Detector

Abstract

To provide a detector that can prevent a sensor substrate and a target member from interfering with each other.SOLUTION: A detector is applied to a wheel unit. The wheel unit comprises a hub bearing including an outer ring member 50, an inner ring member 60, and rolling element 41. The detector comprises: an annular target member 80 that is provided on the inner ring member 60, and extends in a circumferential direction of the inner ring member 60 centered on the center of rotation of the inner ring member 60; a sensor substrate 100 that is provided at a position facing the target member 80 in an axial direction; and a projection 90 that is formed extending radially inward from an inner peripheral edge part of the target member 80. The projection 90 has a shape such that it is brought into contact with an outside cylindrical part 51 of the outer ring member 50 when an inclination angle is a contact angle θa that is less than a predetermined angle θb.SELECTED DRAWING: Figure 8

Description

[Technical Field]

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

[0002] A hub bearing with a sensor is known that detects displacement by utilizing the relative displacement of an inner ring member with respect to an outer ring member of the hub bearing. A hub bearing with a sensor is described in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-275508 Summary of the Invention [Problem to be solved by the invention]

[0004] A detection device applied to a mechanical device having a rotating body is known. The detection device includes a bearing member. The bearing member includes a first bearing portion (e.g., an outer ring member), a second bearing portion (e.g., an inner ring member), and a rolling element. The first bearing portion is fixed to a base portion. The rotating body is fixed to the second bearing portion. The rolling element is provided between the first bearing portion and the second bearing portion. In this way, the bearing member supports the rotating body rotatably relative to the base portion.

[0005] The detection device includes a detection target and a sensor substrate as components for detecting displacement or force. The detection target is annular and extends in the circumferential direction of the bearing member around the center of rotation of the first bearing portion. The sensor substrate is provided at a position facing the detection target and the bearing member in the axial direction. The sensor substrate outputs a voltage signal corresponding to the relative displacement of the detection target with respect to the sensor substrate. The displacement or force is detected based on the output voltage signal.

[0006] An excessive force may be temporarily applied to the rotating body. In this case, an excessive force may also be temporarily applied to the bearing member, causing the central axis of the first bearing unit to tilt excessively relative to the central axis of the second bearing unit. In this case, there is a concern that the sensor board may interfere with the object to be detected.

[0007] A primary object of the present disclosure is to provide a detection device that can prevent interference between a sensor substrate and a detection target. [Means for solving the problem]

[0008] A first configuration of the present disclosure includes: In a detection device applied to a mechanical device having a rotating body, the mechanical device includes a bearing member that rotatably supports the rotating body relative to a base portion, The bearing member is a first bearing portion extending in an axial direction, which is a direction in which a rotation center axis of the bearing member extends, and fixed to the base portion; a second bearing portion provided at a position facing the first bearing portion in a radial direction perpendicular to the axial direction, and to which the rotating body is fixed; a rolling element provided between the first bearing portion and the second bearing portion; the second bearing portion is rotatably supported relative to the base portion, a detection target portion that is provided in the second bearing portion and has an annular shape and extends in a circumferential direction of the second bearing portion around a rotation center of the second bearing portion; a sensor substrate that is provided at a position facing the detection target in the axial direction and outputs a voltage signal corresponding to the displacement of the detection target; a limiting mechanism that limits displacement of the second bearing portion relative to the first bearing portion so that the detection target portion does not come into contact with the sensor substrate; Equipped with.

[0009] According to the first configuration, even if an excessive force is applied to the bearing member, the displacement of the second bearing portion relative to the first bearing portion is limited so that the detection target does not come into contact with the sensor board, thereby preventing interference between the sensor board and the detection target.

[0010] The configuration in the first configuration, "a limiting mechanism that limits the displacement of the second bearing portion relative to the first bearing portion so that the detection target portion does not come into contact with the sensor substrate," can be realized by the following second configuration.

[0011] The second configuration is the first configuration, The limiting mechanism includes a protrusion formed to extend radially inward from an inner peripheral edge of the detection target portion, When the second bearing portion is inclined around a rotation center of the second bearing portion relative to the first bearing portion, an inclination angle of the second bearing portion relative to the first bearing portion when the detection target portion comes into contact with the sensor substrate is defined as a first predetermined angle, The protrusion is shaped to come into contact with the first bearing portion when the inclination angle is a second predetermined angle that is less than the first predetermined angle.

[0012] In the second configuration, when the tilt angle becomes a second predetermined angle smaller than the first predetermined angle, the protrusion formed on the detection target portion comes into contact with the first bearing portion. In this case, the displacement of the second bearing portion relative to the first bearing portion stops with the protrusion in contact with the first bearing portion. This makes it possible to realize a configuration in which the displacement of the second bearing portion relative to the first bearing portion is limited until the detection target portion comes into contact with the sensor substrate. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a perspective view of a wheel unit according to the first embodiment. [Figure 2] FIG. [Figure 3] FIG. 10 is an enlarged view of a portion near the hub bearing of the wheel unit. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 2 is a diagram showing the electrical configuration of a sensor substrate and a processing unit. [Figure 8] 3A and 3B are diagrams showing the shape of a target member and the like. [Figure 9] FIG. 10 is a diagram showing a state in which the protrusion is in contact with the outer cylindrical portion. [Figure 10] 10A and 10B are diagrams showing the shapes of a target member and the like according to a second embodiment. [Figure 11] 10A to 10C are diagrams showing shapes of protrusions and the like according to other embodiments. [Figure 12] 10A and 10B are diagrams showing shapes of target members and the like according to other embodiments. [Figure 13] 10A and 10B are diagrams showing shapes of target members and the like according to other embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0014] Several embodiments will be described with reference to the drawings. In several embodiments, functionally and / or structurally corresponding and / or associated parts may be assigned the same reference numerals or reference numerals that differ in the hundredth or more digit. For corresponding and / or associated parts, reference may be made to the descriptions of other embodiments.

