Physical quantity detection sensor and rotor assembly having the same

Abstract

To provide an angle sensor which prevents damage by a decentration of a rotor and is unitized.SOLUTION: An angle sensor 1 includes: a magnetic field detection element 5 capable of detecting a physical quantity; a magnet 4 for generating a physical quantity input to the magnetic field detection element 5; a support member 6 which is mountable to a rotary shaft 2 rotatable around a rotation center axis RC, and supports the magnet 4; a housing 8 for supporting the magnetic field detection element 5, and rotatably supporting the support member 6; and a displacement regulation part 10 for regulating rotation of the housing 8 in a circumferential direction C around the rotation center axis RC, and permitting displacement of the housing 8 in at least any one of an axial direction X and a radial direction R of the rotation center axis RC.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a physical quantity detection sensor. [Background technology]

[0002] Angle sensors that detect the rotation angle of a rotating body such as a rotating shaft are known. Patent Document 1 describes a magnetic angle sensor that combines a magnet and a magnetic field detection element into a unit. The magnet is attached to a rotating shaft, the rotating shaft is supported by a case, and the magnetic field detection element is attached to a housing fixed to the case. Patent Document 2 also discloses a magnetic angle sensor with a similar configuration. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-071652 A [Patent Document 2] JP 2010-66222 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the magnetic angle sensors described in Patent Documents 1 and 2, the relative positions of the magnet and the magnetic field detection element are fixed, so that misalignment between them is unlikely to occur during installation. Therefore, the angle sensor can be calibrated before installation, and the measurement accuracy of the angle sensor is unlikely to decrease. However, the rotating body is often eccentric and may deform during rotation. The deformation of the rotating body exerts a force on the housing, which may damage the housing and magnet, or cause misalignment between the magnet and the magnetic field detection element. This problem can occur not only in magnetic angle sensors but also in other types of physical quantity detection sensors.

[0005] An object of the present invention is to provide a unitized physical quantity detection sensor that is less susceptible to damage caused by eccentricity of a rotating body. [Means for solving the problem]

[0006] The physical quantity detection sensor of the present invention includes a detection element capable of detecting a physical quantity, a physical quantity generating device that generates a physical quantity to be input to the detection element, a support member that can be attached to a rotating body that can rotate around a central axis of rotation and supports the physical quantity generating device, a housing that supports the detection element and rotatably supports the support member, and a displacement regulating portion that regulates the housing from rotating in a circumferential direction around the central axis of rotation and allows displacement in at least one of the axial and radial directions of the central axis of rotation. Effect of the Invention

[0007] According to the present invention, it is possible to provide a unitized physical quantity detection sensor which is less susceptible to damage caused by eccentricity of a rotating body. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of an angle sensor according to a first embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the angle sensor shown in FIG. [Diagram 3] 2 is a cross-sectional view of a rotating body assembly including the angle sensor shown in FIG. 1. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Diagram 5] FIG. 5 is a cross-sectional view taken along line BB in FIG. [Figure 6] 13 is a modified example of a structure for fixing a support member to a rotating shaft. [Figure 7] FIG. 2 is a perspective view of a main body portion of a housing. [Figure 8] 10 is a diagram conceptually showing the relationship between the angle of the rotating shaft output by a magnetic field detection unit and the actual angle of the rotating shaft. FIG. [Figure 9] FIG. 13 is a side view showing a modified example of the outer member. [Figure 10] 11A to 11C are perspective views of angle sensors according to a second embodiment and a modification thereof. [Figure 11]FIG. 11 is a perspective view of an angle sensor according to a third embodiment. [Figure 12] FIG. 13 is a perspective view of an angle sensor according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, several embodiments of the present invention will be described with reference to the drawings. In the following description and drawings, the axial direction X means a direction parallel to the central axis of rotation RC of the rotor 2, the circumferential direction C means a direction around the central axis of rotation RC of the rotor 2, and the radial direction R means a direction perpendicular to the axial direction X and starting from the central axis of rotation RC of the rotor 2 and moving away from the central axis of rotation RC. In the following embodiments, the rotor 2 is a rotating shaft 2, but the shape of the rotor 2 is not limited as long as it can rotate around the central axis of rotation. The physical quantity detection sensor of the present invention can also be applied to, for example, a rotation speed sensor, but an angle sensor will be described here.

