Rotation detection device

Abstract

To provide a rotation detection device capable of suppressing interference between a member existing around a rotating member and a magnetic sensor.SOLUTION: A rotation detection device includes: a plate-like magnetic encoder mounted to a rotating member; and a plate-like magnetic sensor configured so as to detect a magnetic field from the magnetic encoder. The magnetic sensor is disposed in a virtual region sandwiched between a first virtual plane to which one main surface of the magnetic encoder belongs and a second virtual plane to which the other main surface of the magnetic encoder belongs. A thickness direction of the magnetic encoder matches a thickness direction of the magnetic sensor.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a rotation detection device. [Background technology]

[0002] A rotation detection device is disclosed in Patent Document 1. The rotation detection device includes a magnetic encoder attached to a rotating member, and a magnetic sensor configured to detect a magnetic field from the magnetic encoder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-179450 Summary of the Invention [Problem to be solved by the invention]

[0004] In a conventional rotation detection device, there is a possibility that a magnetic sensor may interfere with a member existing around a rotating member. In one aspect of the present disclosure, it is preferable to provide a rotation detection device capable of suppressing interference between a member existing around a rotating member and a magnetic sensor. [Means for solving the problem]

[0005] One aspect of the present disclosure is a rotation detection device including a plate-shaped magnetic encoder attached to a rotating member and a plate-shaped magnetic sensor configured to detect a magnetic field from the magnetic encoder. The magnetic sensor is disposed in a virtual area between a first virtual plane to which one main surface of the magnetic encoder belongs and a second virtual plane to which the other main surface of the magnetic encoder belongs. A thickness direction of the magnetic encoder coincides with a thickness direction of the magnetic sensor.

[0006] In a rotation detection device according to one aspect of the present disclosure, a magnetic sensor is disposed in a virtual area. In many cases, components other than the rotation detection device are not disposed in the virtual area. Therefore, interference between the magnetic sensor and components other than the rotation detection device can be suppressed. [Brief description of the drawings]

[0007] [Figure 1] 2 is a cross-sectional view showing the configuration of a rotation detection device in a cross section parallel to the directions X and Y and thickness directions TE and TS. [Diagram 2] 2 is a cross-sectional view showing the configuration of a rotation detection device in a cross section parallel to the directions X and Y and perpendicular to the thickness directions TE and TS. [Diagram 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Exemplary embodiments of the present disclosure will now be described with reference to the drawings. First Embodiment 1. Configuration of rotation detection device 1 The configuration of the rotation detection device 1 will be described with reference to Fig. 1 to Fig. 3. As shown in Fig. 1 and Fig. 2, the rotation detection device 1 includes a magnetic encoder 3. The magnetic encoder 3 is attached to a rotating member 5.

[0009] As shown in Fig. 1, the rotating member 5 can rotate around a rotating shaft 7. At least a portion of the rotating member 5 to which the magnetic encoder 3 is attached has, for example, a cylindrical shape. The central axis of the cylindrical shape coincides with the rotating shaft 7. The rotating member 5 is, for example, an inner ring that constitutes a wheel bearing device provided in a vehicle. A wheel can be attached to the inner ring.

[0010] The magnetic encoder 3 is attached to, for example, the outer circumferential surface 5A of the rotating member 5. The magnetic encoder 3 extends, for example, along the circumferential direction of the rotating member 5. When viewed from a certain viewpoint in the direction of the rotating shaft 7, the magnetic encoder 3 has an annular shape centered on the rotating shaft 7. The magnetic encoder 3 rotates integrally with the rotating member 5 around the rotating shaft 7.

[0011] The magnetic encoder 3 has a plate-like shape. As shown in Fig. 1, the thickness direction TE of the magnetic encoder 3 is parallel to the direction of the rotating shaft 7 and parallel to the outer circumferential surface 5A of the rotating member 5. The thickness direction is the thickness direction of the plate in the plate-like member.

[0012] The magnetic encoder 3 includes a plurality of N magnetic poles 9 and a plurality of S magnetic poles 11. The N magnetic poles 9 and the S magnetic poles 11 are alternately arranged in the circumferential direction of the rotating member 5 and the magnetic encoder 3. As shown in Fig. 1, an imaginary plane to which one main surface 13A of the magnetic encoder 3 belongs is defined as a first imaginary plane 15A. An imaginary plane to which the other main surface 13B of the magnetic encoder 3 belongs is defined as a second imaginary plane 15B.

[0013] The first imaginary plane 15A is a plane including a portion that coincides with the main surface 13A and a portion that is an extension of the main surface 13A. The second imaginary plane 15B is a plane including a portion that coincides with the main surface 13B and a portion that is an extension of the main surface 13B.

