 to move in the horizontal direction of the drawing. An engaging portion 206 provided at the tip of the rod 205 can be engaged with and disengaged from gear teeth 207 . In this parking lock system 210 , the rotation of parking gear 208 is restricted by shifting from the unlocked state shown in FIG. 15A to the locked state shown in FIG. 15B. Specifically, when the motor 202 rotates the shaft 203 and the lever 204 to the right in the drawing, the rod 205 slides to the right in the drawing, the engaging portion 206 engages with the gear teeth 207, and the parking gear 208 is locked. be done. Conversely, by shifting from the locked state shown in FIG. 15B to the unlocked state shown in FIG. 15A, the restriction on rotation of parking gear 208 is released. Specifically, when the motor 202 rotates the shaft 203 and the lever 204 to the left in the drawing, the rod 205 slides to the left in the drawing, the engaging portion 206 is separated from the gear teeth 207, and the parking gear 208 is locked. be released. Here, by detecting the rotation angle of shaft 203 using angle detection system 100 of the above-described embodiment, it can be determined with high accuracy whether parking gear 208 is locked or unlocked. It has become.

(Second application example)
16A and 16B are schematic diagrams showing pedal system 300 having angle detection system 100 described in the above embodiment. FIG. 16A shows an initial state in which pad 303B (described later) of pedal 303 is not operated, and FIG. 16B shows a depressed state in which pad 303B is operated.

The pedal system 300 includes, for example, a housing 301, a shaft 302 fixed to the housing 301, and a bearing portion 303A through which the shaft 302 is inserted. and a biasing member 304, such as a tension spring.

The pedal 303 includes, for example, a pad 303B operated by the driver's foot, an arm 303C connecting the pad 303B and the bearing portion 303A, and a lever 303D provided on the opposite side of the arm 303C across the bearing portion 303A. I'm in. The lever 303D is connected to a biasing member 304 and is biased by the biasing member 304 so as to approach the wall portion 301W of the housing 301 .

The angle detection system 100 provided near the bearing portion 303A accurately detects the rotation angle of the arm 303C with the shaft 302 as the rotation center, and transmits a voltage signal (proportional signal) corresponding to the rotation angle to the control device 305. It is designed to The control device 305 analyzes this voltage signal and controls the opening/closing operation of the throttle valve so that the throttle valve opening degree corresponds to the voltage signal.

In this pedal system 300, when the pad 303B is stepped on by the driver in the initial state shown in FIG. 16A, the pedal 303 rotates counterclockwise on the paper surface about the shaft 302, and shifts to the stepped-on state shown in FIG. 16B. At that time, the opening degree of the throttle valve increases. Conversely, when the driver reduces the amount of depression of the pad 303B or stops depressing the pad 303B, the depression state shown in FIG. 16B shifts to the initial state shown in FIG. 16A. At that time, the opening degree of the throttle valve decreases.

As described above, in the pedal system 300, the rotation angle of the arm 303C can be accurately detected by the angle detection system 100 of the above embodiment, so the throttle valve opening can be adjusted with high accuracy.

<5. Other modified examples>
Although the present invention has been described above with reference to the embodiments and some modifications, the present invention is not limited to the above-described embodiments and the like, and various modifications are possible. For example, in the above-described embodiments and the like, a vertical Hall element has been exemplified as a magnetic detection element, but the magnetic detection element of the present invention may be any element that has a function of detecting a magnetic field. The concept also includes magnetoresistive elements (MR elements) such as resistance effect elements (AMR elements), spin-valve giant magnetoresistive effect (GMR) elements, and tunnel magnetoresistive effect (TMR) elements. When using an MR element such as a GMR element or a TMR element, changes in the direction and strength of the magnetic field in the plane perpendicular to the rotation axis J1 are detected. In the present invention, it is possible not only to reduce variations in the magnetic field strength distribution (magnetic flux density distribution) in the direction of the rotation axis, but also to reduce variations in the magnetic field strength distribution (magnetic flux density distribution) in the plane perpendicular to the rotation axis. It is also possible to apply a magnetic detection element that detects changes in the direction and strength of the magnetic field in the plane perpendicular to the rotation axis J1. Also, the dimensions of each component, the layout of each component, etc. are examples, and are not limited to these.

Further, in the above-described embodiment and modification, the sensor chip 11 including the magnetic detection element 41 is fixed, and the yoke portion 30 and the magnetic field generation portion 20 are provided so as to rotate together. However, the present invention is not limited to this. In the present invention, for example, the magnet and yoke may be fixed, and the magnetic detection element may be provided rotatably around the rotation axis. Alternatively, both the magnet and yoke and the magnetic detection element may be rotatably provided around the same rotation axis.

