Sensor device

Abstract

A magnetic shield (42) is provided with a first split shield (91) and a second split shield (92) that are split in the axial direction of a rotary shaft. The first split shield (91) has a first end wall (101) that comes into contact with a sensor body (41) from the axial direction, and a first side wall (102) that extends from the circumferential edge of the first end wall (101) toward the second split shield (92). The second split shield (92) has a second end wall (111) that covers the sensor body (41) from a direction opposite to the first end wall (101), and a second side wall (112) that extends from the circumferential edge of the second end wall (111) toward the first split shield (91). The second split shield (92) further has a pressing part (117) that presses the sensor body (41) toward the first split shield (91).

Description

Sensor Device

[0001] The present disclosure relates to a sensor device.

[0002] Conventionally, sensor devices that detect torque applied to a rotating shaft are known. Such a rotating shaft includes an input shaft and an output shaft connected to the input shaft via a torsion bar. For example, a sensor device described in Patent Document 1 includes a permanent magnet that rotates integrally with the input shaft, a pair of yoke cores that rotate integrally with the output shaft, and a sensor main body that is fixed to a housing that rotatably accommodates the rotating shaft. The sensor main body includes a pair of magnetic flux collecting rings disposed on the outer peripheries of the pair of yoke cores and a magnetic sensor that generates a signal corresponding to magnetic flux flowing through the pair of magnetic flux collecting members. The torque applied to the rotating shaft is detected based on the signal output from the magnetic sensor.

[0003] As described above, the sensor device of Patent Document 1 detects torque based on magnetic flux, and therefore, if the sensor device is affected by an external magnetic field, it will be unable to detect torque accurately. Therefore, Patent Document 2, for example, discloses covering the entire sensor device with a magnetic shield made of a magnetic material.

[0004] JP 2023-110681 A JP 2003-149062 A

[0005] Although Patent Document 2 discloses that the entire sensor device is covered with a magnetic shield, it does not disclose a specific manner in which the magnetic shield is assembled, which may result in rattle of the components of the sensor device within the magnetic shield.

[0006] One aspect of the present disclosure provides a sensor device configured to detect torque applied to a rotating shaft. The rotating shaft includes a first shaft and a second shaft connected to the first shaft via a torsion bar. The sensor device includes a permanent magnet configured to rotate integrally with the first shaft, first and second yoke cores configured to rotate integrally with the second shaft, and a fixing unit fixed to a housing that accommodates the rotating shaft. The fixing unit includes a sensor main body and a magnetic shield fixed to the housing and covering the sensor main body. The sensor main body includes a first magnetic flux collector disposed at a distance from the first yoke core, a second magnetic flux collector disposed at a distance from the second yoke core, and a magnetic sensor configured to generate a signal corresponding to magnetic flux flowing through the first and second magnetic flux collectors. The magnetic shield includes a first divided shield and a second divided shield divided in the axial direction of the rotating shaft. The first divided shield has a first end wall that contacts the sensor main body in the axial direction and a first side wall that extends from a peripheral edge of the first end wall toward the second divided shield. The second divided shield has a second end wall that covers the sensor main body from the direction opposite the first end wall and a second side wall that extends from a peripheral edge of the second end wall toward the first divided shield. The second divided shield further has a pressing portion configured to press the sensor main body toward the first divided shield.

[0007] Fig. 2 is an exploded perspective view of a sensor device according to an embodiment; Fig. 3 is a cross-sectional view taken at a position passing through the axis of the sensor device of Fig. 1; Fig. 4 is an exploded perspective view of a fixing unit provided in the sensor device of Fig. 1; Fig. 5 is a cross-sectional view taken at a position passing through a pressing portion of the sensor device of Fig. 1; Fig. 6 is an enlarged cross-sectional view of a fitting portion between a first divided shield and a second divided shield in the sensor device of Fig. 2;

