Sensor Device

Abstract

To provide a sensor device which can further enhance waterproofness.SOLUTION: A sensor device includes a sensor housing. The sensor housing has a first storage chamber to which a rotation shaft is inserted, and a second storage chamber for storing a substrate. The sensor housing has a cylindrical inner housing 25B as a resin molding, and an outer housing as a resin molding to which the inner housing 25B is inserted. The inner periphery of the inner housing 25B is exposed to the inside of the first storage chamber. A part of the outer periphery of the inner housing 25B is exposed to the inside of the second storage chamber. The inner housing 25B has an uneven part 81 provided over the full length in an axial direction, in two regions of the outer periphery that are adjacent to each other in a circumferential direction with respect to a part exposed to inside the second storage chamber.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] For example, the sensor device disclosed in Patent Document 1 includes a sensor that measures the physical quantity of a detection target, a substrate on which the sensor is mounted, and a resin substrate housing that houses the substrate. The outer surface of the substrate housing is covered with a resin outer case. The outer case is molded to surround the periphery of the substrate housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-25819 Summary of the Invention [Problem to be solved by the invention]

[0004] The sensor device of Patent Document 1 has the following concerns. Specifically, when the outer case is molded, a small gap may be formed between the outer surface of the substrate accommodating portion and the inner surface of the outer case. Water may seep in through this gap. There is a need to further improve the waterproofing of the sensor device. [Means for solving the problem]

[0005] A sensor device that can solve the above problem includes a sensor configured to detect a physical quantity related to the rotational motion of a rotating shaft that is a detection target, a substrate on which the sensor is mounted, and a sensor housing having a first accommodating chamber into which the rotating shaft is inserted and a second accommodating chamber into which the substrate is accommodated. The sensor housing includes a cylindrical inner housing that is a resin molded product, and an outer housing that is also a resin molded product into which the inner housing is inserted. The inner periphery of the inner housing is exposed inside the first accommodating chamber, while a portion of the outer periphery of the inner housing is exposed inside the second accommodating chamber. The inner housing has uneven portions that are provided over the entire axial length in two regions of the outer periphery that are circumferentially adjacent to the portion exposed inside the second accommodating chamber.

[0006] If water gets inside the sensor housing, there is a risk that the water will leak out onto the outer periphery of the inner housing through a small gap between the inner housing and the outer housing.

[0007] In the sensor device described above, the molding shrinkage phenomenon that occurs when the outer housing is molded narrows the radial gap between the convex portion of the concave-convex portion and the outer housing, which prevents water that has entered the sensor housing from flowing along the outer periphery of the inner housing and into the second housing chamber.

[0008] In the above-mentioned sensor device, the uneven portion may have a groove portion having a plurality of concave curved surfaces extending over the entire axial length of the inner housing and spaced apart circumferentially of the inner housing, and a protrusion portion formed between the plurality of groove portions by providing the groove portion.

[0009] According to the sensor device described above, the radial gap between the protrusions of the concave-convex portion and the outer housing is further narrowed by the molding shrinkage phenomenon that occurs when the outer housing is molded. In the above-mentioned sensor device, the uneven portion may have protrusions having multiple convex curved surfaces extending over the entire axial length of the inner housing and spaced apart circumferentially around the inner housing, and grooves formed between the multiple protrusions by providing the protrusions.

[0010] According to the sensor device described above, the radial gap between the protrusions of the concave-convex portion and the outer housing is further narrowed by the molding shrinkage phenomenon that occurs when the outer housing is molded. In the sensor device, the inner housing may have a wall portion provided to separate the first housing chamber and the second housing chamber.

[0011] If the part of the inner housing exposed to the inside of the second housing chamber has an opening, water that has entered the inside of the sensor housing may flow into the second housing chamber through the opening.

[0012] According to the sensor device, the wall separates the first and second housing chambers, preventing water that has entered the sensor housing from flowing into the second housing chamber.

[0013] The sensor device may include a permanent magnet located within the first housing chamber and rotatable integrally with the rotating shaft; a magnetic yoke located within the first housing chamber and whose rotational position relative to the permanent magnet changes with twisting of the rotating shaft; a first magnetic flux collector ring inserted into the inner housing and exposed to the inner periphery of the inner housing so as to surround the magnetic yoke and collect magnetic flux from the magnetic yoke; and a second magnetic flux collector ring inserted into the inner housing and exposed to the inner periphery of the inner housing at a different axial position of the magnetic yoke from the first magnetic flux collector ring. The first magnetic flux collector ring and the second magnetic flux collector ring may each have a magnetic flux collector protrusion protruding radially outward from their outer peripheries and penetrating the wall portion to be exposed inside the second housing. The sensor may be a magnetic sensor interposed between two magnetic flux collector protrusions and configured to generate an electric signal corresponding to magnetic flux leaking between the two magnetic flux collector protrusions. The inner surface regions of the first and second magnetic flux collecting rings where the magnetic flux collecting protrusions are provided may be covered with a resin that forms the inner housing.

