Sensor device

Abstract

To provide a sensor device capable of improving waterproof performance.SOLUTION: A sensor device includes a substrate 51, a magnetic sensor 52, a first holder 31, a second holder 32 and a cover part 70. The magnetic sensor 52 for detecting torque added to a rotational axis is provided on the substrate 51; the first holder 31 stores the substrate 51; the second holder 32 combined with the first holder 31 in the axial direction of the rotational axis stores the substrate 51 together with the first holder 31; and the cover part 70 provided in the second holder 32 covers an interface being a mating surface between the first holder 31 and the second holder 32 from the outside.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a sensor device. [Background technology]

[0002] Conventionally, there are torque detection devices that detect torque applied to a rotating shaft. For example, the sensor device of Patent Document 1 detects torque based on magnetic flux that changes with the twist of a torsion bar that constitutes the rotating shaft. The sensor device has a magnetic flux collector holder that holds a magnetic flux collector ring that induces magnetic flux. The magnetic flux collector holder includes a first magnetic flux collector holder and a second magnetic flux collector holder that are combined with each other. The mating surfaces of the first magnetic flux collector holder and the second magnetic flux collector holder are formed by combining the uneven shape of the first magnetic flux collector holder with the uneven shape of the second magnetic flux collector holder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-017596 A Summary of the Invention [Problem to be solved by the invention]

[0004] According to the sensor device of Patent Document 1, the uneven shape of the mating surface hinders the movement of water that penetrates through the mating surface. This prevents water from penetrating into the magnetic flux collector holder. However, depending on the product specifications, the sensor device may be required to have higher waterproof performance. [Means for solving the problem]

[0005] A sensor device that can solve the above problem includes a sensor for detecting a physical quantity related to the rotational motion of a rotating shaft that is an object to be detected, a substrate on which the sensor is mounted, a first holder for accommodating the substrate, a second holder that is combined with the first holder in the axial direction of the rotating shaft and that accommodates the substrate together with the first holder, and a covering portion that is provided on the first holder or the second holder and that covers from the outside an interface that is the mating surface between the first holder and the second holder.

[0006] According to this configuration, at least a part of the interface between the first holder and the second holder is covered from the outside by the covering portion, which prevents water from entering through the interface, thereby improving the waterproof performance of the sensor device.

[0007] In the above sensor device, the first holder may have a first holding part which is a cylindrical body into which the rotating shaft is inserted, a first board holding part which is a box-shaped body that holds the board, and a fixing part which is attached to an attachment target, the fixing part being provided on a side of the first board holding part so as to be perpendicular to the first board holding part, and a rib being provided between the fixing part and the side of the first board holding part. The second holder may have a second holding part which is a cylindrical body into which the rotating shaft is inserted, and a second board holding part which is a box-shaped body that houses the board. In this case, the covering part may have a first covering part which covers from the outside an interface which is a mating surface between the first board holding part and the second board holding part, and a second covering part which houses and covers the rib inside.

[0008] According to this configuration, the interface, which is the mating surface between the first substrate holding part and the second substrate holding part, is covered from the outside by the first cover part. This prevents water from entering through the interface. Also, the rib is covered by being housed inside the second cover part. This prevents water from adhering to the rib and, ultimately, from running down the rib to reach the interface.

[0009] In the sensor device, the first substrate holding part may have a substrate accommodating part for accommodating the substrate, the substrate accommodating part being formed by providing a surrounding wall part on an end surface facing the second substrate holding part, in which case the second substrate holding part may be fitted to an outer periphery of the surrounding wall part.

[0010] With this configuration, even if water reaches the interface between the first and second substrate holding parts, the water must overcome the surrounding wall to enter the inside of the substrate accommodating part, which makes it possible to prevent water from entering the inside of the substrate accommodating part.

[0011] The above sensor device may include a first magnetic flux collecting ring held by the first holder and inducing a magnetic flux corresponding to a torsion of the rotating shaft, and a second magnetic flux collecting ring held by the second holder and inducing a magnetic flux corresponding to a torsion of the rotating shaft. In this case, the sensor may be configured to generate an electric signal corresponding to a magnetic flux leaking between a part of the first magnetic flux collecting ring and a part of the second magnetic flux collecting ring.

[0012] With this configuration, it is possible to obtain the torque applied to the rotating shaft based on the electrical signal generated by the sensor. In the above sensor device, the rotating shaft may be a steering shaft of a vehicle, or a pinion shaft that meshes with a steered shaft of the vehicle.