[0015] First Embodiment A first embodiment of a detection device according to the present disclosure will be described below with reference to the drawings. The detection device of this embodiment is configured to be able to calculate the force acting on wheels (drive wheels or driven wheels) as rotating bodies. A vehicle equipped with wheels is, for example, a four-wheeled passenger vehicle (for example, private or commercial use) having two front wheels and two rear wheels. However, the vehicle is not limited to this, and may be a vehicle other than a four-wheeled vehicle, such as a two-wheeled vehicle. Furthermore, the use of the vehicle is not limited to passenger use.

[0016] The wheel unit 10 as a mechanical device will be described using Figures 1 to 5. Figure 1 is a perspective cross-sectional view in which the wheel unit 10 is partially cut away, and Figure 2 is a cross-sectional view in which the wheel unit 10 is cut along a plane that passes through the center of rotation of the wheel unit 10 and extends vertically. Figure 3 is a partially enlarged view of Figure 2. Figures 4 and 5 are exploded perspective views of the wheel unit 10.

[0017] As shown in Figures 1 and 2, the wheel unit 10 includes a wheel 11 and a tire 14 that constitute a wheel. The wheel 11 includes 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 includes a disc mounting portion 18 located in the center of the disc portion 13, and spoke portions 19 that extend radially from the disc mounting portion 18 to the rim portion 12. The tire 14 is mounted on the outer periphery of the rim portion 12.

[0018] As shown in Figures 1 to 5, the wheel unit 10 includes a brake device 20 and a hub bearing 40 as a bearing member. The brake device 20 is a disc-type friction braking device and includes a disc rotor 21 that is disk-shaped overall, and a brake caliper 33. The brake caliper 33 is operated by hydraulic pressure, an electric signal, or the like, and includes a pair of disc pads that come into contact with the disc rotor 21 to generate braking force, a piston that presses the disc pads against the disc rotor 21, and a caliper body that supports the brake pads and the piston. As shown in Figure 4, the brake caliper 33 is fixed to the knuckle 15, which is a base portion, by a bolt 34.

[0019] In the following, the direction in which the rotational center 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 center axis is referred to as the radial direction, and the direction extending circumferentially around the rotational center axis is referred to as the circumferential direction.

[0020] The disc rotor 21 of this embodiment is a ventilated disc having an internal cavity for ventilation. 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 hat portion 22 has a disk-shaped bottom surface portion 24 and a disc peripheral wall portion 25. A mounting hole 26 is formed in the center of the bottom surface portion 24. Bolt insertion holes 27 that axially penetrate the bottom surface portion 24 are formed in a circumferential direction around the mounting hole 26. The disc rotor 21 is connected to the hub bearing 40 using the mounting holes 26 and the bolt insertion holes 27. The disc peripheral wall portion 25 is cylindrical and extends from the outer circumferential edge of the bottom surface portion 24, forming the peripheral surface of the hat portion 22.

[0021] A sliding portion 23 is connected to the end of the disc peripheral wall portion 25 opposite the bottom surface portion 24. The sliding portion 23 is formed to protrude outward in an annular shape from the disc peripheral wall portion 25. The front and back surfaces of the sliding portion 23 form a pair of sliding surfaces that are pressed against by the disc pad.

[0022] The sliding portion 23 includes an inner disk portion 28, an outer disk portion 29 disposed on the outer side of the inner disk portion 28, and fins 30. The fins 30 connect the inner disk portion 28 and the outer disk portion 29 at multiple locations in the circumferential direction. The fins 30 extend radially, and the space surrounded by the inner disk portion 28, the outer disk portion 29, and the fins 30 forms an air passage penetrating in the radial direction (diameter direction). The air passage is a passage that extends from an air intake port 31 formed on the radially inner side of the sliding portion 23 to an air exhaust port 32 formed on the radially outer side.

[0023] The hub bearing 40 is a rolling bearing (specifically, a radial ball bearing) and includes an outer ring member 50 (corresponding to the "first bearing portion"), an inner ring member 60 (corresponding to the "second bearing portion"), and a plurality of rolling elements 41 (specifically, balls) arranged between the outer ring member 50 and the inner ring member 60. The hub bearing 40 of this embodiment has a structure in which the rolling elements 41 are arranged in two rows in the axial direction. Note that the hub bearing 40 may also be a radial roller bearing provided with rollers as the rolling elements 41.

[0024] The inner ring member 60 includes an inner cylindrical portion 61 extending in the axial direction, and a flange portion 62 extending radially from a first 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 it in the axial direction. A spline is formed on the inner peripheral surface of the shaft insertion hole 63. A shaft (not shown) to which rotational power of a driving power source such as a motor is transmitted is fitted in the shaft insertion hole 63.

