Detection device

Abstract

To provide a detection device capable of protecting a detection object part from foreign matter.SOLUTION: The detection device includes a sensor member 100 and a target member 80. In the detection target portion of the target member 80, convex portions and concave portions are alternately provided in the circumferential direction. The sensor member 100 includes an exciting coil, a receiving coil, and a case member that houses the exciting coil and the receiving coil. A peripheral wall part 150 extending toward a flange part 62 side of the hub bearing 40 from an outside part in the axial direction up to a position for covering the detection object part from the outside in the radial direction, is arranged in the outside part in the radial direction of a body part 141 of the case member.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Conventionally, an inductive rotation angle sensor has been known that includes a rotor provided on a rotating shaft of a mechanical device and a sensor body disposed opposite the rotor in the axial direction of the rotating shaft. Such a sensor is described, for example, in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5447345 Summary of the Invention [Problem to be solved by the invention]

[0004] A detection device is known that is applied to a wheel unit including a vehicle wheel and a hub bearing that rotatably supports the wheel relative to the vehicle knuckle. The hub bearing includes a first bearing member (e.g., an outer ring member), a second bearing member (e.g., 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 of the rotational center axis of the hub bearing, and is fixed to the knuckle. The second bearing member has a second cylindrical portion provided at a position facing the first cylindrical portion in a radial direction perpendicular to the axial direction, and a flange portion extending radially outward from the second cylindrical portion. The rolling elements are provided between the first cylindrical portion and the second cylindrical portion.

[0005] The detection device includes a sensor member and a detection target portion as components for detecting a force acting on a wheel. The sensor member is provided at a position offset toward the knuckle relative to the flange portion in the axial direction and has a flat shape with the axial direction as its thickness direction. The detection target portion is provided at a portion of the flange portion facing the sensor member in the axial direction and has an annular shape extending in the circumferential direction of the second cylindrical portion. The detection target portion is provided with convex portions that protrude toward the knuckle in the axial direction and portions that recede from the convex portions in the axial direction to the opposite side of the knuckle, alternately provided in the circumferential direction.

[0006] There is a concern that foreign matter (e.g., sand) may get into the space where the detection target and the sensor board are arranged from the radial outside of the detection target, and if foreign matter gets in, there is a concern that the detection target may be damaged.

[0007] A primary object of the present disclosure is to provide a detection device that can protect a detection target from foreign matter. [Means for solving the problem]

[0008] The present disclosure provides a vehicle wheel; a hub bearing that rotatably supports the wheel relative to a knuckle of the vehicle; A detection device applied to a wheel unit comprising: The hub bearing is a first bearing member having a first cylindrical portion extending in an axial direction that is the direction of the rotational center axis of the hub bearing and fixed to the knuckle; a second bearing member including a second cylindrical portion provided at a position facing the first cylindrical portion in a radial direction perpendicular to the axial direction, and a flange portion extending radially outward from the second cylindrical portion; a rolling element provided between the first cylindrical portion and the second cylindrical portion; the second bearing member is rotatably supported relative to the knuckle, a flat sensor member that is provided at a position shifted toward the knuckle with respect to the flange portion in the axial direction and has a thickness direction that coincides with the axial direction; a detection target portion that is provided in a portion of the flange portion that faces the sensor member in the axial direction and has an annular shape that extends in a circumferential direction of the second cylindrical portion; Equipped with The detection target portion is provided with convex portions that protrude toward the knuckle in the axial direction and portions that recede toward the opposite side of the knuckle from the convex portions in the axial direction, alternately in the circumferential direction, The sensor member an excitation coil to which an excitation voltage is supplied; a receiving coil that induces a voltage when an excitation voltage is supplied to the exciting coil and outputs a voltage signal corresponding to the relative displacement of the detection target portion with respect to the receiving coil; a case member that houses the excitation coil and the receiving coil; and The case member extends in the circumferential direction.