[0013] The above-described sensor device is suitable for use in vehicles where improved waterproof performance is required. Effect of the Invention

[0014] According to the sensor device of the present invention, the waterproof performance can be improved. [Brief description of the drawings]

[0015] [Figure 1]1 is an exploded perspective view showing a configuration of an embodiment of a sensor device; [Diagram 2] FIG. 2 is an exploded perspective view of the magnetic flux collecting unit according to the embodiment. [Diagram 3] FIG. 4 is a perspective view of a second magnetic flux collector holder according to the embodiment, as viewed from the inside. [Figure 4] FIG. 2 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] 4 is a cross-sectional view showing a main part taken along line IV-IV in FIG. [Figure 6] 6 is a cross-sectional view showing a main part taken along line VI-VI in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] An embodiment of the sensor device will be described below. <Overall composition> As shown in Fig. 1, the sensor device 10 is provided on a rotating shaft 11 that is an object to be detected. The rotating shaft 11 has an input shaft 11A, a torsion bar 11B, and an output shaft 11C. The input shaft 11A and the output shaft 11C are connected to each other via the torsion bar 11B. The rotating shaft 11 is, for example, a steering shaft that constitutes a steering device of a vehicle, or a pinion shaft that meshes with a steering shaft that steers the steered wheels of the vehicle.

[0017] The sensor device 10 detects the torque applied to a rotating shaft 11. The sensor device 10 has a permanent magnet 12, a magnetic yoke 13, and a magnetic flux collecting unit . The permanent magnet 12 is cylindrical. The permanent magnet 12 is magnetized so that S poles and N poles are alternately arranged in the circumferential direction. The inner peripheral surface of the permanent magnet 12 and the outer peripheral surface of the input shaft 11A are fitted together. The inner peripheral surface of the permanent magnet 12 is fixed to the outer peripheral surface of the input shaft 11A.

[0018] The magnetic yoke 13 is a cylindrical body having a circular cross-sectional shape. The permanent magnet 12 is inserted into the magnetic yoke 13 in a non-contact state. The magnetic yoke 13 has a first yoke 21, a second yoke 22, and a holder 23. The first yoke 21 and the second yoke 22 are annular members made of a magnetic material. The first yoke 21 and the second yoke 22 are aligned along the axis of the rotating shaft 11. The outer circumferential surface of the first yoke 21 and the outer circumferential surface of the second yoke 22 are exposed on the outer circumferential surface of the magnetic yoke 13. The magnetic yoke 13 is formed by molding the first yoke 21 and the second yoke 22 with a synthetic resin material. The holder 23 is a part of the magnetic yoke 13 formed with a synthetic resin material. The holder 23 maintains the positional relationship between the first yoke 21 and the second yoke 22. The magnetic yoke 13 is fixed to the output shaft 11C.

[0019] The first yoke 21 has a plurality of first tooth portions 21A. The first tooth portions 21A are arranged at equal intervals in the circumferential direction of the first yoke 21. The second yoke 22 has a plurality of second tooth portions 22A. The second tooth portions 22A are arranged at equal intervals in the circumferential direction of the second yoke 22. The first tooth portions 21A and the second tooth portions 22A extend in opposite directions in the axial direction. The first tooth portions 21A and the second tooth portions 22A are alternately arranged in the circumferential direction of the first yoke 21 and the second yoke 22. When no torsional deformation occurs in the torsion bar 11B, the center of the first tooth portion 21A in the circumferential direction and the center of the second tooth portion 22A in the circumferential direction coincide with the boundary between the N pole and the S pole of the permanent magnet 12. The first teeth portion 21A and the second teeth portion 22A are exposed to the inner peripheral surface of the magnetic yoke 13.

[0020] The magnetic flux collecting unit 14 has a first holder 31 and a second holder 32. The first holder 31 and the second holder 32 are combined with each other in the axial direction. The magnetic flux collecting unit 14 has a cylindrical portion having a circular cross-sectional shape. The magnetic yoke 13 is inserted into the cylindrical portion in a non-contact state.

[0021] The permanent magnet 12, the magnetic yoke 13, and a part of the magnetic flux collecting unit 14 are accommodated inside a sensor housing made of synthetic resin. The rotating shaft 11 passes through the sensor housing. <First holder 31> As shown in FIG. 2, the first holder 31 is made of synthetic resin, and has a first holding portion 41, a first substrate holding portion 42, two fixing portions 43, and two ribs 44.