[0025] The outer ring member 50 has an outer cylindrical portion 51 provided at a position facing radially outward from the inner cylindrical portion 61. The rolling elements 41 are provided between the outer cylindrical portion 51 and the inner cylindrical portion 61.

[0026] The flange portion 62 is disk-shaped and extends radially outward beyond the outer cylindrical portion 51. A plurality of bolt insertion holes 64, through which hub bolts 17 for fixing the wheel 11 are inserted, are formed in the flange portion 62 and aligned in the circumferential direction. In this embodiment, as shown in FIG. 5, for example, five hub bolts 17 are formed aligned in the circumferential direction. Therefore, five bolt insertion holes 64 are also formed.

[0027] The wheel unit 10 is provided with a dust cover 70, which is a heat shield. The dust cover 70 is provided on the inner side in the vehicle width direction of the hub bearing 40 and the sliding portion 23 of the disc rotor 21. The dust cover 70 extends radially outward beyond the outer peripheral edge of the sliding portion 23.

[0028] The wheel unit 10 is equipped with a detection device. The detection device is provided in the inner space of the wheel 11 and includes a target member 80 (corresponding to a "detection target") and a sensor board 100. The detection device is a device for detecting the rotational speed of the wheel consisting of the wheel 11 and tire 14, the lateral force Fy acting between the ground contact surface (ground) GL and the wheel (specifically, the tire 14), and the force acting between the ground contact surface GL and the wheel in a direction perpendicular to the ground contact surface GL (hereinafter referred to as a vertical load Fz). The direction in which the lateral force Fy acts is perpendicular to the direction in which the vertical load Fz acts. For example, the calculated rotational speed, lateral force Fy, and vertical load Fz are used in a control device (specifically, an ECU: Electronic Control Unit) provided in the vehicle to control the running of the vehicle, which is a moving object. The structure of the detection device will be described below.

[0029] The target member 80 is made of a metal material (e.g., aluminum or iron). The target member 80 has an annular shape extending in the circumferential direction around the central axis of rotation of the hub bearing 40. The target member 80 is provided in a position facing the sensor substrate 100 in the axial direction, without contacting the sensor substrate 100.

[0030] In this embodiment, the target member 80 is divided into two parts in the circumferential direction, as shown in Figures 4 and 5, more specifically, the two parts are divided into two parts with equal circumferential lengths. The reason for dividing the target member 80 is to facilitate the assembly of the target member 80 to the hub bearing 40. For example, the target member 80 can be attached to a completed hub bearing 40 later. Hereinafter, one of the divided parts of the target member 80 will be referred to as a first divided part 80A, and the other part will be referred to as a second divided part 80B.

[0031] The target member 80 has protrusions 81, which protrude inward in the vehicle width direction in the axial direction and have flat surfaces, lined up in the circumferential direction. The flat surfaces between the protrusions 81 lined up in the circumferential direction are recesses 82. The protrusions 81 and recesses 82 are arranged alternately in the circumferential direction. In this embodiment, 12 pairs of protrusions 81 and recesses 82 are provided.

[0032] 6, LCi indicates the center axis of the inner ring member 60. In this embodiment, the angle α1 formed by the axis passing through the center axis LCi and one circumferential end of the protruding portion 81 and the axis passing through the center axis LCi and the other circumferential end of the protruding portion 81 is equal to the angle α2 formed by the axis passing through the center axis LCi and one circumferential end of the recessed portion 82 and the axis passing through the center axis LCi and the other circumferential end of the recessed portion 82. Therefore, the circumferential length of the multiple protruding portions 81 and the circumferential length of the multiple recessed portions 82 are equal to each other.

[0033] Next, a configuration for fixing the target member 80 to the flange portion 62 will be described.

[0034] 5, a plurality of bolt insertion holes 62a (six are shown in the figure) that penetrate in the axial direction are formed in the flange portion 62 and aligned in the circumferential direction. The bolt insertion holes 62a are formed in positions that are shifted in the circumferential direction from the protruding positions of the hub bolts 17. The flange portion 62 is formed with a mounting surface 62b that is a flat surface with which the bottom surface portion 24 of the disc rotor 21 abuts (specifically, comes into surface contact with).

[0035] Each of the divided members 80A, 80B constituting the target member 80 has a portion opposite to the surface on which the convex portion 81 and the concave portion 82 are formed, and has female threaded holes 84, 86 extending in the axial direction, through which a bolt 83 is inserted. With the divided members 80A, 80B abutting against the flange portion 62 and the bolt 83 inserted into the bolt insertion hole 62a, the male thread of the bolt 83 is screwed into the female threaded holes 84, 86. This fixes each of the divided members 80A, 80B to the flange portion 62. Note that the side surface portion 85 of the target member 80 does not protrude beyond the flange portion 62 in a front view of the mounting surface 62b. This makes it possible to suppress an increase in the radial dimension of the sensor-equipped bearing module.

[0036] Next, a configuration for fixing the wheel 11 and the disc rotor 21 to the flange portion 62 will be described.

[0037] As shown in Fig. 3, the disc mounting portion 18 has a bolt insertion hole 18a formed therethrough in the axial direction. With the bottom surface portion 24 and the disc mounting portion 18 overlapping the mounting surface 62b of the flange portion 62, a hub bolt 17 is inserted into the bolt insertion holes 27, 18a. A nut 35 is threaded onto the hub bolt 17, thereby fixing the disc mounting portion 18 and the disc rotor 21 to the hub bearing 40. This makes the target member 80, disc rotor 21, and inner ring member 60 coaxial, and causes the target member 80, disc rotor 21, and wheel 11 to rotate integrally.