[0008] An embodiment of a sensor device will be described below with reference to the drawings. In this specification, the term "cylindrical" refers to a cylindrical shape as long as it can be considered as a whole, and includes shapes formed by combining multiple components and shapes with a notch or other feature, such as a C-shape. Cylindrical shapes include, but are not limited to, circular, elliptical, and polygonal shapes with sharp or rounded corners when viewed in the axial direction. In this specification, the term "annular" refers to a circular shape as long as it can be considered as a whole, and includes shapes formed by combining multiple components and shapes with a notch or other feature, such as a C-shape. An annular shape includes, but is not limited to, circular, elliptical, and polygonal shapes with sharp or rounded corners when viewed in the axial direction. In this specification, "facing" refers to surfaces or components facing each other, and includes not only cases where the surfaces or components are completely facing each other, but also cases where the surfaces or components are partially facing each other. In addition, in this specification, "facing" refers to both cases where a separate component is interposed between two components and cases where there is no component interposed between the two components.

[0009] (Overall Configuration) As shown in Figures 1 and 2, the sensor device 1 is provided around a rotating shaft 2. The rotating shaft 2 is rotatably accommodated in a housing 3. The rotating shaft 2 includes an input shaft 4, which is a first shaft, a torsion bar 5, and an output shaft 6, which is a second shaft. The input shaft 4 and the output shaft 6 are connected to each other via the torsion bar 5. The input shaft 4, the torsion bar 5, and the output shaft 6 are located on the same axis L.

[0010] In this embodiment, the rotating shaft 2 is a pinion shaft of a rack-and-pinion mechanism that constitutes a steering device of a vehicle, and the housing 3 is a sensor housing fixed to a rack housing that rotatably supports the pinion shaft. In the following description, one end side of the rotating shaft 2, i.e., one side in the direction along the axis L, is referred to as the upper side, and the other end side of the rotating shaft 2, i.e., the other side in the direction along the axis L, is referred to as the lower side. A steering wheel is connected to the upper end of the pinion shaft via an intermediate shaft and a column shaft. In other embodiments, the rotating shaft 2 may be a column shaft.

[0011] The sensor device 1 includes a magnet assembly 11 that rotates integrally with the input shaft 4, a magnetic yoke assembly 12 that rotates integrally with the output shaft 6, and a fixed unit 13 that is fixed to the housing 3. In other words, even when the rotating shaft 2 rotates, the fixed unit 13 does not rotate. When torque is applied to the rotating shaft 2 through the driver's operation of the steering wheel, the torsion bar 5 twists, causing the input shaft 4 and the output shaft 6 to rotate relative to each other. As a result, the relative circumferential positions of the magnet assembly 11 and the magnetic yoke assembly 12 change, and the magnetic flux passing through the first magnetic flux collector 51 and the second magnetic flux collector 52 of the fixed unit 13 (described later) changes. In other words, the magnetic flux passing through the first magnetic flux collector 51 and the second magnetic flux collector 52 changes depending on the magnitude of the input torque. The sensor device 1 detects the torque applied to the rotating shaft 2 based on this change in magnetic flux. The sensor device 1 of this embodiment is configured to detect not only the torque applied to the rotating shaft 2 (steering torque) but also the rotation angle (steering angle) of the rotating shaft 2. Each component of the sensor device 1 will be described in detail below.

[0012] (Magnet assembly 11) The magnet assembly 11 includes a magnet holder 21 fixed to the outer circumferential surface of the input shaft 4 and a permanent magnet 22 held by the magnet holder 21. The permanent magnet 22 is cylindrical. In this embodiment, the permanent magnet 22 has a circular shape when viewed in the axial direction. The permanent magnet 22 is magnetized in a radial direction perpendicular to the axial direction of the rotating shaft 2 so that magnetic poles of different polarities are arranged alternately in the circumferential direction. In another embodiment, the permanent magnet 22 may be directly fixed to the outer circumferential surface of the input shaft 4 so as to be rotatable integrally with the input shaft 4. Alternatively, the permanent magnet 22 may be a plurality of plate-shaped magnets.