[0022] The first holding part 41 is a cylindrical body having a circular cross-sectional shape. The first holding part 41 has a first magnetic flux collecting ring 41A. The first magnetic flux collecting ring 41A is provided integrally with the first holding part 41 by insert molding. The first magnetic flux collecting ring 41A is an arc-shaped plate member curved along the outer periphery of the magnetic yoke 13, and is exposed on the inner circumferential surface of the first holding part 41. The first magnetic flux collecting ring 41A corresponds to the first yoke 21. In a state where the sensor device 10 is assembled, the first magnetic flux collecting ring 41A faces the outer circumferential surface of the first yoke 21 in the radial direction. The first magnetic flux collecting ring 41A guides the magnetic flux from the first yoke 21.

[0023] The first magnetic flux collecting ring 41A has two magnetic flux collecting protrusions 41A1. The magnetic flux collecting protrusions 41A1 are part of the first magnetic flux collecting ring 41A. The magnetic flux collecting protrusions 41A1 penetrate the peripheral wall of the first holding portion 41 radially outward and are exposed to the outside.

[0024] The first holding portion 41 has a plurality of engaging protrusions 41B. The engaging protrusions 41B are provided on a first end face of the first holding portion 41. The first end face is a face of the first holding portion 41 that faces the second holder 32 in the axial direction. The engaging protrusions 41B extend in the axial direction from the first end face. An engaging claw is provided at the tip of the engaging protrusions 41B. The multiple engaging protrusions 41B are arranged at intervals in the circumferential direction.

[0025] The first substrate holding part 42 is a box-shaped body having a rectangular cross-sectional shape. The first substrate holding part 42 extends radially outward from the outer circumferential surface of the first holding part 41. The long sides of the first substrate holding part 42 extend in a direction intersecting the outer circumferential surface of the first holding part 41. The short sides of the first substrate holding part 42 extend in a tangential direction to the outer circumferential surface of the first holding part 41.

[0026] The first substrate holding portion 42 has a substrate accommodating portion 42A. The substrate accommodating portion 42A is provided on a first end surface of the first substrate holding portion 42. The first end surface is a surface of the first substrate holding portion 42 that faces the second holder 32 in the axial direction. The substrate accommodating portion 42A is formed by providing a surrounding wall portion 42B on the first end surface of the first substrate holding portion 42. The surrounding wall portion 42B has two long side walls extending in the long side direction of the first substrate holding portion 42 and one short side wall extending in the short side direction of the first substrate holding portion 42. A first end of the long side wall is connected to the peripheral wall of the first holding portion 41. The short side wall connects second ends of the two long side walls. The surrounding wall portion 42B cooperates with a part of the peripheral wall of the first holding portion 41 to form a non-through hole having a rectangular cross-sectional shape. The depth of the hole may be greater than the height of the surrounding wall portion B based on the first end face of the first substrate holding portion .

[0027] Two magnetic flux collecting protrusions 41A1 are exposed inside the substrate accommodating section 42A. A substrate 51 is accommodated in the substrate accommodating section 42A. The substrate 51 has two magnetic sensors 52. The magnetic sensors 52 are provided on a first end surface of the substrate 51. The first end surface is a surface of the substrate 51 that faces the second holder 32 in the axial direction. The two magnetic sensors 52 are arranged to face the two magnetic flux collecting protrusions 41A1 in the axial direction. The two magnetic sensors 52 are arranged at an interval in the short side direction of the first substrate holding section 42.

[0028] A harness 53 is attached to the first board holding part 42. The harness 53 is drawn out from a first end of the first board holding part 42 on the side opposite to the first holding part 41. The harness 53 is a multi-core electric wire in which a plurality of insulated electric wires are bundled with a sheath that is an insulating coating. The first end of the harness 53 is connected to the board 51 via a plurality of terminals. The terminals and the pattern wiring of the board 51 are electrically connected. The second end of the harness 53 is connected to an external device. The external device is, for example, a control device for a steering device.

[0029] The two fixing parts 43 are used to fix the magnetic flux collecting unit 14 to the sensor housing. The fixing parts 43 are attached to the sensor housing by, for example, bolts. The sensor housing is the object to which the magnetic flux collecting unit 14 is attached.

