Rotation detection device

Abstract

The utility model provides a rotation detection device which can restrain interference between parts around a rotating part and a magnetic sensor. A rotation detection device is provided with: 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 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. The thickness direction of the magnetic encoder is consistent with the thickness direction of the magnetic sensor.

Description

Technical Field

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

[0002] Patent Document 1 discloses a rotation detection device. 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.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-179450 Utility Model Content

[0006] Issues to be solved by the utility model

[0007] In conventional rotation detection devices, components existing around a rotating member may interfere with a magnetic sensor. In one embodiment of the present disclosure, it is preferable to provide a rotation detection device that can suppress interference between components existing around a rotating member and a magnetic sensor.

[0008] Solutions to Problems

[0009] One embodiment of the present disclosure is a rotation detection device comprising: a plate-shaped magnetic encoder mounted on a rotating component; and a plate-shaped magnetic sensor configured 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 principal surface of the magnetic encoder belongs and a second virtual plane to which the other principal surface of the magnetic encoder belongs. The thickness direction of the magnetic encoder coincides with the thickness direction of the magnetic sensor.

[0010] In one embodiment of the present disclosure, a rotation detection device is configured such that a magnetic sensor is disposed in a virtual region. Components other than the rotation detection device are generally not disposed in the virtual region. Therefore, interference between components other than the rotation detection device and the magnetic sensor can be suppressed.

[0011] Specifically, the solutions of the present utility model are as follows.

[0012] A first embodiment is a rotation detection device comprising: a plate-shaped magnetic encoder mounted on a rotating member; and a plate-shaped magnetic sensor configured to detect a magnetic field from the magnetic encoder.

[0013] The magnetic sensor is arranged in a virtual area 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.

[0014] The thickness direction of the magnetic encoder is consistent with the thickness direction of the magnetic sensor.

[0015] Solution 2 is a rotation detection device based on Solution 1, which is characterized by:

[0016] It further comprises: a lead wire connected to the magnetic sensor; and a capacitor connected to the lead wire,

[0017] The lead and the capacitor are arranged in the imaginary area.

[0018] Solution 3 is a rotation detection device based on Solution 2, which is characterized by:

[0019] Also provided is a cable connected to the lead wire,

[0020] A connection portion between the lead wire and the cable is disposed in the imaginary area.

[0021] Solution 4 is a rotation detection device based on Solution 3, which is characterized by:

[0022] It also includes a molded body covering the magnetic sensor, the lead wire, the capacitor, and a portion of the cable on the lead wire side.

[0023] An outlet for leading the cable out of the molded body is arranged in the imaginary area.

[0024] Solution 5 is a rotation detection device based on Solution 4, which is characterized by:

[0025] further comprising a holding portion for holding the molded body,

[0026] The holding portion includes a through hole into which the molded body is inserted.

[0027] The magnetic sensor is arranged on a side of the magnetic encoder relative to the through hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 1 is a cross-sectional view showing the structure of the rotation detection device in a cross section parallel to the directions X, Y and the thickness directions TE, TS.

[0029] Figure 2 1 is a cross-sectional view showing the structure of the rotation detection device in a cross section parallel to directions X and Y and perpendicular to thickness directions TE and TS.

[0030] Figure 3 yes Figure 1 Cross-sectional view of section III-III in FIG.

[0031] Explanation of symbols

[0032] 1—rotation detection device, 3—magnetic encoder, 5—rotating member, 5A—outer peripheral surface, 7—rotating shaft, 9—N magnetic pole, 11—S magnetic pole, 13A, 13B—main surfaces, 15A—first imaginary plane, 15B—second imaginary plane, 17—imaginary region, 21—sensor portion, 23—magnetic sensor, 25A, 25B—leads, 27—capacitor, 29—end surface, 31—cable, 33A, 33B—electric wire, 34—sheath, 35—center conductor, 37—insulator, 39A, 39B—connecting portion, 41—molded body, 43—lead outlet, 45—protrusion, 51—holding portion, 53—through hole, 53A—entrance, 55—end surface, 57—bolt. DETAILED DESCRIPTION

[0033] Illustrative embodiments of the present disclosure are described with reference to the accompanying drawings.

[0034] <First embodiment>

[0035] 1. Structure of the Rotation Detection Device 1

[0036] based on Figures 1 to 3 The structure of the rotation detection device 1 is described. Figure 1 、 Figure 2 As shown, the rotation detection device 1 includes a magnetic encoder 3 . The magnetic encoder 3 is attached to a rotating member 5 .