[0013] (Magnetic Yoke Assembly 12 ) The magnetic yoke assembly 12 includes a first yoke core 31 , a second yoke core 32 , a collar 33 , and a yoke holder 34 that holds the first yoke core 31 , the second yoke core 32 , and the collar 33 .

[0014] The first yoke core 31 and the second yoke core 32 are made of a magnetic material and have an annular shape. In this embodiment, the first yoke core 31 and the second yoke core 32 have a circular shape when viewed in the axial direction. The first yoke core 31 and the second yoke core 32 are arranged with a gap between them in the axial direction.

[0015] The first yoke core 31 and the second yoke core 32 are arranged on the outer circumferential side of the permanent magnet 22 with a gap between them. The first yoke core 31 and the second yoke core 32 each have a plurality of claw portions 35, 36 that face the permanent magnet 22 in the radial direction. The claw portions 35, 36 protrude in directions that bring them closer to each other. The claw portions 35 are provided at equal intervals in the circumferential direction on the first yoke core 31, and the claw portions 36 are provided at equal intervals in the circumferential direction on the second yoke core 32. The claw portions 35 and the claw portions 36 are arranged alternately in the circumferential direction.

[0016] The collar 33 is made of, for example, a metal material and has an annular shape. In this embodiment, the collar 33 has a circular shape when viewed in the axial direction. The collar 33 is disposed below the first yoke core 31 and the second yoke core 32 with a gap therebetween. The collar 33 is fixed to the outer periphery of the upper end of the output shaft 6 so as to be rotatable together with the output shaft 6. As a result, the magnetic yoke assembly 12 is fixed to the outer periphery of the output shaft 6 via the collar 33 so as to be rotatable together with the output shaft 6.

[0017] The yoke holder 34 is made of, for example, a resin material and has a cylindrical shape. In this embodiment, the yoke holder 34 has a circular shape when viewed in the axial direction. The yoke holder 34 holds the first yoke core 31, the second yoke core 32, and the collar 33 so that the inner surfaces of the claws 35, 36 and the inner peripheral surface of the collar 33 are exposed on the inner peripheral side of the yoke holder 34. The yoke holder 34 has a gear portion 37 including a plurality of external teeth that protrudes on the outer peripheral side of the yoke holder 34. The gear portion 37 is provided on the upper end of the yoke holder 34.

[0018] The yoke holder 34 in this embodiment is a resin molded part formed by insert molding using the first yoke core 31, the second yoke core 32, and the collar 33 as insert parts. In other embodiments, the first yoke core 31 and the second yoke core 32 may not be insert parts, and the first yoke core 31, the second yoke core 32, and the collar 33 may be assembled to a separately formed yoke holder 34.

[0019] 2 to 4, the fixed unit 13 includes a sensor main body 41 and a magnetic shield 42 that is fixed to the housing 3 and covers substantially the entire sensor main body 41. The magnetic shield 42 is fixed to the housing 3 by, for example, bolts (not shown). The magnetic shield 42 will be described in detail later.

[0020] The sensor main body 41 includes a magnetic flux collector assembly 45, a gear assembly 46, and a circuit board 47. The magnetic flux collector assembly 45 includes a first magnetic flux collector member 51, a second magnetic flux collector member 52, a first magnetic flux collector holder 53 that holds the first magnetic flux collector member 51, and a second magnetic flux collector holder 54 that holds the second magnetic flux collector member 52.

[0021] The first magnetic flux collecting member 51 and the second magnetic flux collecting member 52 are made of a magnetic material and have an annular shape. In this embodiment, the first magnetic flux collecting member 51 and the second magnetic flux collecting member 52 have a C-shape when viewed in the axial direction. The first magnetic flux collecting member 51 and the second magnetic flux collecting member 52 are arranged at an interval from each other in the axial direction. The first magnetic flux collecting member 51 is arranged at an interval on the outer circumferential side of the first yoke core 31. The second magnetic flux collecting member 52 is arranged at an interval on the outer circumferential side of the second yoke core 32. The first magnetic flux collecting member 51 has two first protrusions 61 protruding in the radial direction, and the second magnetic flux collecting member 52 has two second protrusions 62 protruding in the radial direction.

