JP2021135139A - Sensor device - Google Patents

Abstract

To provide a sensor device capable of enhancing detection accuracy of a sensor.SOLUTION: A permanent magnet 21 is attached to a rotary shaft 11. A magnetic yoke 22 is arranged so as to surround the permanent magnet 21. An upper magnetic flux collection ring has an upper magnetic flux collection unit including an annular upper ring unit surrounding the magnetic yoke 22 and a portion extending radially outward from the upper ring unit. A lower magnetic flux collection ring has an annular lower ring unit surrounding the magnetic yoke 22 and a lower magnetic collection unit including a portion extending radially outward from the lower ring unit. A magnetic sensor is disposed between the upper and lower magnetic collection units that oppose each other in an axial direction O. The magnetic sensor detects a magnetic flux of a magnetic circuit formed by the permanent magnet 21, the magnetic yoke 22, the upper magnetic flux collection ring, and the lower magnetic flux collection ring. A magnetic shielding 131 for a sensor is arranged outside the magnetic sensor so as to overlap with the magnetic sensor in the axial direction O.SELECTED DRAWING: Figure 1

Description

The present invention relates to a sensor device.

Patent Document 1 discloses a sensor device that detects the torque applied to the steering wheel. The sensor device is provided on the steering shaft connected to the steering wheel. The steering shaft is composed of an input shaft, an output shaft, and a torsion bar connecting the input shaft and the output shaft.

The sensor device uses a permanent magnet fixed to the input shaft, two magnetic yokes fixed to the output shaft, two magnetic flux collecting rings that induce magnetic flux from the magnetic yoke, and magnetic flux induced in the magnetic collecting ring. It has a magnetic sensor to detect. When torque is applied to the input shaft and the torsion bar is twisted and deformed, the relative positions of the permanent magnet and the magnetic yoke in the rotational direction change. The magnetic sensor detects the torque applied to the torsion bar based on the change in the magnetic flux of the magnetic collecting ring due to the change in the relative position between the permanent magnet and the magnetic yoke.

The sensor device of Patent Document 1 is provided with a magnetic shield that surrounds the radial outside of the magnetic collection ring in order to block magnetic noise from other than the detection target from being transmitted to the magnetic collection ring.

Japanese Unexamined Patent Publication No. 2004-125717

Magnetic noise from other than the detection target may be directly transmitted to the magnetic sensor. However, in the sensor device of Patent Document 1, no measures are taken to block magnetic noise from other than the detection target directly transmitted to the magnetic sensor. Therefore, the detection accuracy of the sensor device may decrease.

The sensor device for solving the above problems includes a permanent magnet attached to a rotating shaft and magnetized in the circumferential direction, a magnetic yoke arranged in a magnetic field formed by the permanent magnet so as to surround the permanent magnet, and the above. An upper magnetic collecting ring having an annular upper ring portion surrounding the magnetic yoke and an upper magnetic collecting portion including a portion extending radially outward from the upper ring portion, and the upper magnetic collecting ring and the axis of the rotating shaft. A lower magnetic collection portion that is arranged side by side in the direction and has an annular lower ring portion that surrounds the magnetic yoke and a lower magnetic collection portion that includes a portion that extends radially outward from the lower ring portion. The ring is arranged between the upper magnetic collecting portion and the lower magnetic collecting portion facing each other in the axial direction, and the permanent magnet, the magnetic yoke, the upper magnetic collecting ring, and the lower collecting portion. It includes a magnetic sensor that detects the magnetic flux of a magnetic circuit formed by a magnetic ring, and a magnetic shield for a sensor that is arranged outside the magnetic sensor so as to overlap the magnetic sensor in the axial direction.

According to the above configuration, the detection target of the magnetic sensor is the magnetic flux of the magnetic circuit. The magnetic flux of the magnetic circuit passes between the upper magnetic collecting portion and the lower magnetic collecting portion in the axial direction. By arranging the magnetic sensor between the upper magnetic collecting part and the lower magnetic collecting part, the magnetic flux of the magnetic circuit passing between the upper magnetic collecting part and the lower magnetic collecting part in the axial direction is detected. .. The magnetic shield for the sensor is arranged outside the magnetic sensor so as to overlap the magnetic sensor in the axial direction. As a result, it is possible to suppress the transmission of magnetic noise other than the detection target to the magnetic sensor from the axial direction. Therefore, it is possible to prevent the magnetic sensor from detecting magnetic noise from a source other than the detection target.

In the above sensor device, the permanent magnet, the magnetic yoke, the upper magnetic collecting ring, the lower magnetic collecting ring, and a sensor housing for accommodating the magnetic sensor are provided, and the magnetic shield for the sensor is an outer surface of the sensor housing. It is preferable that it is assembled in.

In the above configuration, since the magnetic shield for the sensor is assembled to the outer surface of the sensor housing, it is possible to minimize the design change of the sensor housing and each configuration housed in the sensor housing.

In the above sensor device, it is preferable to include an upper ring portion magnetic shield arranged above the upper ring portion so as to overlap the upper ring portion in the axial direction.

In the above configuration, by arranging the upper ring portion magnetic shield above the upper ring portion, it is possible to suppress the transmission of magnetic noise other than the detection target from above to the upper ring portion.

In the above sensor device, it is preferable to provide a lower ring portion magnetic shield arranged below the lower ring portion so as to overlap the lower ring portion in the axial direction.

In the above configuration, by arranging the lower ring portion magnetic shield below the lower ring portion, it is possible to suppress the transmission of magnetic noise other than the detection target from the lower side to the lower ring portion.

In the above sensor device, the magnetic shield of the upper ring portion arranged above the upper ring portion so as to overlap the upper ring portion in the axial direction, and the lower ring portion so as to overlap the lower ring portion in the axial direction. It is provided with a lower ring portion magnetic shield arranged below the lower ring portion, and a connecting portion for axially connecting the upper ring portion magnetic shield and the lower ring portion magnetic shield.

In the above configuration, by arranging the upper ring portion magnetic shield above the upper ring portion and arranging the lower ring portion magnetic shield below the lower ring portion, magnetic noise other than the detection target is generated from the axial direction to the upper ring. It is possible to suppress transmission to the portion and the lower ring portion. Further, when the upper ring portion magnetic shield and the lower ring portion magnetic shield are connected by a connecting portion, magnetic noise is concentrated on either the upper ring portion magnetic shield or the lower ring portion magnetic shield. However, the magnetic noise can be passed to the other magnetic shield. As a result, the magnetic noise can be dispersed between the upper ring portion magnetic shield and the lower ring portion magnetic shield, so that even if the magnetic noise is partially concentrated, the magnetic noise is transmitted to each ring portion. It can be suppressed.

In the above sensor device, the connection portion is provided on the peripheral portion of the upper ring portion magnetic shield and the lower ring portion magnetic shield on the opposite side of the rotation shaft from the sensor magnetic shield. Is preferable.

In the above configuration, since the connecting portion is provided on the opposite side of the magnetic shield for the sensor with the rotation shaft sandwiched between them, the connecting portion connecting the magnetic shield of each ring portion does not extend so as to surround the outer side of each magnetic collecting portion. The connection length of the connection part can be shortened by a good amount.

In the above sensor device, it is preferable that the sensor magnetic shield includes a portion arranged outside the magnetic sensor so as to overlap the magnetic sensor in a direction orthogonal to the axial direction.

In the above configuration, by arranging the magnetic shield for the sensor in the direction orthogonal to the axial direction of the magnetic sensor, it is possible to suppress the transmission of magnetic noise other than the detection target to the magnetic sensor from the direction orthogonal to the axial direction. ..

In the above sensor device, the magnetic permeability of the material constituting the sensor magnetic shield is preferably set lower than the magnetic permeability of the material constituting the upper magnetic collecting ring and the lower magnetic collecting ring.

