Torque sensor

Abstract

In order to set the positional relationship between a stator and a magnetic collection yoke to a desired positional relationship, a torque sensor (10) is provided with: a stator (60) fixed to a first pinion gear (88a); and a magnetic collection yoke assembly (40) that is attached to the housing (20) and that has a magnetic collection yoke (46) that is disposed so as to overlap the flange section (61) of the stator (60) and that detects a change in magnetic flux corresponding to a change in the relative position between the stator (60) and the magnet (65), the magnetic collection yoke assembly (40) having a plurality of movement-restricting protrusions (44) that face the inner wall (25) of a housing section (24) provided in the housing (20), and the movement-restricting protrusions (44) being attached to the housing (20). Two of the plurality of movement restricting protrusions (44) are disposed so as to be separated from each other in at least one of the longitudinal direction (Y) and the width direction (X), and two of the plurality of movement restricting protrusions (44) are disposed so as to be separated from each other in the other direction. Alternatively, the at least one movement restricting projection (44) extends longer in the other direction than in the one direction.

Description

Technical Field

[0001] The present invention relates to a torque sensor. Background Art

[0002] As an example of a torque sensor that detects the torque applied to a rotating body of a steering device, there is a torque sensor that detects torque by detecting a change in magnetism. For example, the magnetic detection module described in Patent Document 1 includes: a multi-pole magnet fixed to an input shaft; a set of magnetic yokes fixed to an output shaft; a magnetic flux guiding member that guides the magnetic flux of a magnetic circuit to a magnetic sensor; and a magnetic sensor that detects the magnetic flux guided by the magnetic flux guiding member and converts it into a voltage signal.

[0003] In addition, Patent Document 1 describes the following embodiment: The sensor unit that houses the magnetic sensor is provided to protrude from the end surface of the cylindrical portion, and the magnetic detection module is mounted on the housing by inserting the cylindrical portion into the mounting hole of the housing. And, Patent Document 1 describes that the fitting clearance on one side between the mounting hole of the housing and the cylindrical portion is set to be smaller than the minimum clearance between the ring portion of the magnetic yoke and the sensor unit.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-8547 Summary of the Invention

[0007] Technical Problems to be Solved by the Invention

[0008] Here, in Patent Document 1, an O-ring used as a seal is interposed between the mounting hole of the housing and the cylindrical portion inserted into the mounting hole. The O-ring has elasticity, and when the cylindrical portion is inserted into the mounting hole of the housing, the O-ring is in a flattened state. Therefore, when an elastic O-ring is interposed between the cylindrical portion provided with the sensor unit and the mounting hole of the housing, the positional relationship of the cylindrical portion with respect to the mounting hole changes according to the degree of flattening of the O-ring, and thus the positional relationship of the cylindrical portion with respect to the housing changes. Therefore, when the O-ring is interposed between the cylindrical portion provided with the sensor unit and the housing, the clearance between the ring portion of the magnetic yoke and the sensor unit changes according to the degree of flattening of the O-ring.

[0009] On the other hand, for a torque sensor, if the distance between the flux concentrating yoke as a flux guiding component and the stator that transmits the magnetic flux from the multi-pole magnet to the flux concentrating yoke changes with respect to the designed distance, the output characteristics change when the torque sensor detects torque. Therefore, when an elastic component such as an O-ring is disposed between the component having the flux concentrating yoke and the housing to which the component is mounted, and the distance between the flux concentrating yoke and the stator changes according to the compression state of the O-ring, the output characteristics from the torque sensor are likely to change, and individual differences in the output characteristics occur. Therefore, there is room for improvement in terms of the positioning when mounting the component having the flux concentrating yoke with respect to the housing.

[0010] The present invention has been made in view of the above circumstances, and an object thereof is to provide a torque sensor capable of making the positional relationship between the stator and the flux concentrating yoke a desired positional relationship.

[0011] Technical means for solving the problem

[0012] The torque sensor of the present invention includes: a housing; a shaft disposed inside the housing; a pair of stators each having a flange portion protruding outward in the radial direction of the shaft and fixed to the shaft; a cylindrical magnet disposed opposite to the stator; and a flux concentrating yoke assembly detachably mounted to the housing and having: a pair of flux concentrating yokes overlapping the flange portions of the stator with a gap in the axial direction of the shaft and detecting a change in magnetic flux corresponding to a change in the relative position of the pair of stators and the magnet; and a Hall element that outputs a change in magnetic flux detected by the flux concentrating yoke as an electrical signal. The housing has a receiving portion for receiving the flux concentrating yoke assembly, and the flux concentrating yoke assembly has a plurality of movement restricting convex portions facing the inner wall of the receiving portion. The plurality of movement restricting convex portions are respectively disposed on both sides in the axial direction of the flux concentrating yoke assembly. Two of the plurality of movement restricting convex portions are respectively disposed on both sides in the axial direction of the flux concentrating yoke assembly. The two of the plurality of movement restricting convex portions are disposed separately in at least any one of the length direction along the radial direction and the width direction orthogonal to both the length direction and the axial direction. The two of the plurality of movement restricting convex portions are disposed separately in the other direction, or at least one of the plurality of movement restricting convex portions extends longer in the other direction than in the one direction.

[0013] According to this structure, when the magnetic yoke assembly is accommodated in the accommodating portion, the movement restricting convex portion abuts against the inner wall of the accommodating portion, whereby the position in the axial direction with respect to the housing is restricted and it is fixed with respect to the housing in a desired positional relationship. In addition, a plurality of movement restricting convex portions are arranged on both axial sides of the magnetic yoke assembly, and two of the plurality of movement restricting convex portions are arranged separately in at least one of the length direction and the width direction. In addition, two of the plurality of movement restricting convex portions are arranged separately in the other direction, or at least one of the plurality of movement restricting convex portions extends longer in the other direction than in one direction. Therefore, when the magnetic yoke assembly is accommodated in the accommodating portion, the movement restricting convex portion abuts against the inner wall of the accommodating portion, whereby the mounting angle of the magnetic yoke assembly with respect to the housing is also fixed at a desired mounting angle. Thereby, the magnetic yoke assembly can fix the magnetic yoke included in the magnetic yoke assembly with respect to the housing in a desired positional relationship and can be arranged with respect to the stator fixed to the shaft in a desired positional relationship. As a result, the positional relationship between the stator and the magnetic yoke can be made a desired positional relationship.

[0014] As a preferred mode, the magnetic yoke assembly has a magnetic yoke accommodating portion for accommodating the magnetic yoke, and the movement restricting convex portion is arranged on the magnetic yoke accommodating portion.

[0015] According to this structure, when the magnetic yoke assembly is accommodated in the accommodating portion of the housing, positioning of the magnetic yoke accommodating portion for accommodating the magnetic yoke with respect to the housing can be performed. Thereby, the magnetic yoke assembly fixed to the housing can arrange the magnetic yoke accommodated in the magnetic yoke accommodating portion with respect to the stator in an appropriate positional relationship. As a result, the positional relationship between the stator and the magnetic yoke can be made a desired positional relationship.

[0016] As a preferred mode, the movement restricting convex portion is arranged in a region including both ends in the length direction and both ends in the width direction of both axial sides including the magnetic yoke accommodating portion.

[0017] According to this structure, the movement restricting convex portion is arranged in a region at each corner of both axial sides of the magnetic yoke accommodating portion. Therefore, when the magnetic yoke assembly is accommodated in the accommodating portion of the housing, the magnetic yoke assembly can position the magnetic yoke accommodating portion at an appropriate position by making the movement restricting convex portions at the four corners of the magnetic yoke accommodating portion abut against the inner wall of the accommodating portion. Thereby, the magnetic yoke assembly accommodated in the accommodating portion can arrange the magnetic yoke accommodated in the magnetic yoke accommodating portion with respect to the stator in an appropriate positional relationship. As a result, the positional relationship between the stator and the magnetic yoke can be made a desired positional relationship.

[0018] As a preferred embodiment, a sealing member that abuts against the inner wall of the receiving portion is disposed outside the magnetic flux collecting yoke receiving portion in the radial direction in the magnetic flux collecting yoke assembly.

[0019] According to this structure, in the magnetic flux collecting yoke assembly, a sealing member that abuts against the inner wall of the receiving portion is disposed outside the magnetic flux collecting yoke receiving portion in the radial direction. Therefore, it is possible to suppress the intrusion of water or the like from the outside of the housing into the receiving portion. In addition, since the magnetic flux collecting yoke assembly has a plurality of movement restricting convex portions, even when the sealing member that abuts against the inner wall of the receiving portion is disposed on the magnetic flux collecting yoke assembly, the magnetic flux collecting yoke assembly can be positioned at an appropriate position by the movement restricting convex portions regardless of the flattening state of the sealing member when the magnetic flux collecting yoke assembly is received in the receiving portion. Thus, the magnetic flux collecting yoke assembly received in the receiving portion can suppress the intrusion of water or the like from the outside of the housing into the receiving portion by the sealing member, and the magnetic flux collecting yoke received in the magnetic flux collecting yoke receiving portion can be disposed with respect to the stator in an appropriate positional relationship. As a result, the positional relationship between the stator and the magnetic flux collecting yoke can be made the desired positional relationship.

[0020] As a preferred embodiment, the movement restricting convex portions disposed on both surfaces of the magnetic flux collecting yoke assembly are arranged such that a plurality of them are separated from each other at least in the length direction on each surface. The magnetic flux collecting yoke assembly has a cover portion that covers the openings of the magnetic flux collecting yoke receiving portion formed on both axial sides of the magnetic flux collecting yoke receiving portion, and the cover portion is disposed between the movement restricting convex portions separated from each other in the length direction.

[0021] According to this structure, the magnetic flux collecting yoke assembly can ensure dustproofness for the magnetic flux collecting yoke by the cover portion, and the movement restricting convex portions facing the inner wall of the receiving portion are disposed on both axial sides of the magnetic flux collecting yoke assembly. Thus, the magnetic flux collecting yoke assembly received in the receiving portion can ensure dustproofness of the magnetic flux collecting yoke receiving portion, and the magnetic flux collecting yoke received in the magnetic flux collecting yoke receiving portion can be disposed with respect to the stator in an appropriate positional relationship. As a result, the positional relationship between the stator and the magnetic flux collecting yoke can be made the desired positional relationship.

[0022] As a preferred embodiment, at least a part of the plurality of movement restricting convex portions are separated from the inner wall of the receiving portion and face the inner wall, and the maximum value of the distance H1 between the movement restricting convex portion and the inner wall is narrower than the distance H2 between the flange portion of the stator and the magnetic flux collecting yoke.

[0023] According to this structure, when the magnetic flux concentrating yoke assembly is received in the receiving portion of the housing, even when the movement restricting convex portion abuts against the inner wall of the receiving portion, the axial distance between the flange portion of the stator and the magnetic flux concentrating yoke can be ensured. Thus, the magnetic flux concentrating yoke assembly received in the receiving portion can position the magnetic flux concentrating yoke axially relative to the housing at an appropriate position, and the magnetic flux concentrating yoke can be arranged relative to the stator in an appropriate positional relationship. As a result, the positional relationship between the stator and the magnetic flux concentrating yoke can be made into a desired positional relationship.