[0010] (First embodiment) FIG. 1 is a perspective view of the angle sensor 1, FIG. 2 is an exploded perspective view of the angle sensor 1, FIG. 3 is a cross-sectional view of a rotating body assembly 100 including the angle sensor 1, FIG. 4 is a cross-sectional view along the line AA in FIG. 3, and FIG. 5 is a cross-sectional view along the line BB in FIG. 4. In FIGS. 2 to 5, the harness 15 is omitted. As shown in FIG. 3, the rotating body assembly 100 has the angle sensor 1, a rotating shaft 2, and a drive device 3 for the rotating shaft 2. The drive device 3 is not limited, and may be, for example, a motor or an engine. The angle sensor 1 of this embodiment is a magnetic angle sensor. The angle sensor 1 has a magnet 4 and a magnetic field detection element 5 that detects the intensity of a magnetic field generated by the magnet 4. As will be described later, the present invention can also be applied to angle sensors other than magnetic types. The magnetic field detection element 5 is an example of a detection element that can detect a physical quantity, the magnet 4 is an example of a physical quantity generating device that generates a physical quantity input to the detection element, and the magnetic field intensity is an example of a physical quantity.

[0011] The angle sensor 1 has a support member 6 that supports a magnet 4. The support member 6 is made of resin or metal. The magnet 4 is cylindrical and is separated into an N pole and an S pole in the radial direction R. The support member 6 can be attached to a rotating shaft 2 that can rotate around a rotation center axis RC. As shown in FIG. 2, the support member 6 has a protruding portion 61 that protrudes in the axial direction X, and the rotating shaft 2 has a hole 21 that engages with the protruding portion 61 on the end face facing the support member 6. Both the protruding portion 61 and the hole 21 are circular, and the diameters of the protruding portion 61 and the hole 21 are approximately equal. The protruding portion 61 is press-fitted into the hole 21. The support member 6 has a positioning pin 62 that protrudes outward in the radial direction R, and the rotating shaft 2 has a groove portion 22 that engages with the positioning pin 62. As a result, the support member 6 is attached to the rotating shaft 2 at a predetermined angular position. Although not shown in the figures, the rotating shaft 2 may have a protruding portion protruding in the axial direction X, and the support member 6 may have a hole that engages with the protruding portion. When the absolute angle of the rotating shaft 2 is required as the output of the angle sensor 1, it is preferable to provide a positioning pin 62 and a groove portion 22, but these are not necessary when only the amount of rotation angle needs to be known.

[0012] FIG. 6 shows a modified structure for fixing the support member 6 to the rotating shaft 2. The support member 6 has a protruding portion 63 protruding in the axial direction X, and the rotating shaft 2 has a hole 23 that engages with the protruding portion 63. The protruding portion 63 and the hole 23 have a substantially rectangular cross section, and the shape and size of the cross section are substantially equal. The protruding portion 63 is press-fitted into the hole 23. Although not shown in the figure, the rotating shaft 2 may have a protruding portion protruding in the axial direction X, and the support member 6 may have a hole that engages with the protruding portion. With these structures, the support member 6 can be attached to the rotating shaft 2 at a predetermined angular position. The shapes of the protruding portion 63 and the hole 23 are not limited to rectangular, and may be non-circular. The method for fixing the support member 6 to the rotating shaft 2 is not limited to these, and adhesive or screwing on the side of the rotating shaft 2 may also be used.

[0013] As shown in FIG. 3, the magnetic field detection element 5 has a magnetic field detection unit 51 composed of a magnetoresistance effect element (e.g., AMR element, TMR element, GMR element) or a Hall element. The magnetic field detection element 5 is provided on the surface of the circuit board 7 facing the magnet 4. The magnetic field detection element 5 is provided facing the magnet 4 in the axial direction X, and the magnetic field detection unit 51 approximately coincides with the rotation center axis RC of the rotating shaft 2. It is also possible to provide a plurality of magnetic field detection units 51, and in this case, each magnetic field detection unit 51 can be provided at a position shifted in the radial direction R from the rotation center axis RC of the rotating shaft 2. Since the center of the detection unit and the magnet 4 coincides with the rotation center axis RC of the rotating shaft 2, the magnetic flux generated by the magnet 4 rotates around the rotation center axis RC. The magnetic field detection element 5 detects the change in magnetic field strength accompanying the rotation of the rotating shaft 2 and measures the rotation angle of the rotating shaft 2.

