Detection device
By forming the detection target area with overlapping ends of segmented members, the detection device minimizes noise interference, improving the accuracy of displacement and force detection.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- SOKEN CO LTD
- Filing Date
- 2024-11-15
- Publication Date
- 2026-05-27
Smart Images
Figure 2026087360000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a detection device.
Background Art
[0002] Conventionally, a hub bearing with a sensor that detects displacement by utilizing the relative displacement of an inner ring member with respect to an outer ring member of a hub bearing is known. The hub bearing with a sensor is described in, for example, Patent Document 1.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] A detection device applied to a mechanical device is known. The mechanical device includes a rotating body and a hub bearing. The hub bearing includes a first bearing member (for example, an outer ring member), a second bearing member (for example, an inner ring member), and rolling elements. The first bearing member has a first cylindrical portion extending in the axial direction, which is the direction in which the rotation center axis of the hub bearing extends, and is fixed to a base portion (for example, a knuckle) of the mechanical device. The second bearing member has a second cylindrical portion provided at a position facing the first cylindrical portion in the radial direction orthogonal to the axial direction, and a flange portion extending in the radial direction from the second cylindrical portion to which the rotating body is fixed. Rolling elements are provided between the first cylindrical portion and the second cylindrical portion. Thereby, the hub bearing rotatably supports the rotating body with respect to the base portion.
[0005] The detection device includes a detection target portion and a sensor substrate. The detection target portion is provided on the base portion side in the axial direction of the flange portion. The detection device is configured to detect the relative displacement of the detection target portion with respect to the sensor substrate or the force acting on the rotating body.
[0006] The sensor board is positioned facing the object to be detected in a predetermined direction. The sensor board has an excitation coil to which an excitation voltage is supplied, and a receiving coil. When an excitation voltage is supplied to the excitation coil, a magnetic flux is generated in the excitation coil. At least a portion of the generated magnetic flux links with the receiving coil, thereby inducing a voltage in the receiving coil. Eddy currents flow in the conductive object to be detected due to the magnetic flux caused by the energization of the excitation coil. The eddy currents flowing in the object to be detected flow in a direction that weakens the induced voltage in the receiving coil. Furthermore, the magnitude of the eddy currents flowing in the object to be detected changes according to the relative displacement of the object to be detected with respect to the sensor board. For this reason, the receiving coil outputs a voltage signal corresponding to the relative displacement of the object to be detected with respect to the sensor board. Based on the output voltage signal, displacement or force is detected.
[0007] Furthermore, there are concerns that the accuracy of displacement or force detection may decrease due to noise superimposed on the voltage signal of the receiving coil.
[0008] The primary object of this disclosure is to provide a detection device that can suppress a decrease in the accuracy of displacement or force detection. [Means for solving the problem]
[0009] This disclosure relates to a detection device applied to a machine or apparatus, The aforementioned mechanical device is A rotating body and A hub bearing that rotatably supports the aforementioned rotating body relative to the base portion, Equipped with, The aforementioned hub bearing is The hub bearing has a first cylindrical portion that extends in the axial direction, which is the direction in which the rotational axis of the hub bearing extends, and a first bearing portion that is fixed to the base portion, A second cylindrical portion is provided at a position opposite the first cylindrical portion in the radial direction perpendicular to the axial direction, and a second bearing portion has a flange portion that extends radially from the second cylindrical portion and to which the rotating body is fixed, A rolling element provided between the first bearing portion and the second bearing portion, It has the following features, and the second bearing portion is rotatably supported with respect to the base portion, The flange portion includes an annular detection target portion provided on the base portion side in the axial direction, which extends in the circumferential direction of the second bearing portion with respect to the rotation center of the second bearing portion, A sensor substrate is provided at a position facing the detection target in a predetermined direction, Equipped with, The aforementioned sensor board is An excitation coil to which an excitation voltage is supplied, A receiving coil, which induces a voltage when an excitation voltage is supplied to the excitation coil, It has, The receiving coil outputs a voltage signal corresponding to the relative displacement of the detection target with respect to the sensor substrate. The detection target portion is formed in an annular shape by combining a plurality of conductive segmented members that extend in the circumferential direction. Of the circumferentially adjacent dividing members, the circumferential end of one dividing member and the circumferential end of the other dividing member are adjacent in the circumferential direction and overlap in the predetermined direction.
[0010] When forming the detection target area in an annular shape by combining multiple circumferentially extending segmented members, dimensional and assembly variations may cause gaps to form at the boundaries between adjacent segmented members in the circumferential direction. These gaps at the boundaries may result in the generation of magnetic flux from the energizing coil that does not generate eddy currents in the detection target area. In this case, there is a concern that noise may be superimposed on the voltage signal of the receiving coil.
[0011] Therefore, in the present disclosure, among the divided members adjacent in the circumferential direction, the end portion in the circumferential direction of one divided member and the end portion in the circumferential direction of the other divided member are adjacent to each other in the circumferential direction and overlap in a predetermined direction. Thereby, it is possible to suppress the generation of magnetic flux that does not generate eddy current in the detection target portion at the boundary portion between the divided members arranged adjacent to each other. Therefore, it is possible to suppress the superimposition of noise on the voltage signal of the receiving coil, and it is possible to suppress the decrease in the detection accuracy of displacement or force.
Brief Description of the Drawings
[0012] [Figure 1] Perspective view of a wheel unit according to the first embodiment. [Figure 2] Longitudinal sectional view near the hub bearing of the wheel unit. [Figure 3] Exploded perspective view of the wheel unit. [Figure 4] Plan view of the target member. [Figure 5] Diagram showing the electrical configuration of the sensor substrate and the processing unit. [Figure 6] Diagram for explaining the detection principle of force, displacement, and rotation angle. [Figure 7] Diagram for explaining the detection principle of force, displacement, and rotation angle. [Figure 8] Diagram showing the target member of the comparative example. [Figure 9] Perspective view of the target member. [Figure 10] Cross-sectional view taken along line 10-10 of FIG. 4. [Figure 11] Enlarged view of the boundary portion between the first end portions of the divided members. [Figure 12] Plan view of the target member according to a modification of the first embodiment. [Figure 13] Cross-sectional view taken along line 13-13 of FIG. 12. [Figure 14] Enlarged view of the boundary portion between the first end portions of the divided members. [Figure 15] Longitudinal sectional view of the target member. [Figure 16] Longitudinal sectional view of the target member. [Figure 17] Longitudinal cross-sectional view of the target member. [Figure 18] A perspective view of the target member according to the second embodiment. [Figure 19] Plan view of the target component. [Figure 20] A magnified view of the boundary between the second ends of each divided member. [Figure 21] A plan view of a target member according to a modified example of the second embodiment. [Figure 22] Perspective view of the target component. [Figure 23] Plan view of the target component. [Figure 24] A view of the target member from the radially outer side. [Figure 25] Plan view of the target component. [Figure 26] Plan view of the target component. [Figure 27] Plan view of the target component. [Modes for carrying out the invention]
[0013] Multiple embodiments will be described with reference to the drawings. In multiple embodiments, functionally and / or structurally corresponding and / or related parts may be given the same reference numeral, or reference numerals that differ by hundreds or more digits. For corresponding and / or related parts, refer to the descriptions of other embodiments.
