Sensor Device

Abstract

This sensor device comprises a magnetism collection assembly (31) having a first magnetism collection member (41), a second magnetism collection member (42), and a resin holder (43). The first magnetism collection member (41) has a first body part (44), and first claw parts (45a, 45b) that are bent from the first body part (44) and protrude toward the outer peripheral side of the resin holder (43). The second magnetism collection member (42) has a second body part (46), and second claw parts (47a, 47b) that are bent from the second body part (46) and protrude toward the outer peripheral side of the resin holder (43). The resin holder (43) holds the first magnetism collection member (41) and the second magnetism collection member (42) such that at least a linking portion between the first body part (44) and the first claw parts (45a, 45b) and a linking portion between the second body part (46) and the second claw parts (47a, 47b) are not exposed at the inner peripheral surface of the resin holder (43).

Description

[Technical Field]

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

[0002] Conventionally, as described in Patent Document 1, for example, a sensor device is known that is provided on a rotating shaft including an input shaft and an output shaft connected to the input shaft via a torsion bar, and that detects torque applied to the rotating shaft.

[0003] The sensor device of Patent Document 1 includes a sensor magnet that rotates integrally with the input shaft, a pair of yoke cores that rotate integrally with the output shaft, a magnetic flux collector assembly having a pair of magnetic flux collector rings, and a magnetic sensor that generates a signal corresponding to the magnetic flux flowing through the pair of magnetic flux collector rings. The magnetic flux collector assembly includes a cylindrical resin holder that holds the pair of magnetic flux collector rings. Each magnetic flux collector ring has an annular portion and claws that bend from the annular portion and protrude toward the outer periphery. Each magnetic flux collector ring is held in the resin holder so that the annular portion is exposed to the inner periphery of the resin holder and the claws protrude toward the outer periphery of the resin holder. The magnetic sensor is disposed between the claws of the magnetic flux collector member on the outer periphery of the resin holder. This prevents liquid such as water from penetrating the inner periphery of the resin holder and directly adhering to the magnetic sensor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-25819 Summary of the Invention [Problem to be solved by the invention]

[0005] Even in a sensor device configured as in Patent Document 1, there is still a risk that liquid may reach the magnetic sensor through the interface between the magnetic flux collecting ring and the resin holder. In particular, if there is a gap between the magnetic flux collecting ring and the resin holder on the inner circumferential surface of the resin holder, liquid is more likely to reach the magnetic sensor. [Means for solving the problem]

[0006] A sensor device according to one aspect of the present disclosure includes a magnetic flux collector assembly including a sensor magnet configured to rotate integrally with a first shaft, first and second yoke cores configured to rotate integrally with a second shaft connected to the first shaft via a torsion bar, a first magnetic flux collector arranged at a distance from the first yoke core, a second magnetic flux collector arranged at a distance from the second yoke core, and a cylindrical resin holder; and a magnetic sensor that generates a signal corresponding to magnetic flux flowing through the first and second magnetic flux collectors. The first magnetic flux collector has a first main body portion facing the first yoke core and first claws that bend from the first main body and protrude toward the outer periphery of the resin holder. The second magnetic flux collector has a second main body portion facing the second yoke core and second claws that bend from the second main body and protrude toward the outer periphery of the resin holder. The magnetic sensor is disposed between the first and second claws on the outer periphery of the resin holder. The resin holder holds the first magnetic collecting member and the second magnetic collecting member so that at least the connecting portion between the first main body portion and the first claw portion and the connecting portion between the second main body portion and the second claw portion are not exposed on the inner surface of the resin holder. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is an exploded perspective view of the sensor device according to the embodiment; [Figure 2] 2 is a partial cross-sectional view taken along the axial direction of the sensor device of FIG. 1. FIG. [Figure 3] FIG. 2 is a perspective view of a magnetic flux collecting assembly that constitutes the sensor device of FIG. [Figure 4]4 is a perspective view of a first magnetic flux collector member and a second magnetic flux collector member that constitute the magnetic flux collector assembly of FIG. 3. FIG. [Figure 5A] 4 is an enlarged cross-sectional view showing an example of a connecting portion between a first main body portion and a first claw portion in a state in which molten resin is injected during insert molding of a resin holder that constitutes the magnetic flux collecting assembly of FIG. 3. FIG. [Figure 5B] 4 is an enlarged cross-sectional view showing an example of a connecting portion between a first main body portion and a first claw portion in a state in which molten resin has solidified during insert molding of a resin holder that constitutes the magnetic flux collecting assembly of FIG. 3. FIG. [Figure 6] FIG. 2 is a plan view of a magnetic flux collecting assembly that constitutes the sensor device of FIG. [Figure 7] 4 is a perspective view of a magnetic flux collecting assembly constituting the sensor device of FIG. 1, seen from a different viewpoint from that of FIG. 3. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of a sensor device will be described below with reference to the drawings. As shown in FIG. 1, the sensor device 1 is provided on the outer periphery of a rotating shaft 2. The rotating shaft 2 includes an input shaft 3, which is a first shaft, a torsion bar 4, and an output shaft 5, which is a second shaft. The input shaft 3 and the output shaft 5 are connected to each other via the torsion bar 4. The input shaft 3, the torsion bar 4, and the output shaft 5 are located on the same axis L. The rotating shaft 2 is, for example, a pinion shaft of a rack-and-pinion mechanism that constitutes a steering device of a vehicle. A steering wheel is connected to the upper end of the pinion shaft via an intermediate shaft and a column shaft.