[0024] As a preferred mode, all of the movement restricting convex portions of the plurality of movement restricting convex portions abut against the inner wall of the receiving portion.

[0025] According to this structure, when the magnetic flux concentrating yoke assembly is received in the receiving portion, all of the movement restricting convex portions of the magnetic flux concentrating yoke assembly abut against the inner wall of the receiving portion. Therefore, the magnetic flux concentrating yoke assembly can position the axial position accuracy relative to the housing with high precision. Thus, the magnetic flux concentrating yoke can be arranged relative to the stator in an appropriate positional relationship, and the positional relationship between the stator and the magnetic flux concentrating yoke can be made into a desired positional relationship.

[0026] Advantages of the Invention

[0027] The torque sensor of the present invention has the effect of making the positional relationship between the stator and the magnetic flux concentrating yoke into a desired positional relationship. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic view for explaining a steering device of an embodiment.

[0029] Figure 2 is a cross-sectional view of a torque sensor included in the steering device of the embodiment.

[0030] Figure 3 is a schematic view for explaining an overview of a magnet, a stator, and a magnetic flux concentrating yoke included in the torque sensor.

[0031] Figure 4 is an exploded perspective view of the magnetic flux concentrating yoke assembly.

[0032] Figure 5 is a schematic view showing the arrangement position of the movement restricting convex portion in the magnetic flux concentrating yoke receiving portion.

[0033] Figure 6 is a detailed view showing a state before the magnetic flux concentrating yoke assembly is mounted on the first housing.

[0034] Figure 7 is a detailed view of the gap between the inner wall of the receiving portion and the movement restricting convex portion and the gap between the flange portion of the stator and the magnetic flux concentrating yoke.

[0035] Figure 8 It is a schematic diagram showing a state where a magnetic shielding cover is disposed in a magnetic yoke housing portion.

[0036] Figure 9 It is a modification example of the torque sensor of the embodiment and is an explanatory diagram of a movement restricting convex portion extending in the length direction.

[0037] Figure 10 It is a modification example of the torque sensor of the embodiment and is an explanatory diagram of a movement restricting convex portion extending in the width direction. Detailed implementation mode

[0038] Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, the present invention is not limited to the following embodiments for implementing the invention. In addition, the constituent elements in the following embodiments include elements that can be easily conceived by those skilled in the art, substantially identical elements, and so-called equivalent range elements. Furthermore, the constituent elements disclosed in the following embodiments can be appropriately combined.

[0039] [Embodiment]

[0040] Figure 1 It is a schematic diagram for explaining the steering device 80 of the embodiment. As Figure 1 shown, the steering device 80 includes a steering wheel 81, a steering shaft 82, a universal joint 84, an intermediate shaft 85, a universal joint 86, a short shaft 87, a steering gear 88, and a tie rod 89 in the order of force transmission from the operator. In addition, the steering device 80 includes a control device (hereinafter referred to as ECU (Electronic Control Unit)) 100, a torque sensor 10, and an electric motor 102. A vehicle speed sensor 101 is provided in the vehicle, and outputs a vehicle speed signal V to the ECU 100 through CAN (Controller Area Network) communication.

[0041] One end of the steering shaft 82 is connected to the steering wheel 81, and the other end is connected to the universal joint 84.

[0042] One end of the intermediate shaft 85 is connected to the universal joint 84, and the other end is connected to the universal joint 86. One end of the short shaft 87 is connected to the universal joint 86, and the other end is connected to the torque sensor 10. One end of the torque sensor 10 is connected to the short shaft 87, and the other end is connected to a first pinion 88a of the steering gear 88.

[0043] Specifically, the first pinion 88a is a shaft-like member having a gear (not shown) formed at an end opposite to the side connected to the short shaft 87 and meshing with a rack bar 88b described later. The short shaft 87 and the first pinion 88a are connected via a torsion bar 87a (refer toFigure 2 ) Connection. One end of the torsion bar 87a is connected to the short shaft 87, and the other end is connected to the first pinion 88a. The torsion bar 87a transmits the rotational torque between the short shaft 87 and the first pinion 88a.

[0044] The torque sensor 10 is a torque detection device that detects the torque acting on the shaft connected to the torque sensor 10, and detects the rotational torque transmitted between the short shaft 87 and the first pinion 88a via the torsion bar 87a. That is, the short shaft 87 and the first pinion 88a connected via the torsion bar 87a become the shafts to be detected when the torque sensor 10 detects the torque.

[0045] The steering gear 88 includes a first pinion 88a, a rack bar 88b, and a second pinion 88c. The first pinion 88a is connected to the short shaft 87 via the torsion bar 87a. The rack teeth (not shown) formed on the rack bar 88b mesh with the gear of the first pinion 88a. In addition, the rack bar 88b meshes with the second pinion 88c at a position different from the first pinion 88a.

[0046] An electric motor 102 is connected to the second pinion 88c via a worm reduction gear (not shown), and the second pinion 88c can rotate by the driving force transmitted from the electric motor 102. The electric motor 102 rotates the second pinion 88c via a worm reduction gear (not shown). The electric motor 102 is, for example, a brushless motor, but it can also be a motor having a brush (sliding member) and a commutator (rectifying member).

[0047] The steering gear 88 converts the rotational motion transmitted to the first pinion 88a and the second pinion 88c into a straight-line motion by using the rack bar 88b disposed inside a rack housing (not shown). The steering device 80 of the present embodiment is a double-pinion assist type in which the rack bar 88b performs a straight-line motion by the rotational motion transmitted from the first pinion 88a and the second pinion 88c. The tie rod 89 is connected to the rack bar 88b. That is, the steering device 80 is a rack and pinion type electric power steering device.

[0048] The torque sensor 10 detects the driver's steering force transmitted to the steering shaft 82 via the steering wheel 81 as a steering torque. The vehicle speed sensor 101 detects the traveling speed (vehicle speed) of the vehicle on which the steering device 80 is mounted. The electric motor 102, the torque sensor 10, and the vehicle speed sensor 101 are electrically connected to the ECU 100.

[0049] The ECU 100 controls the operation of the electric motor 102. In addition, the ECU 100 obtains signals from the torque sensor 10 and the vehicle speed sensor 101 respectively. That is, the ECU 100 obtains the steering torque T from the torque sensor 10 and the vehicle speed signal V of the vehicle from the vehicle speed sensor 101. The ECU 100 is supplied with power from the power supply device (e.g., in-vehicle battery) 104 in a state where the ignition switch 103 is turned on. The ECU 100 calculates an assist steering command value of the assist command based on the steering torque T and the vehicle speed signal V. And the ECU 100 adjusts the power value E supplied to the electric motor 102 based on the calculated assist steering command value. The ECU 100 obtains information on the induced voltage from the electric motor 102 or information output from a rotation detection device such as a resolver provided in the electric motor 102 as the operation information M.

[0050] The steering force of the operator (driver) input to the steering wheel 81 is transmitted to the first pinion 88a. The steering force transmitted to the first pinion 88a is transmitted to the tie rod 89 via the steering gear 88, displacing the wheels.

[0051] In addition, the steering force of the operator input to the steering wheel 81 is transmitted to the torque sensor 10 disposed in the transmission path of the steering force from the steering wheel 81 to the first pinion 88a. At this time, the ECU 100 obtains the steering torque T from the torque sensor 10 and the vehicle speed signal V from the vehicle speed sensor 101. And the ECU 100 controls the operation of the electric motor 102. The assist steering torque generated by the electric motor 102 is transmitted to the second pinion 88c.

[0052] The assist steering torque transmitted to the second pinion 88c is transmitted to the tie rod 89 via the steering gear 88, displacing the wheels. That is, the steering device 80 displaces the wheels by using, in addition to the steering force of the operator transmitted to the rack bar 88b via the first pinion 88a, the assist steering torque of the electric motor 102 transmitted to the rack bar 88b via the second pinion 88c.

[0053] As Figure 1 shown, the steering device 80 is a double pinion type that applies an assist force to the second pinion 88c, but is not limited thereto. The steering device 80 may be, for example, a column assist type that applies an assist force to the steering shaft 82, a single pinion assist type of an electric power steering device that applies an assist force to the first pinion 88a. In addition, it may be a rack assist type of an electric power steering device of a type that applies an assist force to the rack bar 88b without passing through a pinion, such as a ball screw type that applies an assist force to the rack bar 88b by a ball screw.

[0054] Figure 2FIG. 0 is a cross-sectional view of a cross-section of the steering device 80 of the embodiment including the torque sensor 10. It should be noted that in the following description, when the direction is not specifically described, the axial direction Z of the short shaft 87 and the first pinion 88a where the torque sensor 10 is disposed is also described as the axial direction Z in the torque sensor 10. Similarly, the circumferential direction centered on the axes of the short shaft 87 and the first pinion 88a is also described as the circumferential direction in the torque sensor 10, and the radial direction centered on the axes of the short shaft 87 and the first pinion 88a is also described as the radial direction in the torque sensor 10. In addition, the direction in the radial direction of the torque sensor 10 along the radial direction ( Figure 2 the left-right direction of the paper surface in) at the position where the magnetic flux concentrating yoke assembly 40 is disposed in the circumferential direction is described as the length direction Y of the torque sensor 10 or the length direction Y of the magnetic flux concentrating yoke assembly 40. In addition, the direction orthogonal to both the length direction Y and the axial direction Z ( Figure 2 the depth direction of the paper surface in) is described as the width direction X of the torque sensor 10 or the width direction X of the magnetic flux concentrating yoke assembly 40. In the present embodiment, the length direction Y is the direction orthogonal to the axial direction Z in a cross-section passing through the axes of the short shaft 87, the first pinion 88a, and the center of the magnetic flux concentrating yoke assembly 40 in the width direction X.

[0055] A housing 20 is disposed around a portion of the short shaft 87 and the first pinion 88a that are connected via a torsion bar 87a. The housing 20 has a first housing 21 and a second housing 31 that are connected to each other. The first housing 21 is disposed at a position near the short shaft 87 in the axial direction Z and mainly covers the short shaft 87, and the second housing 31 is disposed at a position near the first pinion 88a in the axial direction Z and mainly covers the first pinion 88a. In other words, at least a part of the short shaft 87 and the first pinion 88a is disposed inside the first housing 21 and the second housing 31, at least a part of the short shaft 87 is disposed inside the first housing 21, and at least a part of the first pinion 88a is disposed inside the second housing 31. The first housing 21 is fixed to the second housing 31 by mounting bolts (not shown), whereby the first housing 21 is fixed to the second housing 31.