[0038] The target member 80 is provided radially inward of the disk peripheral wall portion 25 that constitutes the disk rotor 21. This allows the disk rotor 21 to protect against foreign matter from the outside.

[0039] Next, the sensor substrate 100 will be described.

[0040] The sensor substrate 100 is a so-called eddy current inductive sensor. The sensor substrate 100 is disposed such that the plate surface of the sensor substrate 100 extends in the vertical direction. The sensor substrate 100 is disposed in an arrangement space that is adjacent to the flange portion 62 on the inner side in the vehicle width direction and that is radially outward of the inner cylindrical portion 61 and the outer cylindrical portion 51. In the arrangement space, a target member 80 is disposed at a position facing the sensor substrate 100 in the axial direction. In this embodiment, the sensor substrate 100 is disposed at a position facing the upper end of the target member 80 in the axial direction. The sensor substrate 100 is disposed between the flange portion 62 and the hub mounting portion 52.

[0041] The sensor substrate 100 has an arc shape that follows the target member 80. As shown in FIG. 7, 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 of the coils 110 to 112 is a planar coil that follows the surface of the sensor substrate 100. The sensor substrate 100 is a multi-layer substrate. Each of the coils 110 to 112 is formed by wiring patterns, vias, etc., formed on each layer of the sensor substrate 100.

[0042] The sensor substrate 100 includes an excitation circuit 113 that supplies a high-frequency excitation voltage to the excitation coil 110, and a receiving circuit 114. When an excitation voltage is supplied to the excitation coil 110, an excitation current flows through the excitation coil 110, and a voltage having the same or equivalent frequency as the excitation voltage is induced in each of the coils 111 and 112. The receiving circuit 114 detects output voltage signals at both ends of each of the coils 111 and 112. When an excitation voltage is supplied to the excitation coil 110, the phase difference between the first output voltage signal of the first receiving coil 111 and the output voltage signal of the second receiving coil 112 is 90 degrees.

[0043] The sensor board 100 is provided with a connector 115 electrically connected to the excitation circuit 113 and the receiving circuit 114. The connector 115 is electrically connected to a processing unit 117 via a cable 116. The processing unit 117 may be provided on the vehicle body or may be built into the wheel unit 10.

[0044] The processing unit 117 includes a CPU (Central Processing Unit). The functions of the processing unit 117 can be provided by software stored in a physical memory device and a computer executing the software, by software alone, by hardware alone, or by a combination of these. For example, if the microcomputer of the processing unit 117 is provided by a hardware electronic circuit, the function can be provided by a digital circuit including multiple logic circuits or an analog circuit. For example, the microcomputer executes a program stored in a non-transitory tangible storage medium serving as a storage unit of the microcomputer. The program includes, for example, a program for a load calculation process, which will be described later. A set of instructions constituting the program is executed to perform a method corresponding to the program. The storage unit is, for example, a non-volatile memory. The program stored in the storage unit can be updated via a communication network such as the Internet, for example, via OTA (Over The Air) or the like.

[0045] Next, the load calculation process will be described.

[0046] 2, when a lateral force Fy acts on the wheel, the inclination angle θ of the central axis LCi of the inner ring member 60 relative to the central axis LCo of the outer ring member 50 increases. In this case, the axial distance between each of the coils 111, 112 and the target member 80 changes, and the amplitude of the output voltage signal of each of the coils 111, 112 changes. The processing unit 117 calculates the axial displacement ΔY of the target member 80 based on this change in amplitude, and performs processing to calculate the lateral force Fy based on the calculated axial displacement ΔY.

[0047] On the other hand, when a vertical load Fz acts on the wheel, the central axis LCi of the inner ring member 60 is displaced in a direction perpendicular to the central axis LCo 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 so that the amplitude of the output voltage signals of the first receiving coil 111 and the second receiving coil 112 changes. Based on this change in amplitude, the processing unit 117 calculates the displacement of the target member 80 in a direction perpendicular to the axial direction and the vehicle length direction (hereinafter referred to as the vertical displacement ΔZ), and performs processing to calculate the vertical load Fz based on the calculated vertical displacement ΔZ.

[0048] 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 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 differential value of the rotation angle.

[0049] The sensor substrate 100 and the load calculation process are described in, for example, Japanese Patent Application Laid-Open No. 2023-130285.

[0050] Next, a configuration for fixing the sensor board 100 to the knuckle 15 will be described with reference to FIGS.

[0051] The wheel unit 10 includes a board mounting member 120 as a component for fixing the sensor board 100 to the knuckle 15. The board mounting member 120 is plate-shaped and annular. The board mounting member 120 is made of, for example, synthetic resin or a metal material (e.g., aluminum). A circular (specifically, perfect circular) through-hole 122 is formed in the center of the board mounting member 120. The through-hole 122 penetrates in the axial direction from the first plate surface 121a to the second plate surface 121b of the board mounting member 120, and the outer cylindrical portion 51 is fitted into the through-hole 122.