[0009] In the present disclosure, the radially outer portion of the case member that houses the excitation coil and the receiving coil is provided with a peripheral wall portion that extends from the outer portion toward the flange portion in the axial direction to a position that covers the detection target portion from the radial outside.

[0010] This makes it difficult for foreign matter to enter the space in which the detection target is disposed, and the detection target can be protected from foreign matter. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a perspective view of a wheel unit according to the first embodiment. [Figure 2] FIG. [Figure 3] Enlarged view of a portion of Figure 2. [Figure 4] FIG. 10 is a view of the target member as seen from the knuckle side. [Figure 5] FIG. 2 is a diagram showing the electrical configuration of a sensor member and a processing unit. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. 4 is a perspective view of a sensor member, a hub bearing, a bracket member, etc. [Figure 10] FIG. 10 is a perspective view of a sensor member according to a second embodiment. [Figure 11] FIG. [Figure 12] FIG. 11 is a partial enlarged view of a wheel unit according to a third embodiment. [Figure 13] FIG. 10 is a view of a sensor member according to another embodiment, viewed from the flange portion side. DETAILED DESCRIPTION OF THE INVENTION

[0012] 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.

[0013] 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.

[0014] The wheel unit 10 as a mechanical device will be described with reference to Figures 1 to 3. 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.

[0015] 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.

[0016] The wheel unit 10 includes a brake device 20 and a hub bearing 40. 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 (not shown). The brake caliper is operated by hydraulic pressure, an electric signal, or the like, and includes a pair of brake pads that come into contact with the disc rotor 21 to generate braking force, a piston that presses the brake pads against the disc rotor 21, and a caliper body that supports the brake pads and the piston. The brake caliper is fixed with bolts to a knuckle 15, which serves as a base.

[0017] 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.

[0018] 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 disc 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.

[0019] A disc sliding portion 23 is connected to the end of the disc peripheral wall portion 25 opposite the bottom surface portion 24. The disc 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 disc sliding portion 23 form a pair of sliding surfaces that are pressed against by the brake pads.

[0020] The disc sliding portion 23 includes an inner disc portion 28, an outer disc portion 29 disposed on the outer side of the inner disc portion 28, and fins 30. The fins 30 connect the inner disc portion 28 and the outer disc portion 29 at multiple locations in the circumferential direction. The fins 30 extend radially, and the space surrounded by the inner disc portion 28, the outer disc portion 29, and the fins 30 forms an air passage 30a penetrating in the radial direction (diametrical direction). The air passage 30a is a passage that extends from an air intake port 31 formed on the radially inner side of the disc sliding portion 23 to an air exhaust port 32 formed on the radially outer side.

[0021] 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 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. 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.

[0022] The inner ring member 60 includes an inner cylindrical portion 61 (corresponding to a "second cylindrical portion") 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 traveling power source such as a motor is transmitted is fitted in the shaft insertion hole 63.

[0023] The outer ring member 50 has an outer cylindrical portion 51 (corresponding to a "first cylindrical portion") provided at a position facing radially outward from the inner cylindrical portion 61. A rolling element 41 is provided between the outer cylindrical portion 51 and the inner cylindrical portion 61.

[0024] The flange portion 62 is disk-shaped and extends radially outward beyond the outer cylindrical portion 51. A plurality of bolt insertion holes 64, into 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, for example, as shown in FIG. 5, five hub bolts 17 are formed aligned in the circumferential direction. Therefore, five bolt insertion holes 64 are also formed.

[0025] 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 disc sliding portion 23 of the disc rotor 21. The dust cover 70 extends radially outward beyond the outer peripheral edge of the disc sliding portion 23.

[0026] 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 and a sensor member 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 vertical load Fz). The direction in which the lateral force acts and the direction in which the vertical load acts are perpendicular to each other. For example, the calculated rotational speed, lateral force, and vertical load 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.