[0030] The two fixing portions 43 are provided on two long side surfaces extending in the long side direction of the first substrate holding portion 42, respectively. The fixing portion 43 is a plate-like member having a rectangular cross-sectional shape, and is perpendicular to the first substrate holding portion 42. In other words, the short side direction of the fixing portion 43 and the long side direction of the first substrate holding portion 42 are perpendicular to each other. The fixing portion 43 is adjacent to the first holding portion 41. The fixing portion 43 extends on both sides of the first holding portion 41 in the axial direction relative to the first substrate holding portion 42.

[0031] The fixed portion 43 has a guide groove 43A. The guide groove 43A is provided in an area on the second holder 32 side with respect to the first end face of the first substrate holding portion 42, among the side surfaces of the two fixed portions 43 facing each other in the short side direction of the first substrate holding portion 42. The guide groove 43A extends in the short side direction of the fixed portion 43. The guide groove 43A is open to the second holder 32 side with respect to the first end face of the first substrate holding portion 42.

[0032] The rib 44 is for reinforcing the first holder 31, and is provided at a corner formed by the fixing portion 43 and the long side surface of the first substrate holding portion 42. The long side surface is a surface extending in the long side direction of the first substrate holding portion 42. The rib 44 has, for example, a triangular cross-sectional shape. A first end surface of the rib 44 is flush with a first end surface of the first substrate holding portion 42. The first end surface is a surface of the rib 44 or the first substrate holding portion 42 that faces the second holder 32 in the axial direction. Flush refers to a flat state in which there is no step between the two surfaces.

[0033] <Second Holder 32> As shown in FIG. 2, the second holder 32 is made of synthetic resin, and has a second holding portion 61 and a second substrate holding portion 62.

[0034] The second holding portion 61 is a cylindrical body having a circular cross-sectional shape. However, a flat wall surface extending in the tangential direction is formed on a part of the peripheral wall of the second holding portion 61. The second holding portion 61 has a semi-elliptical contour shape when viewed from the axial direction. The second holding portion 61 has a second magnetic flux collecting ring 61A. The second magnetic flux collecting ring 61A is provided integrally with the second holding portion 61 by insert molding. The second magnetic flux collecting ring 61A is an arc-shaped plate member curved along the outer periphery of the magnetic yoke 13, and is exposed on the inner periphery of the second holding portion 61. The second magnetic flux collecting ring 61A corresponds to the second yoke 22. In a state in which the sensor device 10 is assembled, the second magnetic flux collecting ring 61A faces the outer periphery of the second yoke 22 in the radial direction. The second magnetic flux collecting ring 61A induces magnetic flux from the second yoke 22.

[0035] The second holding portion 61 has a plurality of engaging recesses 61B. The number of the engaging recesses 61B is the same as the number of the engaging protrusions 41B. The engaging recesses 61B extend in the axial direction of the second holding portion 61 and are open on both sides in the axial direction.

[0036] When the first holder 31 and the second holder 32 are assembled in the axial direction, the engaging protrusion 41B is axially inserted into the engaging recess 61B. The engaging claw at the tip of the engaging protrusion 41B engages with a part of the first end face of the second holding part 61. The first end face is the surface of the second holding part 61 that is opposite to the first holding part 41 in the axial direction. The second end face of the second holding part 61 is maintained in contact with the first end face of the first holding part 41 by the engaging claw at the tip of the engaging protrusion 41B engaging with a part of the first end face of the second holding part 61. The second end face of the second holding part 61 is the surface of the second holding part 61 that is opposite to the first end face in the axial direction.

[0037] The second substrate holding portion 62 is a box-shaped body having a rectangular cross-sectional shape. The second substrate holding portion 62 extends radially outward from the flat wall surface of the second holding portion 61. The long sides of the second substrate holding portion 62 extend in a direction perpendicular to the flat wall surface of the second holding portion 61. The short sides of the second substrate holding portion 62 extend in the same direction as the second holding portion 61.

[0038] The second substrate holding portion 62 has a fitting wall 62A. The fitting wall 62A is provided on a first end face of the second substrate holding portion 62. The first end face is a face of the second substrate holding portion 62 that is opposite to the first substrate holding portion 42 in the axial direction. The fitting wall 62A is a plate-like member having a rectangular cross-sectional shape, and is perpendicular to the first end face of the second substrate holding portion 62. The fitting wall 62A extends in the short side direction of the second substrate holding portion 62. The fitting wall 62A is adjacent to the second holding portion 61.