[0052] The first plate surface 121a of the substrate mounting member 120 is provided with mounting portions 130 for mounting the sensor substrate 100. The mounting portions 130 extend from the first plate surface 121a toward the flange portion 62 in the axial direction. A plurality of mounting portions 130 (three are illustrated in the drawing) are formed spaced apart in the circumferential direction.

[0053] Each mounting portion 130 is formed with a bolt insertion hole that penetrates in the axial direction and through which a board mounting bolt 131 is inserted. Meanwhile, the sensor board 100 is formed with the same number of female screw holes 101 as the bolt insertion holes, into which the male screws of the board mounting bolts 131 are screwed.

[0054] The board mounting member 120 and the sensor board 100 have a configuration that makes it easy to position the sensor board 100 relative to the board mounting member 120. More specifically, the sensor board 100 has a first plate surface 102a and a second plate surface 102b that is the back surface of the first plate surface 102a. Positioning pins 103 that extend axially toward the board mounting member 120 are provided at both circumferential ends of the second plate surface 102b. Of the multiple mounting portions 130, the mounting portions 130 at both circumferential ends are formed with pinholes that extend axially and through which the positioning pins 103 are inserted.

[0055] By inserting the positioning pins 103 into the pin holes, the female screw holes 101 at both circumferential ends of the sensor board 100 are aligned with the bolt insertion holes of the mounting portion 130. In this aligned state, the board mounting bolts 131 are inserted into the bolt insertion holes 132 from the second plate surface 121b side of the board mounting member 120, and the male threads of the board mounting bolts 131 are screwed into the female screw holes 101. As a result, the sensor board 100 is fixed to the board mounting member 120 while maintaining a predetermined relative positional relationship between the sensor board 100 and the board mounting member 120. In this case, the plate surfaces of the sensor board 100 and the board mounting member 120 are parallel to each other. Furthermore, the sensor board 100 is supported by the mounting portion 130 while being spaced apart from the first plate surface 121a of the board mounting member 120.

[0056] The board mounting member 120 is formed with bolt insertion holes 123 that penetrate from the first plate surface 121a to the second plate surface 121b and through which the bolts 16 are inserted. In this embodiment, three bolt insertion holes 123 are formed spaced apart in the circumferential direction.

[0057] An extension 124 extending axially toward the dust cover 70 is formed on the periphery of the through hole 122 of the board mounting member 120. The extension 124 is formed over the entire periphery of the periphery of the through hole 122.

[0058] The dust cover 70 includes a first wall portion 73, a connecting portion 74, and a second wall portion 75. The connecting portion 74 extends radially outward from the radially outer end portion of the first wall portion 73. The second wall portion 75 extends radially outward from the radially outer end portion of the connecting portion 74.

[0059] The first wall portion 73 of the dust cover 70 has a circular (specifically, perfect circular) through-hole 72 formed therein, which extends in a direction perpendicular to the plate surface of the first wall portion 73 and into which the extension portion 124 of the board mounting member 120 is fitted. The knuckle 15 has a circular (specifically, perfect circular) through-hole 15a formed therein, which extends in the axial direction and into which the outer cylindrical portion 51 of the outer ring member 50 is fitted.

[0060] A bolt insertion hole 71 through which the bolt 16 is inserted is formed in the first wall portion 73 of the dust cover 70. A bolt insertion hole 15b through which the bolt 16 is inserted is formed in the knuckle 15.

[0061] The hub bearing 40 has hub mounting portions 52, the number of which is the same as the number of bolt insertion holes 123. The hub mounting portions 52 are spaced apart in the circumferential direction. Each hub mounting portion 52 has a female screw hole 52a that penetrates in the axial direction and into which the bolt 16 is screwed. Each hub mounting portion 52 has a flat surface 52b that extends in a direction perpendicular to the axial direction.

[0062] The board mounting member 120, the dust cover 70, and the knuckle 15 are provided with a configuration that facilitates relative positioning of the dust cover 70 and the knuckle 15 with respect to the board mounting member 120. More specifically, the knuckle 15 is provided with a positioning pin 15c that extends axially toward the board mounting member 120. The first wall portion 73 of the dust cover 70 is formed with a pin hole 76 that extends axially and through which the positioning pin 15c is inserted. The board mounting member 120 is formed with a pin hole 126 that extends axially and through which the positioning pin 15c is inserted.

[0063] The end of the through hole 15a of the knuckle 15 on the PCB mounting member 120 side in the axial direction is an expanded diameter portion 15d whose radial dimension is enlarged. The positioning pin 15c is inserted into the pin holes 76 and 126, and the extension portion 124 of the PCB mounting member 120 is fitted into the expanded diameter portion 15d. This aligns the centers of the through holes 15a, 72, and 122. The extension portion 124 and the expanded diameter portion 15d can improve the alignment accuracy.

[0064] The board mounting member 120, the first wall portion 73 of the dust cover 70, and the knuckle 15 are formed with cable insertion holes 127, 77, and 15e through which the cable 116 connected to the connector 115 of the sensor board 100 is inserted.

[0065] With the dust cover 70, board mounting member 120, and hub mounting portion 52 of the outer ring member 50 overlapping on the knuckle 15, the bolt 16 is inserted into the bolt insertion holes 15b, 71, 123, and the male thread of the bolt 16 is screwed into the female threaded hole 52a of the hub mounting portion 52. In this way, the sensor board 100 and the dust cover 70 are fixed to the knuckle 15.