[0027] The target member 80 is made of a metal material through which magnetic flux flows. Specifically, for example, the target member 80 is made of a paramagnetic metal material (e.g., aluminum) having a relative permeability greater than 1, or a ferromagnetic metal material (e.g., iron) having a relative permeability greater than 1. The target member 80 has an annular shape extending in the circumferential direction about the central rotation axis of the hub bearing 40. The target member 80 is provided at a position facing the sensor member 100 in the axial direction without contacting the sensor member 100. The target member 80 is fixed to, for example, the flange portion 62, and rotates integrally with the inner ring member 60.

[0028] As shown in Fig. 4, protrusions 82 each having a flat surface 82a and projecting toward the knuckle 15 in the axial direction (i.e., toward the inside in the vehicle width direction) are formed in a row in the circumferential direction on the portion of the target member 80 facing the sensor member 100. The flat surfaces between the protrusions 82 lined up in the circumferential direction are recesses 83. As a result, the protrusions 82 and recesses 83 are alternately provided in the circumferential direction. In this embodiment, 12 pairs of protrusions 82 and recesses 83 are provided. The protrusions 82 and recesses 83 form a detection target portion 84.

[0029] 4, 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 82 and the axis passing through the center axis LCi and the other circumferential end of the protruding portion 82 is equal to the angle α2 formed by the axis passing through the center axis LCi and one circumferential end of the recessed portion 83 and the axis passing through the center axis LCi and the other circumferential end of the recessed portion 83. Therefore, the circumferential length of the multiple protruding portions 82 and the circumferential length of the multiple recessed portions 83 are equal to each other.

[0030] Next, a configuration for fixing the wheel 11, the disc rotor 21, and the target member 80 to the flange portion 62 will be described.

[0031] As shown in Figures 2 and 3, the target member 80 is provided radially inward of the disk peripheral wall portion 25 that constitutes the disk rotor 21. A bolt insertion hole 18a is formed in the disk mounting portion 18, penetrating in the axial direction. Hub bolts 17 are inserted into the bolt insertion holes 27, 18a with the bottom surface portion 24 and the disk mounting portion 18 overlapping the mounting surface 62b of the flange portion 62. Nuts 35 are threaded onto the hub bolts 17, thereby fixing the disk mounting portion 18 and the disk rotor 21 to the hub bearing 40. This makes the target member 80, disk rotor 21, and inner ring member 60 coaxial. The disk rotor 21 and wheel 11 rotate integrally with the target member 80.

[0032] Next, the sensor member 100 will be described.

[0033] The sensor member 100 is a so-called eddy current inductive sensor. The sensor member 100 has a flat shape with its thickness aligned in the axial direction. The sensor member 100 is provided in an arrangement space that is adjacent to the flange portion 62 on the inner side in the vehicle width direction and radially outward of the inner cylindrical portion 61 and the outer cylindrical portion 51. In the arrangement space, the detection object portion 84 of the target member 80 is provided at a position axially opposite the sensor member 100. In this embodiment, the sensor member 100 is provided at a position axially opposite the lower end of the detection object portion 84. In other words, the sensor member 100 is disposed lower with respect to the central axis LCi. The sensor member 100 is provided between the flange portion 62 and the hub mounting portion 52.

[0034] As shown in Figs. 6 to 8, the sensor member 100 has an arc-shaped plate surface that conforms to the detection target portion 84 when viewed from the front. As shown in Fig. 5, the sensor member 100 includes an excitation coil 110, a receiving coil, and a case member 140 that houses the excitation coil 110 and the 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 conforms to the plate surface of an arc-shaped substrate 116. The substrate 116 is a multi-layer substrate. Each of the coils 110 to 112 is formed by wiring patterns, vias, and the like formed on each layer of the substrate 116.

[0035] The sensor member 100 includes an excitation circuit 113 that supplies a high-frequency excitation voltage to the excitation coil 110, and a receiving circuit 114. The excitation circuit 113 and the receiving circuit 114 are mounted on a substrate 116. 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. In this embodiment, the coils 110 to 112 have the same circumferential center position. Furthermore, the circumferential center positions of the coils 110 to 112 are located opposite the lower end of the detection target portion 84 in the axial direction.