[0014] According to the above sensor device, water that has entered the sensor housing is prevented from flowing into the second storage chamber through the gap at the boundary between the inner housing and the portion where the magnetic flux collecting protrusions of the first magnetic flux collecting ring and the second magnetic flux collecting ring are provided.

[0015] In the sensor device described above, the portions of the first and second magnetic flux collecting rings where the magnetic flux collecting protrusions are provided may be positioned radially outward relative to other portions. According to the sensor device described above, when molding the outer housing, the inner surface area of ​​the portion where the magnetic flux collecting protrusions of the first magnetic flux collecting ring are provided can be easily covered with the resin that constitutes the inner housing. Also, when molding the outer housing, the inner surface area of ​​the portion where the magnetic flux collecting protrusions of the second magnetic flux collecting ring are provided can be easily covered with the resin that constitutes the inner housing.

[0016] In the above sensor device, the rotation shaft may be a pinion shaft that meshes with a steering shaft that steers steered wheels of a vehicle. The above-described sensor device is suitable for use in vehicles where waterproofing is required. [Effects of the Invention]

[0017] According to the sensor device of the present invention, waterproofing can be further improved. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is an exploded perspective view of an embodiment of a sensor device. [Figure 2] 1 is a cross-sectional view of a sensor device according to an embodiment taken along an axial direction; [Figure 3] FIG. 2 is a perspective view of a magnetic flux collecting ring according to an embodiment. [Figure 4] FIG. 2 is a perspective view of an inner housing according to an embodiment. [Figure 5] FIG. 2 is a perspective view of an inner housing according to an embodiment. [Figure 6] 3 is a cross-sectional view of an inner housing according to an embodiment, taken in the axial direction at a position corresponding to a magnetic flux collecting protrusion. FIG. [Figure 7] 7 is a cross-sectional view of the inner housing of the embodiment taken along line VII-VII in FIG. 6. [Figure 8] FIG. 2 is a perspective view of an inner housing according to an embodiment. [Figure 9] FIG. 2 is a perspective view of an inner housing according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment of the sensor device will be described below. <Overall configuration of the sensor device> As shown in FIG. 1, the sensor device 10 is provided on a rotating shaft 11 that is the detection target. The rotating shaft 11 has an input shaft 12, a torsion bar 13, and an output shaft 14. The input shaft 12 and the output shaft 14 are connected to each other via the torsion bar 13. The input shaft 12, the torsion bar 13, and the output shaft 14 are located on the same axis O. The rotating shaft 11 is, for example, a pinion shaft of a rack-and-pinion mechanism that constitutes a steering device of a vehicle. A steering wheel is connected to the pinion shaft via a steering shaft.

[0020] The sensor device 10 detects torque applied to the rotary shaft 11 through operation of the steering wheel. The sensor device 10 has a permanent magnet 21, a magnetic yoke 22, a substrate 23, a sensor housing 25, and a cover 26.

[0021] The permanent magnet 21 is cylindrical. The permanent magnet 21 is magnetized with S poles and N poles alternately in the circumferential direction. The inner peripheral surface of the permanent magnet 21 and the outer peripheral surface of the input shaft 12 fit together. The inner peripheral surface of the permanent magnet 21 is fixed to the outer peripheral surface of the input shaft 12.

[0022] The magnetic yoke 22 is cylindrical. A permanent magnet 21 is inserted inside the magnetic yoke 22. The magnetic yoke 22 has a first yoke 31, a second yoke 32, and a holder 33. The first yoke 31 and the second yoke 32 are annular members made of magnetic material. The first yoke 31 and the second yoke 32 are aligned along the axis O of the rotating shaft 11. The magnetic yoke 22 is formed by molding the first yoke 31 and the second yoke 32 with a synthetic resin material. The holder 33 is a portion of the magnetic yoke 22 made of a synthetic resin material. The holder 33 maintains the positional relationship between the first yoke 31 and the second yoke 32. The magnetic yoke 22 is fixed to the output shaft 14.

[0023] The first yoke 31 has a plurality of teeth 31a. The teeth 31a are arranged at equal intervals in the circumferential direction of the first yoke 31. The second yoke 32 has a plurality of teeth 32a. The teeth 32a are arranged at equal intervals in the circumferential direction of the second yoke 32. The teeth 31a and the teeth 32a extend in opposite directions in the direction along the axis O of the rotating shaft 11. The teeth 31a and the teeth 32a are arranged alternately in the circumferential direction of the first yoke 31 and the second yoke 32. When no torsional deformation occurs in the torsion bar 13, the centers of the teeth 31a and 32a in the circumferential direction coincide with the boundary between the north pole and the south pole of the permanent magnet 21.