[0066] The sensor substrate 100 is housed in a housing made of a material such as synthetic resin, and is a component with lower strength than the target member 80 made of a metal material. Therefore, it is desirable that the target member 80 and the sensor substrate 100 are configured so as not to interfere with each other.

[0067] An excessive force may be temporarily applied to the tire 14, which may also temporarily apply an excessive force to the hub bearing 40. When an excessive force is applied to the hub bearing 40, the hub bearing 40 may be excessively deformed such that the inner ring member 60 tilts relative to the outer ring member 50. For example, if the vehicle runs over a step, a large force may temporarily act on the tire 14, causing the hub bearing 40 to be excessively deformed. In this case, there is a concern that the sensor substrate 100 and the target member 80 may interfere with each other.

[0068] Specifically, the description will be made with reference to an enlarged view of the hub bearing 40 and its surroundings shown in FIG. 8. FIG. 8 shows a case where the outer ring member 50 and the inner ring member 60 are in a reference state position. The reference state can be set arbitrarily. The reference state is, for example, a state where the vehicle is stopped, and more specifically, a state where the vehicle is stopped on a level road surface. In this embodiment, in the reference state, the center axis LCi of the inner ring member 60 overlaps with the center axis LCo of the outer ring member 50.

[0069] In FIG. 8, the rotation center Oc is located on the central axis LCo of the outer ring member 50 and is the center of the two rows of balls arranged in the axial direction. The rotation center Oc is also called the tilt center. When a force is applied to the hub bearing 40, a counterclockwise moment about the rotation center Oc may be generated in the inner ring member 60. In this case, the target member 80 may tilt toward the sensor substrate 100, which may cause interference between the sensor substrate 100 and the target member 80.

[0070] Therefore, in this embodiment, the detection device is provided with a limiting mechanism that limits the displacement of the inner ring member 60 relative to the outer ring member 50 so that the target member 80 does not come into contact with the sensor substrate 100. The limiting mechanism will be described below.

[0071] A protrusion 90 is formed on the target member 80. The protrusion 90 is formed to extend radially inward from the inner peripheral edge of the target member 80. The protrusion 90 is provided over the entire circumferential area of ​​the inner peripheral edge of the target member 80 and has an annular shape. The protrusion 90 faces the outer cylindrical portion 51 in the radial direction.

[0072] 8 shows two concentric circles centered on the rotation center Oc: an imaginary circle Ca that passes through the end 90a of the protrusion 90, and an imaginary circle Cb that passes through the end 80b of the target member 80. When a counterclockwise moment is generated around the rotation center Oc, the central axis LCi of the inner ring member 60 tilts relative to the central axis LCo of the outer ring member 50. In this case, each end 90a, 80b is displaced counterclockwise along the corresponding imaginary circle Ca, Cb by the tilt angle θ.

[0073] 9 shows a case where the inclination angle θ is a contact angle θa. The contact angle θa is the inclination angle θ when the end 90a of the protrusion 90 is displaced from the position in the reference state to a position where it contacts the outer cylindrical portion 51.

[0074] 8, if the inner ring member 60 is tilted relative to the outer ring member 50 until the tilt angle θ reaches the predetermined angle θb, there is a concern that the end 80b of the target member 80 may come into contact with the sensor substrate 100. In this regard, it is considered that the target member 80 will not come into contact with the sensor substrate 100 if the change in the tilt angle θ is within a range smaller than the predetermined angle θb.

[0075] Therefore, in this embodiment, the protrusion 90 is shaped so that the contact angle θa is less than the predetermined angle θb. In this case, when the inner ring member 60 is displaced so as to tilt counterclockwise around the rotation center Oc by the contact angle θa, the end 91a of the protrusion 90 contacts the outer cylindrical portion 51 (see FIG. 9 ). As a result, the protrusion 90 and the outer cylindrical portion 51 come into contact with each other before the target member 80 and the sensor substrate 100 come into contact, and the displacement of the inner ring member 60 relative to the outer ring member 50 is stopped. This limits the displacement of the inner ring member 60 relative to the outer ring member 50 so that the target member 80 does not contact the sensor substrate 100, even if an excessive force is applied to the hub bearing 40. This prevents interference between the sensor substrate 100 and the target member 80.

[0076] The protrusions 90 are provided over the entire circumferential area on the radially inner side of the target member 80. This makes it possible to make the protrusions 90 less likely to be damaged when the protrusions 90 come into contact with the outer cylindrical portion 51.

[0077] In this embodiment, the predetermined angle θb corresponds to the "first predetermined angle", and the contact angle θa corresponds to the "second predetermined angle".

[0078] Second Embodiment The second embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, the shapes of the target member 80 and the sensor substrate 100 are changed.

[0079] 10, the radially outer end of the target member 180 is tapered. Specifically, the radially outer dimension of the target member 180 becomes smaller in the axial direction as it approaches the sensor substrate 1100 side.

[0080] The sensor substrate 1100 has a tapered outer end in the radial direction. Specifically, the outer diameter of the sensor substrate 1100 decreases in the axial direction toward the target member 180.