[0036] 6 to 8, the case member 140 includes a main body 141 in which the substrate 116 is disposed, and a lid 142 that covers an opening 141a of the main body 141. The lid 142 is provided with a connector 117 that is electrically connected to the excitation circuit 113 and the receiving circuit 114. The connector 117 is electrically connected to a processing unit 119 via a cable 118. The processing unit 119 may be provided on the vehicle body, or may be built into the wheel unit 10.

[0037] The processing unit 119 includes a CPU (Central Processing Unit). The functions of the processing unit 119 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 119 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.

[0038] Next, the load calculation process will be described.

[0039] 2, when a lateral force Fy acts on the wheel, the inclination θ of the central axis LCi of the inner ring member 60 relative to the central axis of the outer ring member 50 increases. In this case, the axial distance between each of the coils 111, 112 and the detection object 84 changes, and the amplitude of the output voltage signal of each of the coils 111, 112 changes. Based on this change in amplitude, the processing unit 119 calculates the axial displacement ΔY of the detection object 84, and performs processing to calculate the lateral force Fy based on the calculated axial displacement ΔY.

[0040] 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 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 member 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 119 calculates the displacement of the detection object portion 84 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.

[0041] The processing unit 119 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 119 calculates the rotation speed of the wheel based on the calculated rotation angle. Specifically, for example, the processing unit 119 may calculate the rotation speed based on the time differential value of the rotation angle.

[0042] The substrate 116 and the load calculation process are described in, for example, Japanese Patent Application Laid-Open No. 2023-130285.

[0043] Next, a configuration for fixing the sensor member 100 to the outer ring member 50 of the hub bearing 40 will be described with reference to FIGS.

[0044] The wheel unit 10 includes a bracket member 120 as a component for fixing the sensor member 100 to the outer ring member 50. As shown in Fig. 9, the bracket member 120 is plate-shaped and annular. The bracket member 120 is made of a non-magnetic material, such as synthetic resin or a metal material (e.g., aluminum). A circular (specifically, perfect circular) through-hole 122 is formed in the center of the bracket member 120. The through-hole 122 penetrates the bracket member 120 in the axial direction from the first plate surface 121a to the second plate surface 121b, and the outer cylindrical portion 51 is fitted into the through-hole 122.

[0045] A protrusion 130 to which the sensor member 100 is attached is formed on the first plate surface 121a of the bracket member 120. The protrusion 130 extends from the first plate surface 121a toward the flange portion 62 in the axial direction. A plurality of (for example, three) protrusions 130 are formed spaced apart in the circumferential direction. Of the plurality of protrusions 130, the protrusions 130 at both ends in the circumferential direction are protrusions for attaching both ends of the sensor member 100 in the circumferential direction. Of the plurality of protrusions 130, the protrusion 130 sandwiched between the protrusions 130 at both ends in the circumferential direction is a protrusion for attaching an intermediate portion of the sensor member 100 in the circumferential direction.

[0046] Each protrusion 130 is formed with a bolt insertion hole 132 that penetrates in the axial direction and through which a board mounting bolt 131 is inserted. Meanwhile, as shown in Fig. 8, the main body 141 of the sensor member 100 is formed with the same number of female screw holes 101 as the bolt insertion holes 132, into which the male screws of the board mounting bolts 131 are screwed.

[0047] The female screw holes 101 provided at both circumferential ends of the main body 141 are aligned with the bolt insertion holes 132 of the protrusions 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 bracket 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 member 100 is fixed to the bracket member 120 while maintaining a predetermined relative positional relationship between the sensor member 100 and the bracket member 120. In this case, the plate surface of the sensor member 100 (specifically, the board 116) and the plate surface of the bracket member 120 are parallel to each other. The sensor member 100 is supported by the protrusions 130 while spaced apart from the first plate surface 121a of the bracket member 120. The bracket member 120 and the outer ring member 50 are fixed to the knuckle 15, which serves as a base, by bolts, for example. As a result, the bracket member 120 and the outer ring member 50 are arranged so as not to be displaceable relative to the knuckle 15.