[0009] The sensor device 1 detects torque applied to a rotating shaft 2 through operation of the steering wheel by a driver. The sensor device 1 includes a sensor magnet 11, a magnetic yoke assembly 12, and a fixing unit 13.

[0010] The sensor magnet 11 is a cylindrical ring magnet. In this specification, "cylindrical" means that the magnet can be considered cylindrical as a whole, and includes a magnet formed by combining multiple parts, or a magnet with a cutout such as a C-shape. The "cylindrical" shape includes, but is not limited to, a circle, an ellipse, and a polygon with sharp or rounded corners when viewed in the axial direction. In this embodiment, the sensor magnet 11 has a circular shape when viewed in the axial direction.

[0011] The sensor magnet 11 is magnetized in the radial direction so that magnetic poles of different polarities are alternately arranged in the circumferential direction. The sensor magnet 11 is fixed to the outer circumferential surface of the input shaft 3 directly or via a holder (not shown) so as to be rotatable together with the outer circumferential surface of the input shaft 3. In another embodiment, the sensor magnet 11 may be a plurality of plate-shaped magnets.

[0012] The magnetic yoke assembly 12 includes a first yoke core 21, a second yoke core 22, and a yoke holder 23 that holds the first yoke core 21 and the second yoke core 22. The magnetic yoke assembly 12 is disposed on the outer periphery of the sensor magnet 11 with a gap therebetween. The magnetic yoke assembly 12 is fixed to the outer periphery of the output shaft 5 so as to be rotatable integrally therewith.

[0013] Each of the first yoke core 21 and the second yoke core 22 is made of a magnetic material and has an annular shape. In this specification, "annular" means that the entire structure can be considered annular, and includes structures formed by combining multiple components and structures with a cutout, such as a C-shape. "Annular" shapes include, but are not limited to, circles, ellipses, and polygons with sharp or rounded corners when viewed in the axial direction. In this embodiment, each of the first yoke core 21 and the second yoke core 22 has a circular shape when viewed in the axial direction.

[0014] The first yoke core 21 and the second yoke core 22 are arranged at intervals along the axis L. The first yoke core 21 and the second yoke core 22 each have a plurality of teeth 24, 25. The teeth 24, 25 protrude in directions approaching each other. The teeth 24 are provided at equal intervals in the circumferential direction on the first yoke core 21, and the teeth 25 are provided at equal intervals in the circumferential direction on the second yoke core 22. The teeth 24 and the teeth 25 are arranged alternately in the circumferential direction.

[0015] The yoke holder 23 is made of, for example, a resin material and has a cylindrical shape. In this embodiment, the yoke holder 23 has a circular shape when viewed in the axial direction. The axial direction of the yoke holder 23 coincides with the direction along the axis L.

[0016] The yoke holder 23 is a resin-molded part formed by insert molding with the first yoke core 21 and the second yoke core 22 as insert parts. In other words, the yoke holder 23 is a part of the magnetic yoke assembly 12 made of resin material. The yoke holder 23 holds the first yoke core 21 and the second yoke core 22 on the axis L. Specifically, the yoke holder 23 holds the first yoke core 21 and the second yoke core 22 so that the inner surfaces of the tooth portions 24, 25 are exposed on the inner circumferential side of the yoke holder 23.