[0014] The main surface is a plane having a relatively large area among the surfaces of a plate-like member. In the magnetic encoder 3, the main surface 13B is the main surface opposite to the main surface 13A. The first imaginary plane 15A and the second imaginary plane 15B are, for example, parallel to each other. A virtual area sandwiched between the first imaginary plane 15A and the second imaginary plane 15B is defined as a virtual area 17.

[0015] 1 and 2, the rotation detection device 1 includes a sensor unit 21. The sensor unit 21 includes a magnetic sensor 23, two lead wires 25A and 25B, and a capacitor 27.

[0016] The magnetic sensor 23 detects the magnetic field from the magnetic encoder 3. The magnetic sensor 23 includes a magnetic detection element and a signal processing circuit. The signal processing circuit processes the signal output from the magnetic detection element. The magnetic sensor 23 has a plate-like shape.

[0017] 1, the thickness direction TS of the magnetic sensor 23 coincides with the thickness direction TE of the magnetic encoder 3. The thickness direction TS and the thickness direction TE coinciding with each other does not only mean that they completely coincide with each other, but also means that there is a slight deviation between the thickness direction TS and the thickness direction TE within a range that can solve the problem of the present disclosure. An example of the slight deviation range is a range of -3° to 3°.

[0018] When viewed from a viewpoint in the thickness direction TS, the magnetic sensor 23 has a rectangular shape as shown in Fig. 2. As shown in Fig. 1, the magnetic sensor 23 is disposed in a virtual area 17. For example, the entire magnetic sensor 23 is disposed in the virtual area 17. Examples of the magnetic sensor 23 include a GMR (Giant Magneto Resistive effect) sensor, an AMR (Anisotropic Magneto Resistive) sensor, and a TMR (Tunneling Magneto Resistive) sensor.

[0019] The lead wires 25A, 25B are strip-shaped members connected to an end face 29 of the magnetic sensor 23. The lead wires 25A, 25B are made of, for example, a conductive metal. The end face 29 is the end face of the magnetic sensor 23 on the direction X side. The direction X is a direction from the rotating shaft 7 toward the radial outside of the rotating member 5 and the magnetic encoder 3, and is a direction passing through the magnetic sensor 23. The end face 29 is, for example, perpendicular to the direction X. The thickness direction of the lead wires 25A, 25B coincides with the thickness direction TS, for example.

[0020] The lead wires 25A and 25B extend in the direction X from the end surface 29. As shown in Fig. 2, the lead wires 25A and 25B are arranged at intervals in the circumferential direction of the rotating member 5 and the magnetic encoder 3. As shown in Fig. 1, the lead wires 25A and 25B are arranged in the imaginary area 17. For example, the entire lead wires 25A and 25B are arranged in the imaginary area 17.

[0021] The capacitor 27 is connected to the lead wires 25A and 25B. The capacitor 27 has a function of suppressing noise. The capacitor 27 is disposed on the direction X side of the magnetic sensor 23. As shown in FIG. 1, the capacitor 27 is disposed in the virtual area 17. For example, the entire capacitor 27 is disposed in the virtual area 17.

[0022] 1 and 2, the rotation detector 1 includes a cable 31. As shown in Fig. 3, the cable 31 includes two electric wires 33A and 33B and a sheath 34. The electric wires 33A and 33B are twisted together.

[0023] The electric wire 33A includes a central conductor 35 and an insulator 37. The central conductor 35 is, for example, a stranded conductor formed by stranding wires having good electrical conductivity. Examples of the wires having good electrical conductivity include wires made of copper, aluminum, or the like.

[0024] The insulator 37 covers the central conductor 35. The insulator 37 is made of, for example, an insulating resin. Examples of the insulating resin include cross-linked polyethylene. The electric wire 33B has the same configuration as the electric wire 33A.

[0025] The sheath 34 collectively covers the electric wires 33A and 33B. The sheath 34 is made of, for example, insulating resin. The cable 31 is disposed on the direction X side of the sensor unit 21. The cable 31 extends along the direction X.

[0026] At the end of the cable 31 on the direction Y side, the sheath 34 is removed to expose the electric wires 33A and 33B. The direction Y is opposite to the direction X. At the end of the exposed electric wires 33A and 33B on the direction Y side, the insulator 37 is removed to expose the central conductor 35.

[0027] 2, exposed central conductor 35 of electric wire 33A is connected to lead wire 25A at connection portion 39A. Also, exposed central conductor 35 of electric wire 33B is connected to lead wire 25B at connection portion 39B. Connection portions 39A and 39B are disposed in imaginary region 17. Connection portion 39A corresponds to the connection portion between lead wire 25A and cable 31. Connection portion 39B corresponds to the connection portion between lead wire 25B and cable 31. Cable 31 has a function of transmitting a signal output by sensor unit 21.