[0048] When an excitation voltage is applied to the excitation coil 110 of the sensor member 100, a current flows through each of the coils 110-112, causing each of the coils 110-112 to generate heat. For this reason, it is desirable to provide a configuration for effectively cooling each of the coils 110-112. As shown in FIG. 3, the sensor member 100 is disposed radially inward of the air intake 31 of the disc rotor 21. Furthermore, since the sensor member 100 and the first plate surface 121a of the bracket member 120 are separated by the protrusion 130, an air passage is formed between the sensor member 100 and the first plate surface 121a of the bracket member 120. In this case, as the disc rotor 21 rotates, airflow is generated from this air passage toward the air intake 31. As a result, the sensor member 100 can be effectively cooled.

[0049] The bracket 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.

[0050] 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. As shown in Fig. 3, each hub mounting portion 52 has a female threaded 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.

[0051] In a front view of the plate surface of the bracket member 120, the sensor member 100 and the bolt insertion hole 123 are disposed at positions where they do not overlap. Furthermore, in a front view of the plate surface of the bracket member 120, the hub mounting portion 52 and the bolt insertion hole 123 are disposed at positions where they do not overlap in the circumferential direction. This prevents the sensor member 100 from interfering with the hub mounting portion 52 when the first plate surface 121a of the bracket member 120, to which the sensor member 100 is attached, is brought into contact (specifically, surface contact) with the flat surface 52b of the hub mounting portion 52. The bracket member 120 is formed with a cable insertion hole 127 through which the cable 118 connected to the connector 117 of the sensor member 100 is inserted.

[0052] In this embodiment, even if foreign matter (e.g., sand or pebbles) flies in from below the hub bearing 40 as the wheel rotates, the structure is such that the foreign matter is unlikely to enter the arrangement space of the target member 80 and the sensor member 100. More specifically, as shown in FIGS. 6 to 9, a peripheral wall portion 150 extending along the outer radial portion 141b is provided on the radially outer portion 141b of the main body portion 141 of the case member 140. As shown in FIGS. 3 and 9, the peripheral wall portion 150 extends radially beyond a position facing the recess 83 of the detection target portion 84 and toward the outer side in the vehicle width direction in the axial direction. In other words, the peripheral wall portion 150 extends toward the flange portion 62 side to a position where it covers the detection target portion 84 from the radial outside. In this embodiment, the peripheral wall portion 150 extends to a position where it covers the entire target member 80 from the radial outside.

[0053] The peripheral wall portion 150 makes it difficult for foreign matter to enter the arrangement space of the detection target portion 84 and the sensor member 100. This makes it possible to prevent, for example, foreign matter from getting caught between the protrusion 82 of the detection target portion 84 and the main body portion 141. This makes it possible to protect the detection target portion 84 and the sensor member 100 from foreign matter.

[0054] The peripheral wall portion 150 is made of a non-magnetic material (for example, synthetic resin). In this embodiment, the peripheral wall portion 150 and the main body portion 141 are configured as a single member. The reason why the peripheral wall portion 150 is made of a non-magnetic material will be described below.

[0055] When an excitation voltage is supplied to the excitation coil 110, a magnetic flux is generated in the excitation coil 110. At least a portion of the generated magnetic flux interlinks with the receiving coils 111 and 112, thereby inducing a voltage in the receiving coils 111 and 112. The receiving coils 111 and 112 output a voltage signal corresponding to the relative displacement of the detection target portion 84 with respect to the receiving coils 111 and 112. The displacement or force is detected based on the output voltage signal.

[0056] Here, if the peripheral wall 150 is made of a magnetic material (for example, aluminum or iron), there is a concern that part of the magnetic flux generated in the exciting coil 110 will flow into the peripheral wall 150. In this case, the relationship between the relative displacement and the output signals of the receiving coils 111 and 112 will deviate from the reference relationship (for example, the relationship assumed at the time of design). As a result, there is a concern that the accuracy of detecting the displacement or force based on the output signals of the receiving coils 111 and 112 will decrease.