[0022] The first magnetic flux collecting holder 53 has an annular first frame portion 63 and a support portion 64 provided contiguous to the first frame portion 63 on the outer periphery of the first frame portion 63. In the present embodiment, the first frame portion 63 has a circular shape when viewed in the axial direction. The first frame portion 63 holds the first magnetic flux collecting member 51 such that the inner circumferential surface of the first magnetic flux collecting member 51 is exposed to the inner circumferential side of the first magnetic flux collecting holder 53. The support portion 64 is provided with a connector for connecting the sensor device 1 to an external control device or the like.

[0023] The second magnetic flux collecting holder 54 has an annular second frame portion 65 and a cover portion 66 provided contiguous with the second frame portion 65 on the outer periphery of the second frame portion 65. In the present embodiment, the second frame portion 65 has a circular shape when viewed in the axial direction. The second frame portion 65 holds the second magnetic flux collecting member 52 such that the inner circumferential surface of the second magnetic flux collecting member 52 is exposed on the inner circumferential side of the second magnetic flux collecting holder 54. When the first magnetic flux collecting holder 53 and the second magnetic flux collecting holder 54 are assembled together, the first protrusion 61 and the second protrusion 62 face each other in the axial direction.

[0024] In the present embodiment, the first magnetic flux collecting holder 53 is a resin molded product formed by insert molding with the first magnetic flux collecting member 51 as an insert part, and the second magnetic flux collecting holder 54 is a resin molded product formed by insert molding with the second magnetic flux collecting member 52 as an insert part. In other embodiments, the first magnetic flux collecting member 51 may not be an insert part, but may be assembled to a separately formed first magnetic flux collecting holder 53. Similarly, the second magnetic flux collecting member 52 may not be an insert part, but may be assembled to a separately formed second magnetic flux collecting holder 54.

[0025] The gear assembly 46 includes two driven gears 71, 72 and a support plate 73. The gear assembly 46 is held above the support portion 64 of the first magnetic flux collector holder 53. Each of the driven gears 71, 72 meshes with the gear portion 37 of the magnetic yoke assembly 12. The driven gears 71, 72 have different numbers of teeth. Therefore, when the gear portion 37 (output shaft 6) rotates, the rotation angles of the driven gears 71 and 72 are different from each other. A sensor magnet (not shown) is fixed to each of the driven gears 71, 72 so as to be rotatable integrally therewith.

[0026] The support plate 73 has a flat plate shape and rotatably supports the driven gears 71 and 72. The support plate 73 is fixed to the first magnetic flux collector holder 53 so that the driven gears 71 and 72 are sandwiched between the support plate 73 and the support portion 64 of the first magnetic flux collector holder 53.

[0027] The circuit board 47 has a flat plate shape. Various circuit elements including a magnetic sensor 81 and two rotation sensors 82, 83 are mounted on the circuit board 47. The circuit board 47 is held below the support part 64 of the first magnetic flux collector holder 53. The cover part 66 of the second magnetic flux collector holder 54 covers the circuit board 47 from below.

[0028] The magnetic sensor 81 is, for example, a Hall sensor or a magnetoresistive sensor. The magnetic sensor 81 is mounted on the circuit board 47 in a region sandwiched between the first protrusion 61 and the second protrusion 62. In another embodiment, a redundant magnetic sensor other than the magnetic sensor 81 may be mounted on the circuit board 47 in another region sandwiched between the first protrusion 61 and the second protrusion 62. As described above, the magnetic flux passing through the first magnetic flux collecting member 51 and the second magnetic flux collecting member 52 changes depending on the magnitude of the torque input to the rotating shaft 2. The magnetic sensor 81 generates a signal corresponding to this magnetic flux, i.e., a signal indicating the torque applied to the rotating shaft 2.

