Angle sensor

Abstract

The present disclosure provides an angle sensor capable of suppressing the influence caused by the movement of a rotating shaft in the axial direction. An angle sensor (1) is provided with a rotor (2), a stator (3), and a frame (4). The rotor (2) has a cylinder (10) and a plurality of metal bodies (5) fixed to the cylinder (10). The frame (4) is fixed to the stator (3). The stator (3) is provided with: a cylinder (30) having an inner peripheral surface (31) as an inner surface located on the rotor (2) side and an outer peripheral surface (32) as an outer surface located on the frame (4) side; and a plurality of coils (20) attached to the outer peripheral surface (32) of the cylinder (30).

Description

TECHNICAL FIELD

[0001] The present application relates to an angle sensor, and particularly relates to an inductance type angle sensor. BACKGROUND

[0002] Conventionally, various sensors are used to detect a rotation angle of a motor or the like. Among such angle sensors that detect a rotation angle, there is an inductance type sensor (for example, refer to Patent Literature 1).

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2019-200106 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The conventional inductance type sensor has room for improvement in terms of detection accuracy.

[0008] Therefore, an object of the present application is to provide an angle sensor that can improve detection accuracy.

[0009] SOLUTION TO PROBLEM

[0010] An angle sensor according to one aspect of the present application includes a rotor having a cylinder and a plurality of metal bodies fixed to the cylinder; a stator; and a frame fixed to the stator, the stator including a cylinder having an inner surface on the rotor side and an outer surface on the frame side, and a plurality of coils fitted to the outer surface of the cylinder. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a perspective view that schematically shows the structure of an angle sensor according to one embodiment of the present application, and schematically shows the structure inside the angle sensor by passing through a part of the member.

[0012] Figure 2 is a perspective view that schematically shows the structure of an angle sensor.

[0013] Figure 3 is a front view that schematically shows the structure of an angle sensor.

[0014] Figure 4 is a side view that schematically shows the structure of an angle sensor.

[0015] Figure 5 is a perspective view that shows one specific example of a rotor.

[0016] Figure 6is a perspective view schematically showing the structure of the stator.

[0017] Figure 7 is a side view schematically showing the structure of the stator.

[0018] Figure 8 is a sectional view schematically showing a section obtained by a plane including the axis of the stator.

[0019] Figure 9 is a perspective view of the coil structure.

[0020] Figure 10 is a perspective view schematically showing the structure of the frame.

[0021] Figure 11 is a rear view schematically showing the structure of the frame.

[0022] Figure 12 is a sectional view schematically showing a section obtained by a plane including the axis of the frame.

[0023] Figure 13 is a sectional view schematically showing a section obtained by a plane including the axis x of the stator and the frame in the assembled state.

[0024] Figure 14 is a perspective view showing a modification example of the stator and the frame.

[0025] Figure 15 is a perspective view showing a modification example of the stator. DETAILED DESCRIPTION

[0026] Hereinafter, one embodiment of the present application will be described with reference to the drawings. Note that in the drawings, for a plurality of components, part of the reference numerals of a plurality of constituent elements is not always shown and part of the reference numerals is omitted. Figure 1 is a perspective view schematically showing the structure of the angle sensor 1 of one embodiment of the present application, and is a perspective view schematically showing the internal structure by seeing through part of the components of the angle sensor 1. Figure 2 is a perspective view schematically showing the structure of the angle sensor 1, Figure 3 is a front view schematically showing the structure of the angle sensor 1, Figure 4 is a side view schematically showing the structure of the angle sensor 1. As Figures 1-4As shown, the angle sensor 1 includes a rotor 2, a stator 3, and a frame 4. The rotor 2 has a cylinder 10 and multiple metal bodies 5 fixed to the cylinder 10. The frame 4 is fixed to the stator 3. The stator 3 includes: a cylinder 30 having an inner circumferential surface 31 located on the rotor 2 side as an inner surface and an outer circumferential surface 32 located on the frame 4 side as an outer surface; and multiple coils 20 assembled on the outer circumferential surface 32 of the cylinder 30. The structure of the angle sensor 1 will be described in detail below. It should be noted that, in Figures 2-4 In the diagram, rotor 2 and stator 3 are shown in a prescribed positional relationship. This prescribed positional relationship is an example of the positional relationship between rotor 2 and stator 3 when angle sensor 1 is mounted on the application object in its operating state. In angle sensor 1, rotor 2 is disposed inside stator 3.

[0027] The metal body 5, acting as a conductor, is made of a conductive metallic material. Multiple metal bodies 5 are arranged, for example, circumferentially about the rotation axis x of the angle sensor 1, such as... Figure 1 As shown schematically, multiple metal bodies 5 form a cylindrical shape extending in a ring around an axis x (hereinafter referred to as metal body structure 6). The metal body structure 6 is the shape formed by arranging multiple metal bodies 5. The conductor can be any component having a metal body and a conductive member (a component capable of generating so-called eddy currents or induced currents (currents) in one plane); a metal body is described below as an example. The metal body structure 6 can be embedded inside the cylinder 10 or provided on the surface of the cylinder 10. Each metal body 5 has a portion extending along the axis x. Furthermore, multiple metal bodies 5 can be interconnected. Multiple metal bodies 5 are connected by one or more connecting parts, which can be formed of a non-conductive component (e.g., resin) or a conductive component (e.g., metal), and the multiple metal bodies 5 can also be electrically connected.