[0037] like Figure 1 As shown, the rotating member 5 is rotatable about a rotating shaft 7. At least the portion of the rotating member 5 where the magnetic encoder 3 is mounted 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 of a wheel bearing device included in a vehicle. A wheel can be mounted on the inner ring.

[0038] The magnetic encoder 3 is attached to, for example, the outer peripheral 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 point 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 is integral with the rotating member 5 and rotates about the rotating shaft 7.

[0039] The magnetic encoder 3 has a plate-like shape. Figure 1 As shown, the thickness direction TE of the magnetic encoder 3 is parallel to the direction of the rotating shaft 7 and parallel to the outer peripheral surface 5A of the rotating member 5. The thickness direction refers to the thickness direction of the plate in the plate-like member.

[0040] 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. Figure 1As shown, a virtual plane to which one principal surface 13A of the magnetic encoder 3 belongs is referred to as a first virtual plane 15A, and a virtual plane to which the other principal surface 13B of the magnetic encoder 3 belongs is referred to as a second virtual plane 15B.

[0041] 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.

[0042] The term "principal surface" refers to a relatively large surface area within the surface of a plate-like member. In the magnetic encoder 3, principal surface 13B is the principal surface opposite principal surface 13A. First imaginary plane 15A and second imaginary plane 15B are, for example, parallel. The imaginary region enclosed by first imaginary plane 15A and second imaginary plane 15B is referred to as imaginary region 17.

[0043] like Figure 1 、 Figure 2 As shown, 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 .

[0044] 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.

[0045] like Figure 1 As shown, the thickness direction TS of the magnetic sensor 23 coincides with the thickness direction TE of the magnetic encoder 3. The consistency between the thickness directions TS and TE includes not only complete consistency but also slight deviation between the thickness directions TS and TE within a range that can solve the problems of the present disclosure. Examples of slight deviations include a range of -3° to 3°.

[0046] When viewed from a point in the thickness direction TS, Figure 2 As shown, the shape of the magnetic sensor 23 is a rectangle. Figure 1 As shown, the magnetic sensor 23 is arranged in the virtual area 17. For example, the entire magnetic sensor 23 is arranged 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.

[0047] Lead wires 25A and 25B are strip-shaped components connected to the end surface 29 of the magnetic sensor 23. Lead wires 25A and 25B are made of, for example, a conductive metal. End surface 29 is the end surface of the magnetic sensor 23 located on the side in the direction X. Direction X is the direction from the rotating shaft 7 toward the radially outward direction of the rotating member 5 and the magnetic encoder 3, and is the direction passing through the magnetic sensor 23. End surface 29 is, for example, orthogonal to direction X. The thickness direction of lead wires 25A and 25B coincides with, for example, the thickness direction TS.

[0048] Leads 25A, 25B extend from end surface 29 in direction X. Figure 2 As shown in FIG. 1 , the lead wires 25A and 25B are arranged at intervals in the circumferential direction of the rotating member 5 and the magnetic encoder 3. Figure 1 As shown, the leads 25A and 25B are arranged in the imaginary region 17. For example, the leads 25A and 25B are arranged in the imaginary region 17 as a whole.

[0049] The capacitor 27 is connected to the leads 25A and 25B. The capacitor 27 has a function of suppressing noise. The capacitor 27 is arranged on the side of the direction X compared to the magnetic sensor 23. Figure 1 As shown, the capacitor 27 is arranged in the imaginary region 17. For example, the entire capacitor 27 is arranged in the imaginary region 17.

[0050] like Figure 1 、 Figure 2 As shown, the rotation detection device 1 includes a cable 31. Figure 3 As shown, the cable 31 includes two electric wires 33A and 33B and a sheath 34. The electric wires 33A and 33B are twisted.

[0051] 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 twisting highly conductive wires. Examples of highly conductive wires include copper and aluminum wires.

[0052] 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 also has the same structure as the electric wire 33A.

[0053] The sheath 34 covers the wires 33A and 33B. The sheath 34 is made of, for example, an insulating resin. The cable 31 is arranged on the side of the sensor unit 21 in the direction X. The cable 31 extends along the direction X.

[0054] At the end of the cable 31 in the direction Y, the jacket 34 is removed, exposing the wires 33A and 33B. The direction Y is the opposite direction of the direction X. At the ends of the exposed wires 33A and 33B in the direction Y, the insulation 37 is removed, exposing the center conductor 35.