[0024] The substrate 23 is a rectangular plate. The substrate 23 has a first main surface and a second main surface that are located opposite each other in the direction along the axis O. The substrate 23 also has three support holes 41, multiple terminal connection holes 42, a first magnetic sensor 45, and a second magnetic sensor 46. The support hole 41 is provided near the center of the substrate 23. The support holes 41 are aligned in a row along the long side of the substrate 23. The terminal connection holes 42 are aligned, for example, in two rows along the first long side of the substrate 23. The first magnetic sensor 45 and the second magnetic sensor 46 are provided on the first main surface of the substrate 23. The first magnetic sensor 45 and the second magnetic sensor 46 are aligned along the second long side of the substrate 23. The first magnetic sensor 45 and the second magnetic sensor 46 are used to detect the rotation angle of the rotating shaft 11 and are, for example, Hall sensors. The rotation angle of the rotating shaft 11 is a physical quantity related to the rotational motion of the rotating shaft 11 .

[0025] The sensor housing 25 has an outer housing 25A and a cylindrical inner housing 25B. The outer housing 25A and the inner housing 25B are each molded from resin. The inner housing 25B is formed integrally with the outer housing 25A by insert molding. Insert molding is a molding technique in which the inner housing 25B, which is an insert part, is attached to an open mold, and then the mold is closed to perform injection molding. Inside the mold, the inner housing 25B is enveloped, except for a portion, by molten resin injected into the mold. This molten resin cools and solidifies, forming the outer housing 25A outside the inner housing 25B. The sensor housing 25 has a protruding portion that protrudes radially outward from the inner housing 25B. The rotating shaft 11 is provided to penetrate the sensor housing 25 in the axial direction.

[0026] The sensor housing 25 has a cylindrical insertion hole 51, a cylindrical first accommodating chamber 52, and a second accommodating chamber 53. The insertion hole 51 and the first accommodating chamber 52 are in communication with each other. The insertion hole 51 and the first accommodating chamber 52 are located on the same axis O. The inner diameter of the insertion hole 51 is slightly larger than the outer diameter of the rotary shaft 11. The input shaft 12 is inserted into the insertion hole 51 via the first accommodating chamber 52.

[0027] The inner diameter of the first accommodating chamber 52 is slightly larger than the outer diameter of the magnetic yoke 22. The inner circumferential surface of the inner housing 25B forms the inner circumferential surface of the first accommodating chamber 52. The first accommodating chamber 52 accommodates the permanent magnet 21 and the magnetic yoke 22.

[0028] The second accommodating chamber 53 is provided in the protruding portion of the sensor housing 25. The second accommodating chamber 53 accommodates the substrate 23. The second accommodating chamber 53 has a rectangular opening 53a. The opening 53a opens radially outward from the inner housing 25B. The opening 53a is closed by the cover 26.

[0029] Three support protrusions 54 are provided on the inner end surface of the second housing chamber 53. The support protrusions 54 are, for example, in the shape of a stepped cylinder. The support protrusions 54 are lined up in a row along the long side of the opening 53a. Each support protrusion 54 corresponds to a corresponding support hole 41 in the substrate 23.

[0030] First ends of a plurality of terminals 55 protrude from the inner end surface of second accommodating chamber 53. Terminals 55 are arranged, for example, in two rows along the long side of opening 53a. The first ends of terminals 55 are located outside support protrusion 54 in the opening direction of opening 53a. Terminals 55 correspond to terminal connection holes 42 provided in substrate 23.

[0031] A rectangular cylindrical connector fitting portion 56 protrudes from the outer surface of the end wall of the protruding portion of the sensor housing 25. Second ends of the multiple terminals 55 penetrate the end wall of the protruding portion of the sensor housing 25 and are exposed inside the connector fitting portion 56. A wiring connector (not shown) that electrically connects the terminals 55 of the board 23 to an external device is fitted into the connector fitting portion 56. The external device is, for example, a steering device control device.

[0032] A first magnetic flux collecting ring 61 and a second magnetic flux collecting ring 62 are provided on the inner peripheral surface of the first housing chamber 52. The first magnetic flux collecting ring 61 and the second magnetic flux collecting ring 62 are provided integrally with the inner housing 25B by insert molding. The first magnetic flux collecting ring 61 and the second magnetic flux collecting ring 62 are arc-shaped plates that curve along the outer periphery of the magnetic yoke 22. The first magnetic flux collecting ring 61 and the second magnetic flux collecting ring 62 are aligned in a direction along the axis O of the rotation shaft 11. The first magnetic flux collecting ring 61 corresponds to the first yoke 31. The second magnetic flux collecting ring 62 corresponds to the second yoke 32. The first magnetic flux collecting ring 61 has two magnetic flux collecting protrusions 61a and 61b. These magnetic flux collecting protrusions 61a and 61b are exposed inside the second housing chamber 53. The second magnetic flux collecting ring 62 has two magnetic flux collecting protrusions 62a and 62b. These magnetic flux collecting protrusions 62a, 62b are exposed to the inside of the second housing chamber 53. The magnetic flux collecting protrusions 61a and 62a of one pair face each other in the direction along the axis O. The magnetic flux collecting protrusions 61b and 62b of the other pair face each other in the direction along the axis O.