[0039] The two side surfaces of the fitting wall 62A that are opposite to each other in the short side direction of the second substrate holding portion 62 are flush with the two side surfaces of the second substrate holding portion 62 that are opposite to each other in the short side direction. Being flush means a flat state with no step between the two surfaces. The length of the fitting wall 62A in the short side direction of the first substrate holding portion 42 is approximately the same as the distance between the two fixing portions 43 that face each other in the short side direction of the first substrate holding portion 42.

[0040] When the first holder 31 and the second holder 32 are assembled in the axial direction, the fitting wall 62A is fitted between two fixing parts 43 facing each other in the short side direction of the first substrate holding part 42. However, the portion between the two fixing parts 43 into which the fitting wall 62A is fitted is a portion of the two fixing parts 43 on the second holder 32 side with respect to the first end face of the first substrate holding part 42.

[0041] The fitting wall 62A has a guide protrusion 62B. The guide protrusion 62B is provided on two side surfaces of the fitting wall 62A that are opposite to each other in the short side direction of the second board holding portion 62. The guide protrusion 62B extends in a direction perpendicular to the first end face of the second board holding portion 62. The guide protrusion 62B is provided continuously from the side surface of the fitting wall 62A to the side surface of the second board holding portion 62.

[0042] When the first holder 31 and the second holder 32 are assembled in the axial direction, the guide protrusion 62B is fitted in the guide groove 43A in the axial direction. The second substrate holding portion 62 has two engagement protrusions 62C. The engagement protrusions 62C are provided on a second end face of the second substrate holding portion 62. The second end face is a face of the second substrate holding portion 62 that faces the first holder 31 in the axial direction. The engagement protrusions 62C extend in the axial direction from the second end face. The two engagement protrusions 62C face each other in the short side direction of the second substrate holding portion 62. The distance between the two engagement protrusions 62C in the short side direction of the second substrate holding portion 62 is approximately the same as the length of the first substrate holding portion 42 in the short side direction. An engagement claw is provided at the tip of the engagement protrusion 62C.

[0043] When first holder 31 and second holder 32 are assembled in the axial direction, the engagement claw at the tip of engagement protrusion 62C engages with a portion of the second end face of first board holding portion 42. The second end face is the surface of first board holding portion 42 that is on the opposite side to second board holding portion 62 in the axial direction. In a state in which the engagement claw at the tip of engagement protrusion 62C engages with a portion of the second end face of first board holding portion 42, the inner surface of engagement protrusion 62C is maintained in contact with the outer surface of first board holding portion 42.

[0044] The second substrate holding portion 62 has two covering portions 70. The covering portions 70 are provided on two long side surfaces that are opposite to each other in the short side direction of the second substrate holding portion 62. The two long side surfaces are side portions in the short side direction of the second substrate holding portion 62. The covering portion 70 has a first covering portion 71 and a second covering portion 72.

[0045] The first cover portion 71 is a plate-like portion having an L-shaped cross section of the covering portion 70. The first cover portion 71 has a first connecting wall 71A and a first side wall 71B. The first connecting wall 71A is provided on a portion of the long side surface of the second substrate holding portion 62, close to the second end face of the second substrate holding portion 62. The first connecting wall 71A is provided in the long side direction of the second substrate holding portion 62, from a position near the engaging protrusion 62C to a position near the longitudinal center of the second substrate holding portion 62. The height of the first connecting wall 71A based on the long side surface of the second substrate holding portion 62 is slight.

[0046] The first side wall 71B is connected to the long side surface of the second substrate holding portion 62 via the first connecting wall 71A. In the long side direction of the second substrate holding portion 62, the length of the first side wall 71B is the same as the length of the first connecting wall 71A. The first side wall 71B extends in a direction perpendicular to the second end face of the second substrate holding portion 62 and away from the second end face of the second substrate holding portion 62. The first side wall 71B is parallel to the long side surface of the second substrate holding portion 62.

[0047] The second cover portion 72 is a box-shaped portion having a triangular cross-sectional shape of the covering portion 70. The internal shape of the second cover portion 72 corresponds to the external shape of the rib 44 of the first holder 31. The second cover portion 72 has a second connecting wall 72A and a second side wall 72B.