[0028] like Figures 2-4 As shown, the cylinder 10 of rotor 2 is a cylindrical component extending along axis x. The cylinder 10 of rotor 2 is mounted on a rotating component of an external device used as the object of the angle sensor 1, and axis x is aligned with or approximately aligned with the rotation axis of the rotating component of the external device. For example... Figures 2-4 As shown, the cylinder 10 of the rotor 2 has: an inner circumferential surface 11, which is a cylindrical surface extending along a cylindrical surface centered on the axis x; and an outer circumferential surface 12, which is a cylindrical surface facing away from the inner circumferential surface 11 on the radially outer side (hereinafter also referred to as the "outer circumferential side"). It should be noted that the radial direction is orthogonal to the axis x. In addition, the cylinder 10 has surfaces facing various directions extending from the axis x, namely end faces 13 and 14. The inner circumferential surface 11 and the outer circumferential surface 12 extend between the end face 13 (at one end) and the end face 14 (at the other end). The angle sensor 1 is used, for example, in a motor, where the motor shaft passes through the inner circumferential surface 11 of the cylinder 10 of the rotor 2, and the rotor 2 is fixed to the shaft.

[0029] The cylinder 10 of the rotor 2 is made of, for example, a resin material, a non-magnetic body, a non-conductive material, or the like. The resin material of the cylinder 10 is, for example, an epoxy-based resin (a thermosetting resin). Note that the material of the cylinder 10 can be another resin. For example, a recyclable resin can be used as the material of the cylinder 10. Further, the non-magnetic body can have non-conductivity.

[0030] Figure 5 is a perspective view showing one specific example of the rotor 2. Figure 5 The inside of the cylinder 10 is shown in Figure 5 The plurality of metal bodies 5 are arranged in a ring shape, and the plurality of metal bodies 5 form a metal body structure 6. The metal bodies 5 extend in the axial direction x along the cylinder 10, and further, the metal bodies 5 extend in the circumferential direction along the cylinder 10, have a plate shape facing the radial direction, and form a surface facing the outer peripheral side. As shown in Figure 5 The metal bodies 5 are, for example, plate-shaped metal bodies having a curved shape, specifically, a circular arc or a shape along an arc, in a cross section orthogonal to the axis x, and the cross section orthogonal to the axis x is uniform or substantially uniform in the entire axial direction x. Specifically, for example, the metal bodies 5 have a curved shape (a shape of a portion of a cylinder or a substantially cylinder) having the axis x as a center axis or a substantially center axis, and have a constant or substantially constant width in the circumferential direction around the axis x. Further, as shown in Figure 5 The plurality of metal bodies 5 are arranged at a prescribed distance apart in the circumferential direction of the cylinder 10. That is, two metal bodies 5 adjacent to each other are separated by a prescribed distance around the axis x. The plurality of metal bodies 5 are, for example, arranged at equal or substantially equal angles in the circumferential direction in a manner along a cylindrical surface having the axis x as a center axis. Note that the shape of the metal bodies 5 is not limited to the shape described above. Further, as described above, the metal bodies 5 can be embedded in the cylinder 10 or can be provided on the surface of the cylinder 10. For example, the plurality of metal bodies 5 can be arranged as shown in Figure 5

[0031] Further, the plurality of metal bodies 5 have, for example, two end portions and a portion (an intermediate portion) between the two end portions in the circumferential direction. In the radial direction, the distance from the end portions of the metal bodies 5 to the outer peripheral surface 12 of the cylinder 10 of the rotor 2 is greater than the distance from the intermediate portion of the metal bodies 5 to the outer peripheral surface 12 of the cylinder 10 of the rotor 2, and the end portions of the metal bodies 5 are farther from the outer peripheral surface 12 of the cylinder 10 of the rotor 2 than the intermediate portion.

[0032] Figure 6 is a perspective view showing the outline structure of the stator 3, Figure 7 is a side view showing the outline structure of the stator 3, Figure 8 is a cross-sectional view schematically showing a cross section obtained by a plane including the axis x of the stator 3. As Figures 6-8 ​As shown, the cylinder 30 of the stator 3 is a cylindrical member extending along the axis x, and has a portion of the cylinder (hereinafter, referred to as a base portion) 33 and a plurality of protruding portions 34. The base portion 33 is provided with the inner peripheral surface 31 and the outer peripheral surface 33a of the cylinder 30 described later. The protruding portions 34 are portions protruding from the base portion 33 to the outer peripheral side (radial r outer side). The base portion 33 is provided with the protruding portions 34 at, for example, equal or approximately equal angles with respect to the axis x. The protruding portions 34 protrude from the base portion 33 to the radial r, and, for example, a cross section orthogonal to the radial r is elliptical or approximately elliptical. Note that the cross-sectional shape of the protruding portions 34 is not limited to elliptical, and can be other shapes.

[0033] The inner peripheral surface 31 of the cylinder 30 of the stator 3 is formed in the base portion 33. For example Figures 6-8 As shown, the base portion 33 has the inner peripheral surface 31 and the outer peripheral surface 33a which are cylindrical surfaces extending along the axis x. The inner peripheral surface 31 and the outer peripheral surface 33a face away from each other in the radial direction. The inner peripheral surface 31 of the base portion 33 forms a space in which the rotor 2 is accommodated, and faces the outer peripheral surface 12 of the cylinder 10 of the rotor 2 with a ring-shaped gap (magnetic gap) therebetween. The inner peripheral surface 31 of the base portion 33 is, for example, a cylindrical surface extending along a cylindrical surface having the axis x as a central axis.