[0057] Therefore, the peripheral wall 150 is made of a non-magnetic material. This makes it difficult for part of the magnetic flux generated in the excitation coil 110 to flow to the peripheral wall 150. As a result, it is possible to prevent the relationship between the relative displacement of the detection object 84 with respect to the receiving coils 111, 112 and the output signals of the receiving coils 111, 112 from deviating from the reference relationship. In this way, according to this embodiment, it is possible to prevent foreign matter from entering the arrangement space of the detection object 84 and the sensor member 100, while also preventing a decrease in the detection accuracy of the displacement or force.

[0058] 3, gaps are provided between the peripheral wall portion 150 and the disk peripheral wall portion 25 and between the peripheral wall portion 150 and the disk sliding portion 23. This allows the gaps to function as a heat insulating layer, making it difficult for heat generated in the disk sliding portion 23 to be transmitted to the target member 80 and the sensor member 100. As a result, temperature increases in the target member 80 and the sensor member 100 can be suppressed.

[0059] Furthermore, the gap can be used as a passage for the airflow generated by the rotation of the disc rotor 21. This makes it difficult for the heat generated at the disc sliding portion 23 to be transmitted to the target member 80 and the sensor member 100, thereby suppressing the temperature rise of the target member 80 and the sensor member 100.

[0060] By suppressing the temperature rise of the target member 80, it is possible to suppress thermal deformation of the target member 80 and to suppress a decrease in the detection accuracy of displacement or force. Furthermore, by suppressing the temperature rise of the sensor member 100, it is possible to suppress the occurrence of a situation in which the reliability of the sensor member 100 decreases.

[0061] <Modification of the first embodiment> In case member 140, the boundary between outer portion 141b of main body 141 and peripheral wall 150 may be a curved portion that connects outer portion 141b and peripheral wall 150 with a smooth curved surface. In this case, the strength of peripheral wall 150 can be improved.

[0062] Second Embodiment The second embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, as shown in Figures 10 and 11, a through hole 160 is formed in the peripheral wall portion 150. More specifically, when the sensor member 100 is mounted on a vehicle, the through hole 160 is formed at a position lower than the middle position in the up-down direction of the peripheral wall portion 150.

[0063] According to the present embodiment described above, the detection target portion 84 and the sensor member 100 can be protected from foreign matter, while the peripheral wall portion 150 can be made to drain well.

[0064] <Modification of the second embodiment> In the peripheral wall portion 150, a plurality of through holes 160 may be formed, for example, along the circumferential direction.

[0065] Third Embodiment The third embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, as shown in Fig. 12, the peripheral wall 151 of the sensor member 100 expands radially outward as it approaches the flange 62 in the axial direction. As a result, the lower portion of the peripheral wall 151 is inclined downward toward the flange 62.

[0066] According to the present embodiment described above, even if water seeps into the arrangement space of the detection target portion 84 and the sensor member 100, the seeping water can be easily discharged from the lower end side of the peripheral wall portion 151. In this way, according to the present embodiment, the detection target portion 84 and the sensor member 100 can be protected from foreign matter, while the peripheral wall portion 151 can be well drained.

[0067] <Other embodiments> The above-described embodiments may be modified as follows.

[0068] In the third embodiment, instead of the entire peripheral wall portion 151, only the lower portion of the peripheral wall portion 151 may be expanded radially outward as it approaches the flange portion 62 in the axial direction.

[0069] As shown in FIG. 13, the peripheral wall portion 152 may extend beyond the main body portion 141 in the circumferential direction, thereby forming a cylindrical shape.

[0070] In the target member 80, a hole that passes through the target member 80 in the axial direction may be formed instead of the recess 83. The hole is a portion that is recessed toward the flange portion 62 side relative to the protrusion 82.

[0071] The target member 80 may not be provided, and a detection target portion having a protrusion and a recess may be formed on the flange portion 62.