In the above configuration, the material that constitutes each magnetic collection ring is set to a material that allows the magnetic flux to pass through more easily than the material that constitutes the magnetic shield for the sensor, so that the magnetic flux of the magnetic circuit that is the detection target of the magnetic sensor is set. , It is possible to suppress the transmission from each magnetic flux collecting ring to the magnetic shield for the sensor.

According to the sensor device of the present invention, the detection accuracy of the sensor can be improved.

The perspective view which disassembled the sensor device of one Embodiment. The perspective view which disassembled the partial assembly of one Embodiment. The perspective view of the partial assembly of one Embodiment. A perspective view of the sensor device in the assembled state. Development view of the external magnetic shield. The perspective view which shows the schematic structure of the magnetic shield and the magnetic collecting ring of another embodiment.

An embodiment of the sensor device will be described with reference to the drawings.
As shown in FIG. 1, the sensor device 10 is provided on the rotating shaft 11. 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 a torsion bar 13. The input shaft 12, the torsion bar 13, and the output shaft 14 are located on the same axis. The rotating shaft 11 is, for example, a steering shaft connected to the steering wheel of the steering device. In the present embodiment, the side of the input shaft 12 is "upper" and "upper" with respect to the output shaft 14, and the side of the output shaft 14 is "lower" and "lower" with respect to the input shaft 12.

The sensor device 10 includes a permanent magnet 21, a magnetic yoke 22, a subassembly 23, a housing 24, and an external magnetic shield 25.
The permanent magnet 21 has a cylindrical shape. The permanent magnet 21 has S poles and N poles alternately magnetized along its circumferential direction. The permanent magnet 21 is fixed to the outer peripheral surface of the input shaft 12.

The magnetic yoke 22 has a cylindrical shape. A permanent magnet 21 is inserted inside the magnetic yoke 22. The magnetic yoke 22 is formed by molding an annular lower magnetic yoke 31 and an upper magnetic yoke 32 made of a magnetic material with a synthetic resin material. The portion of the magnetic yoke 22 formed of the synthetic resin material functions as a holder 33 that holds the positional relationship between the lower magnetic yoke 31 and the upper magnetic yoke 32. A driving gear 34 is integrally molded at the end of the holder 33. The lower magnetic yoke 31 and the upper magnetic yoke 32 are aligned in the direction along the axis of the rotating shaft 11, that is, in the axial direction O. The magnetic yoke 22 is fixed to the output shaft 14.

A plurality of tooth portions are provided on the lower magnetic yoke 31 and the upper magnetic yoke 32 at equal intervals along the circumferential direction. These teeth extend toward opposite sides in the axial direction O. The lower magnetic yoke 31 and the upper magnetic yoke 32 are held so that their teeth are alternately positioned in the circumferential direction. In the lower magnetic yoke 31 and the upper magnetic yoke 32, the centers of the plurality of teeth in the circumferential direction coincide with the boundary between the north and south poles of the permanent magnet 21 in a state where the torsion bar 13 is not twisted and deformed. It is provided as follows.

The subassembly 23 is made to be able to be handled integrally by attaching a part for detecting the rotation angle of the rotating shaft 11 and a part for detecting the torque applied to the rotating shaft 11 to the holder 50. The subassembly 23 will be described in detail later.

A rotation shaft 11 is passed through the housing 24. Further, the permanent magnet 21, the magnetic yoke 22, and a part of the subassembly 23 are housed inside the housing 24. The housing 24 is provided in a stepped tubular shape. The housing 24 is made of a synthetic resin material. The housing 24 has a semi-cylindrical large diameter portion 41 and a cylindrical small diameter portion 42. The large diameter portion 41 and the small diameter portion 42 have through holes in the axial direction O. The input shaft 12 of the rotating shaft 11 is inserted into the small diameter portion 42. The large diameter portion 41 houses a permanent magnet 21, a magnetic yoke 22, and a part of the subassembly 23. A flange portion 41a is formed on the outer peripheral edge of the large diameter portion 41 opposite to the small diameter portion 42. The flange portion 41a is provided with insertion holes 41b and 41b penetrating in a circular shape. When viewed from the axial direction O, the insertion holes 41b and 41b are provided on opposite sides of the small diameter portion 42.

The large-diameter portion 41 is provided with a rectangular insertion port 43 into which the subassembly 23 is inserted so as to open laterally. The large diameter portion 41 is provided with two mounting walls 44 and 45 for fixing the subassembly 23. The two mounting walls 44, 45 extend toward opposite sides in a direction orthogonal to the axial direction O. The two mounting walls 44 and 45 are provided so as to be flush with each other with respect to the peripheral edge portion 43a of the insertion port 43. The two mounting walls 44, 45 are provided with insertion holes 44a, 45a penetrating in a circle. The subassembly 23 is fixed to the housing 24 with a part thereof inserted into the insertion port 43 of the housing 24.

The external magnetic shield 25 is assembled to the outer surfaces of the subassembly 23 and the housing 24 in a state where the sensor device 10 is assembled. The external magnetic shield 25 is provided to block magnetic noise other than the detection target from being transmitted to the inside of the sensor device 10. The external magnetic shield 25 will be described in detail later.

The subassembly 23 will be described in detail.
As shown in FIG. 2, the subassembly 23 has a lower holder 51 and an upper holder 52 constituting the holder 50. Further, the subassembly 23 has two driven gears 53 and 54, a substrate 55, a cover 56, and a magnetic shield 57.

The lower holder 51 is integrally molded with a synthetic resin material. The lower holder 51 has a lower yoke insertion portion 61 having an arcuate contour and a lower substrate accommodating portion 62 having a rectangular contour.

The lower yoke insertion portion 61 is provided with a circular insertion hole 63 into which the magnetic yoke 22 is inserted. The inner diameter of the insertion hole 63 is set to a length slightly longer than the outer diameter of the magnetic yoke 22. An annular lower magnetic collecting ring 64 is provided on the inner peripheral surface of the insertion hole 63. The lower magnetic collection ring 64 is a portion corresponding to the lower magnetic yoke 31 of the magnetic yoke 22. Further, the lower yoke insertion portion 61 is provided with two engaging claws 65 and 66. These engaging claws 65 and 66 are provided at intervals along the peripheral edge portion of the lower yoke insertion portion 61 opposite to the lower substrate accommodating portion 62. The two engaging claws 65 and 66 extend along the axial direction O, respectively. Engagement protrusions 65a and 66a are provided at the tips of the two engaging claws 65 and 66. These engaging protrusions 65a and 66a project inward in the radial direction of the insertion hole 63.

The lower magnetic collecting ring 64 includes two lower magnetic collecting portions 64b and 64c including an annular lower ring portion 64a surrounding the lower magnetic yoke 31 and a portion extending radially outward from the lower ring portion 64a. And have. The two lower magnetic collecting portions 64b and 64c extend in parallel with each other. The two lower magnetic collecting portions 64b and 64c extend upward from the upper end surface of the lower ring portion 64a and extend radially outward from the portion extending upward. The lower magnetic collecting ring 64 is made of a metal material.

The lower substrate accommodating portion 62 is provided with a recess 71. Two lower magnetic collecting portions 64b and 64c provided in the lower magnetic collecting ring 64 are exposed in a portion of the inner bottom surface of the recess 71 in the vicinity of the insertion hole 63. Further, two substrate support portions 72 and 73 having a stepped columnar shape are provided near the center of the inner bottom surface of the recess 71. Further, a plurality of terminals 74 are provided so as to project from the portion of the inner bottom surface of the recess 71 opposite to the insertion hole 63. The plurality of terminals 74 are arranged in a row along the inner peripheral edge opposite to the insertion hole 63 in the recess 71. The plurality of terminals 74 are connected to an arithmetic circuit (not shown) provided outside the sensor device 10 via wiring 75.