[0034] The outer peripheral surface 33a of the base portion 33 is, for example, a cylindrical surface extending in a manner of a cylindrical surface having the axis x as a central axis. Further, for example Figures 6-8 As shown, the base portion 33 has ring-shaped portions protruding to the outer peripheral side from the outer peripheral surface 33a, that is, the flange portions 35 and 36. The flange portion 35 and the flange portion 36 face each other in the axis x direction with the outer peripheral surface 33a therebetween. The protruding portions 34 are provided on the outer peripheral surface 33a and protrude to the outer peripheral side from the outer peripheral surface 33a. As shown Figure 7 , Figure 8 As shown, a gap is formed between the protruding portion 34 and the flange portions 35 and 36 in the axis x direction. The outer peripheral portion of the cylinder 30 of the stator 3 is provided with the outer peripheral surface 32 including the outer peripheral surface 33a of the base portion 33 and the flanges 35 and 36.

[0035] As shown Figures 6-8 As shown, the flange portion 35 has a ring-shaped surface facing the outer peripheral side, that is, an end surface 35a. The end surface 35a is, for example, a cylindrical surface extending in a manner of a cylindrical surface having the axis x as a central axis. Further, the flange portion 36 has a ring-shaped surface facing the outer peripheral side, that is, an end surface 36a. The end surface 36a is, for example, a cylindrical surface extending in a manner of a cylindrical surface having the axis x as a central axis. The size (diameter) of the outer shape of the end surface 35a of the flange portion 35 is the same as or approximately the same as the size (diameter) of the outer shape of the end surface 36a of the flange portion 36. Note that the size (diameter) of the outer shape of the end surface 35a of the flange portion 35 and the size (diameter) of the outer shape of the end surface 36a of the flange portion 36 can be different. Hereinafter, the size of the outer shape is referred to as a diameter.

[0036] Further, as shown in Figure 7 , Figure 8 , a stepped portion 37 is provided annularly on the cylinder 30 around the axis x. The stepped portion 37 is provided in abutment with the base portion 33 in the axis x direction, for example, on the side surface 33b of the flange portion 35 formed on the base portion 33 as shown in Figure 7 , Figure 8 . The side surface 33b of the base portion 33 is an annular surface facing the opposite side of the flange portion 36 in the axis x direction. The stepped portion 37 is an annular portion protruding in the axis x direction from the side surface 33b, and an annular surface, i.e., a stepped surface 37a, facing the outer peripheral side is formed. The diameter of the stepped surface 37a is, for example, smaller than the diameter of the flange portion 35. Further, the stepped surface 37a is, for example, a cylindrical surface extending in the manner of a cylindrical surface having the axis x as a center axis. The annular recessed portion 37b is formed on the stepped surface 37a toward the inner peripheral side.

[0037] As described above, the plurality of coils 20 are fitted to the outer peripheral surface 32 of the cylinder 30 of the stator 3. The coil 20 is formed of, for example, a wire such as an electromagnetic wire, and the wire is made of a material having electrical conductivity. Specifically, as shown in Figures 6-8 , the plurality of coils 20 are wound around the plurality of protruding portions 34 of the base portion 33 of the cylinder 30, and a cylindrical shape extending annularly around the axis x (hereinafter referred to as a coil configuration 7) is formed on the cylinder 30. The coil configuration 7 is a shape formed by arranging the plurality of coils 20. The coil 20 is, for example, a coil formed by winding an electromagnetic wire. The coil 20 is formed by winding the electromagnetic wire around the plurality of protruding portions 34. The coil 20 has an annular shape wound around the radial direction r of the cylinder 30, and surrounds a space having a planar shape facing the radial direction. The plurality of coils 20 are formed on the cylinder 30 of the stator 3 in a manner arranged around the axis x, and the coil configuration 7 is formed.

[0038] Figure 9 is a perspective view showing the coil configuration 7. As shown in Figure 9 , the coil configuration 7 has two pieces (hereinafter referred to as coil configuration pieces) 7a, 7b. The coil configuration piece 7a is formed by connecting a plurality of coils 20, i.e., coils 20a, in series in an annular manner. Further, the coil configuration piece 7b is also formed by connecting a plurality of coils 20, i.e., coils 20b, in series in an annular manner. That is, the plurality of annular coils 20a or 20b are arranged in the circumferential direction. Note that the coil configuration piece 7a and the coil configuration piece 7b are formed of a member having electrical conductivity. Further, the coil configuration piece 7a and the coil configuration piece 7b are covered with a material having insulating properties (an insulating film or a coating film), for example, and are electrically insulated from each other. As shown in Figure 9As shown, coil construction pieces 7a and 7b overlap radially to form coil construction 7. In coil construction pieces 7a and 7b, a portion of the space enclosed by coil 20a is offset circumferentially from a portion of the space enclosed by coil 20b, and another portion of the space enclosed by coil 20a overlaps circumferentially with another portion of the space enclosed by coil 20b. Specifically, the space enclosed by coil 20a is located at a position offset circumferentially from the space enclosed by coil 20b by half the width of the space enclosed by coil 20a. It should be noted that the number of coils 20a and 20b in each of coil construction pieces 7a and 7b corresponds to the axial multiple angle set by angle sensor 1. Furthermore, the number of coil construction pieces 7a and 7b corresponds to the number of detection signals output by coil construction 7.