[0072] The sensor member 100 may be attached to the outer ring member 50 instead of the bracket member 120 .

[0073] The hub bearing is not limited to an inner ring rotation type, and may be an outer ring rotation type. Specifically, the inner ring axial member (corresponding to the "first bearing member") constituting the outer ring rotation type hub bearing has an inner cylindrical portion (corresponding to the "first cylindrical portion") extending axially and is fixed to the knuckle 15. The outer ring axial member (corresponding to the "second bearing member") constituting the hub bearing has an outer cylindrical portion (corresponding to the "second cylindrical portion") provided radially outside the inner cylindrical portion, and a flange portion extending radially from the outer cylindrical portion and to which the wheel is fixed.

[0074] The sensor member 100 may be arranged so that the circumferential center positions of the first and second receiving coils 111, 112 are positioned axially opposite the upper end of the target member 80, rather than axially opposite the lower end of the target member 80.

[0075] Furthermore, the sensor member 100 may be provided so that the circumferential center positions of the first and second receiving coils 111, 112 are not axially opposed to the lower end or upper end of the target member 80, but are axially opposed to the right end or left end of the target member 80. In this case, the processing unit 119 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 and the direction in which the longitudinal load Fx acts are perpendicular to each other. The longitudinal load Fx is used by the control device to control the running of the vehicle.

[0076] The disc rotor is not limited to a ventilated disc, but may be, for example, a solid disc made of a single circular plate. [Explanation of symbols]

[0077] 10...wheel unit, 15...knuckle, 40...hub bearing, 80...target member, 84...detection object portion, 100...sensor member, 110...excitation coil, 111, 112...receiving coils, 140...case member, 150...peripheral wall portion.

Claims

1. Wheels (11, 14) of a vehicle; a hub bearing (40) that rotatably supports the wheel relative to a knuckle (15) of the vehicle; A detection device applied to a wheel unit (10) comprising: The hub bearing is a first bearing member (50) having a first cylindrical portion (51) extending in an axial direction, which is the direction of the rotational center axis of the hub bearing, and fixed to the knuckle; a second bearing member (60) having a second cylindrical portion (61) provided at a position facing the first cylindrical portion in a radial direction perpendicular to the axial direction, and a flange portion (62) extending radially outward from the second cylindrical portion; a rolling element (41) provided between the first cylindrical portion and the second cylindrical portion; the second bearing member is rotatably supported relative to the knuckle, a flat sensor member (100) that is provided at a position shifted toward the knuckle with respect to the flange portion in the axial direction and has a thickness direction that is the axial direction; a detection target portion (84) that is provided in a portion of the flange portion that faces the sensor member in the axial direction and has an annular shape that extends in a circumferential direction of the second cylindrical portion; Equipped with The detection target portion is provided with convex portions (82) that protrude toward the knuckle in the axial direction and portions (83) that recede toward the opposite side of the knuckle from the convex portions in the axial direction, alternately in the circumferential direction, The sensor member an excitation coil (110) to which an excitation voltage is supplied; a receiving coil (111, 112) that induces a voltage when an excitation voltage is supplied to the exciting coil and outputs a voltage signal corresponding to the relative displacement of the detection target portion with respect to the receiving coil; a case member (140) that houses the excitation coil and the receiving coil; and The case member extends along the circumferential direction, A detection device in which a peripheral wall portion (150-152) is provided on the radially outer portion of the case member, extending from the outer portion toward the flange portion in the axial direction to a position that covers the detection target portion from the radial outside.

2. The detection device according to claim 1 , wherein the peripheral wall portion is made of a non-magnetic material.

3. the sensor member is disposed lower than the central axis of rotation, The detection device according to claim 1 or 2, wherein a through-hole penetrating in the radial direction is formed in at least a lower portion of the peripheral wall portion (150).

4. the sensor member is disposed lower than the central axis of rotation, 3. The detection device according to claim 1, wherein at least a lower portion of the peripheral wall portion (151) expands radially outward as it approaches the flange portion in the axial direction.

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