The lower substrate accommodating portion 62 is provided with two rectangular plate-shaped fixing portions 76 and 77. The two fixing portions 76 and 77 are provided on two side surfaces of the lower substrate accommodating portion 62 located opposite to each other in the direction orthogonal to the arrangement direction of the lower yoke insertion portion 61 and the lower substrate accommodating portion 62. There is. The two fixing portions 76 and 77 are provided so as to be orthogonal to the bottom wall of the lower substrate accommodating portion 62. Further, the lower substrate accommodating portion 62 is provided with two engaging portions 78 and 79. The two engaging portions 78 and 79 are two side surfaces and two sides of the lower substrate accommodating portion 62 located opposite to each other in the direction orthogonal to the alignment direction of the lower yoke insertion portion 61 and the lower substrate accommodating portion 62. It is provided at a corner formed by the fixing portions 76 and 77. The two fixing portions 76, 77 are provided with insertion holes 76a, 77a penetrating in a circular shape. The two engaging portions 78 and 79 are located on the opposite sides of the insertion holes 63 with respect to the fixed portions 76 and 77. The two engaging portions 78 and 79 are provided with rectangular engaging holes 78a and 79a.

The upper holder 52 is integrally molded with a synthetic resin material. The upper holder 52 is basically provided corresponding to the shape of the lower holder 51. The upper holder 52 has an upper yoke insertion portion 81 having an arcuate contour and an upper substrate accommodating portion 82 having a rectangular contour.

The upper yoke insertion portion 81 is provided with a circular insertion hole 83 into which the magnetic yoke 22 is inserted. The inner diameter of the insertion hole 83 is set to a length slightly longer than the outer diameter of the magnetic yoke 22. The insertion hole 83 coincides with the insertion hole 63 of the lower holder 51 when the sensor device 10 is assembled. An annular upper magnetic collecting ring 84 is provided on the inner peripheral surface of the insertion hole 83. The upper magnetic collecting ring 84 is a portion of the magnetic yoke 22 corresponding to the upper magnetic yoke 32. Further, the upper yoke insertion portion 81 is provided with two engaging recesses 85 and 86. The two engaging recesses 85 and 86 are provided at intervals along the peripheral edge portion of the upper yoke insertion portion 81 opposite to the upper substrate accommodating portion 82. The two engaging recesses 85 and 86 are provided on the peripheral edge of the upper yoke insertion portion 81 at a portion opposite to the lower holder 51 in the axial direction O. The two engaging recesses 85, 86 correspond to the two engaging claws 65, 66 in the lower holder 51. Further, in the upper yoke insertion portion 81, two engaging holes 87 and 88 are provided near the boundary with the upper substrate accommodating portion 82. The two engaging holes 87 and 88 are provided at a predetermined interval along the insertion hole 83.

The upper magnetic collecting ring 84 has an annular upper ring portion 84a surrounding the upper magnetic yoke 32, and two upper magnetic collecting portions 84b and 84c including a portion extending radially outward from the upper ring portion 84a. There is. The two upper magnetic collecting portions 84b and 84c extend in parallel with each other. The two upper magnetic collecting portions 84b and 84c extend downward from the lower end surface of the upper ring portion 84a and extend radially outward from the downwardly extending portion. The upper magnetic collecting ring 84 is made of a metal material.

In the upper substrate accommodating portion 82, two support holes 91 and 92 are provided in a portion near the insertion hole 83. Further, on the surface on the lower holder 51 side of the upper substrate accommodating portion 82, that is, the portion near the insertion hole 83 on the lower surface in FIG. 2, the two upper magnetic collecting portions 84b provided on the upper magnetic collecting ring 84, 84c is exposed. The two upper magnetic collecting portions 84b and 84c are shafts with respect to the two lower magnetic collecting portions 64b and 64c of the lower magnetic collecting ring 64 held by the lower holder 51 in the state where the sensor device 10 is assembled. Oppose in direction O. Further, two engaging protrusions 93 and 94 are provided on the two side surfaces of the upper substrate accommodating portion 82 located opposite to each other in the direction orthogonal to the arrangement direction of the upper yoke insertion portion 81 and the upper substrate accommodating portion 82. Has been done. The two engaging protrusions 93, 94 are located on opposite sides of the insertion hole 83 with respect to the two support holes 91, 92.

The driven gears 53 and 54 are rotatably supported with respect to the upper holder 52. The driven gear 53 has a shaft portion 53a, a gear portion 53b, and a permanent magnet 53c. The driven gear 54 also has a shaft portion 54a, a gear portion 54b, and a permanent magnet 54c. The permanent magnets 53c and 54c are fixed to the tip portions of the shaft portions 53a and 54a. The shaft portion 53a of the driven gear 53 is inserted into the support hole 91 of the upper holder 52, and the shaft portion 54a of the driven gear 54 is inserted into the support hole 92 of the upper holder 52. The gear portions 53b and 54b are slidably and rotatably supported with respect to the upper surface of the upper holder 52 in a state where the shaft portions 53a and 54a are inserted into the support holes 91 and 92. The number of teeth of the gear portions 53b and 54b is different. In the assembled state of the sensor device 10, the two driven gears 53 and 54 mesh with the main gear 34 provided on the magnetic yoke 22.

The substrate 55 is provided in a rectangular shape. The substrate 55 is attached to the recess 71 of the lower holder 51. Two support holes 101 and 102 are provided near the center of the substrate 55. The tips of the two substrate support portions 72 and 73 provided on the inner bottom surface of the recess 71 are inserted into the support holes 101 and 102. Further, the substrate 55 is provided with the same number of connection holes 103 as the terminals 74 in a row. Terminals 74 are inserted into these connection holes 103, respectively. By performing soldering or the like with each terminal 74 inserted in each connection hole 103, a wiring pattern (not shown) of the substrate 55 and each terminal 74 are connected.

Two magnetic sensors 104 and 105 for angle detection are provided on the upper surface of the substrate 55 on the upper holder 52 side. The two angle detection magnetic sensors 104 and 105 are provided side by side along the long side edge of the substrate 55. In the assembled state of the sensor device 10, the two magnetic sensors 104 and 105 for angle detection face the permanent magnets 53c and 54c of the driven gears 53 and 54 in the axial direction O. As the angle detection magnetic sensors 104 and 105, for example, a hall sensor is adopted. The two angle detection magnetic sensors 104 and 105 generate an electric signal according to a change in the magnetic field accompanying the rotation of the driven gears 53 and 54.

Two torque detection magnetic sensors 106 and 107 are provided on the upper surface of the substrate 55 on the upper holder 52 side. The two torque detection magnetic sensors 106 and 107 are located between the two angle detection magnetic sensors 104 and 105 in the direction along the long side edge of the substrate 55. Further, in the assembled state of the sensor device 10, the torque detection magnetic sensor 106 is opposed to each other in the axial direction O. It is arranged between the magnetic portion 84b and the magnetic portion 84b. Further, in the assembled state of the sensor device 10, the torque detection magnetic sensor 107 is opposed to each other in the axial direction O. It is arranged between the magnetic portion 84c and the magnetic portion 84c. In the axial direction O, the sizes of the torque detection magnetic sensors 106 and 107 are formed to be larger than the sizes of the lower magnetic collecting portions 64b and 64c and the upper magnetic collecting portions 84b and 84c. That is, when viewed from the axial direction O, the outer edge portions of the torque detection magnetic sensors 106 and 107 protrude from the lower magnetic collecting portions 64b and 64c and the upper magnetic collecting portions 84b and 84c. As the torque detection magnetic sensors 106 and 107, for example, a hall sensor is adopted. The torque detection magnetic sensors 106 and 107 detect the magnetic flux induced from the lower magnetic yoke 31 and the upper magnetic yoke 32 of the magnetic yoke 22 to the lower magnetic collecting ring 64 and the upper magnetic collecting ring 84. That is, the torque detecting magnetic sensors 106 and 107 detect the magnetic flux of the magnetic circuit formed by the permanent magnet 21, the magnetic yoke 22, the lower magnetic collecting ring 64, and the upper magnetic collecting ring 84. The torque detection magnetic sensors 106 and 107 generate an electric signal according to the strength of the applied magnetic field. The magnetic sensors described in the claims correspond to the magnetic sensors 106 and 107 for torque detection.