[0039] like Figures 6-9 As shown, an electromagnetic wire is wound radially around each protrusion 34 of the stator 3's cylinder 30, forming multiple loop coils 20 along the protrusions 30 radially around r, thereby forming a coil structure 7 on the stator 3. For example, coil structure pieces 7a and 7b are formed by winding an electromagnetic wire around multiple protrusions 34 of the cylinder 30. Specifically, for example, facing one side in the circumferential direction, the electromagnetic wire is alternately wound around each of two adjacent protrusions 34 from one side and the other side in the x-axis direction, and then folded back after one revolution around the cylinder 30, and then wound around the protrusions 34 in the same manner to the other side in the circumferential direction, forming coil structure pieces 7a and 7b. In this case, each coil 20a, 20b is formed around two protrusions 34. Furthermore, coil structure pieces 7a and 7b are offset by one protrusion 34 in the circumferential direction. It should be noted that each coil 20a and 20b is not limited to being formed around two protrusions 34, but can also be formed around other numbers of protrusions 34. Furthermore, while the case of the electromagnetic wire being wound around once has been described, the winding method of the electromagnetic wire is not limited to this; it can also be wound more than twice. In other words, the coil formed by winding the electromagnetic wire can, for example, be provided with one layer in the radial or axial direction, or with two, three, four, five, or other multiple layers. In this case, compared to the case of one or one layer, the output signal or the detected signal (e.g., the amplitude of the signal waveform) can be amplified.

[0040] In addition, such as Figure 7 , Figure 8 As shown, the excitation circuit 38 is accommodated in the recess 37b of the stepped portion 37 of the cylinder 30 of the stator 3.

[0041] The cylinder 30 of the stator 3 is formed of an insulating material, for example, resin material. In addition, the cylinder 30 of the stator 3 can also be formed of, for example, resin material, non-magnetic material, non-conductive material, or the like. Note that the non-magnetic material can also have non-conductivity. The resin material forming the cylinder 30 of the stator 3 is, for example, epoxy-based resin (thermosetting resin). Note that the material forming the cylinder 30 of the stator 3 can also be other resin.

[0042] Figure 10 is a perspective view schematically showing the structure of the frame 4, Figure 11 is a rear view schematically showing the structure of the frame 4, Figure 12 is a sectional view schematically showing a cross section obtained by a plane including the axis x of the frame 4. As described above, in the angle sensor 1, the frame 4 is fixed to the stator 3, and the frame 4 can be fixed to the stator 3.

[0043] As shown in Figures 10-12 , the frame 4 has a cover 40 covering the plurality of coils 20 formed in the stator 3. The cover 40 is, for example, a cylindrical portion corresponding to the cylinder 30 of the stator 3. The cover 40 forms a space capable of accommodating the cylinder 30 of the stator 3 in the inside, and has an inner peripheral surface 41 dividing the space. In addition, the cover 40 has an outer peripheral surface 42 on the outer peripheral side facing away from the inner peripheral surface 41. The inner peripheral surface 41 is a cylindrical surface extending along the axis x, and is, for example, a cylindrical surface extending in a manner of a cylindrical surface with the axis x as a center axis. Specifically, the inner peripheral surface 41 of the cover 40 is formed as a flange portion 35, 36 capable of accommodating the cylinder 30 of the stator 3, and the inner peripheral surface 41 of the cover 40 opposes each end surface 35a, 36a of the flange portion 35, 36 in the radial direction when the cylinder 30 is accommodated in the space formed by the inner peripheral surface 41. The inner peripheral surface 41 of the cover 40 has, for example, an inner diameter such that the inner peripheral surface 41 contacts each end surface 35a, 36a of the flange portion 35, 36 when the cylinder 30 is accommodated in the space formed by the inner peripheral surface 41, and the cylinder 30 is pressed into the space formed by the inner peripheral surface 41. In addition, the inner peripheral surface 41 of the cover 40 has, for example, an inner diameter such that the inner peripheral surface 41 does not contact each end surface 35a, 36a of the flange portion 35, 36 when the cylinder 30 is accommodated in the space formed by the inner peripheral surface 41, and an annular gap is formed between the inner peripheral surface 41 and each end surface 35a, 36a.

[0044] In addition, as shown in Figures 10-12 , the cover 40 of the frame 4 is formed with an annular portion protruding toward the inner peripheral side from the inner peripheral surface 41, that is, a flange portion 43. The flange portion 43 is formed, for example, at one end in the axis x direction of the inner peripheral surface 41. When the cylinder 30 is accommodated in the space formed by the inner peripheral surface 41 of the cover 40, the flange portion 43 engages (contacts) the cylinder 30 in the axis x direction, and becomes a stopper of the cylinder 30.