[0028] 1 and 2, the rotation detector 1 includes a molded body 41. Examples of materials for the molded body 41 include PA (polyamide) 612, nylon 66 (nylon is a registered trademark), and PBT (polybutylene terephthalate).

[0029] The molded body 41 covers the sensor unit 21. The molded body 41 also covers the portions of the cable 31 on the side of the lead wires 25A and 25B. The molded body 41 covers the connection portions 39A and 39B. The molded body 41 covers the portions of the cable 31 where the electric wires 33A and 33B are exposed and where the central conductor 35 is exposed.

[0030] The molded body 41 has a form extending along the directions X and Y. The molded body 41 has an outlet 43 at an end on the direction X side. The cable 31 is drawn out from the molded body 41 at the outlet 43. On the direction X side of the outlet 43, the cable 31 is not covered by the molded body 41. As shown in FIG. 1, the outlet 43 is disposed in the imaginary region 17.

[0031] The molded body 41 has a protruding portion 45. The protruding portion 45 is a portion that protrudes in the direction Z shown in Fig. 2 compared to other portions of the molded body 41. The direction Z is a direction perpendicular to the directions X and Y and the thickness directions TE and TS. The protruding portion 45 is provided on a portion of the molded body 41 on the direction X side. Further, direction Z is a direction intersecting with the direction in which cable 31 is pulled out from molded body 41 and also intersecting with rotation axis 7. For example, direction Z is a direction perpendicular to the direction in which cable 31 is pulled out from molded body 41. For example, direction Z is a direction perpendicular to rotation axis 7. In this embodiment, the entire protrusion 45 is disposed in virtual area 17 as shown in FIG. 1 .

[0032] 1 and 2, the rotation detection device 1 includes a holder 51. The holder 51 holds the molded body 41. The holder 51 holds the molded body 41, and thereby indirectly holds the sensor unit 21 and the cable 31.

[0033] The holding portion 51 is a member that does not rotate relative to the rotating member 5. The sensor unit 21 and the cable 31 held by the holding portion 51 also do not rotate relative to the rotating member 5. The holding portion 51 is, for example, a knuckle connected to the vehicle body. The knuckle is a member that rotatably supports the inner ring.

[0034] The holder 51 has a through hole 53. The through hole 53 penetrates the holder 51 in the directions X and Y. The molded body 41 is inserted into the through hole 53. A portion of the molded body 41 on the direction Y side protrudes toward the magnetic encoder 3 beyond the through hole 53. The magnetic sensor 23 is disposed on the magnetic encoder 3 side beyond the through hole 53.

[0035] Note that being disposed closer to the magnetic encoder 3 than the through-hole 53 means being disposed closer to the magnetic encoder 3 than the entrance 53A of the through-hole 53 on the magnetic encoder 3 side. For example, the entire magnetic sensor 23 is disposed closer to the magnetic encoder 3 than the through-hole 53.

[0036] A portion of molded body 41 on the direction X side protrudes in direction X beyond through hole 53. Protruding portion 45 is located on the direction X side beyond through hole 53. As shown in FIG. 2, protruding portion 45 contacts end face 55 of retaining portion 51. End face 55 is an end face on the direction X side. Protruding portion 45 and end face 55 are fixed together using, for example, bolts 57 or the like.

[0037] 2. Effects of the rotation detection device 1 (1A) When the rotating member 5 rotates, the magnetic encoder 3 also rotates together with the rotating member 5. In the magnetic encoder 3, the north magnetic poles 9 and the south magnetic poles 11 are arranged alternately in the circumferential direction of the magnetic encoder 3. Therefore, when the magnetic encoder 3 rotates, the magnetic field in the magnetic sensor 23 changes periodically. The sensor unit 21 detects the rotation of the rotating member 5 based on the change in the magnetic field.

[0038] Therefore, the rotation detection device 1 can detect the rotation of the rotating member 5. The rotation detection device 1 can detect, for example, the rotation of a wheel attached to the rotating member 5. In that case, the rotation detection device 1 can be used, for example, in an ABS (anti-lock braking system).

[0039] (1B) The magnetic sensor 23 is disposed in the virtual area 17. In most cases, no components other than the rotation detection device 1 are disposed in the virtual area 17. Therefore, interference between the magnetic sensor 23 and components other than the rotation detection device 1 can be suppressed.

[0040] (1C) The thickness direction TS of the magnetic sensor 23 coincides with the thickness direction TE of the magnetic encoder 3. Therefore, the size of the magnetic sensor 23 in the thickness direction TE can be reduced. As a result, the rotation detection device 1 can be made thinner in the thickness direction TE.

[0041] (1D) The lead wires 25A, 25B and the capacitor 27 are disposed in the imaginary region 17. Therefore, interference between the lead wires 25A, 25B and the capacitor 27 and members other than the rotation detection device 1 can be suppressed.