[0029] The rotation sensors 82, 83 are, for example, Hall sensors or magnetic resistance sensors. On the circuit board 47, the rotation sensor 82 is mounted in an area facing a sensor magnet that rotates integrally with the driven gear 71, and the rotation sensor 83 is mounted in an area facing a sensor magnet that rotates integrally with the driven gear 72. As described above, the driven gears 71, 72 rotate in response to the rotation of the magnetic yoke assembly 12. The rotation sensors 82, 83 generate signals that indicate the rotation angles of the driven gears 71, 72, i.e., the rotation angle of the rotating shaft 2.

[0030] (Magnetic Shield 42) Next, the configuration of the magnetic shield 42 will be described. The magnetic shield 42 includes a first divided shield 91 and a second divided shield 92 that are divided in the axial direction of the rotating shaft 2. The first divided shield 91 covers the sensor main body 41 from the upper side and the outer periphery, and the second divided shield 92 covers the sensor main body 41 from the lower side and the outer periphery. The first divided shield 91 and the second divided shield 92 are formed by bending a metal plate made of, for example, a magnetic material.

[0031] The first divided shield 91 has a first end wall 101 that contacts the sensor main body 41 in the axial direction, and a first side wall 102 that extends from the peripheral edge of the first end wall 101 toward the second divided shield 92. The first end wall 101 has a generally circular, flat plate shape. The first end wall 101 has a first through hole 103 that penetrates in the axial direction. The input shaft 4 is rotatably inserted through the first through hole 103. In this embodiment, the first end wall 101 contacts the magnetic flux collector assembly 45 and the gear assembly 46 of the sensor main body 41 from above. Specifically, the first end wall 101 contacts a portion of the first frame portion 63 of the first magnetic flux collector holder 53 and a portion of the support plate 73 of the gear assembly 46 from above.

[0032] The first side wall 102 has a generally cylindrical shape. In this embodiment, the first side wall 102 has a C-shape when viewed in the axial direction. A portion of the first side wall 102 is cut out to avoid interference with the support portion 64 of the first magnetic flux collecting holder 53. The first side wall 102 has a first base portion 104 and multiple first extension portions 105 extending from the tip of the first base portion 104. In this embodiment, the first side wall 102 has three first extension portions 105. Each first extension portion 105 extends toward the second divided shield 92 by a distance greater than the first base portion 104. The multiple first extension portions 105 are arranged at approximately equal angular intervals in the circumferential direction.

[0033] As shown in FIGS. 3 and 5 , each first extension portion 105 has a fitting hole 106 penetrating radially through the rotating shaft 2. The fitting hole 106 has, for example, a rectangular shape when viewed radially. A locking portion 107 is provided on the inner peripheral edge of each fitting hole 106. In this embodiment, the locking portion 107 is provided on a lower edge of the inner peripheral edge of the fitting hole 106. The locking portion 107 is, for example, a leaf spring formed by bending a portion of the first extension portion 105 and is elastically deformable in the radial direction. When not elastically deformed, the locking portion 107 is inclined inward relative to the first side wall 102 at an angle such that the tip of the locking portion 107 interferes with the second side wall 112 (described later). The multiple locking portions 107 are arranged at approximately equal angular intervals in the circumferential direction.

[0034] As shown in FIGS. 2 and 3 , the second divided shield 92 has a second end wall 111 that covers the sensor main body 41 from the side opposite the first end wall 101, and a second side wall 112 that extends from the peripheral edge of the second end wall 111 toward the first divided shield 91. The second end wall 111 has a generally circular, flat plate shape. The second end wall 111 covers the sensor main body 41 from below. The second end wall 111 has a second through hole 113 that penetrates in the axial direction. The magnetic yoke assembly 12 is rotatably inserted through the second through hole 113. In this embodiment, the second end wall 111 does not contact the sensor main body 41. In other embodiments, the second end wall 111 may contact, for example, the magnetic flux collector assembly 45.