[0014] <First Embodiment> Hereinafter, a first embodiment of the detection device relating to this disclosure will be described with reference to the drawings. The detection device of this embodiment is configured to calculate the force acting on a wheel (drive wheel or driven wheel) as a rotating body. The vehicle equipped with wheels is, for example, a four-wheeled passenger vehicle (e.g., private or commercial) having two front wheels and two rear wheels. However, the vehicle is not limited to this, and may be a two-wheeled vehicle or other vehicle with a different number of wheels. Furthermore, the use of the vehicle is not limited to passenger use.
[0015] The wheel unit 10 as a mechanical device will be explained using Figures 1 to 3. Figure 1 is a perspective cross-sectional view of the wheel unit 10 partially cut, and Figure 2 is a cross-sectional view of the wheel unit 10 cut by a plane passing through the center of rotation of the wheel unit 10 and extending vertically. Figure 3 is an exploded perspective view of the wheel unit 10.
[0016] As shown in Figure 1, the wheel unit 10 comprises a wheel 11 and a tire 14. The wheel 11 comprises a cylindrical rim portion 12 and a disc portion 13 provided at the outer end of the rim portion 12 in the vehicle width direction. The disc portion 13 comprises a disc mounting portion 18 located in the center of the disc portion 13 and spoke portions 19 extending radially from the disc mounting portion 18 to the rim portion 12. The tire 14 is attached to the outer circumference of the rim portion 12.
[0017] As shown in Figures 1 and 2, the wheel unit 10 includes a brake device 20 and a hub bearing 40. The brake device 20 is a disc-type friction brake device and includes a disc rotor 21 which is disc-shaped overall and a brake caliper (not shown). The brake caliper has a pair of disc pads which are operated by hydraulic pressure or an electrical signal and come into contact with the disc rotor 21 to generate braking force, a piston which presses the disc pads against the disc rotor 21, and a caliper body which supports the brake pads and piston. The brake caliper is fixed to the knuckle 15 which is the base part.
[0018] The disc rotor 21 has a hat portion 22 and a sliding portion 23. The hat portion 22 is attached to the hub bearing 40. The sliding portion 23 is connected to the hat portion 22. The front and back surfaces of the sliding portion 23 are a pair of sliding surfaces that are pressed against by the disc pad. The disc rotor 21 is, for example, a ventilated disc having a cavity inside for ventilation.
[0019] In the following, the direction in which the rotational axis of the hub bearing 40 (specifically, for example, the inner ring member 60 of the hub bearing 40) extends is referred to as the axial direction, the direction extending radially from the rotational axis is referred to as the radial direction, and the direction extending circumferentially around the rotational axis is referred to as the circumferential direction.
[0020] The hub bearing 40 is a rolling bearing (specifically a radial ball bearing) and comprises an outer ring member 50 (corresponding to the "first bearing member"), an inner ring member 60 (corresponding to the "second bearing member"), and a plurality of rolling elements 41 (specifically balls) arranged between the outer ring member 50 and the inner ring member 60. In this embodiment, the hub bearing 40 has a structure in which the rolling elements 41 are arranged in two rows in the axial direction. The hub bearing 40 may also be a radial roller bearing with rollers as the rolling elements 41.
[0021] The inner ring member 60 comprises an inner cylindrical portion 61 (corresponding to the "second cylindrical portion") extending in the axial direction and a flange portion 62 extending radially from the end of the inner cylindrical portion 61 in the axial direction. A shaft insertion hole 63 is formed in the inner cylindrical portion 61, penetrating in the axial direction. A spline is formed on the inner circumferential surface of the shaft insertion hole 63. A shaft (not shown), to which rotational power from a driving power source such as a motor is transmitted, is fitted into the shaft insertion hole 63.
[0022] The outer ring member 50 includes an outer cylindrical portion 51 (corresponding to the "first cylindrical portion") provided at a position facing radially outward from the inner cylindrical portion 61. Rolling elements 41 are provided between the outer cylindrical portion 51 and the inner cylindrical portion 61.
[0023] The flange portion 62 is disc-shaped and extends radially beyond the outer cylindrical portion 51. Multiple bolt insertion holes 64 are formed in the flange portion 62, arranged in the circumferential direction, through which hub bolts 17 for fixing the wheel 11 are inserted.
[0024] The wheel 11 and disc rotor 21 are fixed to the flange portion 62. Specifically, as shown in Figure 2, the disc mounting portion 18 has a bolt insertion hole 18a that penetrates in the axial direction. The hat portion 22 of the disc rotor 21 has a disc-shaped bottom surface portion 24. The bottom surface portion 24 has a bolt insertion hole 27 that penetrates in the axial direction. The flange portion 62 has a mounting surface 62b which is a flat surface that abuts (specifically, makes surface contact) with the bottom surface portion 24. With the bottom surface portion 24 and the disc mounting portion 18 overlapping the mounting surface 62b of the flange portion 62, the hub bolts 17 are inserted through the bolt insertion holes 18a and 27. The disc mounting portion 18 and disc rotor 21 are fixed to the hub bearing 40 by screwing nuts 35 onto the hub bolts 17.
[0025] The wheel unit 10 is equipped with a dust cover 70, which is a heat shield. The dust cover 70 is positioned inward in the vehicle width direction from the hub bearing 40 and the sliding portion 23 of the disc rotor 21. The dust cover 70 extends radially beyond the outer peripheral edge of the sliding portion 23. Note that the knuckle 15 and dust cover 70 are not shown in Figure 3.
[0026] The wheel unit 10 is equipped with a detection device. The detection device is located in the inner space of the wheel 11 and comprises a target member 80 (corresponding to the "detection target part") and a sensor substrate 100. The detection device is for detecting the rotational speed of the wheel, which consists of the wheel 11 and the tire 14, and the force acting between the contact surface (ground) and the wheel (specifically the tire 14). Specifically, the detection device detects the lateral force acting between the contact surface (ground) and the wheel (specifically the tire 14), and the force acting between the contact surface and the wheel perpendicular to the contact surface (hereinafter referred to as the vertical load). The direction in which the lateral force acts and the direction in which the vertical load acts are orthogonal. For example, the calculated rotational speed, lateral force, and vertical load are used in the control device (specifically, the ECU: Electronic Control Unit) installed in the vehicle to control the movement of the vehicle, which is a moving object.
[0027] The structure of the detection device will be described below with reference to Figures 3 and 4. Figure 4 is a plan view of the target member 80.
[0028] The target member 80 has an annular shape that extends circumferentially around the rotational axis of the hub bearing 40. The target member 80 is positioned opposite the sensor substrate 100 in the axial direction and is provided without contact with the sensor substrate 100. In this embodiment, the axial direction corresponds to the "predetermined direction".