[0055] like Figure 2 As shown, the exposed center conductor 35 of the wire 33A is connected to the lead wire 25A at the connection portion 39A. Furthermore, the exposed center conductor 35 of the wire 33B is connected to the lead wire 25B at the connection portion 39B. Connection portions 39A and 39B are arranged in the virtual area 17. Furthermore, connection portion 39A corresponds to the connection portion between the lead wire 25A and the cable 31. Connection portion 39B corresponds to the connection portion between the lead wire 25B and the cable 31. The cable 31 has the function of transmitting the signal output by the sensor unit 21.

[0056] like Figure 1 、 Figure 2 As shown, the rotation detection device 1 includes a molded body 41. Examples of the material of the molded body 41 include PA (polyamide) 612, nylon 66 (nylon is a registered trademark), and PBT (polybutylene terephthalate).

[0057] The molded body 41 covers the sensor portion 21. Furthermore, the molded body 41 covers the portion of the cable 31 on the lead wires 25A and 25B side. The molded body 41 covers the connectors 39A and 39B. The molded body 41 covers the exposed portion of the wires 33A and 33B and the exposed portion of the center conductor 35 in the cable 31.

[0058] The molded body 41 has a shape extending in directions X and Y. The molded body 41 has a lead-out port 43 at its end on one side in direction X. The cable 31 is led out of the molded body 41 in the lead-out port 43. The cable 31 is not covered by the molded body 41 on the side closer to the lead-out port 43 in direction X. Figure 1 As shown, the outlet 43 is arranged in the imaginary area 17 .

[0059] The molded body 41 includes a protrusion 45. The protrusion 45 is a portion of the molded body 41 that is tilted relative to the other portions. Figure 2 The portion protruding in the direction Z shown. The direction Z is a direction perpendicular to the directions X, Y and the thickness directions TE, TS. The protrusion 45 is provided on the portion of the molded body 41 on the side of the direction X.

[0060] In addition, the direction Z is a direction that intersects the direction in which the cable 31 is drawn out from the molded body 41 and is a direction that intersects the rotation axis 7. For example, the direction Z is a direction that is orthogonal to the direction in which the cable 31 is drawn out from the molded body 41. For example, the direction Z is a direction that is orthogonal to the rotation axis 7. In addition, in this embodiment, as Figure 1 As shown, the entire protrusion 45 is arranged in the imaginary area 17 .

[0061] like Figure 1 、 Figure 2As shown, the rotation detection device 1 includes a holding portion 51. The holding portion 51 holds the molded body 41. The holding portion 51 holds the molded body 41, thereby indirectly holding the sensor portion 21 and the cable 31.

[0062] The holding portion 51 is a component that does not rotate relative to the rotating member 5. The sensor unit 21 and 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 joint connected to the vehicle body. The joint is a component that rotatably supports the inner ring.

[0063] The holding portion 51 includes a through-hole 53. The through-hole 53 extends through the holding portion 51 in the directions X and Y. The molded body 41 is inserted into the through-hole 53. The portion of the molded body 41 on the Y side protrudes further toward the magnetic encoder 3 than the through-hole 53. The magnetic sensor 23 is positioned closer to the magnetic encoder 3 than the through-hole 53.

[0064] Furthermore, being arranged closer to the magnetic encoder 3 than the through hole 53 means being arranged closer to the magnetic encoder 3 than the entrance 53A on the magnetic encoder 3 side of the through hole 53. For example, the entire magnetic sensor 23 is arranged closer to the magnetic encoder 3 than the through hole 53.

[0065] The portion of the molded body 41 on the side in the direction X protrudes further in the direction X than the through hole 53. The protrusion 45 is located on the side in the direction X than the through hole 53. Figure 2 As shown, the protrusion 45 contacts the end surface 55 of the holding portion 51. The end surface 55 is an end surface on one side in the direction X. The protrusion 45 and the end surface 55 are fixed using, for example, bolts 57 or the like.

[0066] 2. Effects of the Rotation Detection Device 1

[0067] (1A) When the rotating member 5 rotates, the magnetic encoder 3 also rotates integrally with the rotating member 5. In the magnetic encoder 3, the north poles 9 and the south 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.