[0035] The second side wall 112 has a generally cylindrical shape. In this embodiment, the second side wall 112 has a cylindrical shape that is slightly smaller than the first side wall 102. In this embodiment, the second side wall 112 has a C-shape when viewed in the axial direction. A portion of the second side wall 112 is cut out to avoid interference with the support portion 64 of the second magnetic flux collector holder 54. The second side wall 112 has a second base portion 114 and multiple second extension portions 115 extending from the tip of the second base portion 114. In this embodiment, the position of the tip of the second base portion 114 coincides with the position of the tip of the first base portion 104 when viewed in the radial direction. As a result, the first side wall 102 and the second side wall 112 cover the sensor main body 41 so that it is not visible from the outer periphery. In other embodiments, the first base portion 104 and the second base portion 114 may or may not face each other in the radial direction.

[0036] In this embodiment, the second side wall 112 has three second extension portions 115. The second extension portions 115 extend toward the first divided shield 91 more than the second base portion 114. The multiple second extension portions 115 are arranged at approximately equal angular intervals in the circumferential direction. The second extension portions 115 are provided at positions radially opposite the first extension portions 105. As a result, when the first divided shield 91 attempts to move radially relative to the second divided shield 92, the first extension portions 105 abut against the second extension portions 115, thereby restricting the movement of the first divided shield 91. In other words, the first extension portions 105 and the second extension portions 115 are configured to restrict the radial movement of the first divided shield 91 relative to the second divided shield 92.

[0037] 3 and 5 , each second extension portion 115 has a protrusion 116 that protrudes radially outward. The protrusion 116 is inserted into the fitting hole 106 of the corresponding first extension portion 105. The locking portion 107 axially locks onto the protrusion 116 to prevent the first divided shield 91 from moving axially away from the second divided shield 92. Specifically, the tip of the locking portion 107 locks onto the outer peripheral surface of the protrusion 116 from below. As described above, when the locking portion 107 is not elastically deformed, its tip is inclined so as to interfere with the second side wall 112, and therefore the locking portion 107 presses the corresponding first extension portion 105 inward.

[0038] As shown in FIGS. 2 to 4 , the second divided shield 92 further has multiple pressing portions 117 that press the sensor main body 41 toward the first divided shield 91. The pressing portions 117 are, for example, leaf springs formed by bending a portion of the second divided shield 92, and are elastically deformable in the axial direction. In this embodiment, the second divided shield 92 has three pressing portions 117. The pressing portions 117 are provided on the second divided shield 92 at approximately equal angular intervals in the circumferential direction. Specifically, the pressing portions 117 include one end wall pressing portion 121 provided on the second end wall 111 and two side wall pressing portions 122 provided on the second side wall 112. The end wall pressing portion 121 presses the support portion 64 of the first magnetic flux collector holder 53 toward the first divided shield 91 (see FIG. 2 ). Each of the side wall pressing portions 122 presses the first frame portion 63 of the first magnetic flux collecting holder 53 toward the first divided shield 91 (see FIG. 4).

[0039] (Operations and Effects of the Present Embodiment) Next, operations and effects of the present embodiment will be described. (1) The second divided shield 92 has the pressing portion 117 that presses the sensor main body 41 toward the first divided shield 91 .

[0040] According to the above configuration, the sensor main body 41 is pressed toward the first divided shield 91 by the pressing portion 117, and is thereby pressed against the first end wall 101. This makes it possible to prevent the sensor main body 41 from rattling within the magnetic shield 42.

[0041] (2) The second divided shield 92 has a plurality of pressing portions 117 that are spaced apart in the circumferential direction, which effectively prevents the sensor body 41 from rattling within the magnetic shield 42 .