[0029] The target member 80 has detection protrusions 81 that project inward in the vehicle width direction in the axial direction and have flat surfaces, arranged in a circumferential direction. In other words, the detection protrusions 81 project in the axial direction relative to the flange portion 62. The flat surfaces between the circumferentially arranged detection protrusions 81 are designated as detection recesses 82. The detection recesses 82 are recessed toward the flange portion 62 relative to the detection protrusions 81. The target member 80 has detection protrusions 81 and detection recesses 82 arranged alternately in the circumferential direction. In this embodiment, the target member 80 is provided with 12 sets of detection protrusions 81 and detection recesses 82.
[0030] In Figure 4, LCi indicates the central axis of the inner ring member 60. In this embodiment, the angle α1 between the axis passing through the central axis LCi and one circumferential end of the detection projection 81 and the axis passing through the other circumferential end of the central axis LCi and the detection projection 81 is equal to the angle α2 between the axis passing through the central axis LCi and one circumferential end of the detection recess 82 and the axis passing through the other circumferential end of the central axis LCi and the detection recess 82. Therefore, the circumferential lengths of the multiple detection projections 81 and the circumferential lengths of the multiple detection recesses 82 are equal.
[0031] The target member 80 is located on the inner side of the flange portion 62 in the axial direction in the vehicle width direction. More specifically, the flange portion 62 has multiple bolt insertion holes formed in the circumferential direction, penetrating in the axial direction. Bolts 83 (six are shown as an example in the figure) are inserted through the bolt insertion holes. The bolt insertion holes are formed at positions offset from the protruding positions of the hub bolts 17 in the circumferential direction. On the target member 80, female screw holes extending in the axial direction are formed on the side opposite to the surface where the detection protrusions 81 and detection recesses 82 are formed, through which the bolts 83 are inserted. When the target member 80 is in contact with the flange portion 62 and the bolts 83 are inserted through the bolt insertion holes, the male threads of the bolts 83 are screwed into the female screw holes of the target member 80. This fixes the target member 80 to the flange portion 62. In this case, the target member 80, the disc rotor 21, and the wheel 11 rotate together.
[0032] Next, we will explain the sensor board 100.
[0033] The sensor substrate 100 is a so-called eddy current type inductive sensor. The sensor substrate 100 is installed with its plate surface extending in the vertical direction. The sensor substrate 100 is installed in a space adjacent to the flange portion 62 on the inside in the vehicle width direction, and in a space outside the inner cylindrical portion 61 and the outer cylindrical portion 51 in the radial direction. In the installation space, the target member 80 is installed at a position axially opposite to the sensor substrate 100. In this embodiment, the sensor substrate 100 is installed at a position axially opposite to the lower end or upper end of the target member 80. The sensor substrate 100 is installed between the flange portion 62 and the hub mounting portion 52 in the axial direction.
[0034] The wheel unit 10 includes a substrate mounting member 120 for fixing the sensor substrate 100 to the outer ring member 50. The substrate mounting member 120 is plate-shaped and annular. The substrate mounting member 120 is made of, for example, synthetic resin or a metal material (for example, aluminum). In the center of the substrate mounting member 120, there is a circular through-hole 122 that penetrates axially from the first plate surface 121 of the substrate mounting member 120 to the second plate surface, which is the back surface of the first plate surface 121, and into which the outer cylindrical portion 51 is fitted.
[0035] The second plate surface of the substrate mounting member 120 has projections formed on which the sensor substrate 100 is attached. The projections extend axially from the second plate surface toward the flange portion 62. Multiple projections are formed spaced apart in the circumferential direction. Each projection has a bolt insertion hole 132 that penetrates axially and through which the substrate mounting bolts 131 are inserted. On the other hand, the sensor substrate 100 has the same number of female screw holes 101 into which the male threads of the substrate mounting bolts 131 are screwed, as the number of bolt insertion holes 132.
[0036] A mounting bolt 131 is inserted through a bolt insertion hole 132 from the first plate surface 121 side of the mounting member 120, and the male thread of the mounting bolt 131 is screwed into the female screw hole 101. As a result, the sensor board 100 is fixed to the mounting member 120 while maintaining a predetermined relative positional relationship between the sensor board 100 and the mounting member 120. In this case, the plate surface of the sensor board 100 and the plate surface of the mounting member 120 are parallel. The sensor board 100 is also supported by a projection that is spaced apart from the second plate surface of the mounting member 120.
[0037] The substrate mounting member 120 has bolt insertion holes 123 that penetrate from the first plate surface 121 to the second plate surface, through which bolts 16 are inserted. In this embodiment, three bolt insertion holes 123 are formed, spaced apart in the circumferential direction.
[0038] An extension portion 124 is formed on the periphery of the through hole 122 of the substrate mounting member 120, extending axially toward the dust cover 70 side (i.e., inward in the vehicle width direction). The extension portion 124 is formed over the entire circumference of the periphery of the through hole 122.
[0039] As shown in Figure 2, the dust cover 70 is provided with a wall portion 73 that extends radially. The wall portion 73 has a circular (specifically, perfectly circular) through hole 72 that extends perpendicular to the plate surface of the wall portion 73. The extension portion 124 of the substrate mounting member 120 is fitted into the through hole 72. The knuckle 15 has a circular (specifically, perfectly circular) through hole 15a that extends axially. The outer cylindrical portion 51 of the outer ring member 50 is fitted into the through hole 15a.
[0040] A bolt insertion hole 71 is formed in the wall portion 73 of the dust cover 70 through which a bolt 16 is inserted. A bolt insertion hole 15b is formed in the knuckle 15 through which a bolt 16 is inserted.
[0041] The hub mounting portion 52 of the hub bearing 40 is provided with the same number of bolt insertion holes 123. The hub mounting portion 52 is spaced apart in the circumferential direction. The hub mounting portion 52 has a female threaded hole 52a that penetrates axially and into which a bolt 16 is screwed. With the outer cylindrical portion 51 fitted into the through holes 122, 72, and 15a, the bolt 16 is inserted through the bolt insertion holes 15b, 71, and 123, and the male thread of the bolt 16 is screwed into the female threaded hole 52a. This fixes the hub bearing 40 to the knuckle 15.
[0042] The sensor substrate 100 has an arc shape that follows the target member 80. As shown in Figure 5, the sensor substrate 100 includes an excitation coil 110 and a receiving coil. In this embodiment, the receiving coils are a first receiving coil 111 and a second receiving coil 112. Each coil 110 to 112 is a planar coil that follows the surface of the sensor substrate 100. The sensor substrate 100 is a multilayer substrate. Each coil 110 to 112 is composed of wiring patterns and vias formed in each layer of the sensor substrate 100.
[0043] In this embodiment, each coil 110 to 112 has the same circumferential center position. Furthermore, the circumferential center position of each coil 110 to 112 is located opposite the upper or lower end of the target member 80 in the axial direction.
[0044] The sensor board 100 includes an excitation circuit 113 and a receiving circuit 114. The excitation circuit 113 supplies a high-frequency excitation voltage to the excitation coil 110. The receiving circuit 114 detects the voltage induced across each receiving coil 111, 112.
[0045] The sensor board 100 is provided with a connector 115 that is electrically connected to the excitation circuit 113 and the receiving circuit 114. The connector 115 is electrically connected to the processing unit 117 via a cable 116. The processing unit 117 may be located on the vehicle body or built into the wheel unit 10.