[0056] In addition, a bearing (not shown) is disposed inside the first housing 21, and the short shaft 87 is rotatably supported by the first housing 21 via the bearing disposed inside the first housing 21. In addition, a bearing (not shown) is also disposed inside the second housing 31, and the first pinion 88a is rotatably supported by the second housing 31 via the bearing disposed inside the second housing 31.

[0057] The short shaft 87 is rotatably supported by the first housing 21, and the first pinion 88a is rotatably supported by the second housing 31. Therefore, the short shaft 87 and the first pinion 88a connected via the torsion bar 87a rotate integrally and are rotatably supported by the first housing 21 and the second housing 31.

[0058] The housing 20 is installed on the vehicle body in a non-rotatable state, and the housing 20 rotatably supports the short shaft 87 and the first pinion 88a through the bearing disposed in the first housing 21 and the bearing disposed in the second housing 31.

[0059] The torque sensor 10 is disposed inside the first housing 21, near the ends of the short shaft 87 as the first shaft and the first pinion 88a as the second shaft connected to the short shaft 87 via the torsion bar 87a. Both the short shaft 87 and the first pinion 88a are shafts having hollow portions, and the end of one shaft enters the inside of the other shaft from the end of the other shaft. In this embodiment, the short shaft 87 enters the inside of the first pinion 88a.

[0060] The torsion bar 87a is disposed in the range from the inside of the short shaft 87 to the inside of the first pinion 88a, with one end connected to the short shaft 87 and the other end connected to the first pinion 88a. That is, the short shaft 87 and the first pinion 88a are not directly connected, but are connected via the shaft-like member, i.e., the torsion bar 87a. Therefore, the short shaft 87 and the first pinion 88a can rotate relative to each other, and when the torsion bar 87a is twisted, the short shaft 87 and the first pinion 88a rotate relative to each other along with the twist of the torsion bar 87a.

[0061] The torque sensor 10 is disposed near the ends of the short shaft 87 and the first pinion 88a connected via the torsion bar 87a like this, and by detecting the angle of relative rotation between the short shaft 87 and the first pinion 88a, the torque acting between the short shaft 87 and the first pinion 88a can be detected.

[0062] The torque sensor 10 has a magnet 65, a stator 60 (refer to Figure 3 ) and a magnetic flux collecting yoke 46 (refer to Figure 3 ). The magnet 65 and the stator 60 are separately mounted on the short shaft 87 and the first pinion 88a respectively. The magnetic flux collecting yoke 46 is mounted on the sensor housing 41 of the magnetic flux collecting yoke assembly 40, and thus, the magnetic flux collecting yoke 46 is included in the magnetic flux collecting yoke assembly 40. The magnetic flux collecting yoke 46 is fixed to the first housing 21 by mounting the magnetic flux collecting yoke assembly 40 on the first housing 21.

[0063] The magnetic flux concentrating yoke assembly 40 is detachably mounted on the first housing 21. When the magnetic flux concentrating yoke assembly 40 is mounted on the first housing 21, it is received in a receiving portion 24 provided in the first housing 21. The receiving portion 24 is disposed near a portion of the first housing 21 that is connected to the second housing 31 and is formed to protrude radially outward from the outer peripheral surface of the first housing 21. A space communicating with the inside of the first housing 21 is formed inside the receiving portion 24 provided in the first housing 21. The magnetic flux concentrating yoke assembly 40 is received in the receiving portion 24 by disposing a part thereof inside the receiving portion 24 formed in this way.

[0064] Moreover, a magnetic shield cover 70 is mounted on the receiving portion 24 provided in the first housing 21. The magnetic shield cover 70 is formed by bending a metal plate member. Both sides in the axial direction Z of the receiving portion 24 are covered with the magnetic shield cover 70 mounted on the receiving portion 24. Specifically, the magnetic shield cover 70 is formed to extend from a position radially outside the receiving portion 24 toward the inside in the radial direction at both sides of the receiving portion 24 in the axial direction Z. Thus, both sides in the axial direction Z of the receiving portion 24 are covered with the magnetic shield cover 70 extending in the length direction Y.

[0065] The torque sensor 10 configured in this way can detect torque based on a magnetic change when the short shaft 87 rotates relative to the first pinion 88a as the torsion bar 87a twists.

[0066] Figure 3 It is a schematic diagram showing an outline of the magnet 65, the stator 60, and the magnetic flux concentrating yoke 46 included in the torque sensor 10. One of the magnet 65 and the stator 60 included in the torque sensor 10 is mounted on the first shaft, and the other is mounted on the second shaft. In the present embodiment, the magnet 65 is mounted on the short shaft 87 as the first shaft, and the stator 60 is mounted on the first pinion 88a as the second shaft. Among them, the magnet 65 is formed in a substantially cylindrical shape, and is a multi-pole magnet in which a plurality of N poles and S poles are alternately arranged in the circumferential direction.

[0067] The stator 60 has a flange portion 61 and a tooth portion 62. The flange portion 61 is formed in a circular plate shape with the thickness direction being the axial direction Z. The tooth portion 62 extends from the inner peripheral portion of the circular flange portion 61 in the axial direction Z of the flange portion 61, and is formed in a plate shape with the thickness direction being the radial direction of the flange portion 61. In addition, among the tooth portions 62, a plurality of tooth portions 62 are arranged at intervals in the circumferential direction of the flange portion 61.

[0068] The stator 60 thus formed has a pair of stators 60 formed in the same shape, namely a first stator 60a and a second stator 60b. The first stator 60a and the second stator 60b each have a flange portion 61 and a tooth portion 62. That is, the first stator 60a has an annular first flange portion 61a and a plurality of first tooth portions 62a, and the second stator 60b has an annular second flange portion 61b and a plurality of second tooth portions 62b. The first stator 60a and the second stator 60b are both mounted on the same shaft with the two flange portions 61 coaxial and the flange portions 61 facing away from the other stator 60. In this embodiment, both the first stator 60a and the second stator 60b are mounted on the first pinion 88a.

[0069] That is, the first stator 60a is arranged with the first tooth portions 62a extending from the first flange portion 61a toward the second stator 60b side, and the second stator 60b is arranged with the second tooth portions 62b extending from the second flange portion 61b toward the first stator 60a side. At this time, since the plurality of first tooth portions 62a and second tooth portions 62b are both provided at intervals on the first flange portion 61a and the second flange portion 61b, the first stator 60a and the second stator 60b are combined in such a way that the tooth portions 62 of their own stators 60 are located in the circumferential direction at the portions where the tooth portions 62 of the other stator 60 do not exist.

[0070] The magnet 65 mounted on the short shaft 87 is disposed inside the first stator 60a and the second stator 60b thus combined. In addition, the magnet 65 and the stator 60 are arranged with the axial direction Z being the same as the axial direction Z of the short shaft 87 and the first pinion 88a. Therefore, the magnet 65 and the stator 60 are mounted and arranged on the short shaft 87 and the first pinion 88a in a positional relationship where the outer peripheral surface of the magnet 65 faces the tooth portion 62 of the stator 60. The magnet 65 and the stator 60 are arranged in their positional relationship, so that when the torque is transmitted between the short shaft 87 and the first pinion 88a via the torsion bar 87a and the short shaft 87 and the first pinion 88a rotate relatively slightly, along with the change in the relative positional relationship between the magnet 65 and the stator 60, the magnetic flux acting on the stator 60 from the magnet 65 changes.

[0071] In addition, a magnetic flux collecting yoke 46 of the magnetic flux collecting yoke assembly 40 is disposed near the stator 60. The magnetic flux collecting yoke 46 is a component for detecting the change in the magnetic flux acting on the stator 60 from the magnet 65, and is disposed near the flange portion 61 of the stator 60. Since a pair of first stator 60a and second stator 60b are provided as the stator 60, correspondingly, a pair of first magnetic flux collecting yokes 46a and second magnetic flux collecting yokes 46b are also provided for the magnetic flux collecting yoke 46. That is, the magnetic flux collecting yoke 46 has the first magnetic flux collecting yoke 46a disposed near the first flange portion 61a of the first stator 60a, and the second magnetic flux collecting yoke 46b disposed near the second flange portion 61b of the second stator 60b.

[0072] A pair of flux-collecting yokes 46 are located between two flange portions 61 of the stator 60 at a position radially outside the tooth portions 62 of the stator 60, and overlap the flange portions 61 of the stator 60 with a gap in the axial direction Z. That is, the first flux-collecting yoke 46a is disposed near the surface side where the second flange portion 61b is located in the first flange portion 61a of the first stator 60a, and the second flux-collecting yoke 46b is disposed near the surface side where the first flange portion 61a is located in the second flange portion 61b of the second stator 60b. These flux-collecting yokes 46 overlap the flange portions 61 of the stator 60 within a specified range in the circumferential direction. That is, the portions of the first flux-collecting yoke 46a and the second flux-collecting yoke 46b that overlap the flange portions 61 of the stator 60 are formed in a substantially fan shape (refer to Figure 4 ), whereby the first flux-collecting yoke 46a and the second flux-collecting yoke 46b are disposed so as to overlap the flange portions 61 of the stator 60 within a part of the range in the circumferential direction.

[0073] In addition, the pair of flux-collecting yokes 46 may be arranged in a positional relationship in which the pair of flux-collecting yokes 46 sandwich the two flange portions 61 of the pair of stators 60 from both sides in the axial direction Z. That is, it may also be that the first flux-collecting yoke 46a is disposed near the surface on the opposite side of the first flange portion 61a of the first stator 60a from the side where the second flange portion 61b is located, and the second flux-collecting yoke 46b is disposed near the surface on the opposite side of the second flange portion 61b of the second stator 60b from the side where the first flange portion 61a is located. As long as the pair of flux-collecting yokes 46 overlap the flange portions 61 of the stator 60 within a specified range in the circumferential direction, the pair of flux-collecting yokes 46 may be arranged between the first flange portion 61a and the second flange portion 61b, or may be arranged in a positional relationship in which the pair of flux-collecting yokes 46 sandwich the first flange portion 61a and the second flange portion 61b from both sides in the axial direction Z.

[0074] In this way, the flux-collecting yokes 46 are located near the flange portions 61, whereby the pair of flux-collecting yokes 46 can detect a change in magnetic flux corresponding to a change in the relative position of the pair of stators 60 and the magnet 65. That is, the flux-collecting yokes 46 can detect a change in the magnetic flux acting on the stator 60 from the magnet 65 when the short axis 87 rotates slightly relative to the first pinion 88a.