The cover 56 is attached to the upper holder 52. The cover 56 is integrally molded with a synthetic resin material. The cover 56 has a flat plate-shaped pressing portion 111 and two side walls 112 and 112.

An arc surface 111a corresponding to the contour of the insertion hole 83 is provided on one of the four side edges of the pressing portion 111. In the pressing portion 111, engaging claws 113 and 114 are provided at the two corner portions where the arcuate surface 111a and the two side surfaces of the pressing portion 111 intersect, respectively. The two engaging claws 113 and 114 extend in a direction orthogonal to the pressing portion 111. Engagement protrusions 113a and 114a are provided at the tips of the two engaging claws 113 and 114, respectively. The engaging protrusions 113a and 114a project outward in the direction along the alignment direction of the two engaging claws 113 and 114, respectively. The two engaging claws 113 and 114 correspond to the two engaging holes 87 and 88 provided in the upper holder 52.

The two side walls 112, 112 extend in the same direction as the two engaging claws 113, 114. The two side walls 112 and 112 are located near the side edge portion of the pressing portion 111, which is located on the side opposite to the arc surface 111a. Engagement claws 115 and 116 are provided at the tip portions of the two side walls 112 and 112, which are the ends opposite to the pressing portion 111, respectively. Engagement protrusions 115a and 116a are provided at the tips of the two engaging claws 115 and 116, respectively. The engaging protrusions 115a and 116a project outward in the alignment direction of the two side walls 112 and 112, respectively. The two engaging claws 115 and 116 correspond to the two engaging holes 78a and 79a provided in the lower holder 51.

Engagement protrusions 117 and 118 are provided inside the tips of the two side walls 112 and 112 of the cover 56, respectively. These engaging protrusions 117 and 118 face each other in the alignment direction of the two side walls 112 and 112. The sensor housing described in the claims corresponds to a portion of the housing 24 and the subassembly 23 that is integrally molded with a synthetic resin material.

As shown in FIGS. 2 and 3, the magnetic shield 57 is arranged outward in the radial direction of the lower holder 51 and the upper holder 52 in the assembled state of the sensor device 10. Specifically, the magnetic shield 57 is orthogonal to the axial direction O by covering the outer peripheral surfaces of the lower ring portion 64a of the lower magnetic collecting ring 64 and the upper ring portion 84a of the upper magnetic collecting ring 84 from the outside in the radial direction. It is arranged so as to overlap the lower ring portion 64a and the upper ring portion 84a in the direction of the magnetism. The magnetic shield 57 has a U-shaped cross section. The magnetic shield 57 has a U-shaped curved plate-like member. As a material constituting the magnetic shield 57, a metal material capable of blocking magnetism is adopted. The magnetic permeability of the material constituting the magnetic shield 57 is set lower than the magnetic permeability of the material constituting the lower magnetic collecting ring 64 and the upper magnetic collecting ring 84. The length of the magnetic shield 57 in the axial direction O is set to be approximately the same as the thickness of the lower holder 51 and the upper holder 52 in the axial direction O. As shown in FIG. 3, slits 76b and 77b are provided on the surfaces of the two fixing portions 76 and 77 on the insertion hole 63 side. The width of the fixed portions 76, 77 in the slits 76b, 77b in the alignment direction is set to be about the same as the thickness of the magnetic shield 57. Further, the length of the slits 76b, 77b in the direction orthogonal to the arrangement direction of the fixed portions 76, 77 is set to be about the same as the length of the slits 76b, 77b in the axial direction O. The magnetic shield 57 is fixed to the lower holder 51 and the upper holder 52 by inserting both ends 57a and 57b of the magnetic shield 57 in the circumferential direction into the slits 76b and 77b. As a result, in the direction orthogonal to the axial direction O, the magnetic shield 57 overlaps the lower magnetic collecting ring 64 and the upper magnetic collecting ring 84 in the radial direction of the lower magnetic collecting ring 64 and the upper magnetic collecting ring 84. It is located on the outside.

The subassembly 23 configured in this way is inserted into the insertion port 43 of the housing 24 from the insertion holes 63, 83 side thereof. When the subassembly 23 is inserted into the insertion slot 43 of the housing 24, the fixing portions 76, 77 of the subassembly 23 come into contact with the mounting walls 44, 45 of the housing 24. In this state, the bolt 121 is inserted into the insertion holes 76a, 77a of the fixing portions 76, 77 and the insertion holes 44a, 45a of the mounting walls 44, 45, and the nut 122 is tightened to the tip of the bolt 121 to form a partial assembly. 23 is fixed to the housing 24. After that, the external magnetic shield 25 is assembled to the outer surfaces of the subassembly 23 and the housing 24.

As shown in FIGS. 1, 4, and 5, the external magnetic shield 25 includes a sensor magnetic shield 131, an upper ring portion magnetic shield 132, a lower ring portion magnetic shield 133, and a connection portion 134. It has a first fixed portion 135 and a second fixed portion 136.

FIG. 5 shows a developed view of the external magnetic shield 25. As shown in FIG. 5, the magnetic shield 131 for the sensor, the upper ring portion magnetic shield 132, the lower ring portion magnetic shield 133, the connection portion 134, the first fixing portion 135, and the second fixing portion 136 are connected to each other. ing. Further, the external magnetic shield 25 is configured by processing one plate-shaped member into the shape shown in FIG. 5 and bending the plate-shaped member. As a material constituting the external magnetic shield 25, a metal material capable of blocking magnetism is adopted. The magnetic permeability of the material constituting the external magnetic shield 25 is set lower than the magnetic permeability of the material constituting the lower magnetic collecting ring 64 and the upper magnetic collecting ring 84. The magnetic permeability of the materials constituting the external magnetic shield 25, the magnetic shield 57, the lower magnetic collecting ring 64, and the upper magnetic collecting ring 84 is determined by, for example, changing the content of impurities contained in the metal material to be adopted. It will be adjusted accordingly. The broken line in FIG. 5 indicates a bending line. Further, the alternate long and short dash line in FIG. 5 is not a bent line but a virtual line drawn for convenience. Further, in the following description, for convenience of explanation, each configuration of the external magnetic shield 25 will be described individually, and what kind of relationship each of these individual configurations has with each other will be described.

As shown in FIGS. 1, 4, and 5, the magnetic shield 131 for the sensor includes a first axial covering portion 131a, a first orthogonal covering portion 131b, a second orthogonal covering portion 131c, and a third. It has an orthogonal direction covering portion 131d, a second axial covering portion 131e, and a third axial direction covering portion 131f. The sensor magnetic shield 131 has a third axial covering portion 131f as a portion that overlaps the angle detection magnetic sensors 104 and 105 and the torque detection magnetic sensors 106 and 107 in the axial direction O. Further, the magnetic shield 131 for the sensor has a first orthogonal direction covering portion 131b and a second orthogonal portion as a portion overlapping the magnetic sensors 104 and 105 for angle detection and the magnetic sensors 106 and 107 for torque detection in the direction orthogonal to the axial direction O. It has a directional covering portion 131c and a third orthogonal directional covering portion 131d. The three-dimensional magnetic shield 131 for a sensor shown in FIGS. 1 and 4 is formed by bending a shape developed on a plane shown in FIG.

As shown in FIGS. 1, 4, and 5, the first axial covering portion 131a has a rectangular plate shape corresponding to the shape of the upper surface of the upper holder 52. Here, the lateral direction of the first axial covering portion 131a is defined as the direction X, and the longitudinal direction of the first axial covering portion 131a is defined as the direction Y.