[0033] <Sensor device installation status> As shown in FIG. 2, sensor device 10 is attached to housing 15. The interior of sensor housing 25 and the interior of housing 15 are in communication with each other. Housing 15 rotatably supports rotating shaft 11, which is the object to be detected. Housing 15 is, for example, a gear housing that houses a rack-and-pinion mechanism that constitutes a steering device of a vehicle. The rack-and-pinion mechanism has a steering shaft that steers the steered wheels of the vehicle and a pinion shaft that meshes with the rack teeth of the steering shaft. In this embodiment, rotating shaft 11 is the pinion shaft. Magnetic yoke 22 attached to rotating shaft 11 is maintained housed in first housing chamber 52 of sensor housing 25.

[0034] The substrate 23 is attached to the inner end surface of the second accommodating chamber 53. A first main surface of the substrate 23, on which the first magnetic sensor 45 and the second magnetic sensor 46 are provided, faces away from the end wall of the protruding portion of the sensor housing 25. The substrate 23 has two notches 23a. These notches 23a are provided on side edges of the substrate 23 corresponding to the first magnetic sensor 45 and the second magnetic sensor 46. When the substrate 23 is attached to the inner end surface of the second accommodating chamber 53, the magnetic flux collecting protrusions 61a, 61b of the first magnetic flux collecting ring 61 are maintained in a state where they are positioned inside the notches 23a of the substrate 23.

[0035] Although not shown in the drawings, each support protrusion 54 provided on the inner end surface of the second accommodating chamber 53 penetrates each support hole 41 of the substrate 23. This restricts movement of the substrate 23 relative to the inner end surface of the second accommodating chamber 53. Furthermore, a first end of each terminal 55 protruding from the inner end surface of the second accommodating chamber 53 penetrates each terminal connection hole 42 of the substrate 23. The first end of each terminal 55 is joined to the substrate 23 by soldering. The pattern wiring of the substrate 23 and each terminal 55 are electrically connected.

[0036] A permanent magnet 21 is positioned inside the first yoke 31 and the second yoke 32 of the magnetic yoke 22. The permanent magnet 21, the first yoke 31, and the second yoke 32 form a magnetic circuit. In the direction along the axis O of the rotating shaft 11, a first magnetic flux collecting ring 61 is held at a position corresponding to the first yoke 31. The first magnetic flux collecting ring 61 surrounds the periphery of the first yoke 31. The first magnetic flux collecting ring 61 guides the magnetic flux from the first yoke 31. A second magnetic flux collecting ring 62 is held at a position corresponding to the second yoke 32. The second magnetic flux collecting ring 62 surrounds the periphery of the second yoke 32. The second magnetic flux collecting ring 62 guides the magnetic flux from the second yoke 32.

[0037] 3, the magnetic flux collecting protrusion 61a of the first magnetic flux collecting ring 61 and the magnetic flux collecting protrusion 62a of the second magnetic flux collecting ring 62 are parallel to each other. The first magnetic sensor 45 is interposed between the magnetic flux collecting protrusion 61a of the first magnetic flux collecting ring 61 and the magnetic flux collecting protrusion 62a of the second magnetic flux collecting ring 62. The magnetic flux collecting protrusion 61b of the first magnetic flux collecting ring 61 and the magnetic flux collecting protrusion 62b of the second magnetic flux collecting ring 62 are parallel to each other. The second magnetic sensor 46 is interposed between the magnetic flux collecting protrusion 61b of the first magnetic flux collecting ring 61 and the magnetic flux collecting protrusion 62b of the second magnetic flux collecting ring 62. The first magnetic sensor 45 and the second magnetic sensor 46 detect magnetic flux induced in the first magnetic flux collecting ring 61 and the second magnetic flux collecting ring 62.

[0038] When torque is applied to the input shaft 12 through operation of the steering wheel, the torsion bar 13 undergoes torsional deformation. A relative rotational displacement occurs between the input shaft 12 and the output shaft 14 in response to the torque applied to the input shaft 12. This changes the relative position of the permanent magnet 21 and the first yoke 31 in the rotational direction. This changes the magnetic flux induced from the permanent magnet 21 to the first magnetic flux collector ring 61 through the first yoke 31. This also changes the relative position of the permanent magnet 21 and the second yoke 32 in the rotational direction. This changes the magnetic flux induced from the permanent magnet 21 to the second magnetic flux collector ring 62 through the second yoke 32.

[0039] The first magnetic sensor 45 generates an electric signal corresponding to the magnetic flux leaking between the magnetic flux collecting protrusion 61a of the first magnetic flux collecting ring 61 and the magnetic flux collecting protrusion 62a of the second magnetic flux collecting ring 62. The second magnetic sensor 46 generates an electric signal corresponding to the magnetic flux leaking between the magnetic flux collecting protrusion 61b of the first magnetic flux collecting ring 61 and the magnetic flux collecting protrusion 62b of the second magnetic flux collecting ring 62. The electric signals generated by the first magnetic sensor 45 and the second magnetic sensor 46 change depending on the torsional deformation of the torsion bar 13, i.e., the torsion angle of the torsion bar 13. The steering device control device calculates the torque acting on the torsion bar 13 based on the electric signals generated by the first magnetic sensor 45 and the second magnetic sensor 46. Torque is a physical quantity related to the rotational motion of the rotating shaft 11.