[0046] The processing unit 117 is equipped with a CPU (Central Processing Unit). The functions provided by the processing unit 117 can be provided by software recorded in a physical memory device and the computer that executes it, by software only, by hardware only, or by a combination thereof. For example, if the microcontroller of the processing unit 117 is provided by hardware electronic circuits, it can be provided by digital circuits including a large number of logic circuits, or by analog circuits. For example, the microcontroller executes a program stored in a non-transitory tangible storage medium, which serves as its own memory. The program includes, for example, a program for load calculation processing, which will be described later. The method corresponding to the program is executed by executing a set of instructions that constitute the program. The memory is, for example, non-volatile memory. The program stored in the memory can be updated via a communication network such as the Internet, for example, OTA (Over The Air).
[0047] Next, we will explain the load calculation process for calculating the lateral force and vertical load acting on the wheel. The load calculation process is performed by the processing unit 117. Below, we will first explain the detection principles of lateral force, vertical load, and rotation angle with reference to Figures 6 and 7.
[0048] When a high-frequency excitation voltage vr(t) is supplied to the excitation coil, a high-frequency current flows through the excitation coil. The current flowing through the excitation coil generates a magnetic flux φ(t), which links with the receiving coil. A voltage ve(t) proportional to the time rate of change of the linked magnetic flux is induced at both ends of the receiving coil. The receiving circuit 114 detects the output voltage signals at both ends of each receiving coil 111, 112. For example, when an excitation voltage is supplied to the excitation coil 110, the phase difference between the output voltage signal of the second receiving coil 112 and the first output voltage signal of the first receiving coil 111 is 90 degrees.
[0049] Figure 7 shows a state in which the detection projection 81 of the target member 80 and a part of the receiving coil are facing each other in the axial direction. Here, the target member 80 is made of a conductive material, specifically a metallic material such as aluminum or iron. In this case, eddy currents flow in the portion of the detection projection 81 that faces the receiving coil due to the flux linkage caused by the energization of the excitation coil. The eddy currents flowing in the detection projection 81 generate a magnetic flux in a direction that weakens the magnetic flux that generates the induced voltage in the receiving coil, and the amplitude of the induced voltage in the receiving coil becomes smaller.
[0050] When a lateral force acts on the wheel, the inclination of the central axis LCi of the inner ring member 60 with respect to the central axis of the outer ring member 50 increases. In this case, the axial distance between each coil 111, 112 and the target member 80 changes, and the amplitude of the output voltage signals of each coil 111, 112 changes. The processing unit 117 calculates the axial displacement of the target member 80 based on this amplitude change, and then calculates the lateral force based on the calculated axial displacement.
[0051] On the other hand, when a vertical load is applied to the wheel, the central axis LSi of the inner ring member 60 is displaced in a direction perpendicular to the central axis of the outer ring member 50. As a result, the target member 80 fixed to the flange portion 62 is also displaced. In this case, the sensor board 100 is configured such that the amplitude of the output voltage signals of the first receiving coil 111 and the second receiving coil 112 changes. Based on this amplitude change, the processing unit 117 calculates the displacement of the target member 80 in the direction perpendicular to the axial direction and the vehicle length direction (hereinafter referred to as vertical displacement), and performs a process to calculate the vertical load based on the calculated vertical displacement.
[0052] The processing unit 117 calculates the rotation angle of the wheel based on the output signal of at least one of the first receiving coil 111 and the second receiving coil 112. The processing unit 117 then calculates the rotation speed of the wheel based on the calculated rotation angle. Specifically, for example, the processing unit 117 may calculate the rotation speed based on the time derivative of the rotation angle.
[0053] The sensor substrate 100 and the load calculation process are described, for example, in Japanese Patent Publication No. 2023-130285.
[0054] Incidentally, as shown in Figure 3, the target member 80 is divided into two parts in the circumferential direction. More specifically, the target member 80 is divided into two parts such that their circumferential lengths are equal. The target member 80 is divided to facilitate the assembly of the target member 80 to the hub bearing 40. For example, the target member 80 can be retrofitted to a finished hub bearing 40. Hereafter, one of the divided parts of the target member 80 may be referred to as the first divided member 80A, and the other part as the second divided member 80B.
[0055] Due to dimensional and assembly variations when combining the individual segmented components to form the target component in a ring shape, gaps may occur at the boundaries between the segmented components. In this case, there is a concern that noise may be superimposed on the voltage signal of the receiving coil.
[0056] Here, with reference to Figure 8, we will explain how the detection accuracy of displacement or force decreases in a comparative example different from this embodiment. In the comparative example shown in Figure 8, a gap 89 is created at the boundary between each divided member 80C, 80D. As the wheel 11 rotates, the gap 89 at the boundary between each divided member 80C, 80D may be positioned opposite the excitation coil 110 in the axial direction. When the excitation coil 110 and the gap 89 are positioned opposite each other in the axial direction, there is a possibility that a magnetic flux will be generated due to the energization of the excitation coil 110 that does not generate eddy currents in the target member. In this case, there is a concern that noise will be superimposed on the voltage signals of each receiving coil 111, 112, and the detection accuracy of displacement or force will decrease.
[0057] Figure 8 shows a comparison of the circumferential direction of the excitation coil 110 when the coil width is narrow and when it is wide. When the coil width is wide, the range of rotation angles in which the excitation coil 110 and the gap 89 are positioned opposite each other in the axial direction is wider compared to when the coil width is narrow. Therefore, there is concern that the impact on the accuracy of displacement or force detection is greater when the coil width is wide compared to when the coil width is narrow.
[0058] In view of the above, each divided member 80A and 80B has a structure to suppress the superposition of noise on the voltage signal of the receiving coil. The structure of each divided member 80A and 80B will be described below with reference to Figures 4, 9 and 10. Figure 9 is a perspective view of the divided members 80A and 80B in their assembled state. Figure 10 is a cross-sectional view taken along line 10-10 of Figure 4.
[0059] Of the circumferential ends of each divided member 80A, 80B, one first end 86A, 86B is adjacent in the circumferential direction, and the other second end 87A, 87B is adjacent in the circumferential direction. In each divided member 80A, 80B, the second end 87A, 87B is the end opposite to the first end 86A, 86B in the circumferential direction. The first ends 86A, 86B of each divided member 80A, 80B overlap in the axial direction. The second ends 87A, 87B of each divided member 80A, 80B overlap in the axial direction.
[0060] Because the first ends 86A and 86B overlap in the axial direction, and the second ends 87A and 87B also overlap in the axial direction, it is possible to suppress the generation of magnetic flux that does not generate eddy currents in the target member 80 at the boundary portion 85 of each divided member 80A and 80B. Therefore, it is possible to suppress the superposition of noise on the voltage signals of each receiving coil 111 and 112, and to suppress a decrease in the accuracy of displacement or force detection.