[0075] And, a Hall IC 51 is disposed between the two flux-collecting yokes 46 (refer to Figure 3)。The Hall IC 51 is disposed between the flux collecting yokes 46 at a position separated from a portion of the flux collecting yoke 46 near the flange portion 61 of the stator 60. That is, the Hall IC 51 is clamped by the first flux collecting yoke 46a and the second flux collecting yoke 46b of the flux collecting yoke 46. The Hall IC 51 has: a Hall element (not shown) that detects a change in magnetic flux detected by the flux collecting yoke 46; and an output circuit (not shown) that converts an output voltage output from the Hall element into a digital electrical signal according to the change in magnetic flux. Thus, the Hall IC 51 can detect a change in magnetic flux density acting on the two flux collecting yokes 46, and convert the detected change in magnetic flux density into an electrical signal and output it as an electrical signal. In addition, a magnetic sensor applying a magnetoresistive effect or a tunneling magnetoresistive effect can be used instead of the Hall IC 51. In short, as long as the change in magnetic flux density generated between the flux collecting yokes 46 can be output as an electrical signal.

[0076] As Figure 2 shown, the magnet 65 is mounted on the short shaft 87 through the first sleeve 66. The first sleeve 66 is a cylindrical member, and the first sleeve 66 is mounted on the short shaft 87 by pressing the short shaft 87 into the first sleeve 66. The magnet 65 is fixed to the outer peripheral surface of the first sleeve 66 by an adhesive, for example, whereby the magnet 65 can rotate integrally with the short shaft 87.

[0077] The stator 60 is mounted on the first pinion 88a through the second sleeve 63 and the gear holder 64. The second sleeve 63 is a cylindrical member, and the second sleeve 63 is mounted on the first pinion 88a by pressing the first pinion 88a into the second sleeve 63. The gear holder 64 is a cylindrical member and is integrally formed with the second sleeve 63 by injection molding. Therefore, the gear holder 64 is mounted on the first pinion 88a through the second sleeve 63, and thus the gear holder 64 is also mounted on the first pinion 88a together with the second sleeve 63.

[0078] The gear holder 64 mounted on the first pinion 88a through the second sleeve 63 is supported by the second sleeve 63, and is disposed at a position toward the short shaft 87 side from the first pinion 88a and at a position outside the short shaft 87 in the radial direction. And the gear holder 64 is disposed at the same position as the position where the magnet 65 is located in the axial direction Z, and is disposed outside the magnet 65 in the radial direction.

[0079] The stator 60 is mounted on the gear bracket 64 configured as such. Specifically, each stator 60 of the first stator 60a and the second stator 60b is mounted on the gear bracket 64 in a form where the tooth portion 62 is located on the inner side in the radial direction of the gear bracket 64 and the flange portion 61 protrudes from the inner side in the radial direction of the gear bracket 64 toward the outer side. Thus, both the first stator 60a and the second stator 60b, which are a pair of stators 60, are arranged at the same position in the axial direction Z as the position where the magnet 65 is located, and are arranged on the outer side in the radial direction of the magnet 65.

[0080] In addition, the first stator 60a and the second stator 60b are mounted on the gear bracket 64, which is integrally formed with the second sleeve 63 mounted on the first pinion 88a. Therefore, the first stator 60a and the second stator 60b can rotate integrally with the first pinion 88a. In other words, the stator 60 that can be rotatably arranged integrally with the first pinion 88a has a flange portion 61 that protrudes to the outer side in the radial direction of the first pinion 88a and is fixed to the first pinion 88a.

[0081] In this way, the magnet 65 is fixed to the short shaft 87, and the stator 60 is fixed to the first pinion 88a. Thus, the magnet 65 and the stator 60 are arranged inside the housing 20 together with the short shaft 87 and the first pinion 88a.

[0082] On the inner surface side, a mating concave portion 32 is formed near the end portion on the side where the second housing 31 is connected to the first housing 21 in the axial direction Z. The mating concave portion 32 serves as a concave portion into which a mating convex portion 22 of the first housing 21 described later enters.

[0083] The mating concave portion 32 is formed on the end portion side of the second housing 31 where the first housing 21 is arranged. A mating convex portion 22 that enters the mating concave portion 32 is formed on the first housing 21 fixed to the second housing 31. The mating convex portion 22 is formed to protrude from the first housing 21 toward the side where the second housing 31 is located in the axial direction Z. The first housing 21 is radially positioned with respect to the second housing 31 by the mating convex portion 22 entering the mating concave portion 32.

[0084] The mating convex portion 22 is formed in a cylindrical shape and protrudes from the first housing 21, and the outer diameter is slightly smaller than the inner diameter of the mating concave portion 32. A groove portion into which an O-ring 23 serving as a sealing member is fitted is formed on the outer peripheral surface of the mating convex portion 22. The mating convex portion 22 enters the mating concave portion 32 in a state where the O-ring 23 is fitted into the groove portion. Thus, in a state where the mating convex portion 22 enters the mating concave portion 32, the sealing performance between the first housing 21 and the second housing 31 is ensured by the O-ring 23.

[0085] The first housing 21 and the second housing 31 are connected by installing the first housing 21 to the second housing 31 with mounting bolts (not shown) in a state where the mating convex portion 22 of the first housing 21 enters the mating concave portion 32 of the second housing 31.

[0086] The magnetic yoke assembly 40 accommodated in the accommodating portion 24 formed in the first housing 21 is mounted in the accommodating portion 24 in a state of sandwiching the Hall IC 51 from both sides in the axial direction Z by the first magnetic yoke 46a and the second magnetic yoke 46b. Specifically, the Hall IC 51 is disposed on the circuit board 50 included in the magnetic yoke assembly 40, and the circuit board 50 is mounted on the sensor housing 41 included in the magnetic yoke assembly 40. The sensor housing 41 serves as a housing of the magnetic yoke assembly 40 and is composed of a housing main body portion 42 and a lid portion 45 described later.

[0087] In addition, the magnetic yokes 46 are mounted on the sensor housing 41 in a state of sandwiching the Hall IC 51 from both sides in the thickness direction of the circuit board 50 by the first magnetic yoke 46a and the second magnetic yoke 46b. In the present embodiment, the first magnetic yoke 46a is located on the side where the short axis 87 is located in the axial direction Z, and the second magnetic yoke 46b is located on the side where the first pinion 88a is located in the axial direction Z. The magnetic yoke assembly 40 is accommodated in the accommodating portion 24 with the thickness direction of the circuit board 50 on which the Hall IC 51 is disposed facing the axial direction Z. Thus, the first magnetic yoke 46a and the second magnetic yoke 46b sandwich the Hall IC 51 from both sides in the axial direction Z in a state where the magnetic yoke assembly 40 is accommodated in the accommodating portion 24.

[0088] In addition, the position of the accommodating portion 24 of the first housing 21 in the axial direction Z is made close to the positions of the magnet 65 and the stator 60 fixed to the short axis 87 and the first pinion 88a disposed in the housing 20, and is formed to protrude outward in the radial direction. Thus, in a state where the magnetic yoke assembly 40 is accommodated in the accommodating portion 24, the first magnetic yoke 46a and the second magnetic yoke 46b included in the magnetic yoke assembly 40 can be disposed between the first flange portion 61a of the first stator 60a fixed to the first pinion 88a and the second flange portion 61b of the second stator 60b.

[0089] The sensor housing 41 of the magnetic yoke assembly 40 has a lid portion 45. The lid portion 45 is a member that covers the circuit board 50 mounted on the sensor housing 41. The sensor housing 41 has: a first lid portion 45a that is disposed on the side opposite to the second housing 31 in the axial direction Z with respect to the circuit board 50 and covers the circuit board 50; and a second lid portion 45b that is disposed on the side where the second housing 31 is located in the axial direction Z with respect to the circuit board 50 and covers the circuit board 50.

[0090] The magnetic flux collecting yoke assembly 40 has a plurality of movement restricting protrusions 44 opposed to the inner wall 25 of the accommodating portion 24. The plurality of movement restricting protrusions 44 are respectively arranged on both surfaces of the magnetic flux collecting yoke assembly 40 in the axial direction Z. Two of the plurality of movement restricting protrusions 44 of the magnetic flux collecting yoke assembly 40 are separately arranged in at least any one of the length direction Y and the width direction X on both surfaces of the magnetic flux collecting yoke assembly in the axial direction Z. In addition, two of the plurality of movement restricting protrusions 44 are separately arranged in the other direction of the length direction Y and the width direction X, or at least one of the plurality of movement restricting protrusions 44 extends longer in the other direction of the length direction Y and the width direction X than in one direction. The plurality of movement restricting protrusions 44 are arranged within the range of the cover portion 45 where the magnetic flux collecting yoke assembly 40 is arranged in the length direction Y, or near the range where the cover portion 45 is arranged.

[0091] The movement restricting protrusions 44 arranged in this way are formed to protrude from the magnetic flux collecting yoke assembly 40 in the axial direction Z. Therefore, the distance between the movement restricting protrusions 44 and the inner wall 25 of the accommodating portion 24 becomes closer than the portion other than the movement restricting protrusions 44 in the magnetic flux collecting yoke assembly 40. In addition, the inner wall 25 of the accommodating portion 24 opposed to the movement restricting protrusions 44 of the magnetic flux collecting yoke assembly 40 is formed in a flat shape.

[0092] In addition, a sealing member, that is, an O-ring 55, which abuts against both, is arranged between the outer peripheral surface of the sensor housing 41 of the magnetic flux collecting yoke assembly 40 accommodated in the accommodating portion 24 and the inner wall 25 of the accommodating portion 24. The O-ring 55 is arranged at a position radially outside the position where the cover portion 45 is arranged in the length direction Y.

[0093] Specifically, on the housing main body portion 42 of the sensor housing 41, a stepped portion 42c is formed on the outer peripheral surface of a portion radially outside the position where the cover portion 45 is arranged. The stepped portion 42c is formed in a cut-out shape in which the outer peripheral surface of the sensor housing 41 is cut out over a full circumference. The inner peripheral surface of the O-ring 55 is fitted into the stepped portion 42c of the housing main body portion 42 and abuts against the housing main body portion 42, and the outer peripheral surface of the O-ring 55 abuts against the inner wall 25 of the accommodating portion 24, so that the O-ring 55 abuts against both the outer peripheral surface of the housing main body portion 42 and the inner wall 25 of the accommodating portion 24.

[0094] The magnetic shielding cover 70 installed in the accommodating portion 24 of the first housing 21 has a first shielding portion 71 and a second shielding portion 72. The first shielding portion 71 is a portion that covers the accommodating portion 24 from the side opposite to the side where the second housing 31 is located in the axial direction Z. The second shielding portion 72 is a portion that covers the accommodating portion 24 from the side where the second housing 31 is located in the axial direction Z. Thus, both sides of the accommodating portion 24 that houses the magnetic flux concentrating yoke assembly 40 in the axial direction Z are covered by the magnetic shielding cover 70 installed in the accommodating portion 24.

[0095] At least one of the first shielding portion 71 and the second shielding portion 72 of the magnetic shielding cover 70 is disposed to overlap with the Hall IC 51 of the magnetic flux concentrating yoke assembly 40 accommodated in the accommodating portion 24 in the axial direction Z. In the present embodiment, the first shielding portion 71 that covers the accommodating portion 24 from the side opposite to the side where the second housing 31 is located among the first shielding portion 71 and the second shielding portion 72 is disposed to overlap with the Hall IC 51 of the magnetic flux concentrating yoke assembly 40 in the axial direction Z.