[0048] The second connecting wall 72A is a right-angled triangular plate that protrudes laterally from the long side surface of the second board holding portion 62. The second connecting wall 72A is provided on a portion of the long side surface of the second board holding portion 62 that is close to the second end surface of the second board holding portion 62. The second connecting wall 72A is provided in the long side direction of the second board holding portion 62 from a position near the longitudinal center of the second board holding portion 62 to a position near the fitting wall 62A. The second connecting wall 72A is smoothly connected to the first connecting wall 71A at a position near the longitudinal center of the second board holding portion 62. The second connecting wall 72A is flush with the first connecting wall 71A. Of the two orthogonal sides of the second connecting wall 72A, the side that extends in the short side direction of the second board holding portion 62 is located near the fitting wall 62A.

[0049] The second side wall 72B is connected to the oblique side of the second connecting wall 72A. The second side wall 72B is provided over the entire length of the oblique side of the second connecting wall 72A. The second side wall 72B extends in a direction perpendicular to the second end face of the second substrate holding portion 62 and in a direction away from the second end face of the second substrate holding portion 62. The second side wall 72B is smoothly connected to the first side wall 71B at a position near the longitudinal center of the second substrate holding portion 62.

[0050] As shown in FIG. 3, the second end surface of the second substrate holding portion 62 is open. The second end surface is a surface of the second substrate holding portion 62 that faces the first substrate holding portion 42 in the axial direction. The second substrate holding portion 62 has a fitting portion 62D. The fitting portion 62D is a non-through hole-like portion of the second substrate holding portion 62 that has a rectangular cross-sectional shape. The fitting portion 62D is formed by partitioning the inside of the second substrate holding portion 62 with a partition wall 62E. The partition wall 62E extends in the short side direction of the second substrate holding portion 62. Both ends of the partition wall 62E are connected to two long side walls extending in the long side direction of the second substrate holding portion 62. The partition wall 62E is closer to the second holding portion 61 than the short side walls extending in the short side direction of the second substrate holding portion 62. The fitting portion 62D can be fitted onto the outer periphery of the surrounding wall portion 42B.

[0051] The second magnetic flux collecting ring 61A has two magnetic flux collecting protrusions 61A1. The magnetic flux collecting protrusions 61A1 are part of the second magnetic flux collecting ring 61A. The magnetic flux collecting protrusions 61A1 penetrate the peripheral wall of the second holding part 61 radially outward and are exposed inside the fitting part 62D. The two magnetic flux collecting protrusions 61A1 are arranged so as to face the two magnetic sensors 52 in the axial direction when the first holder 31 and the second holder 32 are assembled in the axial direction. The two magnetic flux collecting protrusions 61A1 are arranged with an interval between them in the short side direction of the second substrate holding part 62.

[0052] <Assembled state of the sensor device 10> As shown in Fig. 4, in a state where the first holder 31 and the second holder 32 are assembled in the axial direction, the fitting portion 62D of the second holder 32 is fitted to the outer periphery of the surrounding wall portion 42B of the first holder 31. In a direction perpendicular to the substrate 51, the two magnetic flux collecting protrusions 41A1 of the first magnetic flux collecting ring 41A face the two magnetic flux collecting protrusions 61A1 of the second magnetic flux collecting ring 61A, respectively. The magnetic sensor 52 is interposed between the magnetic flux collecting protrusions 41A1 of the first magnetic flux collecting ring 41A and the magnetic flux collecting protrusions 61A1 of the second magnetic flux collecting ring 61A. The magnetic sensor 52 detects the magnetic flux induced to the first magnetic flux collecting ring 41A and the magnetic flux induced to the second magnetic flux collecting ring 61A.

[0053] When torque is applied to the input shaft 11A, the torsion bar 11B undergoes torsional deformation. A relative rotational displacement occurs between the input shaft 11A and the output shaft 11C in response to the torque applied to the input shaft 11A. This causes a change in the relative position between the permanent magnet 12 and the first yoke 21 in the rotational direction. This causes a change in the magnetic flux induced from the permanent magnet 12 to the first magnetic flux collecting ring 41A through the first yoke 21. In addition, the relative position between the permanent magnet 12 and the second yoke 22 in the rotational direction changes. This causes a change in the magnetic flux induced from the permanent magnet 12 to the second magnetic flux collecting ring 61A through the second yoke 22.