[0068] Therefore, the rotation detection device 1 can detect the rotation of the rotating member 5. For example, the rotation detection device 1 can detect the rotation of a wheel attached to the rotating member 5. In this case, the rotation detection device 1 can be used for an ABS (Anti-lock Braking System), for example.

[0069] (1B) The magnetic sensor 23 is arranged in the virtual area 17. Components other than the rotation detection device 1 are not often arranged in the virtual area 17. Therefore, interference between components other than the rotation detection device 1 and the magnetic sensor 23 can be suppressed.

[0070] (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.

[0071] (1D) The lead wires 25A and 25B and the capacitor 27 are arranged in the virtual area 17. Therefore, interference between components other than the rotation detection device 1 and the lead wires 25A and 25B and the capacitor 27 can be suppressed.

[0072] (1E) The connecting portions 39A and 39B are arranged in the virtual region 17. Therefore, it is possible to suppress interference between components other than the rotation detection device 1 and the connecting portions 39A and 39B.

[0073] (1F) The lead-out port 43 is arranged in the virtual area 17. Therefore, it is possible to suppress interference between components other than the rotation detection device 1 and the cable 31 led out from the lead-out port 43.

[0074] (1G) The magnetic sensor 23 is arranged on the magnetic encoder 3 side with respect to the through hole 53. Therefore, compared with the case where the magnetic sensor 23 is arranged inside the through hole 53, the detection sensitivity of the magnetic sensor 23 can be improved.

[0075] (1H) The protrusion 45 protrudes in the direction Z. The direction Z is perpendicular to the thickness directions TE and TS. Therefore, the thickness of the molded body 41 in the thickness directions TE and TS can be suppressed compared to a case where the protrusion 45 protrudes in other directions.

[0076] <Other Implementation Methods>

[0077] As mentioned above, although embodiment of this disclosure was described, this disclosure is not limited to the said embodiment, Various deformation|transformation can be made and it can be implemented.

[0078] (1) The entire molded body 41 may be disposed in the imaginary region 17, or a portion 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, while 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.

[0079] (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 other than vehicles.

[0080] (3) The rotation detection device 1 may include a connector instead of the cable 31 .

[0081] (4) Some or all of the leads 25A, 25B, capacitor 27, connection portions 39A, 39B, and lead-out port 43 may not be disposed in virtual region 17. In this case, the effects of (1A) to (1C) and (1G) to (1H) can also be achieved.

[0082] (5) The through hole 53 of the magnetic sensor 23 may not be arranged on the side close to the magnetic encoder 3. In this case, the effects of (1A) to (1F) and (1H) can also be achieved.

[0083] (6) The protruding portion 45 may protrude in a direction other than the direction Z. In this case, the effects of (1A) to (1G) can also be achieved.

[0084] (7) It is also possible to have multiple components share the functions of one component in each of the above embodiments, or to have one component perform the functions of multiple components. In addition, it is also possible to omit a portion of the structure of each of the above embodiments. In addition, it is also possible to add or replace at least a portion of the structure of each of the above embodiments with the structure of another of the above embodiments.

[0085] (8) In addition to the above-mentioned rotation detection device 1, the present disclosure can be implemented in various forms, such as a system that uses 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-transitional physical recording medium such as a semiconductor memory that records the program, a rotation detection method, a method for manufacturing a rotation detection device, etc.

Claims

1. A rotation detection device, characterized in that: have: a plate-shaped magnetic encoder mounted on a rotating member; and a plate-shaped magnetic sensor configured to detect the magnetic field from the magnetic encoder, The magnetic sensor is arranged in a virtual area 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. The thickness direction of the magnetic encoder is consistent with the thickness direction of the magnetic sensor.

2. The rotation detection device according to claim 1, wherein: It further comprises: a lead wire connected to the magnetic sensor; and a capacitor connected to the lead wire, The lead and the capacitor are arranged in the imaginary area.

3. The rotation detection device according to claim 2, wherein: Also provided is a cable connected to the lead wire, A connection portion between the lead wire and the cable is disposed in the imaginary area.

4. The rotation detection device according to claim 3, wherein: It also includes a molded body covering the magnetic sensor, the lead wire, the capacitor, and a portion of the cable on the lead wire side. An outlet for leading the cable out of the molded body is arranged in the imaginary area.

5. The rotation detection device according to claim 4, characterized in that: further comprising a holding portion for holding the molded body, The holding portion includes a through hole into which the molded body is inserted. The magnetic sensor is arranged on a side of the magnetic encoder relative to the through hole.

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