[0096] Next, the structure of the magnetic flux concentrating yoke assembly 40 will be described. Figure 4 is an exploded perspective view of the magnetic flux concentrating yoke assembly 40. In addition, Figure 4 is a perspective view of the magnetic flux concentrating yoke assembly 40 shown in Figure 2 viewed from the opposite side in the axial direction Z for illustrating the circuit board 50, and Figure 6 to be described later. The magnetic flux concentrating yoke assembly 40 includes a sensor housing 41, a cover portion 45, a magnetic flux concentrating yoke 46, a circuit board 50, and connection terminals 52. The sensor housing 41 serves as a housing of the magnetic flux concentrating yoke assembly 40 and is composed of a housing main body portion 42 and a cover portion 45.

[0097] The housing main body portion 42 has a flange portion 42a, a connector portion 42b, and a magnetic flux concentrating yoke accommodating portion 43. The flange portion 42a is a portion for mounting the magnetic flux concentrating yoke assembly 40 to the accommodating portion 24 from the outer side in the radial direction. The flange portion 42a is a plate-shaped member formed with the length direction Y in the thickness direction. A bushing insertion hole 42aa that penetrates in the thickness direction of the flange portion 42a and in which a bushing 56 is disposed is formed in the flange portion 42a. The bushing insertion hole 42aa is formed at two positions corresponding to two threaded holes 27 (refer to Figure 6 ) formed in the accommodating portion 24 to be described later. The bushing 56 disposed in the bushing insertion hole 42aa is a member formed in a substantially cylindrical shape made of a metal material, is inserted into the bushing insertion hole 42aa, and is held by the bushing insertion hole 42aa.

[0098] The connector portion 42b and the magnetic flux collecting yoke housing portion 43 are arranged on opposite sides in the thickness direction of the plate-shaped flange portion 42a. The connector portion 42b serves as a part that connects to an external connector (not shown) for outputting an electrical signal from the torque sensor 10 to the outside. The connector portion 42b is arranged between two bushing insertion holes 42aa formed in the flange portion 42a, and is formed to protrude outward in the radial direction from the flange portion 42a, that is, to the opposite side of the side where the magnetic flux collecting yoke housing portion 43 is located in the thickness direction of the flange portion 42a.

[0099] The magnetic flux collecting yoke housing portion 43 is formed in a substantially rectangular frame shape when viewed in the axial direction Z, and houses the magnetic flux collecting yoke 46 and the circuit board 50. The magnetic flux collecting yoke 46 and the circuit board 50 are arranged inside the magnetic flux collecting yoke housing portion 43 formed in a frame shape. The first magnetic flux collecting yoke 46a and the second magnetic flux collecting yoke 46b of the magnetic flux collecting yoke 46 housed in the magnetic flux collecting yoke housing portion 43 are arranged on both sides of the circuit board 50 in the axial direction Z. The first magnetic flux collecting yoke 46a and the second magnetic flux collecting yoke 46b are respectively mounted on the magnetic flux collecting yoke housing portion 43 in a state of sandwiching the circuit board 50 from both sides.

[0100] The O-ring 55 that abuts against the inner wall 25 of the magnetic flux collecting yoke assembly 40 and the housing portion 24 is arranged between the magnetic flux collecting yoke housing portion 43 and the flange portion 42a in the length direction Y. That is, a stepped portion 42c for embedding the O-ring 55 in the housing main body portion 42 of the magnetic flux collecting yoke assembly 40 is formed between the magnetic flux collecting yoke housing portion 43 and the flange portion 42a in the length direction Y. Therefore, the O-ring 55 that abuts against the inner wall 25 of the magnetic flux collecting yoke assembly 40 and the housing portion 24 is arranged outside the magnetic flux collecting yoke housing portion 43 in the radial direction.

[0101] When the magnetic flux collecting yoke 46 is mounted on the magnetic flux collecting yoke housing portion 43, each has two magnetic flux collecting portions close to the Hall IC 51 arranged on the circuit board 50. That is, magnetic flux collecting portions 46aa close to the Hall IC 51 are formed at two places on the first magnetic flux collecting yoke 46a, and magnetic flux collecting portions 46ba close to the Hall IC 51 are formed at two places on the second magnetic flux collecting yoke 46b.

[0102] The cover portion 45 is a component that covers the openings 43a of the magnetic yoke receiving portions 43 formed on both sides in the axial direction Z of the magnetic yoke receiving portion 43 formed in a frame shape and is mounted on the housing main body portion 42. The cover portion 45 has a first cover portion 45a and a second cover portion 45b that match the openings 43a formed on both sides in the axial direction Z of the magnetic yoke receiving portion 43. The first cover portion 45a is disposed on the side where the first magnetic yoke 46a is disposed with respect to the magnetic yoke receiving portion 43 and is mounted on the magnetic yoke receiving portion 43, and the second cover portion 45b is disposed on the side where the second magnetic yoke 46b is disposed with respect to the magnetic yoke receiving portion 43 and is mounted on the magnetic yoke receiving portion 43. Thus, the magnetic yoke receiving portion 43 formed in a frame shape and configured with the magnetic yoke 46 and the circuit board 50 closes the openings 43a from both sides in the axial direction Z by the first cover portion 45a and the second cover portion 45b.

[0103] In addition, connection terminals 52 for electrically connecting to an external connector are disposed in the connector portion 42b of the housing main body portion 42. The connection terminals 52 have a plurality of terminal pins 52a and a holding member 52c that integrally holds these plurality of terminal pins 52a. The connection terminals 52 are disposed inside the connector portion 42b of the sensor housing 41, and a connection portion 52b located on one end side of the terminal pins 52a is connected to the circuit board 50 housed in the magnetic yoke receiving portion 43. The other end side of the terminal pins 52a of the connection terminals 52 can be electrically connected to an external connector connected to the connector portion 42b.

[0104] In the present embodiment, the terminal pins 52a are formed in an L shape, and the connection portion 52b connected to the circuit board 50 is connected to the circuit board 50 in the thickness direction of the circuit board 50. The portion of the terminal pins 52a on the side electrically connected to the external connector extends along the length direction Y. Thus, the connection terminals 52 can electrically connect the circuit board 50 to the external connector.

[0105] In addition, the movement restricting convex portions 44 that face the inner wall 25 of the accommodating portion 24 of the first housing 21 in the magnetic yoke assembly 40 are disposed in the magnetic yoke receiving portion 43. The movement restricting convex portions 44 are formed on the edge portions on both sides in the axial direction Z of the magnetic yoke receiving portion 43 formed in a substantially rectangular frame shape when viewed in the axial direction Z, and are formed by protruding from the edge portions in the axial direction Z.

[0106] In the present embodiment, the movement restricting convex portions 44 are formed at the edges of the portions extending in the length direction Y on both sides in the width direction X of the frame-shaped magnetic yoke accommodating portion 43. Further, for the movement restricting convex portions 44, in each of the portions extending in the length direction Y on both sides in the width direction X of the magnetic yoke accommodating portion 43, a plurality of movement restricting convex portions 44 separated from each other in the length direction Y are respectively arranged near both ends in the length direction Y of the magnetic yoke accommodating portion 43. Therefore, a plurality of movement restricting convex portions 44 separated from each other in the width direction X and the length direction Y are respectively arranged on both surfaces of the magnetic yoke assembly 40 in the axial direction Z.

[0107] Figure 5 FIG. is a schematic diagram showing the arrangement positions of the movement restricting convex portions 44 in the magnetic yoke accommodating portion 43. The movement restricting convex portions 44 arranged in the magnetic yoke accommodating portion 43 are arranged to include the regions Ay at both ends in the length direction Y and the regions Ax at both ends in the width direction X on both surfaces in the axial direction Z of the magnetic yoke accommodating portion 43. That is, the movement restricting convex portions 44 are arranged to include the regions at the four corners on both surfaces in the axial direction Z of the magnetic yoke accommodating portion 43. Here, the regions Ay at both ends in the length direction Y of the magnetic yoke accommodating portion 43 refer to the regions of 20% of the length in the length direction Y of the magnetic yoke accommodating portion 43 starting from the ends in the length direction Y of the magnetic yoke accommodating portion 43. Further, the regions Ax at both ends in the width direction X of the magnetic yoke accommodating portion 43 refer to the regions of 30% of the width in the width direction X of the magnetic yoke accommodating portion 43 starting from the ends in the width direction X of the magnetic yoke accommodating portion 43.

[0108] In the present embodiment, on both surfaces of the magnetic yoke accommodating portion 43 in the axial direction Z, the regions Ay at both ends of the movement restricting convex portions 44 in the length direction Y and the regions Ax at both ends of the movement restricting convex portions 44 in the width direction X are respectively arranged separately from other movement restricting convex portions 44. Therefore, four movement restricting convex portions 44 are respectively arranged on both surfaces of the magnetic yoke accommodating portion 43 in the axial direction Z, that is, the movement restricting convex portions 44 are arranged at the four corners of each of the two surfaces of the magnetic yoke accommodating portion 43 in the axial direction Z. The shapes of the ends in the axial direction Z of the respective movement restricting convex portions 44 are formed into flat shapes along the plane that is the normal direction along the axial direction Z.

[0109] The cover portion 45 covering the opening portion 43a of the magnetic yoke accommodating portion 43 is arranged between the movement restricting convex portions 44 separated from each other in the length direction Y on both surfaces of the magnetic yoke accommodating portion 43 in the axial direction Z. Specifically, the cover portion 45 is formed in a shape that is close to the shape of the magnetic yoke accommodating portion 43 when observed in the axial direction Z, and a cutout 45c for avoiding the movement restricting convex portions 44 is formed at a position corresponding to the position where the movement restricting convex portions 44 are arranged in the magnetic yoke accommodating portion 43.

[0110] Therefore, when the lid portion 45 is disposed in the magnetic yoke housing portion 43 so as to cover the opening 43a of the magnetic yoke housing portion 43, the movement restricting convex portion 44 formed in the magnetic yoke housing portion 43 is located at the portion of the cutout 45c formed in the lid portion 45. Thus, in a state where the lid portion 45 covers the opening portion 43a of the magnetic yoke housing portion 43 and is disposed in the magnetic yoke housing portion 43, the portion of the lid portion 45 between the cutouts 45c in the length direction Y is disposed between the movement restricting convex portions 44 separated from each other in the length direction Y.

[0111] Next, the structure of the installation of the magnetic yoke assembly 40 with respect to the first housing 21 will be described. Figure 6 It is a detailed view showing a state before the magnetic yoke assembly 40 is installed in the first housing 21. The magnetic yoke assembly 40 is accommodated in the accommodation portion 24 provided in the first housing 21 and is installed in the accommodation portion 24.