[0045] When the cylinder 30 is accommodated in the space formed by the inner circumferential surface 41 of the cover 40, the inner circumferential surface 41 of the cover 40 covers the entire cylinder 30. That is, the width of the inner circumferential surface 41 of the cover 40 in the x-axis direction is the same as or greater than the width of the cylinder 30 in the x-axis direction. It should be noted that when the cylinder 30 is accommodated in the space formed by the inner circumferential surface 41 of the cover 40, the inner circumferential surface 41 of the cover 40 may not cover the entire cylinder 30. That is, the width of the inner circumferential surface 41 of the cover 40 in the x-axis direction may be less than the width of the cylinder 30 in the x-axis direction. For example, when the cylinder 30 is accommodated in the space formed by the inner circumferential surface 41 of the cover 40, the width of the inner circumferential surface 41 of the cover 40 in the x-axis direction can be the width covering the outer circumferential surface 33a of the cylinder 30.

[0046] In addition, such as Figures 10-12 As shown, frame 4 has a portion, namely mounting part 44, that is, assembled to an external device that is the object of application. For example... Figures 10-12 As shown, the mounting portion 44 is provided, for example, on the outer peripheral surface 42 of the cover 40, protruding from the cover 40 towards the outer periphery. Furthermore, the mounting portion 44, for example, has a hole (hereinafter referred to as a through hole) 44a through which a fixing member such as a bolt passes, and the mounting portion 44 can be mounted to an external device by means of a fixing member. The frame 4, for example, has three mounting portions 44. It should be noted that the number of mounting portions 44 in the frame 4 is not limited to this. Furthermore, as... Figures 10-12 As shown, the cover 40, for example, has a holding portion 45 that holds the substrate 8, circuits such as ICs provided on the substrate 8, and circuits that perform calculations. Figures 10-12 As shown, the retaining part 45 extends from the outer peripheral surface 42 of the cover 40 along the axis x to the other side in the x-direction. It should be noted that, as... Figure 1 , Figure 2 , Figure 4 As shown, in the angle sensor 1, the substrate 8 is mounted on the holding portion 45 of the frame 4. The substrate 8 may contain one or more electronic components and one or more wirings. These multiple electronic components may also constitute a control unit for performing calculations or processing.

[0047] Frame 4 is formed, for example, of an insulating material, such as resin. Frame 4 is, for example, integrally molded. That is, the various components of frame 4, such as cover 40, mounting part 44, and retaining part 45, are integrally molded from the same material. It should be noted that frame 4 may also not be integrally molded.

[0048] Figure 13 It is a cross-sectional view showing the assembled state of frame 4 fixed to stator 3 and stator 3 and frame 4 after assembly. Figure 13 This represents the cross-section of stator 3 and frame 4 in their assembled state, obtained from a plane containing axis x. For example... Figure 13As shown, the cylinder 30 of the stator 3 is housed in a space formed by the inner peripheral surface 41 of the cover 40 of the frame 4, and the frame 4 is fixed to the stator 3. The fixation of the frame 4 to the stator 3 is performed, for example, by engagement, fitting, or bonding. In addition, the fixation of the frame 4 to the stator 3 is performed, for example, by adhesion. Note that the fixation structure of the frame 4 to the stator 3 is not limited to these structures. As shown in FIG. 2, for example, the fixation of the frame 4 to the stator 3 is performed by adhesion. As shown in FIG. 3, for example, the fixation of the frame 4 to the stator 3 is performed by fitting. Figure 13 As shown, in the assembled state, the entire cylinder 30 is covered by the cover 40 in the axial direction x. Note that, as described above, it can also be that, in the assembled state, the entire cylinder 30 is not covered by the cover 40 in the axial direction x. In addition, as shown in FIG. 2, for example, in the assembled state, the entire cylinder 30 is not covered by the cover 40 in the axial direction x. As shown in FIG. 3, for example, in the assembled state, the entire cylinder 30 is not covered by the cover 40 in the axial direction x. Figure 13 As shown, in the assembled state, the side surface 33b of the cylinder 30 is in contact with the flange portion 43 of the cover 40. Note that it can also be that, in the assembled state, the side surface 33b of the cylinder 30 is not in contact with the flange portion 43 of the cover 40.

[0049] As shown, in the assembled state, the outer peripheral surface 32 of the cylinder 30 of the stator 3 is covered by the cover 40 of the frame 4. Therefore, in the assembled state, the coil structure 7 formed on the outer peripheral surface 32 of the cylinder 30 of the stator 3 is covered by the cover 40 of the frame 4. Thus, even if the coil structure 7 is not protected by potting or the like, the coil structure 7 can be protected, and contact of an object or the like from the outside with the coil structure 7 can be suppressed. In addition, in the case where the recessed portion 37b of the step portion 37 of the cylinder 30 is covered by the cover 40, even if it is not protected by potting or the like, the excitation circuit 38 inside the recessed portion 37b can be protected from contact from the outside.