[0042] (1E) The connection portions 39A and 39B are disposed in the virtual area 17. Therefore, interference between members other than the rotation detection device 1 and the connection portions 39A and 39B can be suppressed. (1F) Lead-out port 43 is disposed in virtual area 17. Therefore, interference between members other than rotation detector 1 and cable 31 led out from lead-out port 43 can be suppressed.

[0043] (1G) The magnetic sensor 23 is disposed closer to the magnetic encoder 3 than the through-hole 53. Therefore, the detection sensitivity of the magnetic sensor 23 can be increased compared to when the magnetic sensor 23 is disposed inside the through-hole 53. (1H) Protrusion 45 protrudes in direction Z. Direction Z is perpendicular to thickness directions TE and TS. Therefore, the thickness of molded body 41 in thickness directions TE and TS can be reduced compared to when protrusion 45 protrudes in other directions.

[0044] <Other embodiments> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms. (1) The entire molded body 41 may be disposed in the imaginary region 17, or a part of the molded body 41 may be disposed in the imaginary region 17. For example, the inner peripheral portion of the molded body 41 may be disposed in the imaginary region 17, and the outer peripheral portion of the molded body 41 may be disposed outside the imaginary region 17. Alternatively, the outer peripheral surface of the molded body 41 may be in contact with the first imaginary plane 15A and the second imaginary plane 15B.

[0045] (2) The rotating member 5 may be a member other than the inner ring of the wheel bearing device. The rotation detection device 1 may be used in devices other than vehicles. (3) The rotation detector 1 may include a connector instead of the cable 31 . (4) Some or all of the lead wires 25A, 25B, capacitor 27, connecting portions 39A, 39B, and outlet 43 do not have to be disposed in virtual area 17. Even in this case, the effects of (1A) to (1C) and (1G) to (1H) can be obtained.

[0046] (5) The magnetic sensor 23 does not have to be disposed on the side of the magnetic encoder 3 relative to the through hole 53. Even in this case, the effects of (1A) to (1F) and (1H) can be obtained. (6) The protruding portion 45 may protrude in a direction other than the direction Z. Even in this case, the effects of (1A) to (1G) can be achieved.

[0047] (7) The function of one component in each of the above embodiments may be shared by multiple components, or the functions of multiple components may be performed by one component. Also, part of the configuration of each of the above embodiments may be omitted. Also, at least part of the configuration of each of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0048] (8) In addition to the above-described rotation detection device 1, the present disclosure can also be realized in various forms, such as a system including the rotation detection device 1 as a component, a program for causing a computer to function as a control unit of the rotation detection device 1, a non-transient physical recording medium such as a semiconductor memory on which the program is recorded, a rotation detection method, a manufacturing method for a rotation detection device, etc. [Explanation of symbols]

[0049] 1...rotation detection device, 3...magnetic encoder, 5...rotating member, 5A...outer peripheral surface, 7...rotating shaft, 9...north magnetic pole, 11...south magnetic pole, 13A, 13B...main surface, 15A...first imaginary plane, 15B...second imaginary plane, 17...imaginary area, 21...sensor portion, 23...magnetic sensor, 25A, 25B...lead wire, 27...capacitor, 29...end surface, 31...cable, 33A, 33B...electric wire, 34...sheath, 35...center conductor, 37...insulator, 39A, 39B...connection portion, 41...molded body, 43...lead outlet, 45...protrusion, 51...holding portion, 53...through hole, 53A...entrance, 55...end surface, 57...bolt

Claims

1. a plate-shaped magnetic encoder attached to a rotating member; a plate-shaped magnetic sensor configured to detect a magnetic field from the magnetic encoder; Equipped with the magnetic sensor is disposed in a virtual area between a first virtual plane to which one main surface of the magnetic encoder belongs and a second virtual plane to which the other main surface of the magnetic encoder belongs, A thickness direction of the magnetic encoder and a thickness direction of the magnetic sensor are aligned. Rotation detection device.

2. 2. The rotation detection device according to claim 1, A lead wire connected to the magnetic sensor; A capacitor connected to the lead wire; Further equipped with the lead wire and the capacitor are disposed in the virtual area; Rotation detection device.

3. 3. The rotation detection device according to claim 2, Further comprising a cable connected to the lead wire, A connection portion between the lead wire and the cable is disposed in the virtual area. Rotation detection device.

4. 4. The rotation detection device according to claim 3, a molded body that covers the magnetic sensor, the lead wires, the capacitor, and a portion of the cable that is on the lead wire side; An outlet through which the cable is pulled out from the molded body is disposed in the virtual area. Rotation detection device.

5. The rotation detection device according to claim 4, Further comprising a holder for holding the molded body, The holding portion has a through hole into which the molded body is inserted, The magnetic sensor is disposed closer to the magnetic encoder than the through hole. Rotation detection device.

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