[0112] An opening portion 26 that opens outward in the radial direction is formed in the portion of the accommodation portion 24 where the magnetic yoke assembly 40 is installed. The opening portion 26 of the accommodation portion 24 forms an opening portion of the space inside the accommodation portion 24. Further, on the outer surface in the radial direction of the accommodation portion 24, a threaded hole 27 into which a mounting bolt 78 for mounting the magnetic yoke assembly 40 in the accommodation portion 24 is screwed is formed on the side of the opening portion 26.

[0113] The magnetic yoke assembly 40 has a flange portion 42a that is installed in the accommodation portion 24 from the outside in the radial direction, a bushing 56 made of a metal member is disposed, and is installed in the accommodation portion 24 by screwing the mounting bolt 78 into the threaded hole 27 of the accommodation portion 24.

[0114] When the magnetic yoke assembly 40 is installed in the accommodation portion 24, the magnetic yoke assembly 40 is inserted into the magnetic yoke housing portion 43 from the opening portion 26 of the accommodation portion 24 with the connector portion 42b facing outward in the radial direction. Thus, the magnetic yoke housing portion 43 that houses the magnetic yoke 46 and the circuit board 50 in the magnetic yoke assembly 40 is accommodated in the accommodation portion 24. Further, the mounting bolt 78 is inserted through the bushing insertion hole 42aa provided in the flange portion 42a of the magnetic yoke assembly 40, and the mounting bolt 78 is screwed into the threaded hole 27 of the accommodation portion 24. Thus, the magnetic yoke assembly 40 is installed in the accommodation portion 24 of the first housing 21 and is fixed to the first housing 21.

[0115] Figure 7This is a detailed view of the gap between the inner wall 25 of the accommodating portion 24 and the movement restricting convex portion 44, and the gap between the flange portion 61 of the stator 60 and the magnetic flux collecting yoke 46. In a state where the magnetic flux collecting yoke accommodating portion 43 is accommodated in the accommodating portion 24 and the magnetic flux collecting yoke assembly 40 is fixed to the first housing 21, at least a part of the movement restricting convex portions 44 formed on the magnetic flux collecting yoke accommodating portion 43 are separated from the inner wall 25 of the accommodating portion 24 and face the inner wall 25. That is, in a state where the magnetic flux collecting yoke assembly 40 is fixed to the first housing 21, among the plurality of movement restricting convex portions 44, all of the movement restricting convex portions 44 are separated from the inner wall 25 of the accommodating portion 24, or some of the movement restricting convex portions 44 are in contact with the inner wall 25 of the accommodating portion 24 and the other movement restricting convex portions 44 are separated from the inner wall 25 of the accommodating portion 24.

[0116] In a state where the magnetic flux collecting yoke assembly 40 is fixed to the first housing 21, for the movement restricting convex portion 44 having such a relationship with respect to the inner wall 25 of the accommodating portion 24, the maximum value of the distance H1 between the movement restricting convex portion 44 and the inner wall 25 is narrower than the distance H2 between the flange portion 61 of the stator 60 and the magnetic flux collecting yoke 46. The distance H2 between the flange portion 61 of the stator 60 and the magnetic flux collecting yoke 46 in this case is the corresponding distance between the flange portion 61 of the stator 60 and the magnetic flux collecting yoke 46, which is the distance between the first flange portion 61a of the first stator 60a and the first magnetic flux collecting yoke 46a, and the distance between the second flange portion 61b of the second stator 60b and the second magnetic flux collecting yoke 46b. In other words, regarding the gap between the inner wall 25 of the accommodating portion 24 and the movement restricting convex portion 44, the distance H1 in the axial direction Z of the gap between the movement restricting convex portion 44 and the inner wall 25 among all the movement restricting convex portions 44 is smaller than the distance H2 in the axial direction Z of the gap between the flange portion 61 of the stator 60 and the magnetic flux collecting yoke 46.

[0117] Next, the operation of the steering device 80 will be described. When driving a vehicle equipped with the steering device 80, when the steering wheel 81 is operated, the steering force applied to the steering wheel 81 is transmitted from the steering wheel 81 to the steering shaft 82. The steering force transmitted to the steering shaft 82 is transmitted as a steering torque from the steering shaft 82 to the intermediate shaft 85, and from the intermediate shaft 85 to the first pinion 88a via the short shaft 87. Thus, the steering gear 88 having the first pinion 88a converts the rotational motion transmitted from the first pinion 88a into a linear motion of the rack bar 88b, causing the tie rod 89 to operate.

[0118] In addition, the steering device 80 of the present embodiment has an electric motor 102 that generates an assist steering torque for assisting the driver's steering. The electric motor 102 generates an assist steering torque based on the steering torque detected by the torque sensor 10 disposed between the short shaft 87 and the first pinion 88a.

[0119] The torque sensor 10 detects the steering torque applied to the short shaft 87 based on the angle of relative rotation when the short shaft 87 rotates relative to the first pinion 88a. That is, the short shaft 87 and the first pinion 88a are connected via a torsion bar 87a. Therefore, when a steering torque is applied to the short shaft 87, the steering torque is transmitted between the short shaft 87 and the first pinion 88a via the torsion bar 87a. At this time, the torsion bar 87a twists slightly, causing the short shaft 87 and the first pinion 88a to rotate relative to each other.

[0120] In the torque sensor 10, a magnet 65 is mounted on the short shaft 87, and a stator 60 is mounted on the first pinion 88a. Thus, when the short shaft 87 rotates relative to the first pinion 88a, the magnet 65 and the stator 60 of the torque sensor 10 also rotate relative to each other. The angle of relative rotation between the magnet 65 and the stator 60 increases as the steering torque acting between the short shaft 87 and the first pinion 88a increases.

[0121] When the magnet 65 and the stator 60 rotate relative to each other, the magnetic flux acting from the magnet 65 on the stator 60 changes. The magnetic flux collecting yoke 46 disposed near the stator 60 can detect the change in the magnetic flux acting from the magnet 65 on the stator 60. Therefore, when the magnet 65 and the stator 60 rotate relative to each other along with the relative rotation of the short shaft 87 and the first pinion 88a, the magnetic flux collecting yoke 46 disposed near the stator 60 can detect the change in the magnetic flux acting from the magnet 65 on the stator 60.

[0122] In this way, the magnetic flux acting from the magnet 65 on the stator 60 detected by the pair of magnetic flux collecting yokes 46 changes according to the angle of relative rotation between the magnet 65 and the stator 60. The Hall IC 51 detects the magnetic flux that changes according to the angle of relative rotation between the magnet 65 and the stator 60 detected by the magnetic flux collecting yoke 46 using a Hall element, and converts it into an electrical signal using an output circuit, and transmits it from the connection terminal 52 to the outside of the first housing 21 and then to the ECU 100. That is, the torque sensor 10 detects the steering torque applied to the short shaft 87 by detecting the change in the magnetic flux acting from the magnet 65 on the stator 60 using the magnetic flux collecting yoke 46 and the Hall IC 51, and transmits the detected steering torque as an electrical signal to the ECU 100.

[0123] The ECU 100 operates the electric motor 102 based on the electrical signal transmitted from the torque sensor 10, causing the electric motor 102 to generate an auxiliary steering torque. That is, the electrical signal transmitted from the Hall IC 51 of the torque sensor 10 varies according to the angle of relative rotation between the magnet 65 and the stator 60, and also varies based on the steering torque T acting between the short shaft 87 and the first pinion 88a. Therefore, the ECU 100 uses the electrical signal transmitted from the Hall IC 51 of the torque sensor 10 as information that varies according to the steering torque T acting on the short shaft 87 and the first pinion 88a, and adjusts the power value E supplied to the electric motor 102 based on the electrical signal transmitted from the Hall IC 51, causing the electric motor 102 to generate an auxiliary steering torque.

[0124] That is, the ECU 100 obtains the signal of the steering torque T from the torque sensor 10, obtains the vehicle speed signal V of the vehicle from the vehicle speed sensor 101, and obtains the operation information M of the electric motor 102 from the rotation detection device provided on the electric motor 102. Based on these operation information M, steering torque T, and vehicle speed signal V, the ECU 100 causes the electric motor 102 to generate an auxiliary steering torque. The auxiliary steering torque generated by the electric motor 102 is transmitted to the second pinion 88c. The steering gear 88 having the second pinion 88c converts the rotational motion transmitted from the second pinion 88c into a linear motion of the rack bar 88b. Thus, the steering force applied by the driver to the steering wheel 81 is assisted by the auxiliary steering torque generated by the electric motor 102.

[0125] Here, regarding the output characteristics when the torque sensor 10 detects the steering torque, by making the distances in the axial direction Z between the pair of flux concentrating yokes 46 and the flange portions 61 of the pair of stators 60 equal, it is possible to detect the steering torque with the desired output characteristics at the time of designing the torque sensor 10. That is, the torque sensor 10 can suppress individual differences in the output characteristics of the torque sensor 10 by making the distance in the axial direction Z between the first flange portion 61a of the first stator 60a and the first flux concentrating yoke 46a and the distance in the axial direction Z between the second flange portion 61b of the second stator 60b and the second flux concentrating yoke 46b at equal intervals.

[0126] Thus, it is important for the torque sensor 10 to make the distances in the axial direction Z between the flange portions 61 of the pair of stators 60 and the pair of flux concentrating yokes 46 equal. Among them, the stator 60 is fixed to the first pinion 88a that is rotatably supported relative to the housing 20. In addition, the flux concentrating yoke 46 houses the flux concentrating yoke assembly 40 having the flux concentrating yoke 46 in the housing portion 24 of the first housing 21 and is mounted on the housing 20.

[0127] On the other hand, considering waterproofness and the like, the magnetic yoke assembly 40 sometimes has an elastic sealing member between it and the housing 20 and is fixed to the housing 20. In this embodiment, an O-ring 55 is also disposed between the magnetic yoke assembly 40 and the receiving portion 24. When the magnetic yoke assembly 40 is received in the receiving portion 24 of the first housing 21 and installed on the housing 20, the O-ring 55 contacts both the magnetic yoke assembly 40 and the first housing 21 and is in a flattened state. Therefore, when the magnetic yoke assembly 40 is installed on the housing 20, the installation position with respect to the housing 20 may change slightly according to the flattening condition of the O-ring 55.

[0128] When the installation position of the magnetic yoke assembly 40 with respect to the housing 20 changes according to the flattening condition of the O-ring 55, the distance in the axial direction Z between the magnetic yoke 46 of the magnetic yoke assembly 40 and the flange portion 61 of the stator 60 also changes according to the flattening condition of the O-ring 55. In this case, the distances in the axial direction Z between the flange portions 61 of the pair of stators 60 and the pair of magnetic yokes 46 may not be equally spaced, so individual differences are likely to occur in the output characteristics of the torque sensor 10.