[0061] In this embodiment, at each adjacent end portion 86A, 86B, 87A, 87B in the circumferential direction, one is a detection projection 81 and the other is a detection recess 82. Specifically, the first end portion 86A of the first dividing member 80A and the second end portion 87B of the second dividing member 80B are detection recesses 82. The first end portion 86B of the second dividing member 80B and the second end portion 87A of the first dividing member 80A are detection projections 81. Note that the first end portion 86A of the first dividing member 80A and the second end portion 87B of the second dividing member 80B correspond to "recessed ends". The first end portion 86B of the second dividing member 80B and the second end portion 87A of the first dividing member 80A correspond to "convex ends".
[0062] Figure 11 is an enlarged view of the boundary portion 85 between the first ends 86A and 86B of the respective divided members 80A and 80B in Figure 10. A circumferential recess 88 is formed in the portion of the first end 86B of the second divided member 80B that faces the first end 86A of the first divided member 80A in the circumferential direction. The circumferential recess 88 is the portion in which the flange portion 62 side of the first end 86B is recessed in the circumferential direction compared to the sensor substrate 100 side in the axial direction. When the respective divided members 80A and 80B are assembled, the first end 86A of the first divided member 80A is positioned in the circumferential recess 88.
[0063] Furthermore, a circumferential recess 88 is formed at the second end 87A of the first dividing member 80A, similar to the first end 86B of the second dividing member 80B. When the dividing members 80A and 80B are assembled, the second end 87B of the second dividing member 80B is positioned in the circumferential recess 88 formed at the second end 87A of the first dividing member 80A.
[0064] When the first end 86A of the first divided member 80A is positioned in the circumferential recess 88, the boundary portion 85 between the first ends 86A and 86B is positioned on the flange portion 62 side relative to the first end 86B of the second divided member 80B in the axial direction. Also, when the second end 87B of the second divided member 80B is positioned in the circumferential recess 88, the boundary portion between the second ends 87A and 87B is positioned on the flange portion 62 side relative to the second end 87A of the first divided member 80A in the axial direction.
[0065] In the arrangement of the ends 86A, 86B, 87A, and 87B described above, the boundary portion 85 between the first ends 86A and 86B and the boundary portion between the second ends 87A and 87B are not positioned opposite the excitation coil 110 in the axial direction. In this case, when the target member 80 is viewed from the sensor substrate 100 side in the axial direction, it has the same shape as if the target member 80 were integrally formed. Therefore, the effect of the gaps that occur at the boundary portions of each divided member 80A and 80B on the detection accuracy can be effectively suppressed.
[0066] Figure 10 schematically shows, with arrows, the magnetic flux that reaches the vicinity of the boundary portion 85 between the first ends 86A and 86B of the excitation coil 110 when it is energized. The magnetic flux that reaches the target member 80 when the excitation coil 110 is energized reaches the target member 80 from the side opposite to the side where the circumferential recess 88 of the second divided member 80B is formed in the axial direction. Therefore, regardless of whether or not there is a gap in the boundary portion 85 between the first ends 86A and 86B, eddy currents flow due to the magnetic flux that reaches each divided member 80A and 80B near the boundary portion 85. As a result, it is possible to accurately suppress a decrease in the accuracy of displacement or force detection while suppressing an increase in the cost of reducing dimensional and assembly variations of each divided member 80A and 80B.
[0067] <Modified form of the first embodiment> The shape of the target member may be changed from a configuration in which detection protrusions 81 and detection recesses 82 are alternately provided in the circumferential direction.
[0068] For example, as shown in Figure 12, the target member 180 may have teeth 181 extending radially outward arranged in the circumferential direction. Between adjacent teeth 181 in the circumferential direction, there may be grooves 182 recessed radially inward relative to the teeth 181. In other words, the target member 180 may have teeth 181 and grooves 182 alternately arranged in the circumferential direction. In this embodiment, the target member 180 is provided with 12 sets of teeth 181 and grooves 182.
[0069] The target member 180 is formed in an annular shape by combining the divided members 180A and 180B. In each divided member 180A and 180B, the first ends 186A and 186B are adjacent in the circumferential direction, and the second ends 187A and 187B are adjacent in the circumferential direction.
[0070] Figure 13 shows a cross-sectional view taken along line 13-13 of Figure 12. Figure 13 shows the boundary portion 185 between the first ends 186A and 186B of each divided member 180A and 180B. When the divided members 180A and 180B are assembled, the first end 186A of the first divided member 180A and the first end 186B of the second divided member 180B are positioned to face each other in the axial direction. Specifically, the first end 186A of the first divided member 180A is positioned to face the flange portion 62 side in the axial direction relative to the first end 186B of the second divided member 180B. As a result, the first ends 186A and 186B of each divided member 180A and 180B overlap in the axial direction. Furthermore, similar to the case of the first ends 186A and 186B, the second ends 187A and 187B of each divided member 180A and 180B are arranged to face each other in the axial direction and overlap in the axial direction.
[0071] Figure 14 shows an enlarged view of the area near the boundary portion 185 between the first ends 186A and 186B shown in Figure 13. In Figures 13 and 14, the magnetic flux that reaches the area near the boundary portion 185 due to the energization of the excitation coil 110 is schematically shown by arrows. Because the first ends 186A and 186B of the respective divided members 180A and 180B overlap in the axial direction, the magnetic flux due to the energization of the excitation coil 110 reaches the first end 186A of the first divided member 180A within the gap of the boundary portion 185. Therefore, compared to a comparative example (see Figure 8) in which the circumferential ends of each divided member do not overlap in the axial direction, it is possible to suppress the generation of magnetic flux that does not generate eddy currents in the target member 80, and it is possible to suppress the superposition of noise on the voltage signals of each receiving coil 111 and 112.
[0072] In this embodiment, each end portion 186A, 186B, 187A, and 187B of each divided member 180A and 180B in the circumferential direction is a groove portion 182. This makes it possible to effectively suppress the influence of the boundary portion between each end portion 186A, 186B, 187A, and 187B on the voltage signal of the receiving coil, compared to a configuration in which each end portion is a toothed portion 181.
[0073] Specifically, when viewing the target member 180 from the axial direction, the area of the gaps that occur at the boundaries between each end 186A, 186B, 187A, and 187B can be made smaller compared to a configuration where each end is a toothed portion 181. In other words, it is possible to minimize the occurrence of gaps that would be noise sources for the voltage signals of each receiving coil 111 and 112.
[0074] Furthermore, as shown by the dashed line in Figure 12, for example, the excitation coil 110a is positioned radially outward from the radially outer end of the groove 182 in the reference state. The reference state is, for example, the state in which a vehicle is stationary, specifically, for example, the state in which a vehicle is stationary on a horizontal road surface. When the excitation coil 110a and the target member 180 are positioned as shown in Figure 12, the groove 182 is less likely to be subject to situations where force or relative displacement is detected compared to the teeth 181. Therefore, by having each end 186A, 186B, 187A, 187B be groove 182, it is possible to effectively suppress the superposition of noise on the voltage signals of each receiving coil 111, 112 compared to a configuration in which each end is a teeth 181. Alternatively, instead of the positioning of the excitation coil 110a, the excitation coil may be positioned radially inward from the radially outer end of the groove 182 in the reference state, or positioned to cover the teeth 181. For example, the excitation coil 110b may be arranged as shown by the dashed line in Figure 12.