[0040] <Water penetration route> The sensor device 10 configured in this manner has the following concerns. That is, tie rods are rotatably connected to both ends of the steering shaft via rack ends. Also, bellows-shaped rubber boots are attached to both ends of the gear housing. The connection between the steering shaft and the tie rod is surrounded by the boots. These boots prevent water and dust from entering the interior of the gear housing. However, cracks or tears may develop in the boots due to aging or other reasons. In this case, water may seep into the gear housing through the cracks or tears and then travel upstream inside sensor housing 25.

[0041] The inner housing 25B is formed integrally with the outer housing 25A by insert molding. However, during insert molding, there is a risk of a small gap being formed at the boundary between the outer housing 25A and the inner housing 25B. Furthermore, the first magnetic flux collecting ring 61 and the second magnetic flux collecting ring 62 are formed integrally with the inner housing 25B by insert molding. However, during insert molding, there is a risk of a small gap being formed at the boundary between the first magnetic flux collecting ring 61 and the inner housing 25B or the boundary between the second magnetic flux collecting ring 62 and the inner housing 25B.

[0042] Therefore, there is a concern that water flowing upstream inside the sensor housing 25 may infiltrate into the second housing chamber 53 through a gap at the boundary between the outer housing 25A and the inner housing 25B. There is also a concern that water flowing upstream inside the sensor housing 25 may infiltrate into the second housing chamber 53 through a gap at the boundary between the first magnetic flux collector ring 61 and the inner housing 25B or a gap at the boundary between the second magnetic flux collector ring 62 and the inner housing 25B. The second housing chamber 53 houses a circuit board 23 on which electronic components are mounted. If water that has infiltrated into the second housing chamber 53 adheres to the circuit board 23, normal operation of the electronic components may be impaired. The electronic components include a first magnetic sensor 45 and a second magnetic sensor 46. Therefore, it is necessary to prevent water from infiltrating into the second housing chamber 53 from inside the sensor housing 25.

[0043] Therefore, in this embodiment, the following configuration is adopted for the inner housing 25B. <Inner housing> As shown in Fig. 4, the inner housing 25B has an inner housing main body 25B1 and a protrusion 25B2. The inner housing main body 25B1 is cylindrical with both ends open. The inner circumferential surface of the inner housing main body 25B1 forms the inner circumferential surface of the first accommodating chamber 52. The protrusion 25B2 protrudes radially outward from the outer circumferential surface of the inner housing main body 25B1.

[0044] The protrusion 25B2 has a first protrusion 71, a second protrusion 72, and a wall 73. The wall 73 is provided on the outer peripheral surface of the inner housing main body 25B1. The wall 73 extends along the axis O over the entire length of the inner housing main body 25B1. The wall 73 has a first end and a second end along the axis O. The first end and the second end are located on opposite sides of each other along the axis O.

[0045] The first protrusion 71 protrudes radially outward from the inner housing main body 25B1 from a first end of the wall portion 73. The second protrusion 72 protrudes radially outward from the inner housing main body 25B1 from a second end of the wall portion 73. The protrusion length of the first protrusion 71 from the wall portion 73 is longer than the protrusion length of the second protrusion 72 from the wall portion 73. The first protrusion 71 and the second protrusion 72 face each other in the direction along the axis O. The first protrusion 71 and the second protrusion 72 are parallel to each other. The surface of the first protrusion 71 facing the second protrusion 72 constitutes a part of the inner end surface of the second accommodation chamber 53.

[0046] The inner peripheral surface of the first magnetic flux collecting ring 61 is exposed to the inside of the inner housing main body 25B1. The inner peripheral surface of the first magnetic flux collecting ring 61 is flush with the inner peripheral surface of the inner housing main body 25B1. The two magnetic flux collecting protrusions 61a, 61b of the first magnetic flux collecting ring 61 penetrate the wall portion 73 and are exposed to the outside of the inner housing main body 25B1. The two magnetic flux collecting protrusions 61a, 61b extend radially outward from the inner housing main body 25B1 along the opposing surface of the first protrusion 71 relative to the second protrusion 72.

[0047] The inner peripheral surface of the second magnetic flux collecting ring 62 is exposed to the inside of the inner housing main body 25B1. The inner peripheral surface of the second magnetic flux collecting ring 62 is flush with the inner peripheral surface of the inner housing main body 25B1. The two magnetic flux collecting protrusions 62a, 62b of the second magnetic flux collecting ring 62 penetrate the wall portion 73 and are exposed to the outside of the inner housing main body 25B1. The two magnetic flux collecting protrusions 62a, 62b extend radially outward from the inner housing main body 25B1 along the opposing surface of the second protrusion 72 relative to the first protrusion 71.