The first orthogonal direction covering portion 131b and the second orthogonal direction covering portion 131c are connected to the two side surfaces in the longitudinal direction of the first axial direction covering portion 131a, that is, in the direction Y. The first orthogonal direction covering portion 131b and the second orthogonal direction covering portion 131c are provided on opposite sides of each other with the first axial direction covering portion 131a in the direction Y. The first orthogonal direction covering portion 131b and the second orthogonal direction covering portion 131c each have the same rectangular plate shape. The side surfaces of the first orthogonal direction covering portion 131b and the second orthogonal direction covering portion 131c in the lateral direction are connected to the two side surfaces of the first axial direction covering portion 131a in the direction Y, respectively. The boundary portion between the first axial direction covering portion 131a and the first orthogonal direction covering portion 131b is bent so that the first orthogonal direction covering portion 131b is located below the first axial direction covering portion 131a. Further, the boundary portion between the first axial direction covering portion 131a and the second orthogonal direction covering portion 131c is bent so that the second orthogonal direction covering portion 131c is located below the first axial direction covering portion 131a. ..

The third orthogonal direction covering portion 131d and the second axial direction covering portion 131e are connected to the two side surfaces of the first axial direction covering portion 131a in the lateral direction, that is, in the direction X. The third orthogonal direction covering portion 131d and the second axial direction covering portion 131e are provided on opposite sides of the first axial direction covering portion 131a in the direction X. The third orthogonal direction covering portion 131d and the second axial direction covering portion 131e each have a rectangular plate shape. The side surfaces of the third orthogonal direction covering portion 131d and the second axial direction covering portion 131e in the lateral direction are connected to the two side surfaces of the first axial direction covering portion 131a in the direction X, respectively. The boundary portion between the first axial direction covering portion 131a and the third orthogonal direction covering portion 131d is bent so that the third orthogonal direction covering portion 131d is located below the first axial direction covering portion 131a. Further, the boundary portion between the first axial covering portion 131a and the second axial covering portion 131e is bent so that the second axial covering portion 131e is located above the first axial covering portion 131a. .. The second axial covering portion 131e is further bent in two steps in a stepped manner so as to be located upward along the longitudinal direction thereof as the distance from the first axial covering portion 131a increases.

A third axial covering portion 131f is connected to the side surface of the second axial covering portion 131e in the lateral direction. The third axial covering portion 131f is provided on the opposite side of the second axial covering portion 131e from the first axial covering portion 131a in the direction X. The third axial covering portion 131f has a rectangular plate shape. The side surface of the second axial covering portion 131e in the lateral direction is connected to the side surface of the third axial covering portion 131f in the lateral direction.

The upper ring portion magnetic shield 132 has a substantially disk shape corresponding to the shape of the upper surface of the semi-cylindrical large diameter portion 41. A through hole 132a penetrating in the plate thickness direction, that is, in the axial direction O is formed in the central portion of the upper ring portion magnetic shield 132. The through hole 132a has a circular shape. The inner diameter of the through hole 132a is substantially the same as the outer diameter of the small diameter portion 42. The upper ring portion magnetic shield 132 has an extending portion 132b extending outward in the radial direction. The extending portion 132b is provided on the side opposite to the third axial direction covering portion 131f with the through hole 132a interposed therebetween in the direction X. The extending portion 132b has a substantially rectangular plate shape. The side surface of the third axial direction covering portion 131f in the lateral direction is connected to the side surface of the upper ring portion magnetic shield 132.

The lower ring portion magnetic shield 133 has a substantially semicircular plate shape corresponding to the shape of the lower surface of the semi-cylindrical large diameter portion 41. A through hole 133a penetrating in the plate thickness direction, that is, in the axial direction O is formed in the central portion of the lower ring portion magnetic shield 133. The through hole 133a has a circular shape. The inner diameter of the through hole 133a is substantially the same as the inner diameter of the inner peripheral surface of the large diameter portion 41. The lower ring portion magnetic shield 133 is formed with insertion holes 133b and 133c that penetrate circularly in the plate thickness direction thereof. The insertion hole 133b and the insertion hole 133c are provided on opposite sides of each other with the through hole 133a in the direction Y.

The connecting portion 134 has a square plate shape. The extension portion 132b of the upper ring portion magnetic shield 132 is connected to one of the two side surfaces of the connection portion 134 in the direction X, and the lower ring is connected to the other of the two side surfaces of the connection portion 134 in the direction X. The magnetic shield 133 is connected. The side surface of the extending portion 132b in the lateral direction is connected to the side surface of the connecting portion 134.

The first fixing portion 135 and the second fixing portion 136 are connected to the two side surfaces of the upper ring portion magnetic shield 132 in the direction Y. The first fixing portion 135 and the second fixing portion 136 each have a substantially rectangular plate shape. The first fixing portion 135 and the second fixing portion 136 are provided on opposite sides of the upper ring portion magnetic shield 132 in the direction Y. The first fixing portion 135 is formed with an insertion hole 135a that penetrates circularly in the plate thickness direction thereof. The insertion hole 135a is formed at the tip of the first fixing portion 135. The boundary portion between the upper ring portion magnetic shield 132 and the first fixing portion 135 is bent so that the first fixing portion 135 is located below the upper ring portion magnetic shield 132. Further, the first fixing portion 135 is bent so that the tip end portion of the first fixing portion 135 is located outside the base end portion.

The second fixing portion 136 is formed with an insertion hole 136a that penetrates circularly in the plate thickness direction thereof. The insertion hole 136a is formed at the tip of the second fixing portion 136. The boundary portion between the upper ring portion magnetic shield 132 and the second fixing portion 136 is bent so that the second fixing portion 136 is located below the upper ring portion magnetic shield 132. Further, the second fixing portion 136 is bent so that the tip end portion of the second fixing portion 136 is located outside the base end portion.

The external magnetic shield 25 configured in this way is assembled to the outer surfaces of the subassembly 23 and the housing 24. In this case, the first axial covering portion 131a is in contact with the upper surface of the upper substrate accommodating portion 82 of the upper holder 52. The first orthogonal direction covering portion 131b and the second orthogonal direction covering portion 131c are located on opposite sides of each other in the direction orthogonal to the arrangement direction of the upper yoke insertion portion 81 and the upper substrate accommodating portion 82, and the upper substrate accommodating portion 82-2. It is in contact with one side surface and two side surfaces of the lower substrate accommodating portion 62. The first orthogonal direction covering portion 131b and the second orthogonal direction covering portion 131c are in the upper substrate accommodating portion 82 and the lower substrate accommodating portion 62 so as not to cover the engaging portions 78, 79 and the engaging protrusions 93, 94. It is attached to a portion displaced in the direction orthogonal to the axial direction O. The second axial covering portion 131e is in contact with the upper surface of the cover 56 in the axial direction O, the side surface of the cover 56 in the direction orthogonal to the axial direction O, and the side surface of the housing 24 in the direction orthogonal to the axial direction O. The upper ring portion magnetic shield 132 is in contact with the upper surface of the large diameter portion 41. The lower ring portion magnetic shield 133 is in contact with the lower surface of the large diameter portion 41. The connecting portion 134 is arranged so as to face the large diameter portion 41 on the radial outer side of the large diameter portion 41. The connection portion 134 is provided on the peripheral portion of the upper ring portion magnetic shield 132 and the lower ring portion magnetic shield 133 on the side opposite to the sensor magnetic shield 131 with the rotation shaft 11 interposed therebetween. The base end portion of the first fixing portion 135 and the base end portion of the second fixing portion 136 are in contact with the outer peripheral surface of the large diameter portion 41. The tip of the first fixing portion 135 and the tip of the second fixing portion 136 are in contact with the upper surface of the flange portion 41a.