[0014] The angle sensor 1 has a housing 8 that rotatably supports the support member 6. The housing 8 is made of resin (for example, engineering plastics such as polyphenylene sulfide (PPS) resin and nylon) or metal. The housing 8 has a main body 81 and a cover 82. FIG. 7 shows a perspective view of the main body 81 of the housing 8. The main body 81 has a cylindrical portion 83 that houses the support member 6, and a tongue portion 84 that protrudes from the cylindrical portion 83 in the radial direction R. A bearing 9 is provided between the cylindrical portion 83 and the support member 6, and the support member 6 is rotatably supported by the main body 81. The cover portion 82 covers an upper opening 85 of the cylindrical portion 83. The circuit board 7 is provided so as to cross the upper opening 85 of the cylindrical portion 83, and is screwed to a step portion 86 along the peripheral wall of the cylindrical portion 83. A harness 15 is connected to the surface of the circuit board 7 opposite to the surface on which the magnetic field detection element 5 is provided, and extends in a direction away from the angle sensor 1 in the radial direction R, as shown in FIG.

[0015] In this way, the magnetic field detection element 5 is supported by the housing 8, and the magnet 4 is supported by the housing 8 via the bearing 9 and the support member 6. As a result, the relative positional relationship between the magnetic field detection element 5 and the magnet 4 is fixed. In principle, there is no misalignment between the magnet 4 and the magnetic field detection element 5, which may occur when the magnet 4 and the magnetic field detection element 5 are attached separately. Misalignment affects the measurement accuracy of the angle sensor 1. Since the magnet 4 and the magnetic field detection element 5 are unitized, the worker can simultaneously attach the magnet 4 and the magnetic field detection element 5 while maintaining their relative positions by simply attaching the angle sensor 1 to the rotating shaft 2. The housing 8 and the support member 6 are supported only by the rotating shaft 2 in the axial direction X. This simplifies the installation work of the angle sensor 1, and makes it easier to ensure measurement accuracy.

[0016] The magnetic field detection element 5 has a signal processing unit 52 that processes the signal output from the magnetic field detection unit 51. The signal output from the magnetic field detection unit 51 is a voltage signal that corresponds to the rotation angle of the rotating shaft 2, but does not necessarily have a linear relationship with the rotation angle. Furthermore, as described above, although misalignment between the magnet 4 and the magnetic field detection element 5 does not occur in principle, the relative positions of the magnet 4 and the magnetic field detection element 5 may vary depending on the product due to misalignment when mounting the magnet 4 on the support member 6 or when mounting the magnetic field detection element 5 on the housing 8.

[0017] FIG. 8 conceptually illustrates the relationship between the rotation angle of the rotating shaft 2 output by the magnetic field detection unit 51 and the actual rotation angle of the rotating shaft 2. The two do not completely match, and the rotation angle output by the magnetic field detection unit 51 includes an error. The signal processing unit 52 calibrates (corrects) the output of the magnetic field detection unit 51 based on this error. For example, if the output of the magnetic field detection unit 51 corresponds to 60° when the actual rotation angle is 70°, the signal processing unit 52 performs a correction to adjust the output of the magnetic field detection unit 51 by a value corresponding to 10°. The error of the magnetic field detection unit 51 is measured in advance before the shipment of the angle sensor 1, and the relationship between the output of the magnetic field detection unit 51 and the correction value is obtained and stored in the signal processing unit 52. The relationship between the output of the magnetic field detection unit 51 and the correction value is preferably stored in the form of a table. By calibrating the output of the magnetic field detection unit 51 in advance, the variation in output for each product is suppressed, and calibration after the angle sensor 1 is attached to the rotating shaft 2 is not required.

[0018] The angle sensor 1 further has a displacement regulating section 10. As shown in Figs. 3 to 5, the displacement regulating section 10 has an inner member 11 and an outer member 12 that sandwiches the inner member 11 from both sides in the circumferential direction C. The inner member 11 is fixed to a base member 13 that is spaced apart from the housing 8. The inner member 11 is made of a metal such as iron. The outer member 12 is a part of the tongue portion 84 described above, and in this embodiment, the outer member 12 is integrated with the housing 8 or is a part of the housing 8. The base member 13 is an arbitrary fixed member, and its use is not limited. The base member 13 may be, for example, a casing that covers the rotating shaft 2, a frame of a fixed structure, or the like.

[0019] The inner member 11 is a rod-shaped member. As shown in FIG. 5, the inner member 11 has a cylindrical shaft portion 111, a cylindrical head portion 112 provided at one end of the shaft portion 111, and a cylindrical screw portion 113 provided at the other end of the shaft portion 111. A screw hole 131 is provided on the surface of the base member 13 facing the inner member 11, and the screw portion 113 is screwed into the screw hole 131. In this way, the rod-shaped member or the inner member 11 is fixed to the base member 13. A hexagonal hole 114 (see FIG. 2) for screwing is provided on the top surface of the head portion 112. The diameter of the head portion 112 is larger than the diameter of the shaft portion 111, and the diameter of the screw portion 113 is smaller than the diameter of the shaft portion 111. Examples of such rod-shaped members include commercially available shoulder screws and shoulder bolts.