[0042] (3) The first side wall 102 and the second side wall 112 have a first extending portion 105 and a second extending portion 115, respectively. The first extending portion 105 and the second extending portion 115 face each other in the radial direction. The second extending portion 115 has a protruding portion 116 that protrudes in the radial direction. The first extending portion 105 has a locking portion 107 that locks with the protruding portion 116 in the axial direction so as to prevent the first divided shield 91 from moving away from the second divided shield 92 in the axial direction.

[0043] According to the above configuration, the locking portion 107 engages with the protrusion 116 in the axial direction, thereby preventing the first divided shield 91 from separating axially from the second divided shield 92. Therefore, compared to a case where the first divided shield 91 is fixed to the second divided shield 92 using, for example, screws, an increase in the number of parts of the sensor device 1 can be suppressed.

[0044] (4) The first extending portion 105 and the second extending portion 115 are configured to restrict the first divided shield 91 from moving radially relative to the second divided shield 92. The locking portion 107 is configured to press the second extending portion 115 radially.

[0045] According to the above configuration, the second divided shield 92 is pressed radially by the locking portion 107, so that rattle between the first divided shield 91 and the second divided shield 92 can be suppressed.

[0046] (5) The first divided shield 91 has a plurality of locking portions 107 spaced apart in the circumferential direction, which effectively suppresses rattle between the first divided shield 91 and the second divided shield 92.

[0047] This embodiment can be modified as follows. This embodiment and the following modifications can be combined to the extent that no technical contradiction occurs. In the above embodiment, the first magnetic flux collecting member 51 may have only one first protrusion. Similarly, the second magnetic flux collecting member 52 may have only one second protrusion.

[0048] In the above embodiment, the first magnetic flux collecting member 51 may be arranged to face the first yoke core 31 in the axial direction. In this case, the first magnetic flux collecting member 51 may be, for example, flat, and the shape thereof may be changed as appropriate. Similarly, the second magnetic flux collecting member 52 may be arranged to face the second yoke core 32 in the axial direction.

[0049] In the above embodiment, the shapes of the first magnetic field collecting holder 53 and the second magnetic field collecting holder 54 can be changed as appropriate. For example, the first magnetic field collecting holder 53 and the second magnetic field collecting holder 54 do not have to have the support portion 64 and the cover portion 66, respectively. Furthermore, instead of the first magnetic field collecting holder 53 and the second magnetic field collecting holder 54, the magnetic field collecting assembly 45 may include a single magnetic field collecting holder that holds both the first magnetic field collecting member 51 and the second magnetic field collecting member 52.

[0050] In the above embodiment, the first side wall 102 has three first extension portions 105. However, this is not limited thereto. The first side wall 102 may have only a single first extension portion 105. The first side wall 102 may also have two or four or more first extension portions 105. Similarly, the second side wall 112 may have only a single second extension portion 115, or may have two or four or more second extension portions 115. When the first side wall 102 has only a single first extension portion 105 and the second side wall 112 has only a single second extension portion 115, each of the first extension portion 105 and the second extension portion 115 may extend over a circumferential range greater than 180° around the axis L. This restricts radial movement of the first divided shield 91 relative to the second divided shield 92.

[0051] In the above embodiment, the first end wall 101 may be in contact with only one of the magnetic flux collector assembly 45 and the gear assembly 46. Furthermore, the first end wall 101 may be in contact with a portion of the sensor main body 41 other than the magnetic flux collector assembly 45 and the gear assembly 46.

[0052] In the above embodiment, the locking portion 107 may be configured not to press the second extending portion 115 in the radial direction. Even in this case, the locking portion 107 may be elastically deformable in the radial direction. In the above embodiment, the first extending portion 105 is provided with the fitting hole 106 and the second extending portion 115 is provided with the protrusion 116, but this is not limited thereto. The first extending portion 105 may be provided with a protrusion that protrudes toward the inner periphery, and the second extending portion 115 may be provided with a fitting hole. In this case, the locking portion provided in the fitting hole of the second extending portion 115 locks onto the protrusion from above.