[0048] As shown in FIGS. 4 and 5, the inner housing main body 25B1 has uneven portions 81. The uneven portions 81 are provided on the outer peripheral surface of the inner housing main body 25B1 in two regions circumferentially adjacent to the protrusion 25B2. The uneven portions 81 have, for example, multiple grooves 81a. The grooves 81a extend along the entire length of the inner housing main body 25B1 in the direction along the axis O. The grooves 81a have, for example, a smoothly concavely curved surface as viewed along the axis O. The grooves 81a are aligned in the circumferential direction of the inner housing main body 25B1. By providing the grooves 81a, protrusions 81b are formed between the grooves 81a. The protrusions 81b have a smoothly convexly curved surface as viewed along the axis O. The grooves 81a are continuous with each other in the circumferential direction of the inner housing main body 25B1 via the protrusions 81b having smoothly curved surfaces.

[0049] The outer periphery of the inner housing 25B is covered by the outer housing 25A except for a portion of the protrusion 25B2. The second protrusion 72 is exposed inside the second accommodating chamber 53. The surface of the first protrusion 71 facing the second protrusion 72 is exposed inside the second accommodating chamber 53. The magnetic flux collecting protrusions 61a and 61b of the first magnetic flux collecting ring 61 and the magnetic flux collecting protrusions 62a and 62b of the second magnetic flux collecting ring 62 are exposed inside the second accommodating chamber 53. Most of the surface of the wall 73 from which the magnetic flux collecting protrusions 61a, 61b, 62a, and 62b protrude is exposed inside the second accommodating chamber 53.

[0050] 6, the wall portion 73 is provided so as to separate the first accommodating chamber 52 and the second accommodating chamber 53 in the radial direction of the inner housing 25B. A first end (lower end in FIG. 6) of the wall portion 73 is located on the opposite side of the first magnetic flux collecting ring 61 from the second magnetic flux collecting ring 62. A second end (upper end in FIG. 6) of the wall portion 73 is located on the opposite side of the second magnetic flux collecting ring 62 from the first magnetic flux collecting ring 61.

[0051] As shown in Fig. 3, the first magnetic flux collecting ring 61 is formed by plastically deforming a metal plate that has been punched into a predetermined shape. The first magnetic flux collecting ring 61 has a C-shaped ring body 91. The ring body 91 has a first end and a second end in the circumferential direction. The first end and the second end face each other closely in the circumferential direction of the ring body 91. A gap is formed between the first end and the second end.

[0052] The ring body 91 has a protrusion 91a. The protrusion 91a is located on the opposite side of the gap in the radial direction of the ring body 91. The protrusion 91a is located radially outward of an imaginary cylinder that includes the outer circumferential surface of the other arc-shaped curved portion of the ring body 91. The protrusion 91a has a rectangular flat plate shape that extends in the tangential direction of the imaginary cylinder. In the circumferential direction of the ring body 91, both ends of the protrusion 91a are bent obliquely and connected to the other arc-shaped curved portion of the ring body 91.

[0053] The protrusion 91a has a first end and a second end in the direction along the axis O. The first end and the second end are located on opposite sides of each other in the direction along the axis O. The two magnetic flux collecting protrusions 61a, 61b are provided at the second end (the upper end in FIG. 3 ) of the protrusion 91a. The magnetic flux collecting protrusions 61a, 61b extend slightly along the axis O in a direction away from the second end and are curved radially outward from the ring body 91.

[0054] The second magnetic flux collecting ring 62 has a structure similar to that of the first magnetic flux collecting ring 61. The second magnetic flux collecting ring 62 has a C-shaped ring body 92. The ring body 92 has a protrusion 92a. The two magnetic flux collecting protrusions 62a, 62b are provided at a first end (the lower end in FIG. 3 ) of the protrusion 92a. The magnetic flux collecting protrusions 62a, 62b extend slightly along the axis O in a direction away from the first end and are curved radially outward from the ring body 92.

[0055] 6, the protrusion 91a of the first magnetic flux collecting ring 61 and the protrusion 92a of the second magnetic flux collecting ring 62 are embedded in the peripheral wall of the inner housing 25B, including the wall portion 73. The two protrusions 91a, 92a are not exposed to the outside of the inner housing 25B in the axial direction of the inner housing 25B.

[0056] As shown in Fig. 7, the inner surface of the protrusion 91a of the first magnetic flux collecting ring 61 is covered with the synthetic resin that constitutes the inner housing 25B. The inner surface is the surface of the protrusion 91a that is opposite to the protrusion direction of the two magnetic flux collecting protrusions 62a, 62b. As shown in Fig. 8, the inner surface of the protrusion 92a of the second magnetic flux collecting ring 62 is covered with the synthetic resin that constitutes the inner housing 25B, similar to the inner surface of the protrusion 91a of the first magnetic flux collecting ring 61. The two protrusions 91a, 92a are not exposed to the inside of the inner housing 25B in the radial direction of the inner housing 25B.