In these states, the bolt 141 is inserted into the insertion hole 135a of the first fixing portion 135, the insertion hole 41b of the flange portion 41a, and the insertion hole 133b of the lower ring portion magnetic shield 133, and a nut is inserted into the tip of the bolt 141. Tighten 142. Further, in these states, the bolt 141 is inserted into the insertion hole 136a of the second fixing portion 136, the insertion hole 41b of the flange portion 41a, and the insertion hole 133c of the lower ring portion magnetic shield 133, and the tip portion of the bolt 141 is inserted. Tighten the nut 142 to. As a result, the external magnetic shield 25 is fixed to the outer surfaces of the subassembly 23 and the housing 24.

In the axial direction O, the third axial covering portion 131f of the magnetic shield 131 for the sensor is interposed with the cover 56 and the upper holder 52 so as to overlap the magnetic sensors 104 and 105 for angle detection and the magnetic sensors 106 and 107 for torque detection. In this state, it is arranged above the angle detection magnetic sensors 104 and 105 and the torque detection magnetic sensors 106 and 107. In the present embodiment, in the axial direction O, the third axial covering portion 131f overlaps the entire angle detection magnetic sensors 104 and 105 and the torque detection magnetic sensors 106 and 107.

In the direction orthogonal to the axial direction O, that is, in the direction X, the third orthogonal direction covering portion 131d of the magnetic shield 131 for the sensor is interposed with the upper holder 52 so as to overlap the magnetic sensors 106 and 107 for torque detection. It is arranged outside the torque detection magnetic sensors 106 and 107. In the direction orthogonal to the axial direction O, that is, in the oblique direction between the directions X and the direction Y, the first orthogonal direction covering portion 131b and the second orthogonal direction covering portion 131c of the sensor magnetic shield 131 are magnetic sensors for torque detection. It is arranged outside the torque detection magnetic sensors 106 and 107 with the upper holder 52 interposed therebetween so as to overlap 106 and 107. Further, in the direction orthogonal to the axial direction O, that is, in the direction X, the upper holder 52 is interposed so that the third orthogonal direction covering portion 131d of the magnetic shield 131 for the sensor overlaps the magnetic sensors 104 and 105 for angle detection. It is arranged outside the magnetic sensors 104 and 105 for angle detection. In the direction orthogonal to the axial direction O, that is, in the oblique direction between the directions X and the direction Y, the first orthogonal direction covering portion 131b and the second orthogonal direction covering portion 131c of the magnetic shield 131 for the sensor are magnetic sensors for angle detection. It is arranged outside the angle detection magnetic sensors 104 and 105 with the upper holder 52 interposed therebetween so as to overlap 104 and 105. In the present embodiment, in the direction orthogonal to the axial direction O, the first orthogonal direction covering portion 131b, the second orthogonal direction covering portion 131c, and the third orthogonal direction covering portion 131d are the angle detection magnetic sensors 104, 105 and the torque. It overlaps with the entire detection magnetic sensors 106 and 107.

In the axial direction O, the upper ring portion magnetic shield 132 is placed on the upper surface of the large diameter portion 41 of the housing 24, the cover 56, and the upper yoke insertion portion 81 of the upper holder 52 so as to overlap the upper ring portion 84a. It is arranged above the ring portion 84a. In the present embodiment, the upper ring portion magnetic shield 132 overlaps the entire upper ring portion 84a in the axial direction O.

In the axial direction O, the lower ring portion magnetic shield 133 is placed on the lower side with the flange portion 41a of the housing 24 and the lower substrate accommodating portion 62 of the lower holder 51 interposed therebetween so as to overlap the lower ring portion 64a. It is arranged below the ring portion 64a. In the present embodiment, the lower ring portion magnetic shield 133 overlaps the entire lower ring portion 64a in the axial direction O.

When torque is applied to the input shaft 12 of the rotating shaft 11 and the torsion bar 13 is twisted and deformed, a relative rotational displacement occurs between the input shaft 12 and the output shaft 14 according to the torque applied to the input shaft 12. Then, the relative position of the permanent magnet 21 and the magnetic yoke 22 in the rotation direction and the relative position of the permanent magnet 21 and the magnetic yoke 22 in the rotation direction change. Along with this, the magnetic flux induced from the permanent magnet 21 to the lower magnetic collecting ring 64 and the upper magnetic collecting ring 84 through the magnetic yoke 22 changes. The torque detection magnetic sensors 106 and 107 are charged with electricity according to the magnetic flux leaking between the lower magnetic collecting portions 64b and 64c of the lower magnetic collecting ring 64 and the upper magnetic collecting portions 84b and 84c of the upper magnetic collecting ring 84. Generate a signal. The electric signals generated by the torque detection magnetic sensors 106 and 107 change according to the torsional deformation of the torsion bar 13 and the torsional angle. The calculation circuit calculates the torque acting on the torsion bar 13 based on the electric signals generated by the torque detection magnetic sensors 106 and 107.

When the rotating shaft 11 rotates, the main gear 34 also rotates integrally with the rotating shaft 11, and the two driven gears 53 and 54 also rotate accordingly. Since the number of teeth of the two driven gears 53 and 54 is different from each other, when the driven gear 34 rotates in conjunction with the rotation of the rotating shaft 11, the rotation of the two driven gears 53 and 54 with respect to the rotation angle of the driven gear 34. The angles have different values. The magnetic field applied to the angle detection magnetic sensors 104 and 105 changes with the rotation of the driven gears 53 and 54. The angle detection magnetic sensors 104 and 105 generate an electric signal according to a change in the magnetic field accompanying the rotation of the driven gears 53 and 54. At this time, since the rotation angles of the two driven gears 53 and 54 with respect to the main gear 34 are different from each other, the phase of the electric signal generated by the magnetic sensors 104 and 105 for angle detection corresponds to the rotation angles of the driven gears 53 and 54. It becomes a thing. The calculation circuit calculates the rotation angle of the rotation shaft 11 over 360 ° in absolute value based on the electric signals generated by the angle detection magnetic sensors 104 and 105.

The operation of this embodiment will be described.
The detection targets of the torque detection magnetic sensors 106 and 107 are the magnetic flux of the magnetic circuit formed by the permanent magnet 21, the magnetic yoke 22, the lower magnetic collecting ring 64, and the upper magnetic collecting ring 84. The magnetic flux of the magnetic circuit passes between the upper magnetic collecting portion 84b and the lower magnetic collecting portion 64b and between the upper magnetic collecting portion 84c and the lower magnetic collecting portion 64c in the axial direction O. The magnetic sensor 106 for torque detection is arranged between the upper magnetic collecting portion 84b and the lower magnetic collecting portion 64b, so that the space between the upper magnetic collecting portion 84b and the lower magnetic collecting portion 64b is axially O. The magnetic flux of the passing magnetic circuit is detected. Further, the magnetic sensor 107 for torque detection is arranged between the upper magnetic collecting portion 84c and the lower magnetic collecting portion 64c, so that the magnetic sensor 107 for torque detection is arranged in the axial direction between the upper magnetic collecting portion 84c and the lower magnetic collecting portion 64c. The magnetic flux of the magnetic circuit passing through O is detected. The sensor magnetic shield 131 is arranged above the torque detection magnetic sensors 106 and 107 so as to overlap the torque detection magnetic sensors 106 and 107 in the axial direction O. As a result, it is possible to prevent magnetic noise other than the detection target from being transmitted from the axial direction O to the torque detection magnetic sensors 106 and 107. Therefore, it is possible to prevent the torque detection magnetic sensors 106 and 107 from detecting magnetic noise from sources other than the detection target.

The effect of this embodiment will be described.
(1) Since it is possible to suppress the detection of magnetic noise by the magnetic sensors 106 and 107 for torque detection from other than the detection target, the detection accuracy of the magnetic flux of the magnetic circuit can be improved, and the torque applied to the torsion bar 13 can be improved. Detection accuracy can be improved.