[0053] In the above embodiment, the fitting holes 106 and the protrusions 116 do not have to be provided in the magnetic shield 42. In this case, the first divided shield 91 may be fixed to the second divided shield 92 using screws, for example.

[0054] In the above embodiment, the rotation sensors 82, 83 may be sensors other than sensors that detect magnetic flux, such as rotary encoders, as long as they can detect the rotation angles of the driven gears 71, 72. In this case, a sensor magnet that rotates integrally with the driven gears 71, 72 is not required.

[0055] In the above embodiment, the sensor device 1 is configured to detect not only the torque applied to the rotating shaft 2 but also the rotation angle of the rotating shaft 2. However, the sensor device 1 may be configured to detect only the torque. In this case, a configuration for detecting the rotation angle of the gear assembly 46 or the like is not required.

[0056] In the above embodiment, the magnet assembly 11 is fixed to the input shaft 4, and the magnetic yoke assembly 12 is fixed to the output shaft 6. However, the magnet assembly 11 may be fixed to the output shaft 6, and the magnetic yoke assembly 12 may be fixed to the input shaft 4. In this case, the input shaft 4 corresponds to the second shaft, and the output shaft 6 corresponds to the first shaft.

[0057] Next, the technical ideas that can be understood from the above embodiment and modified examples are additionally described below. (Supplementary Note 1) The sensor main body may further include a holder that holds the first magnetic flux collecting member and the second magnetic flux collecting member, and the pressing portion may press the holder toward the first divided shield.

[0058] (Note 2) The pressing portion may be one of a plurality of pressing portions, and the plurality of pressing portions may be arranged at intervals in the circumferential direction of the rotating shaft. (Note 3) The locking portion may be one of a plurality of locking portions, and the plurality of locking portions may be arranged at intervals in the circumferential direction of the rotating shaft.

Claims

1. A sensor device configured to detect torque applied to a rotating shaft, the rotating shaft including a first shaft and a second shaft connected to the first shaft via a torsion bar, the sensor device including: a permanent magnet configured to rotate integrally with the first shaft; a first yoke core and a second yoke core configured to rotate integrally with the second shaft; and a fixed unit fixed to a housing that houses the rotating shaft, the fixed unit including: a sensor main body portion; and a magnetic shield fixed to the housing and covering the sensor main body portion, the sensor main body portion including: a first magnetic flux concentrating member disposed at an interval from the first yoke core; a second magnetic flux concentrating member disposed at an interval from the second yoke core; and a magnetic sensor configured to generate a signal according to a magnetic flux flowing through the first magnetic flux concentrating member and the second magnetic flux concentrating member, the magnetic shield including a first divided shield and a second divided shield divided in an axial direction of the rotating shaft, the first divided shield having a first end wall that contacts the sensor main body portion from the axial direction and a first side wall that extends from a peripheral edge of the first end wall toward the second divided shield, the second divided shield having a second end wall that covers the sensor main body portion from a direction opposite to the first end wall and a second side wall that extends from a peripheral edge of the second end wall toward the first divided shield, the second divided shield further having a pressing portion configured to press the sensor main body portion toward the first divided shield.

2. The sensor device according to claim 1, wherein the first side wall and the second side wall each have a first extending portion and a second extending portion, the first extending portion and the second extending portion face each other in a radial direction orthogonal to the axial direction, one of the first extending portion and the second extending portion has a convex portion protruding in the radial direction, and the other of the first extending portion and the second extending portion has a locking portion configured to lock to the convex portion from the axial direction so as to regulate the first divided shield from being axially separated from the second divided shield.

3. The sensor device according to claim 2, wherein the first extension portion and the second extension portion are configured to restrict relative movement of the first divided shield in the radial direction with respect to the second divided shield, and the locking portion is further configured to press either one of the first extension portion and the second extension portion in the radial direction.

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