[0057] <Actions and Effects of the Present Embodiment> This embodiment provides the following functions and effects. (1) On the outer peripheral surface of the inner housing main body 25B1, concave-convex portions 81 are provided in two regions circumferentially adjacent to the protrusion 25B2. Mold shrinkage occurs when the outer housing 25A is molded. Mold shrinkage is a phenomenon in which the volume shrinks when the molten resin filled inside the mold cools and solidifies. By utilizing the mold shrinkage phenomenon, it is possible to reduce the radial gap between the concave-convex portions 81 and the outer housing 25A.

[0058] As shown by arrow D1 in Figure 9, when the molten resin encasing the inner housing 25B solidifies, the resin contracts from the protrusion 81b toward the groove 81a. The tip portion of the protrusion 81b is compressed radially by the resin. The tip portion includes the tip of the protrusion 81b and the area surrounding the tip. This further narrows the radial gap between the tip portion of the protrusion 81b and the outer housing 25A.

[0059] 4 and 5, it is conceivable that water flowing upstream inside sensor housing 25 may leak out onto the outer peripheral surface of inner housing 25B through the axial gap between outer housing 25A and inner housing 25B. The position of the outer peripheral surface from which water leaks may be, for example, on the opposite side of uneven portion 81 from protrusion 25B2 of inner housing 25B.

[0060] However, the radial gap between the tip of the protrusion 81b and the outer housing 25A is narrowed further due to molding shrinkage. This prevents water from flowing circumferentially along the outer circumferential surface of the inner housing 25B and reaching the protrusion 25B2. This in turn prevents water from entering the second housing chamber 53 from the circumferential direction of the inner housing 25B. The substrate 23 housed inside the second housing chamber 53 will not get wet. This further improves the waterproofness of the sensor device 10.

[0061] (2) Inner housing 25B has wall portion 73. Wall portion 73 separates the inside and outside of inner housing main body 25B1 in the radial direction of inner housing 25B. Therefore, as shown by arrow D3 in FIG. 3, water that flows upstream inside sensor housing 25 can be prevented from entering second accommodation chamber 53. Circuit board 23 is also prevented from getting wet. This further improves the waterproofness of sensor device 10 compared to a configuration in which the inside and outside of inner housing main body 25B1 communicate with each other via an opening.

[0062] (3) The first magnetic flux collecting ring 61 has a protrusion 91a that protrudes radially outward. The second magnetic flux collecting ring 62 has a protrusion 92a that protrudes radially outward. Therefore, by molding the outer housing 25A, the inner surfaces of the two protrusions 91a, 92a can be covered with the synthetic resin that constitutes the inner housing 25B.

[0063] Furthermore, when the molten resin encasing the inner housing 25B solidifies during molding of the outer housing 25A, the resin shrinks toward the inside in the radial direction of the inner housing 25B when viewed as the entire sensor housing 25. This further narrows the radially outer gaps between the two protrusions 91a, 92a and the outer housing 25A.

[0064] 3, water that flows upstream inside sensor housing 25 can be prevented from entering second accommodation chamber 53 through the gap at the boundary between inner housing 25B and two protrusions 91a, 92a. This also prevents substrate 23 from getting wet. This further improves the waterproofness of sensor device 10 compared to a configuration in which the inner surfaces of two protrusions 91a, 92a are exposed to the inside of inner housing 25B.

[0065] <Other embodiments> This embodiment may be modified as follows. The number of grooves 81a in the uneven portion 81 may be one, or may be four or more. As the number of grooves 81a increases, the number of protrusions 81b also increases. This increases the number of locations where the radial gap between the inner housing 25B and the outer housing 25A is narrower, further improving the waterproofness of the sensor device 10.

[0066] The grooves 81a of the uneven portion 81 may be inclined in a direction intersecting the axial direction of the inner housing 25B. The uneven portion 81 may have a plurality of grooves 81a in two directions, and the grooves 81a in the two directions may be provided so as to intersect. The width of the grooves 81a may be adjusted as appropriate.

[0067] The protrusions 81b may be provided so as to protrude from the outer peripheral surface of the inner housing 25B. By providing multiple protrusions 81b, grooves 81a are formed between the protrusions 81b. This also provides the uneven portion 81. Therefore, the effect described in section (1) above can be obtained.

[0068] The sensor device 10 may be configured without the first magnetic sensor 45 or the second magnetic sensor 46. In this case, the first magnetic flux collecting ring 61 may be configured without one of the two magnetic flux collecting protrusions 61a, 61b. The second magnetic flux collecting ring 62 may be configured without one of the two magnetic flux collecting protrusions 61a, 61b.

[0069] Depending on the product specifications, the inner surface of the protruding portion 91a of the first magnetic flux collecting ring 61 may not be covered with the synthetic resin that constitutes the inner housing 25B. Also, the inner surface of the protruding portion 92a of the second magnetic flux collecting ring 62 may not be covered with the synthetic resin that constitutes the inner housing 25B.