(2) Since the external magnetic shield 25 such as the magnetic shield 131 for the sensor is assembled to the outer surface of the subassembly 23 and the housing 24, it is housed in the subassembly 23 and the housing 24 and the subassembly 23 and the housing 24. Design changes of each configuration can be minimized.

(3) By arranging the upper ring portion magnetic shield 132 above the upper ring portion 84a, it is possible to suppress the transmission of magnetic noise other than the detection target to the upper ring portion 84a from above.

(4) By arranging the lower ring portion magnetic shield 133 below the lower ring portion 64a, it is possible to prevent magnetic noise other than the detection target from being transmitted from below to the lower ring portion 64a.

(5) By arranging the upper ring portion magnetic shield 132 above the upper ring portion 84a and arranging the lower ring portion magnetic shield 133 below the lower ring portion 64a, magnetic noise other than the detection target can be generated in the axial direction. It is possible to suppress the transmission from the upper ring portion 84a to the lower ring portion 64a. Further, by connecting the upper ring portion magnetic shield 132 and the lower ring portion magnetic shield 133 with the connecting portion 134, magnetic noise is concentrated on either the upper ring portion magnetic shield 132 or the lower ring portion magnetic shield 133. Even if this is the case, the magnetic noise can be passed to the other magnetic shield. As a result, the magnetic noise can be dispersed between the upper ring portion magnetic shield 132 and the lower ring portion magnetic shield 133, so that even if the magnetic noise is partially concentrated, the magnetic noise is transmitted to each ring portion. It can be suppressed.

(6) The connecting portion 134 is provided on the side opposite to the sensor magnetic shield 131 with the rotating shaft 11 interposed therebetween. Therefore, the connection length of the connection portion 134 that connects the upper ring portion magnetic shield 132 and the lower ring portion magnetic shield 133 does not have to be extended so as to surround the outer side of each magnetic collection portion. Can be shortened.

(7) By providing the connecting portion 134, the positional relationship between the upper ring portion magnetic shield 132 and the lower ring portion magnetic shield 133 can be defined. Therefore, when assembling each ring portion magnetic shield, if one of the two ring portion magnetic shields is positioned, the other ring portion magnetic shield does not need to be positioned. As a result, it is possible to suppress an increase in work man-hours when assembling the upper ring portion magnetic shield 132 and the lower ring portion magnetic shield 133.

(8) By arranging the sensor magnetic shield 131 in the direction orthogonal to the axial direction O of the torque detection magnetic sensors 106 and 107, the magnetic noise for torque detection from the direction in which the magnetic noise other than the detection target is orthogonal to the axial direction O It is possible to suppress transmission to the sensors 106 and 107.

(9) Since the material constituting each magnetic collecting ring is set to a material that allows magnetic flux to pass through more easily than the material constituting the magnetic shield for the sensor, it is a detection target of the magnetic sensors 106 and 107 for torque detection. It is possible to prevent the magnetic flux of the magnetic circuit from being transmitted from each magnetic collecting ring to the magnetic shield 131 for the sensor.

(10) The magnetic shield 131 for the sensor is arranged above the magnetic sensors 104 and 105 for angle detection so as to overlap the magnetic sensors 104 and 105 for angle detection in the axial direction O. As a result, it is possible to prevent magnetic noise other than the detection target from being transmitted from the axial direction O to the angle detection magnetic sensors 104 and 105. Therefore, it is possible to prevent the angle detection magnetic sensors 104 and 105 from detecting magnetic noise from sources other than the detection target, and it is possible to improve the detection accuracy of the rotation angle of the rotation shaft 11.

The above embodiment may be modified as follows. In addition, the following other embodiments can be combined with each other to the extent that they are technically consistent.
The magnetic permeability of the material constituting the external magnetic shield 25 may be about the same as the magnetic permeability of the material constituting the lower magnetic collecting ring 64 and the upper magnetic collecting ring 84, or the lower magnetic collecting ring 64. And may be set higher than the magnetic permeability of the material constituting the upper magnetic concentrating ring 84.

-Even if the sensor magnetic shield 131 has an orthogonal covering portion arranged outside the torque detection magnetic sensors 106, 107 so as to overlap the torque detection magnetic sensors 106, 107 in the direction Y. good.

The sensor magnetic shield 131 is a first orthogonal direction covering portion arranged outside the torque detection magnetic sensors 106, 107 so as to overlap the torque detection magnetic sensors 106, 107 in a direction orthogonal to the axial direction O. It is not necessary to have the 131b, the second orthogonal direction covering portion 131c, and the third orthogonal direction covering portion 131d. Further, the magnetic shield 131 for the sensor does not have to have the first axial covering portion 131a and the second axial covering portion 131e. The sensor magnetic shield 131 has a third axial covering portion 131f arranged outside the torque detection magnetic sensors 106, 107 so as to overlap the torque detection magnetic sensors 106, 107 in the axial direction O. Just do it. Further, the third axial covering portion 131f may be arranged so as to overlap the torque detection magnetic sensors 106 and 107 at least in the axial direction O, and overlap with the angle detection magnetic sensors 104 and 105 in the axial direction O. It does not have to be placed in.

The connection portion 134 is provided at a portion of the peripheral edge of the upper ring portion magnetic shield 132 and the lower ring portion magnetic shield 133, which is deviated from the portion opposite to the sensor magnetic shield 131 with the rotation shaft 11 interposed therebetween. It is also good.

-In the above embodiment, the connecting portion 134 for connecting the upper ring portion magnetic shield 132 and the lower ring portion magnetic shield 133 in the axial direction O is provided, but the connecting portion 134 may not be provided. In this case, the upper ring portion magnetic shield 132 and the lower ring portion magnetic shield 133 are configured as separate members.

-Only one of the upper ring portion magnetic shield 132 and the lower ring portion magnetic shield 133 may be provided. In this case, the connecting portion 134 that connects the upper ring portion magnetic shield 132 and the lower ring portion magnetic shield 133 in the axial direction O may not be provided.

-Although the external magnetic shield 25 is assembled on the outer surface of the subassembly 23 and the housing 24, it may be embedded inside the subassembly 23 and the housing 24. That is, the external magnetic shield 25 may be integrally molded with the subassembly 23 and the housing 24. For example, the magnetic shield 200 shown in FIG. 6 may be provided as a magnetic shield corresponding to the external magnetic shield 25.

As shown in FIG. 6, the magnetic shield 200 includes a substantially C-shaped plate-shaped upper portion 201, a substantially C-shaped plate-shaped lower portion 202, and a connecting portion 203 connecting the upper portion 201 and the lower portion 202. Have. The upper ring portion 84a of the upper magnetic collecting ring 84 has a substantially C shape, and the lower ring portion 64a of the lower magnetic collecting ring 64 has a substantially C shape. The length of the lower portion 202 in the direction orthogonal to the axial direction O is set longer than the length of the upper portion 201 in the direction orthogonal to the axial direction O. The inner diameters of the upper portion 201 and the lower portion 202 are set to be substantially the same as the inner diameters of the upper magnetic collecting ring 84 and the lower magnetic collecting ring 64. Further, the circumferential length of the upper portion 201 and the lower portion 202 on the inner peripheral surface is set longer than the circumferential length of the upper magnetic collecting ring 84 and the lower magnetic collecting ring 64 on the inner peripheral surface. .. As described above, the shape of the external magnetic shield 25 can be changed as appropriate. The upper portion 201 is arranged above the upper magnetic collecting ring 84 and the torque detecting magnetic sensors 106 and 107 so as to overlap the upper magnetic collecting ring 84 and the torque detecting magnetic sensors 106 and 107 in the axial direction O. Further, the lower portion 202 is below the lower magnetic collecting ring 64 and the torque detecting magnetic sensor 106, 107 so as to overlap the lower magnetic collecting ring 64 and the torque detecting magnetic sensor 106, 107 in the axial direction O. Have been placed.