[0020] The tongue portion 84 has a slit 87 whose length in the radial direction R is longer than the length in the radial direction R of the shaft portion 111 (the diameter of the shaft portion 111), and the shaft portion 111 is inserted into the slit 87. The slit 87 has a shape in which a semicircle is connected to both sides of a rectangle. The portions of the tongue portion 84 on both sides in the circumferential direction C of the slit 87 constitute the outer member 12 that sandwiches the inner member 11 from both sides in the circumferential direction C. As shown in FIG. 5, the outer member 12 and the inner member 11 face each other in the circumferential direction C in a predetermined range 14 in the axial direction X. In this range 14, the interval between the outer member 12 and the inner member 11 in the circumferential direction C (which is substantially zero as described later) is almost constant. The diameter of the head 112 is larger than the width of the slit 87. During assembly, the housing 8 is fixed to the rotating shaft 2, and then the inner member 11 is inserted into the slit 87 and screwed to the base member 13.

[0021] The width of the slit 87 (dimension D1 in a direction perpendicular to the axial direction X and radial direction R) is slightly wider than and substantially the same as the width (diameter D2) of the shaft portion 111. The gap between the slit 87 and the shaft portion 111 is substantially zero. Taking into account the dimensional tolerances of the slit 87 and the shaft portion 111, it is preferable that the width of the slit 87 is as small as possible within a range in which the shaft portion 111 can be securely inserted into the slit 87. The tongue portion 84 is spaced from the head portion 112 and the base member 13 in the axial direction X. The displacement restricting portion 10 configured as described above substantially restricts the housing 8 from rotating in the circumferential direction C of the rotation center axis RC and allows displacement in the axial direction X and radial direction R of the rotation center axis RC.

[0022] The advantages of this embodiment will be described. The rotating shaft 2 may experience eccentricity or misalignment in the X direction. These include static eccentricity that occurs when the rotating shaft 2 is stationary and dynamic eccentricity that occurs due to the rotation of the rotating shaft 2. For example, if the distance between the hole 21 and the screw hole 131 and the distance between the protruding portion 61 and the inner member 11 are different, static eccentricity occurs. If the distance in the X direction between the end face of the rotating shaft 2 and the base member 13 and the distance in the X direction between the pressing surface of the support member 6 against the rotating shaft 2 and the bottom surface of the outer member 12 are different, static misalignment occurs in the axial direction X. If the actual rotation center axis RC of the rotating shaft 2 is eccentric with respect to the hole 21, dynamic eccentricity occurs. For example, if the mass distribution of the rotating shaft 2 is asymmetric with respect to the axial direction X, such dynamic eccentricity occurs, and the rotating shaft 2 is deflected. The rotating shaft 2 may also be dynamically displaced in the axial direction X due to vibration. If the rotating shaft 2 is displaceable in the axial direction X, displacement or deformation in the axial direction X may occur depending on the rotation speed. In particular, when the dynamic eccentricity or displacement depends on the rotation characteristics of the rotating shaft 2, it may be difficult to deal with it using the angle sensor 1 alone.

[0023] Therefore, if the housing 8 is firmly fixed to the base member 13 with bolts or the like, small eccentricity or misalignment can be absorbed by the elastic deformation of the housing 8 itself, but large eccentricity or misalignment cannot be absorbed, making the housing 8 more susceptible to damage. This increases the possibility that the magnet 4 supported by the housing 8 will also be damaged, deformed, or misaligned. A shaft coupling may be used to mitigate the effects of such eccentricity or misalignment, but this has a significant impact on costs.

[0024] In this embodiment, since the housing 8 is provided with a "relief" in which the housing 8 moves in the axial direction X and radial direction R of the rotation center axis RC, the housing 8 is unlikely to undergo excessive deformation at least in the axial direction X and radial direction R of the rotation center axis RC. On the other hand, if a "relief" is provided in the circumferential direction C, the inner member 11 will collide alternately with the outer members 12 on both sides every time the rotation direction of the rotating shaft 2 changes, causing hysteresis in the output. There is also a possibility that the inner member 11 will move irregularly between the outer members 12 on both sides due to vibration of the rotating shaft 2, causing the output of the angle sensor 1 to fluctuate. For the above reasons, the rotation of the housing 8 is substantially restricted in the circumferential direction C. Note that the angle detection error of the angle sensor 1 is proportional to the gap in the circumferential direction C and inversely proportional to the distance in the radial direction R between the rotating shaft 2 and the inner member 11. For this reason, in order to suppress the angle detection error, it is preferable to increase the distance in the radial direction R between the rotating shaft 2 and the inner member 11.