[0075] Furthermore, as shown in Figure 14, the magnetic flux reaching the first end 186A of the first divided member 180A within the gap of the boundary portion 185 has a longer axial distance from the sensor substrate 100 compared to the magnetic flux reaching the portion of the groove 182 other than the boundary portion 185. In this case, there is a concern that the magnitude of the eddy currents flowing through the target member 180 may change due to factors unrelated to axial and vertical displacement, affecting the accuracy of relative displacement or force detection.
[0076] In contrast, in the first embodiment, when the target member 80 is viewed from the sensor substrate 100 side in the axial direction, it has the same shape as when the target member 80 is integrally formed. In this case, the magnetic flux due to the energization of the excitation coil 110 does not reach the target member 80 within the gaps at the boundaries between each end 86A, 86B, 87A, 87B. Therefore, the influence of the boundary between each end 86A, 86B, 87A, 87B on the magnitude of the eddy currents flowing through the target member 180 can be accurately reduced.
[0077] For example, as shown in Figure 15, the target member 280 may have teeth 281 extending radially inward arranged in the circumferential direction. The space between adjacent teeth 281 in the circumferential direction may be a groove 282 recessed radially outward relative to the teeth 281. In other words, the target member 280 may have teeth 281 and grooves 282 alternately arranged in the circumferential direction. In this embodiment, the target member 280 is provided with 12 sets of teeth 281 and grooves 282.
[0078] The target member 280 is formed in an annular shape by combining the divided members 280A and 280B. In each divided member 280A and 280B, the first ends 286A and 286B are adjacent in the circumferential direction, and the second ends 287A and 287B are adjacent in the circumferential direction.
[0079] In this embodiment, as described in Figures 12-14, the first ends 286A and 286B may overlap in the axial direction, and the second ends 287A and 287B may also overlap. In Figure 15, the boundaries between the divided members 280A and 280B on the plate surface of the flange portion 62 side of the target member 280 are shown by dashed lines. In this embodiment as well, it is possible to suppress the superposition of noise on the voltage signals of the receiving coils 111 and 112.
[0080] The circumferential ends of the target member are not limited to one being a detection projection 81 and the other being a detection recess 82.
[0081] For example, as shown in Figure 16, the circumferential ends of each divided member 380A, 380B constituting the target member 380 may be detection recesses 82. In Figure 16, in each divided member 380A, 380B, the first ends 386A, 386B are adjacent in the circumferential direction, and the second ends 387A, 387B are adjacent in the circumferential direction.
[0082] Furthermore, as shown in Figure 17, for example, the circumferential ends of each divided member 480A, 480B constituting the target member 480 may be detection protrusions 81. In Figure 17, in each divided member 480A, 480B, the first ends 486A, 486B are adjacent in the circumferential direction, and the second ends 487A, 487B are adjacent in the circumferential direction.
[0083] Similar to the explanation of each end 186A, 186B, 187A, and 187B in Figures 12-14, in the target member 380 shown in Figure 16, the first ends 386A and 386B may overlap in the axial direction, and the second ends 387A and 387B may also overlap in the axial direction. Similarly, in the target member 480 shown in Figure 17, the first ends 486A and 486B may overlap in the axial direction, and the second ends 487A and 487B may also overlap in the axial direction.
[0084] <Second Embodiment> The second embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, the target member is provided in a position opposite the sensor substrate in the radial direction, instead of in the axial direction, and is not in contact with the sensor substrate. In this embodiment, the radial direction corresponds to the "predetermined direction".
[0085] The structure of each segmented member 580A and 580B constituting the target member 580 will be described below with reference to Figures 18 and 19. Figure 18 is a perspective view of the assembled segmented members 580A and 580B. Figure 19 is a plan view of the target member 580.
[0086] The target member 580 has teeth 181 and grooves 182, as described in Figure 12, arranged alternately in the circumferential direction. In this embodiment, as shown in Figure 19, the sensor substrate 1100 is provided radially outward from the target member 580. The sensor substrate 1100 is provided with its plate surface oriented perpendicular to the radial direction.
[0087] The sensor substrate 1100 includes an excitation coil, a receiving coil, an excitation circuit, and a receiving circuit, as described in the first embodiment. The excitation coil and receiving coil of the sensor substrate 1100 are planar coils that are aligned with the surface of the sensor substrate 1100. The magnetic flux generated when the excitation coil of the sensor substrate 1100 is energized reaches the radially outer side surface of the target member 580.
[0088] The target member 580 is formed in an annular shape by combining the divided members 580A and 580B. In each divided member 580A and 580B, the first ends 586A and 586B are adjacent in the circumferential direction, and the second ends 587A and 587B are adjacent in the circumferential direction. The first ends 586A overlap in the radial direction. Also, the second ends 587A and 587B overlap in the radial direction.
[0089] In this embodiment, at the circumferentially adjacent first ends 586A, 586B and second ends 587A, 587B, one is a toothed portion 181 and the other is a grooved portion 182. Specifically, the first end 586A of the first divided member 580A and the second end 587B of the second divided member 580B are grooved portions 182. The first end 586B of the second divided member 580B and the second end 587A of the first divided member 580A are toothed portions 181. Note that the first end 586A of the first divided member 580A and the second end 587A of the second divided member 580B correspond to the "grooved end". The first end 586B of the second divided member 580B and the second end 587A of the first divided member 580A correspond to the "toothed end".
[0090] Figure 20 is an enlarged view of the boundary portion 585 between the second ends 587A and 587B of the respective divided members 580A and 580B in Figure 19. A circumferential recess 588 is formed in the portion of the second end 587A of the first divided member 580A that faces the second end 587B of the second divided member 580B in the circumferential direction. The circumferential recess 588 is the portion where the radially inner side of the second end 587A is recessed in the circumferential direction compared to the radially outer side. When the respective divided members 580A and 580B are assembled, the second end 587B of the second divided member 580B is positioned in the circumferential recess 588.
[0091] Furthermore, a circumferential recess is formed at the first end 586B of the second dividing member 580B, similar to the second end 587A of the first dividing member 580A. When the dividing members 580A and 580B are assembled, the first end 586A of the first dividing member 580A is positioned in the circumferential recess formed at the first end 586B of the second dividing member 580B.
[0092] In the arrangement of the ends 586A, 586B, 587A, and 587B described above, the boundary portion 585 between the first ends 586A and 586B, and the boundary portion between the second ends 587A and 587B, are avoided from being positioned radially opposite the excitation coil of the sensor substrate 1100. In this case, when the target member 580 is viewed from the radial outside, it has the same shape as if the target member 580 were integrally formed. Therefore, the influence of the gaps that occur at the boundary portions of each divided member 580A and 580B on detection accuracy can be effectively suppressed.
[0093] Figure 20 schematically shows, with arrows, the magnetic flux that reaches the vicinity of the boundary portion 585 between the second ends 587A and 587B of the excitation coil of the sensor substrate 1100 when energized. The magnetic flux that reaches the second end 587A when energized in the excitation coil reaches the second end 587A from the side opposite to the side where the circumferential recess 588 of the first divided member 580A is formed in the radial direction. Therefore, regardless of whether or not there is a gap in the boundary portion 585 between the second ends 587A and 587B, eddy currents flow due to the magnetic flux that reaches each divided member 580A and 580B near the boundary portion 585. As a result, it is possible to accurately suppress a decrease in the accuracy of displacement or force detection while suppressing an increase in the cost of reducing dimensional and assembly variations of each divided member 580A and 580B.