[0070] The first magnetic flux collecting ring 61 may have a configuration in which the protrusion 91a is omitted. The second magnetic flux collecting ring 62 may have a configuration in which the protrusion 92a is omitted. In this case, the ring body 91 of the first magnetic flux collecting ring 61 and the ring body 92 of the second magnetic flux collecting ring 62 have a smooth arc-shaped plate shape. The inner surface area of ​​the first magnetic flux collecting ring 61 where the magnetic flux collecting protrusions 61a and 61b are provided and the inner surface area of ​​the second magnetic flux collecting ring 62 where the magnetic flux collecting protrusions 62a and 62b are provided may be covered with the synthetic resin that forms the inner housing 25B.

[0071] 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 driving gear is mounted on the outer circumferential surface of the rotating shaft 11 so as to rotate integrally therewith. Two driven gears are rotatably supported inside the second housing chamber 53. These driven gears have different numbers of teeth. A sensor is provided on the substrate 23 to generate an electric signal corresponding to the rotation angle of each driven gear. The driven gears mesh with the main driving gear through an opening provided at the boundary between the first housing chamber 52 and the second housing chamber 53. Therefore, the two driven gears rotate in conjunction with the rotation of the main driving gear. Because the two driven gears have different numbers of teeth, the rotation angles of the two driven gears relative to the rotation angle of the main driving gear are different. Therefore, the phases of the electric signals generated by the first magnetic sensor 45 and the second magnetic sensor 46 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 sensors. By providing the uneven portion 81 on the outer peripheral surface of the inner housing 25B, the effect described in the previous section (1) can be obtained. [Explanation of symbols]

[0072] 10...Sensor device 11...Rotation axis 21...Permanent magnet 22...Magnetic yoke 23... Circuit board 25...Sensor housing 25A...Outer housing 25B...Inner housing 45...First magnetic sensor 46...Second magnetic sensor 52...First containment cell 53...Second containment cell 61...First magnetism collecting ring 61a, 61b...Magnetism collecting protrusion 62...Second magnetism collecting ring 62a, 62b...Magnetism collecting protrusion 81...Uneven part 81a...Groove 81b…Protrusion 73...Wall part

Claims

1. a sensor configured to detect a physical quantity related to the rotational motion of a rotation shaft that is a detection target; a substrate on which the sensor is provided; a sensor housing having a first accommodating chamber into which the rotating shaft is inserted and a second accommodating chamber into which the substrate is accommodated; The sensor housing includes a cylindrical inner housing that is a resin molded product, and an outer housing which is a resin molded product into which the inner housing is inserted, an inner periphery of the inner housing is exposed to the inside of the first accommodating chamber, while a portion of an outer periphery of the inner housing is exposed to the inside of the second accommodating chamber; The inner housing has a portion exposed to the inside of the second accommodating chamber, and the portion has projections and depressions provided along the entire axial length in two circumferentially adjacent regions on the outer periphery.

2. The uneven portion includes a groove portion having a plurality of concave curved surfaces extending over the entire axial length of the inner housing and spaced apart in the circumferential direction of the inner housing; The sensor device according to claim 1 , further comprising: protrusions formed between the plurality of grooves by providing the grooves.

3. The uneven portion includes a plurality of protrusions having convex curved surfaces extending over the entire axial length of the inner housing and spaced apart in the circumferential direction of the inner housing; The sensor device according to claim 1 , further comprising: grooves formed between the plurality of protrusions by providing the protrusions.

4. 4. The sensor device according to claim 1, wherein the inner housing has a wall portion provided so as to separate the first and second chambers.

5. a permanent magnet located inside the first housing chamber and rotatable integrally with the rotation shaft; a magnetic yoke located inside the first housing chamber, the rotational position of which changes relative to the permanent magnet as the rotation shaft twists; a first magnetic flux collecting ring that is inserted into the inner housing in an exposed state so as to surround the magnetic yoke and collects magnetic flux from the magnetic yoke; a second magnetic flux collecting ring that is inserted in an exposed state on the inner periphery of the inner housing so as to surround the magnetic yoke at an axial position of the magnetic yoke different from that of the first magnetic flux collecting ring, and that collects magnetic flux from the magnetic yoke; the first magnetic flux collecting ring and the second magnetic flux collecting ring each have a magnetic flux collecting protrusion that protrudes radially outward from an outer circumferential surface thereof and penetrates the wall portion to be exposed inside the second accommodating chamber, the sensor is a magnetic sensor interposed between the two magnetic flux collecting protrusions and configured to generate an electric signal according to magnetic flux leaking between the two magnetic flux collecting protrusions, 5. The sensor device according to claim 4, wherein the inner surfaces of the first and second magnetic flux collecting rings, where the magnetic flux collecting protrusions are provided, are covered with a resin that constitutes the inner housing.

6. The sensor device according to claim 5 , wherein the portions of the first and second magnetic flux collecting rings where the magnetic flux collecting protrusions are provided are positioned radially outward relative to other portions of the rings.

7. 7. The sensor device according to claim 1, wherein the rotation shaft is a pinion shaft that meshes with a steering shaft that steers steered wheels of a vehicle.

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