Further, in the above-described embodiment and the like, the case where the sensor module 1 of the angle detection device 10 has one magnetic detection element 41 has been exemplified and explained, but the present invention is not limited to this. The angle detection device of the present invention may have, for example, two or more magnetic detection elements. In that case, all of the two or more magnetic detection elements may be arranged on the rotation axis, or all or part of the two or more magnetic detection elements may be arranged around the rotation axis. That is, two or more magnetic detection elements may be provided at different positions around the rotation axis in a plane perpendicular to the rotation axis direction along the rotation axis. It is desirable that the center position equidistant from each of the two or more magnetic detection elements coincide with, for example, the position of the rotating shaft. When two or more magnetic detection elements are arranged around the rotation axis, the magnetic detection elements are preferably positioned between the magnet and the rotation axis in the in-plane direction along the plane orthogonal to the rotation axis.

Further, in the above-described embodiment and the like, the case where the magnetic field generating section 20 of the angle detection device 10 has two magnets has been described as an example, but the present invention is not limited to this. The angle detection device of the present invention may have, for example, only one magnetic field generating member, or may have three or more magnetic field generating members.

DESCRIPTION OF SYMBOLS 100... Angle detection system 10... Angle detection apparatus 1... Sensor module 2... Magnetic field generation module 3, 4... Support body 11... Sensor chip 12... Magnetic shield 13... Terminal part 14... Holder 15 Circuit board 20 Magnetic field generating section 21, 22 Magnet 30 Yoke section 31, 32 Yoke 41 to 43 Magnetic detection element.

Claims (24)

a magnetic detection element;
a magnetic field generating member that forms a magnetic field applied to the magnetic detection element;
a yoke disposed between the magnetic detection element and the magnetic field generating member in a first direction;
with
The magnetic field generating member, the yoke, and the magnetic detection element are provided so as to be relatively rotatable around a rotation axis along the first direction,
the yoke has a planar shape curved in an arc along a circumferential direction of a circle centered on the rotation axis on a plane perpendicular to the rotation axis;
the yoke includes a portion whose dimension in the first direction increases with distance from the rotation axis along a plane orthogonal to the rotation axis;
The portion where the dimension in the first direction increases includes an inclined surface that is inclined with respect to the rotation axis and also with respect to a plane perpendicular to the rotation axis,
The inclined surface faces the magnetic detection element
Angle detector. The angle detection device according to claim 1 , wherein the yoke is positioned so as to overlap the magnetic field generating member in the first direction. The angle detection device according to claim 1 or 2 , wherein the yoke is provided so as to be in contact with the magnetic field generating member. The angle detection device according to any one of claims 1 to 3 , wherein the dimension of the magnetic field generating member in the first direction is larger than the dimension of the yoke in the first direction. The angle detection device according to any one of claims 1 to 4, comprising a plurality of said yokes spaced apart from each other around said rotating shaft. 6. The angle detection device according to claim 5 , wherein the material, shape and size of each of the plurality of yokes are substantially the same as each other. 7. The angle detection device according to claim 5 , wherein distances between the plurality of yokes and the rotation axis are substantially equal to each other. The angle detection device according to any one of claims 5 to 7 , wherein the plurality of yokes include a first yoke and a second yoke that are arranged to face each other with the rotation shaft interposed therebetween. The angle detection device according to any one of claims 1 to 8 , further comprising: a first magnetic shield provided to surround the magnetic detection element along a plane perpendicular to the first direction. . 10. The angle detection device according to claim 9 , further comprising a second magnetic shield provided on the side opposite to the magnetic field generation member when viewed from the magnetic detection element. The angle detection device according to claim 10 , wherein the first magnetic shield and the second magnetic shield are integrated. A first distance between the first magnetic shield and the rotating shaft is
The angle detection device according to any one of claims 9 to 11 , longer than a second distance between the magnetic field generating member and the rotating shaft. 13. The angle detection device according to claim 12 , wherein at least part of the magnetic field generating member is provided so as to overlap the first magnetic shield in an in-plane direction along a plane orthogonal to the first direction. The angle detection device according to any one of claims 1 to 13 , wherein the magnetic field generating member is magnetized parallel to the first direction. The angle detection device according to any one of claims 1 to 14 , wherein the magnetic field generating member is provided around the rotating shaft. The angle detection device according to any one of claims 1 to 15 , comprising a plurality of the magnetic field generation members spaced apart from each other around the rotation axis. 17. The angle detection device according to claim 16 , wherein the material, shape and size of each of said plurality of magnetic field generating members are substantially the same as each other. Each distance between the plurality of magnetic field generating members and the rotation axis is substantially equal to each other
18. The angle detection device according to claim 16 or 17 . The angle detection device according to any one of claims 1 to 18 , wherein the magnetic detection element has a sensitivity axis along a plane perpendicular to the first direction. The angle detection device according to any one of claims 1 to 19 , comprising a plurality of said magnetic detection elements. The angle detection device according to claim 20 , wherein the plurality of magnetic detection elements are provided at different positions along a plane perpendicular to the first direction. an angle detection device according to any one of claims 1 to 21 ;
further comprising a support for supporting the magnetic field generating member;
The support has a mounting hole,
The angle detection system, wherein the yoke is provided on the magnetic field generating member or the support. A park lock system comprising the angle detection system of claim 22 . A pedal system comprising the angle detection system of claim 22 .

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