[0050] As described above, Figures 2-4 An angle sensor 1 in a use state is shown. A plurality of metal bodies 5 and a plurality of coils 20 are opposed to each other in the radial direction with a ring-shaped gap therebetween. In addition, as shown in FIG. 1, the width W1 of the metal body 5 is wider than the width W2 of the coil 20. Note that the width W1 is the distance of the metal body 20 in the axial direction x, and the width W2 is the distance of the coil 20 in the axial direction x. Thus, the width of the coil 20 in the axial direction x is opposed to the metal body 5 in the radial direction as a whole (see FIG. 1). In addition, the metal body 5 protrudes more than the coil 20 in both directions of the axial direction x (see FIG. 1). Figure 4 Figure 4 Figure 2 Figure 4

[0051] ​​​​The rotor 2 and the stator 3 form an inductive angle sensor, and the plurality of coils 20 form detection coils. Further, a magnetic space or a magnetic gap is formed between the rotor 2 and the stator 3. For example, in the angle sensor 1, the plurality of coils 20 are subjected to a periodically changing radial magnetic flux. Specifically, for example, the excitation circuit 38 provided in the stator 3 becomes a magnetic circuit that generates a periodically changing magnetic flux that acts on the plurality of coils 20, respectively. On the other hand, as described above, the plurality of metal bodies 5 are arranged in the circumferential direction around the axis x, and cut the magnetic flux generated by the excitation circuit 38 as the rotor 2 rotates. Further, the projection of the metal body 5 having a portion extending along the axis x in the radial direction moves with respect to the coil 20 as the rotor 2 rotates. Therefore, the magnetic flux from the excitation circuit 38 that acts on the plurality of coils 20, respectively, is canceled out by the eddy current generated in the metal body 5, and thus periodically changes as the rotor 2 rotates. Thus, in the plurality of coils 20, an electromotive force that changes as the rotor 2 rotates is generated by electromagnetic induction, and a signal that changes as the rotor 2 rotates is detected from the plurality of coils 20. Based on the detected signal from the plurality of coils 20, the rotational angle of the rotor 2 is detected in a device having a circuit.

[0052] In the stator 3 of the angle sensor 1 of the present embodiment, the protruding portions 34 protrude from the outer circumferential surface 33a of the base portion 33 to the outer circumferential side, and the electromagnetic wire forming the coil structure pieces 7a, 7b can be wound around the plurality of protruding portions 34 from the outer circumferential side in a manner along the outer circumferential surface 33a. Therefore, compared to the coil structure pieces 7a, 7b in which the electromagnetic wire is wound from the inner circumferential side in a manner along the inner circumferential surface of the stator 3, the coil structure pieces 7a, 7b can reduce the radial gap between the wound electromagnetic wire and the cylinder 30. That is, the radial gap between the electromagnetic wire and the outer circumferential surface 33a can be reduced. Thus, the stator 3 can make the coil structure pieces 7a, 7b have a shape that is more along the outer circumferential surface 33a, that is, a shape that is along a cylindrical surface. Therefore, the stator 3 can make the coil structure pieces 7a, 7b closer to the desired shape, and can improve the detection accuracy of the angle sensor 1.

[0053] The angle sensor 1 has the structure described above, and each of the metal bodies 5 faces the radial direction. Therefore, the metal bodies 5 can suppress the influence of the movement of the rotor 2 in the axis x direction. For example, the rigidity of the metal bodies 5 against the vibration of the rotor 2 in the axis x direction is high, and therefore, the accuracy of the angle sensor 1 is high, and further, the strength of the metal bodies 5 against the vibration of the rotor 2 in the axis x direction is high. Further, in the case where the metal bodies 5 are embedded in the cylinder 10 of the rotor 2 and are located inside the cylinder 10, in this respect as well, the strength of the metal bodies 5 against the vibration of the rotor 2 in the axis x direction is high.

[0054] Further, the cylinder 10 of the rotor 2 is cylindrical extending along the axis x, and even if the thickness in the radial direction is made thin, the strength of the cylinder 10 against the vibration of the rotor 2 in the axis x direction is maintained high. Therefore, the radial thickness of the cylinder 10 can be made thin, the rotor 2 can be made lightweight, and further, the assembling space of the rotor 2 can be reduced. Further, for example, the cylinder 10 of the rotor 2 can be insert-molded with the metal body 5, and the assembling of the plurality of metal bodies 5 to the rotor 2 can be made easy.

[0055] As described above, the coil configuration 7 is cylindrical extending along the axis x, and each coil 20 is along the axis x and faces the radial direction. Therefore, the coil 20 can suppress the influence by the movement of the stator 3 in the axis x direction. For example, the rigidity of the coil 20 against the vibration of the stator 3 in the axis x direction is made high, and therefore, the detection accuracy of the angle sensor 1 is made high, and further, the strength of the coil 20 against the vibration of the stator 3 in the axis x direction is made high. Further, the coil 20 can be formed by the electromagnetic wire, and the connection between the coils 20 can not be needed.

[0056] Further, by making the width W1 of the metal body 5 in the axis x direction larger than the width W2 of the coil 20 in the axis x direction, the metal body 5 can be more extended than the coil 20 in both directions toward which the axis x faces. Thereby, even if the relative movement in the axis x direction between the rotor 2 and the stator 3 occurs, and the positional relationship of the rotor 2 and the stator 3 in the axis x direction deviates from the desired positional relationship, the width W2 of the coil 20 as a whole can be opposed to the metal body 5. Therefore, even if the positional relationship of the rotor 2 and the stator 3 in the axis x direction deviates from the desired positional relationship, the influence on the accuracy of the detected angle is not caused, or the influence on the accuracy of the detected angle can be reduced. Further, even if the eccentricity between the rotor 2 and the stator 3 occurs, the portion in which the radial interval between the plurality of metal bodies 5 and the coil configuration 7 is expanded and the portion in which the radial interval is reduced are balanced, and therefore, in this case, the influence on the accuracy of the detected angle is not caused, or the influence on the accuracy of the detected angle can be reduced.