[0094] <Modified form of the second embodiment> The target member may be configured such that the teeth 281 and grooves 282 described in Figure 15 are alternately arranged in the circumferential direction. In this case, the sensor substrate may be provided radially inward relative to the target member.
[0095] For example, as shown in Figure 21, the target member 680 may be formed in an annular shape by combining the divided members 680A and 680B. In this case, the first ends 686A and 686B of the divided members 680A and 680B may be adjacent to each other and overlap radially. Alternatively, the second ends 687A and 687B of the divided members 680A and 680B may be adjacent to each other and overlap radially. In this case, the second end 687A of the first divided member 680A and the first end 686B of the second divided member 680B may form a toothed portion 281. The first end 686A of the first divided member 680A and the second end 687B of the second divided member 680B may form a grooved portion 282.
[0096] A circumferential recess 688 may be formed at the second end 687A of the first dividing member 680A, and the second end 687B of the second dividing member 680B may be positioned in the circumferential recess 688. A circumferential recess 688 may be formed at the first end 686B of the second dividing member 680B, and the first end 686A of the first dividing member 680A may be positioned in the circumferential recess 688.
[0097] In this embodiment, the second end 687A of the first dividing member 680A and the first end 686B of the second dividing member 680B correspond to the "tooth end". The first end 686A of the first dividing member 680A and the second end 687B of the second dividing member 680B correspond to the "groove end".
[0098] The shape of the target member may be changed from a configuration in which teeth and grooves are alternately provided in the circumferential direction.
[0099] For example, as shown in Figure 22, the target member 780 may have detection protrusions 81 and detection recesses 82 arranged in the circumferential direction, as described in Figures 4 and 9 above.
[0100] The target member 780 is formed in an annular shape by combining the divided members 780A and 780B. In each divided member 780A and 780B, the first ends 786A and 786B are adjacent in the circumferential direction, and the second ends 787A and 787B are adjacent in the circumferential direction.
[0101] Figure 23 shows a plan view of the target member 780. When the divided members 780A and 780B are assembled, the first ends 786A and 786B of each divided member 780A and 780B are arranged to face each other in the radial direction. Specifically, the first end 786A of the first divided member 780A is positioned radially inward relative to the first end 786B of the second divided member 780B. As a result, the first ends 786A and 786B of each divided member 780A and 780B overlap in the radial direction.
[0102] Furthermore, when the divided members 780A and 780B are assembled, the second ends 787A and 787B of each divided member 780A and 780B are positioned to face each other in the radial direction. Specifically, the second end 787B of the second divided member 780B is positioned radially inward relative to the second end 787A of the first divided member 780A. As a result, the second ends 787A and 787B of each divided member 780A and 780B overlap in the radial direction.
[0103] Figure 24 shows an enlarged view of the area near the boundary portion 785 between the second ends 787A and 787B shown in Figure 23. In Figure 24, the magnetic flux that reaches the boundary portion 785 due to the energization of the excitation coil of the sensor substrate 1100 is schematically shown by arrows. Because the second ends 787A and 787B of each divided member 780A and 780B overlap radially, the magnetic flux due to the energization of the excitation coil reaches the second divided member 780B within the gap of the boundary portion 785. As a result, eddy currents flow in the second divided member 780B. Therefore, compared to a comparative example in which the circumferential ends of each divided member 780A and 780B do not overlap radially, it is possible to suppress the superposition of noise on the voltage signal of the receiving coil of the sensor substrate 1100.
[0104] In this embodiment, each end portion 786A, 786B, 787A, and 787B of each divided member 780A and 780B in the circumferential direction is designated as a detection recess 82. This makes it possible to suppress the influence of the boundary portion between each end portion 786A, 786B, 787A, and 787B on the voltage signal of the receiving coil, compared to a configuration in which each end portion is designated as a detection protrusion 81.
[0105] Specifically, when viewing the target member 780 from the radial direction, the area of the gaps that occur at the boundaries between each end portion 786A, 786B, 787A, and 787B can be made smaller compared to a configuration where each end portion is a detection projection 81. In other words, it is possible to minimize the occurrence of gaps that can become a noise source for the voltage signal of the receiving coil.
[0106] Furthermore, as shown by the dashed line in Figure 25, for example, the excitation coil 1100a of the sensor substrate 1100 is positioned on the vehicle body side in the axial direction relative to the detection recess 82 in the reference state. In this case, the detection recess 82 is less likely to be subject to detection of force or relative displacement compared to the detection protrusion 81. Therefore, by having each end 786A, 786B, 787A, and 787B as detection recess 82, it is possible to effectively suppress the superposition of noise on the voltage signal of the receiving coil compared to a configuration in which each end is a detection protrusion 81. In addition to the arrangement of the excitation coil 1100a, the excitation coil may be positioned so as to cover the detection protrusion 81 in the reference state, or on the flange side in the axial direction relative to the detection recess 82. For example, the excitation coil 1100b may be positioned as shown by the dashed line in Figure 25. In this case, in the reference state, the detection protrusion 81 and the detection recess 82 are subject to detection of force or relative displacement.
[0107] • The circumferential ends of the target member are not limited to having one end as a toothed portion and the other as a grooved portion.
[0108] For example, as shown in Figure 26, both ends in the circumferential direction of each divided member 880A, 880B constituting the target member 880 may be grooves 182. In Figure 26, in each divided member 880A, 880B, the first ends 886A, 886B are adjacent in the circumferential direction, and the second ends 887A, 887B are adjacent in the circumferential direction.
[0109] Furthermore, as shown in Figure 27, for example, both ends in the circumferential direction of each divided member 980A, 980B constituting the target member 980 may be teeth 181. In Figure 27, in each divided member 980A, 980B, the first ends 986A, 986B are adjacent in the circumferential direction, and the second ends 987A, 987B are adjacent in the circumferential direction.
[0110] Similar to the explanation of each end 786A, 786B, 787A, and 787B in Figures 22 and 23, in the target member 880 shown in Figure 26, the first ends 886A and 886B may be arranged to face each other radially, and the second ends 887A and 887B may be arranged to face each other radially. Also, in the target member 980 shown in Figure 27, the first ends 986A and 986B may be arranged to face each other radially, and the second ends 987A and 987B may be arranged to face each other radially.
[0111] <Other Embodiments> Furthermore, each of the above embodiments may be implemented with the following modifications.
[0112] In the target member 180 described in Figures 12 and 13, each end of each divided member 180A and 180B in the circumferential direction may be a toothed portion 181. Similarly, in the target member 280 described in Figure 15, each end of each divided member 280A and 280B in the circumferential direction may be a toothed portion 281.
[0113] In the target member 780 described in Figures 22 and 23 above, each end of each divided member 780A and 780B in the circumferential direction may be a detection projection.