[0081] By tapering the radially outer end of the target member 180 and the radially outer end of the sensor substrate 1100, it is possible to increase the predetermined angle θb until contact between the target member 180 and the sensor substrate 1100 when a counterclockwise moment about the rotation center Oc occurs. For convenience, in FIG. 10 , the predetermined angle in the first embodiment is shown as θb1, and the predetermined angle in this embodiment is shown as θb2. By setting the predetermined angle θb2 to be larger than θb1, interference between the sensor substrate 100 and the target member 80 can be reliably suppressed.

[0082] <Modification of the second embodiment> Instead of tapering the radially outer end of the target member 180 and the radially outer end of the sensor substrate 1100, the radially outer end of the target member 180 or the radially outer end of the sensor substrate 1100 may be tapered. Even in this case, the predetermined angle θb can be increased.

[0083] <Other embodiments> The above-described embodiments may be modified as follows.

[0084] As a limiting mechanism, instead of forming the protrusion 90 on the target member 80, a protrusion 190 may be formed on the outer cylindrical portion 51 as shown in Fig. 11. The protrusion 190 is formed to extend radially outward from the outer cylindrical portion 51 and has an annular shape. The protrusion 190 is provided at a position between the target member 80 and the sensor substrate 100 in the axial direction.

[0085] FIG. 11 shows two concentric circles centered on the rotation center Oc: an imaginary circle Cb passing through the radially outer end 80b of the target member 80, and an imaginary circle Cc passing through the radially inner end 90c of the target member 80. In this embodiment, the contact angle θc is the angle when the end 80c of the target member 80 is displaced from a reference position to a position where it contacts the protrusion 190. The protrusion 190 is shaped so that the contact angle θc is less than a predetermined angle θb. By setting the contact angle θc to an angle less than the predetermined angle θb, the target member 80 and the protrusion 190 come into contact with each other before contact between the target member 80 and the sensor substrate 100, thereby limiting the displacement of the inner ring member 60 relative to the outer ring member 50. This prevents interference between the sensor substrate 100 and the target member 80.

[0086] As a limiting mechanism, instead of forming a protrusion 90 on the target member 80, a protrusion 91 may be formed on the target member 80 as shown in FIG. 12. The protrusion 91 is a portion that protrudes from the radially outer end of the target member 80 toward the substrate mounting member 1120 in the axial direction. The protrusion 91 has an annular shape. The substrate mounting member 1120 is formed to extend radially outward to a position opposite the protrusion 91 in the axial direction. The substrate mounting member 1120 is made of a metal material.

[0087] FIG. 12 shows two concentric circles, centered on the rotation center Oc, a virtual circle Cb passing through the end 80b of the target member 80 and a virtual circle Cd passing through the end 91d of the overhanging portion 91. In this embodiment, the contact angle θd is the angle when the end 91d of the overhanging portion 91 is displaced from a reference position to a position where it contacts the substrate mounting member 1120. The overhanging portion 91 is shaped so that the contact angle θd is less than a predetermined angle θb. By setting the contact angle θd to be less than the predetermined angle θb, the overhanging portion 91 and the substrate mounting member 1120 come into contact before the target member 80 and the sensor substrate 100 come into contact, thereby limiting the displacement of the inner ring member 60 relative to the outer ring member 50. This prevents interference between the sensor substrate 100 and the target member 80.

[0088] As a limiting mechanism, instead of forming a protrusion 90 on the target member 80, a protrusion 92 may be formed on the target member 80 as shown in Fig. 13. The protrusion 92 is a portion that protrudes from the radially outer end of the target member 80 toward the dust cover 70 in the axial direction. The protrusion 92 has an annular shape. The protrusion 92 and the dust cover 70 face each other in the axial direction.

[0089] FIG. 13 shows two concentric circles centered on the rotation center Oc: an imaginary circle Cb passing through the end 80b of the target member 80, and an imaginary circle Ce passing through the end 92e of the overhanging portion 92. In this embodiment, the contact angle θe is the angle at which the end 92e of the overhanging portion 92 is displaced from its reference position to a position where it contacts the dust cover 70. The overhanging portion 92 is shaped so that the contact angle θe is less than a predetermined angle θb. By setting the contact angle θe to be less than the predetermined angle θb, the overhanging portion 92 and the dust cover 70 come into contact before the target member 80 and the sensor substrate 100 come into contact, thereby limiting the displacement of the inner ring member 60 relative to the outer ring member 50. This prevents interference between the sensor substrate 100 and the target member 80.

[0090] The detection device may be provided with a hub bearing as a limiting mechanism, in which the tilt angle θ varies within a range smaller than a predetermined angle θb. Even in this case, it is possible to limit the displacement of the inner ring member relative to the outer ring member. For example, it is conceivable to select a hub bearing by focusing on factors that affect the rigidity of the hub bearing, such as the internal clearance and preload of the hub bearing.

[0091] Instead of fixing the target member 80 as the detection object to the flange 62, the detection object may be formed on the flange. In this case, the surface of the flange that faces the sensor substrate 100 in the axial direction may have protrusions and recesses formed thereon, similar to those described for the target member 80.

[0092] The circumferential center positions of the first and second receiving coils 111, 112 may be located at a position axially facing the right or left end of the target member 80, rather than at a position axially facing the upper end of the target member 80. In this case, the sensor board 100 can calculate the force acting between the ground contact surface GL and the wheel in the vehicle length direction (hereinafter referred to as the longitudinal load Fx) instead of the vertical load Fz. The direction in which the lateral force Fy acts is perpendicular to the direction in which the longitudinal load Fx acts. The longitudinal load Fx is used by the control device to control the running of the vehicle.