[0025] The displacement restriction portion 10 restricts the displacement of the housing 8 in the axial direction X and radial direction R of the rotation center axis RC from exceeding a predetermined range. The range of displacement of the inner member 11 in the radial direction R is equal to the difference between the radial length of the slit 87 and the radial length (diameter) of the inner member 11. The range of displacement of the inner member 11 in the axial direction X is equal to the difference between the axial distance between the bottom surface of the head 112 of the outer member 12 and the upper surface of the base member 13 and the axial length of the shaft portion 111 of the inner member 11. In this way, since the displacement restriction portion 10 restricts the displacement of the housing 8 in the axial direction X and radial direction R to within a predetermined range, even if the housing 8 is displaced significantly, the possibility of the housing 8 coming off the rotating shaft 2 can be reduced.

[0026] FIG. 9 is a side view showing modified examples of the outer member 12, seen from the same direction as FIG. 5. As shown in these modified examples, one of the outer member 12 and the inner member 11 is closer to the other of the outer member 12 and the inner member 11 in a part of the range 14 facing each other in the axial direction X than in the other part. Referring to FIG. 9(a), the outer member 12 and the inner member 11 are closer to each other in the center 142 of the range 14 than to both ends 141 of the range 14 facing each other in the axial direction X. Specifically, the outer member 12 and the inner member 11 are closest to each other in the center 142 of the range 14. However, the position where the outer member 12 and the inner member 11 are closest to each other is not limited to the center 142, and may be any position between both ends 141 of the range 14. The part of the outer member 12 closest to the inner member 11 is a curved surface. Since the inner member 11 moves relative to the outer member 12 in the radial direction R, it is preferable that the curved surface be provided over the entire length of two parallel linear side surfaces 88 (see FIG. 7) of the slit 87. Although not shown in the drawings, the portion of the inner member 11 closest to the outer member 12 may be a curved surface.

[0027] 9(b) shows another modified example. In this modified example, the outer member 12 and the inner member 11 are closest to each other at the center 142, but the portion of the outer member 12 closest to the inner member 11 is an edge. It is preferable that the edge is provided over the entire length of the two parallel linear side surfaces 88 of the slit 87. Although not shown in the figure, the portion of the inner member 11 closest to the outer member 12 may also be an edge. In this modified example, the position where the outer member 12 and the inner member 11 are closest to each other is not limited to the center 142, and may be any position between both ends 141 of the range 14.

[0028] 9(c) shows another modified example. In this modified example, at least one, preferably both, of the ends 141 of the outer member 12 are chamfered. In this manner, the portion of the outer member 12 closest to the inner member 11 may have a predetermined length in the axial direction X. Although not shown in the drawings, at least one, preferably both, of the ends of the inner member 11 may be chamfered.

[0029] When the rotating shaft 2 is deformed due to eccentricity, the end of the rotating shaft 2 may tilt with respect to the axial direction X, which may cause the outer member 12 to tilt with respect to the axial direction X as shown by the dashed line. In these modified examples, the portion of the outer member 12 that is closest to the inner member 11 is a point. Therefore, even when the outer member 12 tilts with respect to the axial direction X, the outer member 12 tilts with respect to the inner member 11 at the center as shown by the dashed line, so that the outer member 12 and the inner member 11 are unlikely to come into contact with each other. As a result, the possibility of damage to the housing 8 is further reduced.

[0030] Second embodiment FIG. 10(a) shows a perspective view of the angle sensor 1 according to the second embodiment. The configuration and effects of the second embodiment, which are not described, are the same as those of the first embodiment. The inner member 11 is a rod-shaped member fixed to the base member 13, and the outer member 12 is two arms 121 that are integrated with the housing 8 and extend parallel to each other. The inner member 11 has a configuration similar to that of the first embodiment. The inner member 11 has a shaft portion 111, and the shaft portion 111 is inserted between the two arms 121. The inner member 11 has a head portion 112 that has a larger diameter than the shaft portion 111, and the diameter of the head portion 112 is larger than the distance between the two arms 121. The two arms 121 are separated from the head portion 112 and the base member 13 in the axial direction X. This embodiment has substantially the same effects as the first embodiment, and can make the housing 8 more compact than the first embodiment. A large displacement of the housing 8 in the radial direction R can be absorbed by adjusting the length of the arms 121.