[0129] In contrast, when the magnetic yoke assembly 40 is received in the receiving portion 24 of the first housing 21, the torque sensor 10 according to this embodiment restricts the installation position of the magnetic yoke assembly 40 in the axial direction Z by the movement restricting convex portions 44 disposed on both sides of the magnetic yoke assembly 40 in the axial direction Z. That is, when the magnetic yoke assembly 40 is received in the receiving portion 24, the movement restricting convex portions 44 disposed on the magnetic yoke assembly 40 contact the inner wall 25 of the receiving portion 24, whereby the magnetic yoke assembly 40 is positioned and fixed to the first housing 21 in the axial direction Z. Therefore, the magnetic yoke assembly 40 is fixed to the first housing 21 in a positional relationship as close as possible to the designed positional relationship of the torque sensor 10.

[0130] In addition, the plurality of movement restricting convex portions 44 are disposed separately in the length direction Y and the width direction X. Therefore, by the plurality of movement restricting convex portions 44 contacting the inner wall 25 of the receiving portion 24, the magnetic yoke assembly 40 is positioned and fixed to the first housing 21 with the magnetic yoke 46 parallel to the flange portion 61 of the stator 60.

[0131] Thus, the magnetic flux collecting yoke assembly 40 is fixed to the first housing 21 such that the distances in the axial direction Z between the first flange portion 61a of the first stator 60a and the first magnetic flux collecting yoke 46a and between the second flange portion 61b of the second stator 60b and the second magnetic flux collecting yoke 46b are equally spaced. Therefore, the torque sensor 10 can suppress the case where the distances in the axial direction Z between the pair of magnetic flux collecting yokes 46 and the pair of stators 60 are not equally spaced and the magnetic flux collecting yoke assembly 40 is fixed to the housing 20, and can suppress individual differences in the output characteristics of the torque sensor 10.

[0132] As described above, in the torque sensor 10 according to the present embodiment, the magnetic flux collecting yoke assembly 40 having a pair of magnetic flux collecting yokes 46 has movement restricting convex portions 44 opposed to the inner wall 25 of the accommodating portion 24 of the housing 20, and the movement restricting convex portions 44 are disposed on both surfaces of the magnetic flux collecting yoke assembly 40 in the axial direction Z. Thus, when the magnetic flux collecting yoke assembly 40 is accommodated in the accommodating portion 24, the movement restricting convex portions 44 abut against the inner wall 25 of the accommodating portion 24, so that the position of the magnetic flux collecting yoke assembly 40 in the axial direction Z with respect to the housing 20 is restricted and the magnetic flux collecting yoke assembly 40 is fixed to the housing 20 in a desired positional relationship. In addition, a plurality of movement restricting convex portions 44 are disposed on both surfaces of the magnetic flux collecting yoke assembly 40 in the axial direction Z, and two of the plurality of movement restricting convex portions 44 are disposed separately in at least one of the length direction Y and the width direction X. In addition, two of the plurality of movement restricting convex portions 44 are disposed separately in the other of the length direction Y and the width direction X, or at least one of the plurality of movement restricting convex portions 44 extends longer in the other of the length direction Y and the width direction X than in one direction. Therefore, when the magnetic flux collecting yoke assembly 40 is accommodated in the accommodating portion 24, the movement restricting convex portions 44 abut against the inner wall 25 of the accommodating portion 24, whereby the portions of the accommodating portion 24 and the magnetic flux collecting yoke assembly 40 separated from each other in the length direction Y and the width direction X abut against each other, so that the mounting angle of the magnetic flux collecting yoke assembly 40 with respect to the housing 20 is also fixed at a desired mounting angle.

[0133] Thus, the magnetic flux collecting yoke assembly 40 can fix the magnetic flux collecting yoke 46 included in the magnetic flux collecting yoke assembly 40 to the housing 20 in a desired positional relationship and can dispose the magnetic flux collecting yoke 46 relative to the stator 60 fixed to the first pinion 88a in a desired positional relationship. As a result, the positional relationship between the stator 60 and the magnetic flux collecting yoke 46 can be made a desired positional relationship.

[0134] In addition, by forming a movement restricting convex portion 44 that protrudes axially in the Z direction on the magnetic flux collecting yoke assembly 40 and bringing the movement restricting convex portion 44 into contact with the inner wall 25 of the accommodating portion 24 of the housing 20, it is possible to reduce the manufacturing cost when contacting the inner wall 25 of the accommodating portion 24 with high dimensional accuracy. That is, when the magnetic flux collecting yoke assembly 40 is brought into contact with the inner wall 25 of the accommodating portion 24 with high dimensional accuracy, it is necessary to improve the machining accuracy of the contacting portion for machining. However, in this embodiment, the movement restricting convex portion 44 is formed on the magnetic flux collecting yoke assembly 40, and the movement restricting convex portion 44 is brought into contact with the inner wall 25 of the accommodating portion 24. Therefore, in the magnetic flux collecting yoke assembly 40, the portion for contacting the inner wall 25 of the accommodating portion 24 with high dimensional accuracy in the axial Z direction is only the movement restricting convex portion 44. Therefore, it is not necessary to machine the entire two surfaces of the magnetic flux collecting yoke assembly 40 in the axial Z direction with high dimensional accuracy. Therefore, the range of machining with high dimensional accuracy can be reduced, the manufacturing cost can be reduced, the manufacturing cost can be suppressed, and the positional relationship between the stator 60 and the magnetic flux collecting yoke 46 can be made into a desired positional relationship.

[0135] In addition, the magnetic flux collecting yoke assembly 40 has a magnetic flux collecting yoke accommodating portion 43 that houses the magnetic flux collecting yoke 46, and the movement restricting convex portion 44 is disposed in the magnetic flux collecting yoke accommodating portion 43. Therefore, when the magnetic flux collecting yoke assembly 40 is accommodated in the accommodating portion 24 of the housing 20, positioning of the magnetic flux collecting yoke accommodating portion 43 that houses the magnetic flux collecting yoke 46 relative to the housing 20 can be performed. Thereby, the magnetic flux collecting yoke assembly 40 fixed to the housing 20 can dispose the magnetic flux collecting yoke 46 housed in the magnetic flux collecting yoke accommodating portion 43 relative to the stator 60 in an appropriate positional relationship. As a result, the positional relationship between the stator 60 and the magnetic flux collecting yoke 46 can be made into a desired positional relationship.

[0136] In addition, the movement restricting convex portion 44 is disposed to include a region Ay at both ends in the length direction Y and a region Ax at both ends in the width direction X of the two surfaces in the axial Z direction of the magnetic flux collecting yoke accommodating portion 43. That is, the movement restricting convex portion 44 is disposed to include regions at the respective four corners of the two surfaces in the axial Z direction of the magnetic flux collecting yoke accommodating portion 43. Therefore, when the magnetic flux collecting yoke assembly 40 is accommodated in the accommodating portion 24 of the housing 20, the magnetic flux collecting yoke assembly 40 contacts the inner wall 25 of the accommodating portion 24 through the movement restricting convex portions 44 at the four corners of the magnetic flux collecting yoke accommodating portion 43, so that the magnetic flux collecting yoke accommodating portion 43 can be positioned at an appropriate position. Thereby, the magnetic flux collecting yoke assembly 40 accommodated in the accommodating portion 24 can dispose the magnetic flux collecting yoke 46 housed in the magnetic flux collecting yoke accommodating portion 43 relative to the stator 60 in an appropriate positional relationship. As a result, the positional relationship between the stator 60 and the magnetic flux collecting yoke 46 can be made into a desired positional relationship.

[0137] In addition, in the magnetic flux collecting yoke assembly 40, an O-ring 55 that abuts against the inner wall 25 of the accommodating portion 24 is disposed on the radially outer side with respect to the magnetic flux collecting yoke accommodating portion 43 in the longitudinal direction Y. Therefore, it is possible to suppress the intrusion of water or the like from the outside of the housing 20 into the accommodating portion 24. In addition, the magnetic flux collecting yoke assembly 40 has a plurality of movement restricting convex portions 44. Therefore, even when the O-ring 55 that abuts against the inner wall 25 of the accommodating portion 24 is disposed on the magnetic flux collecting yoke assembly 40, the magnetic flux collecting yoke assembly 40 can be positioned at an appropriate position by the movement restricting convex portions 44 regardless of the flattening state of the O-ring 55 when the magnetic flux collecting yoke assembly 40 is accommodated in the accommodating portion 24. Thus, the magnetic flux collecting yoke assembly 40 accommodated in the accommodating portion 24 can suppress the intrusion of water or the like from the outside of the housing 20 into the accommodating portion 24 by the O-ring 55, and the magnetic flux collecting yoke 46 accommodated in the magnetic flux collecting yoke accommodating portion 43 can be arranged with respect to the stator 60 in an appropriate positional relationship. As a result, the positional relationship between the stator 60 and the magnetic flux collecting yoke 46 can be made into a desired positional relationship.

[0138] In addition, the movement restricting convex portions 44 disposed on both surfaces of the magnetic flux collecting yoke assembly 40 are arranged such that a plurality of them are separated from each other at least in the longitudinal direction Y on each surface, and a cover portion 45 that covers the opening portion 43a of the magnetic flux collecting yoke accommodating portion 43 is disposed between the movement restricting convex portions 44 that are separated from each other in the longitudinal direction Y. Therefore, the magnetic flux collecting yoke assembly 40 can ensure the dustproof property of the magnetic flux collecting yoke 46 and the circuit board 50 by the cover portion 45, and the movement restricting convex portions 44 that face the inner wall 25 of the accommodating portion 24 are disposed on both surfaces of the magnetic flux collecting yoke assembly 40 in the axial direction Z. Thus, the magnetic flux collecting yoke assembly 40 accommodated in the accommodating portion 24 can ensure the dustproof property of the magnetic flux collecting yoke accommodating portion 43, and the magnetic flux collecting yoke 46 accommodated in the magnetic flux collecting yoke accommodating portion 43 can be arranged with respect to the stator 60 in an appropriate positional relationship. As a result, the positional relationship between the stator 60 and the magnetic flux collecting yoke 46 can be made into a desired positional relationship.

[0139] In addition, among the plurality of movement restricting convex portions 44 disposed on the magnetic flux collecting yoke assembly 40, the maximum value of the distance H1 between the movement restricting convex portion 44 and the inner wall 25 is narrower than the distance H2 between the flange portion 61 of the stator 60 and the magnetic flux collecting yoke 46. Therefore, when the magnetic flux collecting yoke assembly 40 is accommodated in the accommodating portion 24 of the housing 20, the magnetic flux collecting yoke assembly 40 can ensure the distance in the axial direction Z between the flange portion 61 of the stator 60 and the magnetic flux collecting yoke 46 even when the movement restricting convex portion 44 abuts against the inner wall 25 of the accommodating portion 24. Thus, the magnetic flux collecting yoke assembly 40 accommodated in the accommodating portion 24 can position the magnetic flux collecting yoke 46 at an appropriate position in the axial direction Z with respect to the housing 20, and can arrange the magnetic flux collecting yoke 46 with respect to the stator 60 in an appropriate positional relationship. As a result, the positional relationship between the stator 60 and the magnetic flux collecting yoke 46 can be made into a desired positional relationship.