[0114] The target member is not limited to two divisions; for example, it may be divided into three, four, or five or more divisions (for example, equally divided in the circumferential direction). In this case, the circumferential ends of one circumferential division member and the circumferential ends of the other circumferential division member may be adjacent in the circumferential direction and overlap in a predetermined direction. In this embodiment as well, it is possible to suppress the generation of magnetic flux that does not generate eddy currents in the target member 80 at the boundary portions of each circumferentially adjacent division member. As a result, a decrease in the accuracy of displacement or force detection can be suppressed.
[0115] The hub bearing is not limited to an inner ring rotating type; it may also be an outer ring rotating type. Specifically, the inner ring axis member (corresponding to the "first bearing member") constituting the outer ring rotating type hub bearing has an inner cylindrical portion (corresponding to the "first cylindrical portion") extending in the axial direction and is fixed to the knuckle 15. The outer ring axis member (corresponding to the "second bearing member") constituting the hub bearing has an outer cylindrical portion (corresponding to the "second cylindrical portion") provided on the outside of the inner cylindrical portion in the radial direction, and a flange portion that extends radially from the outer cylindrical portion and to which the wheel is fixed.
[0116] The circumferential center positions of the first and second receiving coils 111 and 112 may be located not at a position axially opposite to the upper end of the target member 80, but at a position axially opposite to the right end or left end of the target member 80. In this case, the sensor board 100 can calculate the force acting between the ground surface and the wheels in the vehicle's longitudinal direction (hereinafter referred to as longitudinal load) instead of the vertical load. The direction in which the lateral force acts and the direction in which the longitudinal load acts are orthogonal. The longitudinal load is used in the control device for controlling the vehicle's movement.
[0117] The sensor board and board mounting member are not limited to a structure in which they are fixed to the board mounting member at three points; they may also be fixed at one, two, or four or more points.
[0118] The sensor board 100 may be directly attached to the outer ring member 50 instead of the board mounting member 120.
[0119] The disc rotor is not limited to a ventilated disc; for example, it may be a solid disc consisting of a single circular disc.
[0120] The mechanical devices to which the detection device is applied are not limited to wheel units, but may also include, for example, an aircraft equipped with a propeller as a rotating body, a ship equipped with a screw as a rotating body, an internal combustion engine equipped with a crankshaft as a rotating body, or a generator equipped with a turbine as a rotating body.
[0121] Furthermore, the rotating body is not limited to those used with its axis of rotation in a horizontal direction; it may also be used with its axis of rotation in a direction other than horizontal (for example, vertical). [Explanation of symbols]
[0122] 10...Wheel unit, 15...Knuckle, 40...Hub bearing, 80...Target member, 80A, 80B...First and second divided members, 100...Sensor board.
Claims
1. In a detection device applied to a mechanical device (10), The aforementioned mechanical device is A solid of revolution (11, 14) and, A hub bearing (40) rotatably supports the rotating body with respect to the base portion (15), Equipped with, The aforementioned hub bearing is The hub bearing has a first cylindrical portion (51) that extends in the axial direction, which is the direction in which the rotational axis of the hub bearing extends, and a first bearing portion (50) that is fixed to the base portion, A second cylindrical portion (61) is provided at a position opposite the first cylindrical portion in the radial direction perpendicular to the axial direction, and a second bearing portion (60) has a flange portion (62) that extends radially from the second cylindrical portion and to which the rotating body is fixed, A rolling element (41) is provided between the first bearing portion and the second bearing portion, It has the following features, and the second bearing portion is rotatably supported with respect to the base portion, The flange portion includes an annular detection target portion (80, 180, 280, 380, 480, 580, 680, 780, 880, 980) that is provided on the base portion side in the axial direction and extends in the circumferential direction of the second bearing portion with respect to the rotation center of the second bearing portion, A sensor substrate (100, 1100) is provided at a position facing the detection target in a predetermined direction, Equipped with, The aforementioned sensor board is An excitation coil (110) to which an excitation voltage is supplied, A receiving coil (111, 112) from which a voltage is induced when an excitation voltage is supplied to the excitation coil, It has, The receiving coil outputs a voltage signal corresponding to the relative displacement of the detection target with respect to the sensor substrate. The detection target portion is formed in an annular shape by combining multiple conductive segmented members (80A, 80B, 180A, 180B, 280A, 280B, 380A, 380B, 480A, 480B, 580A, 580B, 680A, 680B, 780A, 780B, 880A, 880B, 980A, 980B) that extend in the circumferential direction. A detection device in which, among the circumferentially adjacent dividing members, the circumferential end of one dividing member and the circumferential end of the other dividing member are adjacent in the circumferential direction and overlap in the predetermined direction.
2. The detection device according to claim 1, wherein the predetermined direction is the axial direction.
3. The detection target portion (80) is configured such that, when the multiple divided members are assembled, a plurality of detection protrusions (81) that project in the axial direction relative to the flange portion and detection recesses (82) that are recessed toward the flange portion side relative to the detection protrusions in the axial direction are provided at predetermined intervals in the circumferential direction. Of the circumferentially adjacent divided members, one end in the circumferential direction is a convex end (86B, 87A) that serves as the detection projection, and the other end in the circumferential direction is a concave end (86A, 87B) that is adjacent to the convex end in the circumferential direction and serves as the detection recess. The detection device according to claim 2, wherein the portion of the convex end facing the concave end in the circumferential direction has a circumferential recess (88) formed therein, which is recessed in the circumferential direction and where the concave end is positioned.
4. The detection target portion (180, 280) is configured such that, when the plurality of divided members are assembled, a plurality of teeth (181, 281) extending in the radial direction and grooves (182, 282) recessed in the radial direction relative to the teeth are provided at predetermined intervals in the circumferential direction. The detection device according to claim 2, wherein, of the circumferentially adjacent divided members, the end of one in the circumferential direction and the end of the other in the circumferential direction are the groove portion.
5. The detection device according to claim 1, wherein the predetermined direction is the radial direction.
6. The detection target portion (580, 680) is configured such that, when the plurality of divided members are combined, a plurality of teeth (181, 281) extending in the radial direction and grooves (182, 282) recessed in the radial direction relative to the teeth are provided at predetermined intervals in the circumferential direction. Of the circumferentially adjacent divided members, one end in the circumferential direction is a toothed end (586B, 587A, 686B, 687A) and the other end in the circumferential direction is a grooved end (586A, 587B, 686B, 687A) that is adjacent to the toothed end in the circumferential direction and is a grooved end. The detection device according to claim 5, wherein a circumferential recess (588, 688) is formed in the portion of the tooth end that faces the groove end in the circumferential direction, and which is recessed in the circumferential direction and in which the groove end is positioned.
7. The predetermined direction is the radial direction, The detection target portion (780), when the multiple divided members are assembled, has a configuration in which a plurality of detection projections (81) that protrude in the axial direction relative to the flange portion and detection recesses (82) that are recessed toward the flange portion side relative to the detection projections in the axial direction are provided at predetermined intervals in the circumferential direction. The detection device according to claim 5, wherein, of the circumferentially adjacent divided members, one end in the circumferential direction and the other end in the circumferential direction are the detection recesses.