[0031] Fig. 10(b) shows a modified example of the second embodiment. This modified example is similar to the second embodiment except that the inner member 11 does not have a head 112. This modified example can simplify the configuration of the inner member 11, making it possible to reduce costs compared to the second embodiment. This modified example is preferably applicable when there is no possibility that the housing 8 will be significantly displaced in the axial direction X.

[0032] (Third embodiment) FIG. 11 shows a perspective view of an angle sensor 1 according to the third embodiment. The inner member 11 is a tongue portion 84 integrated with the housing 8, and the outer member 12 is two rod-shaped members 122 fixed to the base member 13, with the tongue portion 84 inserted between the two rod-shaped members 122. This embodiment has the same effects as the first and second embodiments. Although not shown, at least one of the rod-shaped members 122 may have an enlarged head portion similar to that of the inner member 11 of the first embodiment. This makes it possible to prevent a large displacement of the housing 8 in the axial direction X.

[0033] In the embodiment and modified examples described above, the housing 8 is displaceable in both the axial direction X and the radial direction R of the rotation center axis RC. However, the displacement restriction unit 10 may restrict the housing 8 from rotating in the circumferential direction C and from moving in the axial direction X, and permit the housing 8 to move in the radial direction R. This is possible, for example, by making the gap between the tongue portion 84 and the head portion 112 and the gap between the tongue portion 84 and the base member 13 in the axial direction X zero or substantially zero.

[0034] The displacement regulating portion 10 may regulate the housing 8 from rotating in the circumferential direction C and from moving in the radial direction R, and may permit movement in the axial direction X. This is possible, for example, by making the radial length of the slit 87 equal to the radial length of the shaft portion 111. In this manner, it is sufficient for the displacement regulating portion 10 to regulate the housing 8 from rotating in the circumferential direction C, and permit displacement in at least one of the axial direction X and radial direction R of the rotation center axis RC.

[0035] In each of the embodiments described above, the inner member 11 and the rod-shaped member 122 may be formed integrally with the base member 13. In order to suppress wear caused by sliding between the inner member 11 and the outer member 12, they may also be formed from metal. Alternatively, when the inner member 11 or the outer member 12 is made of resin, a collar (bush) made of metal such as iron may be provided on the sliding surface.

[0036] The present invention can also be applied to angle sensors other than the magnetic type. Examples of other types of angle sensors include optical angle sensors and electromagnetic induction angle sensors. FIG. 12(a) shows a schematic configuration of an optical angle sensor 101. The optical angle sensor 101 has a code wheel 103 attached to a rotating body 102 and rotating together with the rotating body 102, a light emitting element 104 provided on one side of the code wheel 103 with respect to the direction of the rotation center axis RC of the rotating body 102, and a light receiving element 105 provided on the other side. The code wheel 103 has a number of slits 106 arranged in the circumferential direction. When the rotating body 102 rotates, the light emitting element 104 passes alternately between a position facing the slit 106 and between the slits 106. In the former position, the light emitted from the light emitting element 104 passes through the slit 106 and is detected by the light receiving element 105. In the latter position, the light emitted from the light emitting element 104 is not detected by the light receiving element 105. The above principle makes it possible to detect the rotation angle of the rotating body 102. The physical quantity generating device is a light emitting element 104 and a code wheel 103, the detecting element is a light receiving element 105, and the physical quantity is the intensity of light.

[0037] 12(b) shows a schematic configuration of an electromagnetic induction type angle sensor 201. The electromagnetic induction type angle sensor 201 has a rotor 203 that is attached to a rotating body 202 and rotates together with the rotating body 202, and a stator 204 that faces the rotor 203 and is fixed. A receiver coil 205 is provided on the stator 204. An electric signal is generated in the receiver coil 205 by a reluctance change between the rotating rotor 203 and the fixed stator 204. The rotation angle of the rotating body 202 is detected based on this electric signal.