[0054] The magnetic sensor 52 generates an electric signal according to the magnetic flux leaking between the magnetic flux collecting protrusion 41A1 of the first magnetic flux collecting ring 41A and the magnetic flux collecting protrusion 61A1 of the second magnetic flux collecting ring 61A. The electric signal generated by the magnetic sensor 52 changes according to the torsional deformation of the torsion bar 11B, i.e., the torsion angle of the torsion bar 11B. The steering device control device calculates the torque acting on the torsion bar 11B based on the electric signal generated by the magnetic sensor 52. The torque is a physical quantity related to the rotational motion of the rotating shaft 11.

[0055] As shown in FIG. 4, when the first holder 31 and the second holder 32 are axially assembled, the two side walls of the second substrate holding portion 62 are maintained in contact with the area of ​​the first end face of the first substrate holding portion 42 surrounding the surrounding wall portion 42B.

[0056] As shown in FIG. 5, an interface S1, which is a mating surface between the first substrate holding part 42 and the second substrate holding part 62, is covered from the outside by a covering part 70. The interface S1 is a boundary surface where the first holder 31 and the second holder 32 come into contact with each other. A first cover part 71 of the covering part 70 wraps around the second substrate holding part 62 to cover the outside of the interface S1. The interface S1 is also a mating surface between the first holder 31 and the second holder 32. A gap is provided between the outer surface of the first substrate holding part 42 and the inner surface of the first cover part 71.

[0057] As shown in FIG. 6, the rib 44 of the first substrate holding part 42 is located inside the second cover part 72 of the covering part 70. An interface S2, which is a mating surface between the second connecting wall 72A of the second cover part 72 and the rib 44, is covered from the outside by the second side wall 72B. The interface S2 is a boundary surface where the second connecting wall 72A and the rib 44 face each other. The interface S2 is blocked from the outside by the contact between the inner surface of the second side wall 72B and the outer surface of the rib 44. Depending on the product specifications, the second connecting wall 72A and the rib 44 may be in contact with each other.

[0058] <Functions and Effects of the Embodiment> Next, the operation and effects of this embodiment will be described. (1) The sensor device 10 may be mounted, for example, with the second holder 32 facing vertically upward. In this case, depending on the mounting position of the sensor device 10, water may drip onto the second holder 32. This water flows from the second holder 32 to the first holder 31 by gravity along the surface of the second holder 32.

[0059] Some of the water may flow from the second substrate holding part 62 toward the first substrate holding part 42. In this case, as shown by the arrow A1 in Fig. 5, some of the water running down the surface of the second substrate holding part 62 drips down the surface of the first cover part 71. This prevents the water from reaching the interface S1 between the first substrate holding part 42 and the second substrate holding part 62.

[0060] The length of the first cover portion 71 covering the outside of the interface S1 is preferably long. The length is the length in the direction from the second substrate holding portion 62 to the first substrate holding portion 42. The longer the length of the first cover portion 71, the longer the water intrusion path from the end of the first cover portion 71 to the interface S1 can be, and water can be prevented from reaching the interface S1. The narrower the gap between the outer surface of the first substrate holding portion 42 and the inner surface of the first cover portion 71, the more water can be prevented from reaching the interface S1.

[0061] 6, part of the water running down the surface of the second substrate holding portion 62 or part of the water running down the surface of the fixing portion 43 drips down the surface of the second cover portion 72. This prevents the water from reaching the interface S2 between the second connecting wall 72A and the rib 44. This also prevents the water from adhering to the rib 44, and thus prevents the water from running down the rib 44 to reach the interface S1.

[0062] Furthermore, the interface S2 is blocked from the outside by the contact between the inner surface of the second side wall 72B and the outer surface of the rib 44. This further prevents water from reaching the interface S2, compared to when the second side wall 72B only covers the outside of the interface S2, i.e., when the inner surface of the second side wall 72B and the outer surface of the rib 44 do not contact each other.

[0063] This prevents water from entering the inside of the substrate accommodating portion 42A through the interfaces S1 and S2, and also prevents water from adhering to the magnetic sensor 52. This improves the waterproof performance of the sensor device 10.

[0064] (2) Even if water reaches interfaces S1 and S2, the water needs to overcome surrounding wall portion 42B to enter substrate accommodating portion 42A. This makes it possible to prevent water from entering substrate accommodating portion 42A.

[0065] (3) The sensor device 10 is suitable for use in vehicles where improved waterproofing is required. <Other embodiments> This embodiment may be modified as follows.