[0057] Further, by burying the metal body 5 in the resin member, the durability of the metal body 5 against oil and heat can be improved, and the scattering of the metal body 5 can be prevented.

[0058] As described above, the coil configuration 7 is formed by winding the electromagnetic wire to the plurality of protrusions 34 protruding from the outer peripheral surface 33a of the base 33 of the cylinder 30 of the stator 3 to the outer peripheral side, and the electromagnetic wire is wound from the outer peripheral side in a manner along the outer peripheral surface 33a of the base 33. Therefore, the radial gap between the coil configuration 7 and the outer peripheral surface 33a of the base 33 can be reduced. Thereby, the coil configuration 7 can be made a shape more along the outer peripheral surface 33a, that is, can be made a shape along the cylindrical surface. Therefore, the stator 3 can make the coil configuration 7 closer to the desired shape, and the detection accuracy of the angle sensor 1 can be improved.

[0059] Moreover, in the case of the shape of the stator 3 as shown in Figure 8 the excitation circuit 38 and the stator coil configuration pieces 7a, 7b can be arranged to partially overlap in the axial direction x, and thus the detection accuracy of the angle sensor 1 can be improved. Furthermore, the excitation circuit 38 can be arranged close to the rotor 2 side, and thus the air gap between the excitation circuit 38 and the rotor 2 can be reduced. Thus, the angle sensor 1 can be downsized.

[0060] Furthermore, as described above, the coil configuration 7 and the excitation circuit 38 can be protected without adding a member such as potting.

[0061] Furthermore, the attachment member, that is, the frame 4, for attaching the angle sensor 1 to an application object is detachable with respect to the stator 3 as described above. Thus, by selecting a corresponding frame 4 according to various application objects, the angle sensor 1 can be attached to various types of application objects. Furthermore, various electronic components (for example, communication devices, power generation devices, batteries, and the like) other than the means for detection can be provided on the frame 4 side. In this case, the frame 4 and the stator 3 can be electrically connected. Note that the above-described various electronic components can also be provided on the stator 3.

[0062] Furthermore, in the radial direction, the cylinder 30 of the stator 3 is interposed between the coil configuration 7 and the rotor 2, and thus contact between the rotor 2 and the coil 20 is suppressed.

[0063] Furthermore, since the frame 4 is located on the outer peripheral side of the stator 3, the width of the stator 3 and the frame 4 in the axial direction x in the assembled state is reduced. In this way, the angle sensor 1 can be reduced in width in the axial direction x.

[0064] In the above-described embodiment, a case in which the stator 3 is provided with a member in the shape of a cylinder, that is, the cylinder 30, the frame 4 is provided with a portion in the shape of a cylinder, that is, the cover 40, and the member in which the stator 3 and the frame 4 are fixed to each other is in the shape of a ring that is continuous in the circumferential direction is described, but the form of the stator 3 and the frame 4 is not limited thereto. Figure 14 is a perspective view showing a modification example of the stator 3 and the frame 4, Figure 15 is a perspective view showing a modification example of the stator 3. For example, as shown in Figure 15 the stator 3 can be in the shape of a circular arc and can extend only in a partial circumferential interval of the entire circumference of the above-described stator 3. The stator 3 of the modification example is formed of the same material as the above-described stator 3. The stator 3 of the modification example is formed of, for example, a resin member having insulating properties. Similarly, the frame 4 corresponds to the stator 3 of the modification example, and as shown in Figure 14The shape shown can be arc-shaped, and may extend only a portion of the circumference of the aforementioned frame 4. The frame 4 in the modified example is formed of the same material as the frame 4 described above. The frame 4 in the modified example is, for example, formed of an insulating resin component. Hereinafter, the stator 3 and frame 4 of the modified example will be described in detail. It should be noted that for each component of the stator 3 and frame 4 in the modified example, for components that are the same as or have the same function as those in the stator 3 and frame 4 described above, the same reference numerals are used and their descriptions are omitted.

[0065] like Figure 15 As shown, specifically, in the modified example, the stator 3, for example, instead of the cylindrical tube 30, has a portion (hereinafter referred to as the arc portion) 30A that extends in an arc shape or approximately an arc shape corresponding to a portion of the circumferential region of the tube 30. Figure 15 As shown, a plurality of protrusions 34 are arranged on the outer peripheral surface 33a of the arc portion 30A, similar to those of the stator 3 described above. The arc portion 30A has multiple protrusions 34 formed on portions corresponding to the arc portion 30A of the cylinder 30. The modified stator 3 is provided with a detection coil and an excitation circuit. The detection coil, like the detection coil (coil structure 7) provided in the stator 3 described above, is formed from multiple coils 20. Specifically, the multiple coils 20 are arranged such that portions of coil structure pieces 7a and 7b are respectively formed on portions of the cylinder 30 corresponding to the arc portion 30A. In the modified stator 3, similar to the multiple coils 20 in the stator 3 described above, the multiple coils 20 are also formed by winding conductive components such as electromagnetic wire around the protrusions 34. The excitation circuit, similar to the excitation circuit 38 described above, is a magnetic circuit that generates periodically changing magnetic flux acting on the multiple coils 20 formed in the arc portion 30A.