[0140] [Modified Example]

[0141] In addition, in the above-described embodiment, at least a part of the plurality of movement restricting convex portions 44 of the magnetic flux concentrating yoke assembly 40 is separated from the inner wall 25 of the accommodating portion 24, but all of the plurality of movement restricting convex portions 44 of the magnetic flux concentrating yoke assembly 40 may also be in contact with the inner wall 25 of the accommodating portion 24. That is, when the magnetic flux concentrating yoke assembly 40 is accommodated in the accommodating portion 24 of the first housing 21, all of the movement restricting convex portions 44 of the magnetic flux concentrating yoke assembly 40 are in contact with the inner wall 25 of the accommodating portion 24, and the magnetic flux concentrating yoke assembly 40 may also be accommodated in a state of being pressed into the inside of the accommodating portion 24. By pressing the magnetic flux concentrating yoke assembly 40 into the inside of the accommodating portion 24, the position accuracy in the axial direction Z with respect to the housing 20 can be configured with high accuracy, and the magnetic flux concentrating yoke 46 can be configured with an appropriate positional relationship with respect to the stator 60. As a result, the positional relationship between the stator 60 and the magnetic flux concentrating yoke 46 can be made into a desired positional relationship.

[0142] In addition, the movement restricting convex portions 44 disposed on both surfaces in the axial direction Z of the magnetic flux concentrating yoke accommodating portion 43 are preferably disposed at the four corners of both ends in the width direction X and both ends in the length direction Y of the magnetic flux concentrating yoke accommodating portion 43, respectively. Figure 8 is a schematic view showing a state in which the magnetic shielding cover 75 is disposed in the magnetic flux concentrating yoke accommodating portion 43. By disposing the movement restricting convex portions 44 at the four corners of both surfaces in the axial direction Z of the magnetic flux concentrating yoke accommodating portion 43, as Figure 8 shown, the magnetic shielding cover 75 can be disposed between the movement restricting convex portions 44 separated from each other in the length direction Y with respect to the magnetic flux concentrating yoke accommodating portion 43. Thereby, the magnetic shielding cover 75 can be easily disposed in the magnetic flux concentrating yoke accommodating portion 43, and the magnetic shielding cover 75 shields an external magnetic field from an external magnetic body when detecting a change in the magnetic flux acting on the stator 60 from the magnet 65 by the magnetic flux concentrating yoke 46 and the Hall IC 51. As a result, the influence of the external magnetic field when detecting the steering torque can be easily suppressed by the magnetic shielding cover 75, and the steering torque can be appropriately detected.

[0143] In addition, by disposing the movement restricting convex portions 44 at four positions at the four corners of both surfaces of the magnetic yoke housing portion 43 in the axial direction Z, the shaking of the magnetic yoke assembly 40 accommodated in the accommodating portion 24 can be prevented. That is, by disposing the movement restricting convex portions 44 at four positions at the four corners of both surfaces of the magnetic yoke housing portion 43, the movement restricting convex portions 44 that abut against the inner wall 25 of the accommodating portion 24 can be used to suppress the rotation of the magnetic yoke assembly 40 accommodated in the accommodating portion 24 in two directions, namely, the rotation centered on the axis extending in the length direction Y and the rotation centered on the axis extending in the width direction X. Thereby, the rotation of the magnetic yoke assembly 40 accommodated in the accommodating portion 24 relative to the accommodating portion 24 can be suppressed by the movement restricting convex portions 44, and the shaking of the magnetic yoke assembly 40 can be prevented.

[0144] In addition, the change in the angle of the magnetic yoke assembly 40 relative to the accommodating portion 24 when the movement restricting convex portions 44 abut against or separate from the inner wall 25 of the accommodating portion 24 becomes smaller as the interval between the movement restricting convex portions 44 disposed on the same surface of the magnetic yoke housing portion 43 becomes larger. Therefore, by disposing the movement restricting convex portions 44 at the four corners of both surfaces of the magnetic yoke housing portion 43 in the axial direction Z respectively, the interval between the movement restricting convex portions 44 disposed on the same surface in the axial direction Z of the magnetic yoke housing portion 43 can be maximally increased, and the angle change of the magnetic yoke housing portion 43 accommodated in the accommodating portion 24 can be maximally suppressed. Thereby, the shaking of the magnetic yoke assembly 40 accommodated in the accommodating portion 24 can be prevented. As a result, the relative positional relationship between the magnetic yoke 46 of the magnetic yoke assembly 40 and the flange portion 61 of the stator 60 can be prevented from changing due to the shaking of the magnetic yoke assembly 40, and the steering torque can be appropriately detected.

[0145] In addition, in the above-described embodiment, the movement restricting convex portions 44 of the magnetic yoke assembly 40 are disposed at the four corners of the magnetic yoke housing portion 43 on both surfaces in the axial direction Z, and the four movement restricting convex portions 44 separated in the length direction Y and the width direction X are disposed at the four corners of the magnetic yoke housing portion 43, but the movement restricting convex portions 44 may not be separated in both the length direction Y and the width direction X.

[0146] Figure 9 It is a modified example of the torque sensor 10 of the embodiment and is an explanatory diagram of the movement restricting convex portion 44 extending in the length direction Y. Figure 10 It is a modified example of the torque sensor 10 of the embodiment and is an explanatory diagram of the movement restricting convex portion 44 extending in the width direction X. For example, as Figure 9 shown, two movement restricting convex portions 44 separated in the width direction X and extending in the length direction Y may be disposed on each of the two surfaces of the magnetic yoke housing portion 43 in the axial direction Z. Or, as Figure 10As shown, two movement restricting protrusions 44 that are separated in the longitudinal direction Y and extend in the width direction X may be respectively disposed on both surfaces of the magnetic flux collecting yoke accommodating portion 43 in the axial direction Z. The movement restricting protrusions 44 may be disposed so as to include the regions Ay (refer to Figure 5 ) at both ends in the longitudinal direction Y and the regions Ax (refer to Figure 5 ) at both ends in the width direction X of both surfaces in the axial direction Z of the magnetic flux collecting yoke accommodating portion 43. Then, between the respective regions Ay and Ax, the movement restricting protrusions 44 may be separated or may extend.

[0147] As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited to the content described in the above embodiments. The structures described as embodiments and modification examples may be appropriately combined.

[0148] Description of Reference Numerals

[0149] 10 Torque sensor

[0150] 20 Housing

[0151] 21 First housing

[0152] 24 Accommodating portion

[0153] 25 Inner wall

[0154] 26 Opening

[0155] 31 Second housing

[0156] 40 Magnetic flux collecting yoke assembly

[0157] 41 Sensor housing

[0158] 42 Housing main body portion

[0159] 43 Magnetic flux collecting yoke accommodating portion

[0160] 43a Opening

[0161] 44 Movement restricting protrusion

[0162] 45 Cover portion

[0163] 46 Magnetic flux collecting yoke

[0164] 50 Circuit board

[0165] 51 Hall IC

[0166] 52 Connection terminal

[0167] 55 O-ring

[0168] 60 Stator

[0169] 61 Flange part

[0170] 62 Tooth part

[0171] 64 Gear carrier

[0172] 65 Magnet

[0173] 80 Steering device

[0174] 81 Steering wheel

[0175] 82 Steering shaft

[0176] 84, 86 Universal joint

[0177] 85 Intermediate shaft

[0178] 87 Short shaft

[0179] 87a Torsion bar

[0180] 88 Steering gear

[0181] 88a First pinion

[0182] 88b Rack bar

[0183] 88c Second pinion

[0184] 89 Tie rod

[0185] 100 ECU

[0186] 101 Vehicle speed sensor

[0187] 102 Electric motor

[0188] 103 Ignition switch

[0189] 104 Power supply device

Claims

1. A torque sensor, characterized in that: have case; A shaft, the shaft being disposed inside the housing; a pair of stators, the pair of stators having flange portions protruding outward in the radial direction of the shaft and fixed to the shaft; a cylindrical magnet, the magnet being arranged to face the stator; and A magnetic collecting yoke assembly, which is detachably mounted on the housing and comprises: a pair of magnetic collecting yokes, which are overlapped with the flange of the stator with a gap in the axial direction of the shaft, and detect changes in magnetic flux corresponding to changes in relative positions of the pair of stators and the magnet; and a Hall element, the Hall element outputting the change of the magnetic flux detected by the magnetic collecting yoke as an electrical signal, The housing has a receiving portion for receiving the magnetic yoke assembly. The magnetic collecting yoke assembly has a plurality of movement limiting protrusions facing the inner wall of the accommodation portion. The plurality of movement limiting protrusions are respectively arranged on two surfaces of the magnetic collecting yoke assembly in the axial direction. Two of the plurality of movement limiting protrusions are respectively arranged on both sides of the magnetic collecting yoke assembly in the axial direction, and the two of the plurality of movement limiting protrusions are separately arranged in at least one direction of the length direction along the radial direction and the width direction which is orthogonal to both the length direction and the axial direction. Two of the plurality of movement restricting protrusions are arranged to be separated in the other direction, or at least one of the plurality of movement restricting protrusions extends longer in the other direction than in the one direction.

2. The torque sensor according to claim 1, characterized in that: The magnetic collecting yoke assembly comprises a magnetic collecting yoke receiving portion for receiving the magnetic collecting yoke. The movement restricting protrusion is arranged on the flux collecting yoke accommodating portion.

3. The torque sensor according to claim 2, characterized in that: The movement restricting protrusion is arranged so as to include regions at both ends in the longitudinal direction and regions at both ends in the width direction of the two axial surfaces of the flux collecting yoke accommodating portion.

4. The torque sensor according to claim 2, characterized in that: In the flux collecting yoke assembly, a sealing member that contacts the inner wall of the accommodation portion is arranged outside the flux collecting yoke accommodation portion in the radial direction.

5. The torque sensor according to claim 2, characterized in that: The movement limiting protrusions arranged on both surfaces of the magnetic collecting yoke assembly are arranged in plurality on each surface at least in the longitudinal direction. The magnetic flux collecting yoke assembly includes a cover portion, the cover portion covering the openings of the magnetic flux collecting yoke accommodating portion formed on both sides of the axial direction of the magnetic flux collecting yoke accommodating portion, respectively. The cover portion is disposed between the movement restricting protrusions that are separated from each other in the longitudinal direction.

6. The torque sensor according to any one of claims 1 to 5, characterized in that: At least a portion of the plurality of movement restricting protrusions are separated from and opposed to the inner wall of the accommodation portion. A maximum value of a distance H1 between the movement restricting protrusion and the inner wall is narrower than a distance H2 between the flange portion of the stator and the flux collecting yoke.

7. The torque sensor according to any one of claims 1 to 5, characterized in that: All of the plurality of movement restricting protrusions are in contact with the inner wall of the accommodation portion.

Images