[0066] Depending on the product specifications, the rib 44 may be omitted. In this case, for example, the second cover portion 72 may be omitted, and the first cover portion 71 may be extended toward the fixing portion 43. Depending on the mounting position or mounting posture of the sensor device 10, one of the two covering parts 70 may be omitted. For example, when the sensor device 10 is provided at an angle to the vertical direction, the upper covering part 70 is left, while the lower covering part 70 is omitted.

[0067] Depending on the product specifications, the covering part 70 may be provided on the first holder 31. When the second holder 32 is above the first holder 31, the covering part 70 opens upward. In this way, it is possible to ensure waterproof performance against water from below.

[0068] The sensor device 10 may be a rotation angle sensor that detects the rotation angle of the rotating shaft 11. In this case, for example, a main gear is attached to the outer circumferential surface of the rotating shaft 11 so as to be rotatable together with the rotating shaft 11. Two driven gears are rotatably supported inside the substrate housing portion 42A. The two driven gears have different numbers of teeth from each other. The substrate 51 is provided with two sensors that generate electric signals corresponding to the rotation angles of the two driven gears. The two driven gears mesh with the main gear through an opening provided in the peripheral wall of the first holding portion 41. Therefore, the two driven gears rotate in conjunction with the rotation of the main gear. Since the two driven gears have different numbers of teeth from each other, the rotation angles of the two driven gears relative to the rotation angle of the main gear are different from each other. Therefore, the phases of the electric signals generated by the first sensor and the second sensor are different from each other. The steering device control device detects the rotation angle of the rotating shaft 11 based on the electric signals generated by the first sensor and the second sensor. The rotation angle of the rotating shaft 11 is a physical quantity related to the rotational motion of the rotating shaft 11 . [Explanation of symbols]

[0069] 10...Sensor device 11...Rotary shaft (steering shaft, pinion shaft) 31…First holder 32…Second holder 41...First holding part 41A…First magnet ring 42...first substrate holder 42A…Board housing section 42B…Enclosing wall part 43…Fixed part 44…Rib 51... Circuit board 52...Magnetic sensor (sensor) 61...Second holding part 61A…Second magnetic flux collecting ring 62...second substrate holder 70…Covering part 71...First cover part 72...Second cover part

Claims

1. a sensor for detecting a physical quantity related to the rotational motion of a rotating shaft that is an object to be detected; a substrate on which the sensor is provided; a first holder for accommodating the substrate; a second holder that is combined with the first holder in an axial direction of the rotation shaft and that accommodates the substrate together with the first holder; A sensor device having a covering portion provided on the first holder or the second holder, the covering portion covering from the outside an interface that is a mating surface between the first holder and the second holder.

2. The first holder includes a first holding portion that is a cylindrical body into which the rotating shaft is inserted, A first substrate holder that is a box-shaped body that holds the substrate; a fixing portion that is attached to an attachment target, the fixing portion being provided on a side of the first board holding portion so as to be perpendicular to the first board holding portion; a rib provided between the fixing portion and a side portion of the first substrate holding portion, The second holder includes a second holding portion that is a cylindrical body into which the rotating shaft is inserted; a second substrate holding portion which is a box-shaped body in which the substrate is accommodated; The covering portion includes a first cover portion that covers, from the outside, an interface that is a mating surface between the first substrate holding portion and the second substrate holding portion; The sensor device according to claim 1 , further comprising: a second cover portion that houses and covers the rib therein.

3. the first substrate holding portion is a substrate accommodating portion for accommodating the substrate, and has a substrate accommodating portion formed by providing a surrounding wall portion on an end surface facing the second substrate holding portion, The sensor device according to claim 2 , wherein the second substrate holding portion is fitted to an outer periphery of the surrounding wall portion.

4. a first magnetic flux collecting ring held by the first holding portion, the first magnetic flux collecting ring inducing magnetic flux corresponding to the torsion of the rotating shaft; a second magnetic flux collecting ring held by the second holding portion, the second magnetic flux collecting ring inducing magnetic flux corresponding to the torsion of the rotating shaft; The sensor device according to claim 2 or 3, wherein the sensor is configured to generate an electric signal according to magnetic flux leaking between a portion of the first magnetic flux collecting ring and a portion of the second magnetic flux collecting ring.

5. 4. The sensor device according to claim 1, wherein the rotating shaft is a steering shaft of a vehicle or a pinion shaft that meshes with a steered shaft of the vehicle.

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