[0066] In addition, such as Figure 14 As shown, specifically, in the modified example, the frame 4, for example, instead of the cylindrical cover 40, has a portion (hereinafter referred to as the arc portion) 40A that extends in an arc shape or a substantially arc shape corresponding to a portion of the circumferential area of ​​the cover 40. The arc portion 40A of the modified example frame 4 extends in an arc shape or a substantially arc shape corresponding to the arc portion 30A of the modified example stator 3.

[0067] Further, as with the above-described frame 4, the frame 4 of the modification example is also provided with a portion to be fitted to an external device as an application target, i.e., a fitting portion 44. In the frame 4 of the modification example, the fitting portion 44 is provided, for example, at both end portions in the circumferential direction of the arc portion 40A. Further, the substrate 8, a circuit portion having an IC or the like not shown, and a circuit device of an arithmetic portion are attached or fixed to the frame 4 of the modification example. Specifically, for example, as with the above-described frame 4, the frame 4 of the modification example is provided with a holding portion 45 that accommodates the substrate 8 and the circuit device. The substrate 8 and the circuit device can also be provided at one side end portion in the circumferential direction of the frame 4, in which case, the region in which the excitation circuit and the detection coil can be provided in the stator 3 of the modification example is wider, and this can contribute to an improvement in detection accuracy. Further, the excitation circuit or the detection coil can also be adjacent to the substrate 8 and the circuit device in the circumferential direction. In other words, in the circumferential direction, the substrate 8 and the circuit device are arranged in a manner sandwiched between the detection coil or the excitation circuit and the fitting portion 44. In this case, the limited space of the stator 3 and the frame 4 can be effectively and flexibly utilized, and thus this can contribute to a reduction in the size of the angle sensor 1.

[0068] Further, in either the above-described stator 3 and frame 4 or the stator 3 of the modification example and the frame 4 of the modification example, the stator 3, the frame 4, and the substrate 8 and the circuit device can be sealed by a resin member or the like having insulating properties. In this case, the stator 3, the frame 4, and the substrate 8 and the circuit device can be protected from foreign matter or the like by the resin.

[0069] Further, either the above-described stator 3 or frame 4 or the stator 3 of the modification example or the frame 4 of the modification example can be provided with a connector that can be electrically connected to an external device. The connector can also be provided adjacent to the substrate 8 and the circuit device, in which case, the connector and the substrate 8 and the circuit device can be connected by the shortest path, and thus this can contribute to a reduction in the size of the angle sensor 1.

[0070] The present application has been described above with reference to the above-described embodiments, but the technical scope of the present application is not limited to the scope described in the above-described embodiments. It will be apparent to those skilled in the art that various changes or modifications can be made to the above-described embodiments. It will be apparent to those skilled in the art from the description of the claims that the technical scope of the present application includes the changes and modifications made to the above-described embodiments.

[0071] The above-described embodiments are for facilitating understanding of the present application and are not intended to limit the present application. Furthermore, the above-described embodiments do not limit the objects to which the present application is applied, and the present application can include all objects as its application objects. The respective constituent elements included in the above-described embodiments, the arrangement, materials, conditions, shapes, and sizes of the respective constituent elements, and the like are not limited to the exemplified contents, and can be appropriately changed. For example, the present application includes differences generated in implementation, such as manufacturing tolerances. Furthermore, the constituent elements shown in different embodiments can be partially replaced with or combined with each other within a range that does not cause technical contradiction. Furthermore, the respective structures can be appropriately selectively combined to function as at least a part of the above-described problems and effects.

[0072] BRIEF DESCRIPTION OF DRAWINGS

[0073] 1: angle sensor; 2: rotor; 3: stator; 4: frame; 5: metal body; 6: metal body structure; 7: coil structure; 7a, 7b: coil structure pieces; 8: substrate; 10: cylinder; 11: inner peripheral surface; 12: outer peripheral surface; 13, 14: end surfaces; 20, 20a, 20b: coils; 30: cylinder; 30A: arc portion; 31: inner peripheral surface; 32: outer peripheral surface; 33: base portion; 33a: outer peripheral surface; 33b: side surface; 34: protruding portion; 35, 36: flange portions; 35a, 36a: end surfaces; 37: step portion; 37a: step surface; 37b: recessed portion; 38: excitation circuit; 40: cover; 40A: arc portion; 41: inner peripheral surface; 42: outer peripheral surface; 43: flange portion; 44: fitting portion; 44a: through-hole; 45: holding portion.

Claims

1. An angle sensor comprising: a rotor having a cylinder and a plurality of metal bodies fixed to the cylinder; a stator; and a frame fixed to the stator, the stator comprising: a cylinder having an inner surface on the rotor side and an outer surface on the frame side; and a plurality of coils fitted to the outer surface of the cylinder.

2. The angle sensor according to claim 1, the outer surface of the cylinder comprising a plurality of protrusions extending in the radial direction, the plurality of coils being wound around the plurality of protrusions.

3. The angle sensor according to claim 1 or 2, a wire forming the coil extending along the outer surface of the cylinder.

4. The angle sensor according to any one of claims 1 to 3, the frame comprising a cover covering the plurality of coils.

5. The angle sensor according to any one of claims 1 to 4, the frame comprising a fitting portion.

6. The angle sensor according to any one of claims 1 to 5, the cylinder of the stator being formed of a resin.

7. The angle sensor according to any one of claims 1 to 6, a substrate being fitted to the frame, one or a plurality of electronic components and one or a plurality of wirings being provided to the substrate. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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