[0093] The disc rotor is not limited to a ventilated disc, but may be, for example, a solid disc made of a single circular plate.

[0094] The mechanical device to which the detection device can be applied is not limited to a wheel unit, but may also be, 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.

[0095] Furthermore, the rotating body is not limited to being used with the axis direction of the rotating body being horizontal, but may also be used with the axis direction being in a direction other than horizontal (for example, up and down).

[0096] The following describes characteristic configurations extracted from the above-described embodiments. [Configuration 1] A detection device applied to a mechanical device (10) having a rotating body (11, 14), The mechanical device includes a bearing member (40) that rotatably supports the rotating body relative to a base portion (15), The bearing member is a first bearing portion (50) extending in an axial direction, which is the direction in which the rotation center axis of the bearing member extends, and fixed to the base portion; a second bearing portion (60) provided at a position facing the first bearing portion in a radial direction perpendicular to the axial direction, and to which the rotating body is fixed; a rolling element (41) provided between the first bearing portion and the second bearing portion; the second bearing portion is rotatably supported relative to the base portion, a detection target portion (80, 180) having an annular shape and provided at the second bearing portion and extending in a circumferential direction of the second bearing portion around a rotation center of the second bearing portion; a sensor substrate (100, 1100) that is provided at a position facing the detection target in the axial direction and outputs a voltage signal corresponding to the displacement of the detection target; a limiting mechanism that limits displacement of the second bearing portion relative to the first bearing portion so that the detection target portion does not come into contact with the sensor substrate; A detection device comprising: [Configuration 2] The limiting mechanism includes a protrusion (90) formed to extend radially inward from an inner peripheral edge of the detection target portion, When the second bearing portion is tilted around a rotation center (Oc) of the second bearing portion relative to the first bearing portion, an inclination angle of the second bearing portion relative to the first bearing portion when the detection target portion contacts the sensor substrate is defined as a first predetermined angle, 2. The detection device according to claim 1, wherein the protrusion is shaped to come into contact with the first bearing portion when the tilt angle is a second predetermined angle that is less than the first predetermined angle. [Configuration 3] 3. The detection device according to claim 2, wherein the protrusion is provided on an inner peripheral edge of the detection target portion over the entire circumferential direction. [Configuration 4] The detection device according to any one of configurations 1 to 3, wherein the detection object (180) has an outer dimension in the radial direction that decreases toward the sensor substrate (1100) in the axial direction. [Configuration 5] The detection device according to any one of configurations 1 to 4, wherein the sensor substrate (1100) has an outer diameter dimension in the radial direction that decreases toward the detection target portion (180) in the axial direction. [Configuration 6] The detection device according to any one of configurations 2 to 5, wherein the sensor substrate and the detection target portion are each made of a material that makes the strength of the sensor substrate lower than the strength of the detection target portion. [Explanation of symbols]

[0097] 10...wheel unit, 11...wheel, 14...tire, 15...knuckle, 40...hub bearing, 41...rolling element, 50...outer ring member, 60...inner ring member, 80...target member, 100...sensor board.

Claims

1. A detection device applied to a mechanical device (10) having a rotating body (11, 14), The mechanical device includes a bearing member (40) that rotatably supports the rotating body relative to a base portion (15), The bearing member is a first bearing portion (50) extending in an axial direction, which is a direction in which a rotation center axis of the bearing member extends, and fixed to the base portion; a second bearing portion (60) provided at a position facing the first bearing portion in a radial direction perpendicular to the axial direction, and to which the rotating body is fixed; a rolling element (41) provided between the first bearing portion and the second bearing portion; the second bearing portion is rotatably supported relative to the base portion, a detection target portion (80, 180) provided in the second bearing portion and extending in a circumferential direction of the second bearing portion around a rotation center of the second bearing portion; a sensor substrate (100, 1100) that is provided at a position facing the detection target in the axial direction and outputs a voltage signal corresponding to the displacement of the detection target; a limiting mechanism that limits displacement of the second bearing portion relative to the first bearing portion so that the detection target portion does not come into contact with the sensor substrate; A detection device comprising:

2. The limiting mechanism includes a protrusion (90) formed to extend radially inward from an inner peripheral edge of the detection target portion, When the second bearing portion is inclined around a rotation center (Oc) of the second bearing portion relative to the first bearing portion, an inclination angle of the second bearing portion relative to the first bearing portion when the detection target portion contacts the sensor substrate is defined as a first predetermined angle, The detection device according to claim 1 , wherein the protrusion is shaped to come into contact with the first bearing portion when the tilt angle is a second predetermined angle that is less than the first predetermined angle.

3. The detection device according to claim 2 , wherein the protrusion is provided on an inner peripheral edge of the detection target portion over the entire circumferential area.

4. A detection device according to any one of claims 1 to 3, wherein the radial outer dimensions of the detection target portion (180) become smaller in the axial direction as it moves toward the sensor substrate (1100).

5. A detection device according to any one of claims 1 to 3, wherein the outer diameter dimension of the sensor substrate (1100) in the radial direction becomes smaller as it moves toward the detection target portion (180) in the axial direction.

6. 4. The detection device according to claim 2, wherein the sensor substrate and the detection target are each made of a material that makes the sensor substrate weaker in strength than the detection target.

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