[0038] (Additional Note) This specification includes the following disclosure. [Configuration 1] A detection element capable of detecting a physical quantity; a physical quantity generating device that generates the physical quantity to be input to the detection element; a support member that can be attached to a rotating body that can rotate around a central axis of rotation and supports the physical quantity generating device; a housing that supports the detection element and rotatably supports the support member; a displacement restriction portion that restricts the housing from rotating in a circumferential direction around the rotation central shaft and allows the housing to displace in at least one of an axial direction and a radial direction of the rotation central shaft; A physical quantity detection sensor having the following features. [Configuration 2] The physical quantity detection sensor according to configuration 1, wherein the displacement regulating portion has an inner member and an outer member sandwiching the inner member from both sides in the circumferential direction, one of the inner member and the outer member being integrated with the housing, and the other being fixed to a base member spaced apart from the housing. [Configuration 3] 3. The physical quantity detection sensor according to configuration 2, wherein one of the outer member and the inner member is closer to the other of the outer member and the inner member in a portion of the range in which they face each other in the axial direction than in another portion of the range. [Configuration 4] 4. The physical quantity detection sensor according to configuration 3, wherein the outer member and the inner member are closest to each other at the center portion. [Configuration 5] 5. The physical quantity detection sensor according to configuration 4, wherein a portion of the outer member closest to the inner member, or a portion of the inner member closest to the outer member, is a curved surface. [Configuration 6] 5. The physical quantity detection sensor according to configuration 4, wherein the portion of the outer member closest to the inner member, or the portion of the inner member closest to the outer member, is an edge. [Configuration 7] 5. The physical quantity detection sensor according to configuration 4, wherein at least one end of the outer member or the inner member in the axial direction is chamfered. [Configuration 8] the inner member is a rod-shaped member fixed to the base member, the outer member being a tongue integral with the housing; The physical quantity detection sensor according to any one of configurations 2 to 7, wherein the rod-shaped member has an axis portion, the tongue portion has a slit whose radial length is longer than the radial length of the axis portion, and the axis portion is inserted into the slit. [Configuration 9] 9. The physical quantity detection sensor according to configuration 8, wherein the rod-shaped member has a head portion having a diameter larger than that of the shaft portion, and the diameter of the head portion is larger than a width of the slit. [Configuration 10] 10. The physical quantity detection sensor according to configuration 9, wherein the tongue portion is spaced apart from the head portion and the base member in the axial direction. [Configuration 11] the inner member is a rod-shaped member fixed to the base member, The outer member is two arms that are integral with the housing and extend parallel to each other, 8. The physical quantity detection sensor according to any one of configurations 2 to 7, wherein the rod-shaped member has a shaft portion, and the shaft portion is inserted between the two arm portions. [Configuration 12] 12. The physical quantity detection sensor according to claim 11, wherein the rod-shaped member has a head having a diameter larger than that of the shaft portion, and the diameter of the head is larger than the distance between the two arms. [Configuration 13] 13. The physical quantity detection sensor according to claim 12, wherein the two arms are spaced apart from the head and the base member in the axial direction. [Configuration 14] the inner member being an integral tongue with the housing; The outer member is two rod-shaped members fixed to the base member, 8. The physical quantity detection sensor according to any one of configurations 2 to 7, wherein the tongue portion is inserted between the two rod-shaped members. [Configuration 15] 15. The physical quantity detection sensor according to any one of configurations 1 to 14, wherein the housing and the support member are supported in the axial direction only by the rotating body. [Configuration 16] the physical quantity generating device is a magnet, the detection element is a magnetic field detection element provided opposite the magnet, 16. The physical quantity detection sensor according to any one of configurations 1 to 15, wherein the physical quantity is a magnetic field intensity. [Configuration 17] the physical quantity generating device is a light emitting element and a rotatable code wheel having a plurality of slits; the detection element is a light receiving element provided on an opposite side of the light emitting element with respect to the code wheel, 16. The physical quantity detection sensor according to any one of configurations 1 to 15, wherein the physical quantity is light intensity. [Configuration 18] The physical quantity generating device is a fixed excitation coil and a rotatable induction coil, the sensing element is a fixed receiving coil; 16. The physical quantity detection sensor according to any one of configurations 1 to 15, wherein the physical quantity is an induced electromotive force. [Configuration 19] A physical quantity detection sensor according to any one of configurations 1 to 18, A rotating body to which the support member is attached; and A rotating body assembly having a driving device for the rotating body. [Configuration 20] The support member has a positioning pin protruding outward in the radial direction, 20. The rotor assembly of claim 19, wherein the rotor has a groove that engages with the positioning pin. [Configuration 21] 21. The rotor assembly of claim 20, wherein one of the support member and the rotor has a protrusion protruding in the axial direction, and the other has a hole that engages with the protrusion, and the protrusion and the hole have a non-circular shape. [Explanation of symbols]

[0039] 1 Angle Sensor 2 Rotating shaft (rotating body) 3. Drive unit 4. Magnets (physical quantity generators) 5 Magnetic field detection element (detection element) 6 Supporting member 8. Housing 10 Displacement control section 11 Inner member 12 Outer member 13 Base material 21 holes 61 Protruding part 62 Locating pin 84 Tongue 87 Slit 100 Rotating body assembly 111 Shaft 112 Head 121 Arm RC Rotational axis