-In the axial direction O, the third axial covering portion 131f may not overlap the whole of the angle detection magnetic sensors 104 and 105 and the torque detection magnetic sensors 106 and 107, but may overlap only a part of the angle detection magnetic sensors 104 and 105. Further, in the direction orthogonal to the axial direction O, the first orthogonal direction covering portion 131b, the second orthogonal direction covering portion 131c, and the third orthogonal direction covering portion 131d are the angle detection magnetic sensors 104 and 105 and the torque detection magnetic. It may overlap only a part of the sensors 106 and 107 instead of overlapping the whole. Further, in the axial direction O, the upper ring portion magnetic shield 132 may not overlap with the entire upper ring portion 84a, but may overlap with only a part of the upper ring portion 84a. Further, in the axial direction O, the lower ring portion magnetic shield 133 may not overlap with the entire lower ring portion 64a, but may overlap only a part of the lower ring portion 64a.

-The external magnetic shield 25 is not limited to the one formed by bending, but may be formed by any processing method such as one formed by cutting or casting.

The external magnetic shield 25 had a sensor magnetic shield 131, an upper ring portion magnetic shield 132, a lower ring portion magnetic shield 133, a connection portion 134, a first fixing portion 135, and a second fixing portion 136. However, it is not limited to this. The external magnetic shield 25 is a portion that overlaps with the torque detection magnetic sensors 106 and 107 in the axial direction O, for example, by adding a portion that covers the radial outside of the upper magnetic collecting ring 84 or deleting the connecting portion 134. If it has, its shape can be changed as appropriate.

The fixing mode of the external magnetic shield 25 to the outer surface of the subassembly 23 and the housing 24 is not limited to the bolt fixing using the bolt 141 and the nut 142, and may be another fixing mode such as snap fit.

The external magnetic shield 25 may be fixed by adhering to the outer surfaces of the subassembly 23 and the housing 24, or may be fixed by fitting to the uneven shape of the outer surface of the subassembly 23 and the housing 24. You may try to do it. In this case, the first fixing portion 135 and the second fixing portion 136 may not be provided.

-Hall sensors have been adopted as the magnetic sensors 104 and 105 for angle detection and the magnetic sensors 106 and 107 for torque detection, but a magnetoresistive sensor may also be adopted.
The size of the torque detection magnetic sensors 106, 107 may be formed to be the same as the size of the lower magnetic collecting portions 64b, 64c and the upper magnetic collecting portions 84b, 84c, or the lower magnetic collecting portions 64b, It may be formed smaller than the size of 64c and the upper magnetic collecting portions 84b and 84c.

The lower magnetic collecting ring 64 is provided with two lower magnetic collecting portions 64b and 64c, and the upper magnetic collecting ring 84 is provided with two upper magnetic collecting portions 84b and 84c. One magnetic collector may be provided. In this case, one magnetic sensor may be arranged between one lower magnetic collecting portion of the lower magnetic collecting ring 64 and one upper magnetic collecting portion of the upper magnetic collecting ring 84.

Although the main gear 34 is integrally formed with the holder 33 of the magnetic yoke 22, the main gear 34 and the magnetic yoke 22 may be provided as separate members.
An annular lower magnetic collecting ring 64 and an upper magnetic collecting ring 84 are used as members for inducing the magnetic flux of the magnetic yoke 22, but as shown in FIG. 6, for example, a C-shape, a semicircular ring, or a quarter ring is used. You may adopt the magnetic flux collecting ring of.

Two driven gears 53 and 54 that mesh with the main gear 34 are provided as a configuration for detecting the rotation angle of the rotating shaft 11, but a configuration having a single driven gear 53 or a driven gear 54 is adopted as the sensor device 10. You may. Even in this way, the rotation angle of the rotation shaft 11 within 360 degrees can be detected. Further, the sensor device 10 may be configured to have three or more driven gears. Further, the configuration for detecting the rotation angle of the rotation shaft 11 may not be adopted. In this case, the main drive gear 34, the two driven gears 53, 54, the angle detection magnetic sensors 104, 105, and the like are not provided.

-As an example of the mounting destination of the sensor device 10, for example, a vehicle steering device can be mentioned. The steering device of this vehicle includes an electric power steering device that applies motor torque as an assist force to the steering shaft as the rotating shaft 11 or the steering shaft, and power transmission between the steering wheel and the steering wheel is separated. A steering device of the steer-by-wire system is included. In this case, the steering shaft that rotates according to the operation of the steering wheel or the pinion shaft connected to the steering shaft of the vehicle corresponds to the rotation shaft 11. Further, the sensor device 10 is not limited to in-vehicle use.

10 ... Sensor device 21 ... Permanent magnet 22 ... Magnetic yoke 23 ... Subassembly 24 ... Housing 25 ... External magnetic shield 64,84 ... Lower magnetic collecting ring, upper magnetic collecting ring 64a, 84a ... Lower ring part, upper side Ring parts 64b, 64c ... Lower magnetic collecting parts 84b, 84c ... Upper magnetic collecting parts 106, 107 ... Magnetic sensor for torque detection 131 ... Magnetic shield for sensor 131f ... Third axial covering part 132, 133 ... Upper ring part magnetic Shield, lower ring part Magnetic shield 134 ... Connection part 135, 136 ... First and second fixed parts

Claims (8)

Permanent magnets attached to the rotating shaft and magnetized in the circumferential direction,
A magnetic yoke arranged in a magnetic field formed by the permanent magnet so as to surround the permanent magnet,
An upper magnetic collecting ring having an annular upper ring portion surrounding the magnetic yoke and an upper magnetic collecting portion including a portion extending radially outward from the upper ring portion.
The lower part includes the annular lower ring portion surrounding the magnetic yoke and the portion extending radially outward from the lower ring portion while being arranged side by side with the upper magnetic collecting ring in the axial direction of the rotating shaft. A lower magnetizing ring with a side focusing part,
It is arranged between the upper magnetic collecting portion and the lower magnetic collecting portion facing each other in the axial direction, and is provided by the permanent magnet, the magnetic yoke, the upper magnetic collecting ring, and the lower magnetic collecting ring. A magnetic sensor that detects the magnetic flux of the formed magnetic circuit,
A sensor device including a sensor magnetic shield arranged outside the magnetic sensor so as to overlap the magnetic sensor in the axial direction. The permanent magnet, the magnetic yoke, the upper magnetic collecting ring, the lower magnetic collecting ring, and a sensor housing for accommodating the magnetic sensor are provided.
The sensor device according to claim 1, wherein the sensor magnetic shield is assembled on an outer surface of a sensor housing. The sensor device according to claim 1 or 2, further comprising an upper ring portion magnetic shield arranged above the upper ring portion so as to overlap the upper ring portion in the axial direction. The sensor device according to any one of claims 1 to 3, further comprising a lower ring portion magnetic shield arranged below the lower ring portion so as to overlap the lower ring portion in the axial direction. An upper ring portion magnetic shield arranged above the upper ring portion so as to overlap the upper ring portion in the axial direction.
A lower ring portion magnetic shield arranged below the lower ring portion so as to overlap the lower ring portion in the axial direction.
The sensor device according to claim 1 or 2, further comprising a connecting portion for axially connecting the upper ring portion magnetic shield and the lower ring portion magnetic shield. The sensor according to claim 5, wherein the connection portion is provided on the peripheral portion of the upper ring portion magnetic shield and the lower ring portion magnetic shield on the opposite side of the rotating shaft from the sensor magnetic shield. Device. The invention according to any one of claims 1 to 6, wherein the sensor magnetic shield includes a portion arranged outside the magnetic sensor so as to overlap the magnetic sensor in a direction orthogonal to the axial direction. Sensor device. Any one of claims 1 to 7, wherein the magnetic permeability of the material constituting the magnetic shield for the sensor is set lower than the magnetic permeability of the material constituting the upper magnetic collecting ring and the lower magnetic collecting ring. The sensor device according to.

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