Claims

1. A detection element capable of detecting a physical quantity; a physical quantity generating device that generates the physical quantity to be input to the detection element; a support member that can be attached to a rotating body that can rotate around a central axis of rotation and supports the physical quantity generating device; a housing that supports the detection element and rotatably supports the support member; a displacement restriction portion that restricts the housing from rotating in a circumferential direction around the rotation central shaft and allows the housing to displace in at least one of an axial direction and a radial direction of the rotation central shaft; A physical quantity detection sensor having the following features.

2. 2. The physical quantity detection sensor according to claim 1, wherein the displacement regulating portion has an inner member and an outer member sandwiching the inner member from both sides in the circumferential direction, one of the inner member and the outer member being integrated with the housing and the other being fixed to a base member spaced apart from the housing.

3. 3. The physical quantity detection sensor according to claim 2, wherein one of the outer member and the inner member is closer to the other of the outer member and the inner member in a portion of the opposing range in the axial direction than in another portion of the opposing range.

4. The physical quantity detection sensor according to claim 3 , wherein the outer member and the inner member are closest to each other at the central portion.

5. The physical quantity detection sensor according to claim 4 , wherein a portion of the outer member closest to the inner member, or a portion of the inner member closest to the outer member, is a curved surface.

6. The physical quantity detection sensor according to claim 4 , wherein the portion of the outer member closest to the inner member, or the portion of the inner member closest to the outer member, is an edge.

7. The physical quantity detection sensor according to claim 4 , wherein at least one end of the outer member or the inner member in the axial direction is chamfered.

8. the inner member is a rod-shaped member fixed to the base member, the outer member being a tongue integral with the housing; 3. The physical quantity detection sensor according to claim 2, wherein the rod-shaped member has a shaft portion, the tongue portion has a slit whose radial length is longer than the radial length of the shaft portion, and the shaft portion is inserted into the slit.

9. The physical quantity detection sensor according to claim 8 , wherein the rod-shaped member has a head portion having a diameter larger than that of the shaft portion, and the diameter of the head portion is larger than a width of the slit.

10. The physical quantity detection sensor according to claim 9 , wherein the tongue portion is spaced apart from the head portion and the base member in the axial direction.

11. the inner member is a rod-shaped member fixed to the base member, The outer member is two arms that are integral with the housing and extend parallel to each other, The physical quantity detection sensor according to claim 2 , wherein the rod-shaped member has a shaft portion, and the shaft portion is inserted between the two arm portions.

12. The physical quantity detection sensor according to claim 11 , wherein the rod-shaped member has a head portion having a diameter larger than that of the shaft portion, and the diameter of the head portion is larger than a distance between the two arm portions.

13. The physical quantity detection sensor according to claim 12 , wherein the two arm portions are spaced apart from the head and the base member in the axial direction.

14. the inner member being an integral tongue with the housing; the outer member is two rod-shaped members fixed to the base member, The physical quantity detection sensor according to claim 2 , wherein the tongue portion is inserted between the two rod-shaped members.

15. The physical quantity detection sensor according to claim 1 , wherein the housing and the support member are supported in the axial direction only by the rotating body.

16. the physical quantity generating device is a magnet, the detection element is a magnetic field detection element provided opposite the magnet, The physical quantity detection sensor according to claim 1 , wherein the physical quantity is a magnetic field intensity.

17. the physical quantity generating device is a light emitting element and a rotatable code wheel having a plurality of slits; the detection element is a light receiving element provided on an opposite side of the light emitting element with respect to the code wheel, The physical quantity detection sensor according to claim 1 , wherein the physical quantity is a light intensity.

18. The physical quantity generating device is a fixed excitation coil and a rotatable induction coil, the sensing element is a fixed receiving coil; The physical quantity detection sensor according to claim 1 , wherein the physical quantity is an induced electromotive force.

19. A physical quantity detection sensor according to any one of claims 1 to 18, A rotating body to which the support member is attached; and A rotating body assembly having a driving device for the rotating body.

20. The support member has a positioning pin protruding outward in the radial direction, 20. The rotating body assembly of claim 19, wherein the rotating body has a groove that engages the locating pin.

21. 20. The rotor assembly of claim 19, wherein one of the support member and the rotor has a protrusion extending in the axial direction and the other has a hole engaging the protrusion, the protrusion and the hole having a non-circular shape.

Images