[0017] 1 and 2, the fixed unit 13 includes a magnetic flux collector assembly 31, an outer case 32 that holds the magnetic flux collector assembly 31, and a circuit board 33. The fixed unit 13 is attached to a housing 34 that rotatably supports the rotating shaft 2. The housing 34 is, for example, a gear housing that houses the rack and pinion mechanism.

[0018] 2 to 4, the magnetic flux collecting assembly 31 includes a first magnetic flux collecting member 41, a second magnetic flux collecting member 42, and a resin holder 43 that holds the first magnetic flux collecting member 41 and the second magnetic flux collecting member 42. The magnetic flux collecting assembly 31 may further include a shield member that is disposed on the outer periphery of the first magnetic flux collecting member 41 and the second magnetic flux collecting member 42.

[0019] The first magnetic flux collector 41 is disposed on the outer circumferential side of the first yoke core 21 with a gap therebetween. The first magnetic flux collector 41 has an annular first main body portion 44 that faces the first yoke core 21 in the radial direction, and two first claw portions 45a, 45b that bend from the first main body portion 44 and protrude toward the outer circumferential side of the resin holder 43. In this embodiment, the first main body portion 44 has a C-shape when viewed in the axial direction. The second magnetic flux collector 42 is disposed on the outer circumferential side of the second yoke core 22 with a gap therebetween. The second magnetic flux collector 42 has an annular second main body portion 46 that faces the second yoke core 22 in the radial direction, and two second claw portions 47a, 47b that bend from the second main body portion 46 and protrude toward the outer circumferential side of the resin holder 43. In this embodiment, the second main body portion 46 has a C-shape when viewed in the axial direction.

[0020] In this specification, "facing" refers to surfaces or components facing each other, and includes not only cases where they are completely facing each other, but also cases where they are partially facing each other. Furthermore, in this specification, "facing" refers to both cases where there is a component separate from the two components between the two components, and cases where there is nothing between the two components.

[0021] The resin holder 43 has a generally cylindrical shape. The resin holder 43 is a resin molded product formed by insert molding with the first magnetic field collecting member 41 and the second magnetic field collecting member 42 as insert parts. In other words, the resin holder 43 is a part of the magnetic field collecting assembly 31 made of a resin material. The first magnetic field collecting member 41, the second magnetic field collecting member 42, and the resin holder 43 will be described in detail later.

[0022] As shown in FIGS. 1 and 2 , the outer case 32 is a resin-molded product formed by insert molding using the magnetic flux collector assembly 31 as an insert component. The outer case 32 includes a case main body 51 that covers the outside of the magnetic flux collector assembly 31 and a protruding portion 52 that protrudes radially outward from the magnetic flux collector assembly 31. The case main body 51 is generally cylindrical and is disposed on the axis L. That is, the case main body 51 is disposed coaxially with the magnetic flux collector assembly 31. The protruding portion 52 is, for example, cylindrical and protrudes in a direction perpendicular to the axis L. In this embodiment, the protruding portion 52 has a rectangular shape when viewed in a direction perpendicular to the axial direction. The open end of the protruding portion 52 is closed by a cover (not shown). The outer case 32 is fixed to the housing 34. As a result, the interior of the resin holder 43 is in communication with the interior of the housing 34 via the case main body 51.

[0023] The circuit board 33 has a rectangular plate shape. The circuit board 33 is disposed within the protruding portion 52. The circuit board 33 is electrically connected to a terminal (not shown) provided within the protruding portion 52. Two magnetic sensors 53a and 53b are mounted on the circuit board 33. One of the magnetic sensors 53a and 53b is a redundant sensor to be used in case the other fails or otherwise malfunctions. The magnetic sensor 53a is mounted on the circuit board 33 so as to be positioned between the first claw 45a of the first magnetic flux collecting member 41 and the second claw 47a of the second magnetic flux collecting member 42. The magnetic sensor 53b is mounted on the circuit board 33 so as to be positioned between the first claw 45b of the first magnetic flux collecting member 41 and the second claw 47b of the second magnetic flux collecting member 42. The magnetic sensors 53a and 53b are, for example, Hall sensors or magnetoresistive sensors, for detecting magnetic flux flowing through the first magnetic flux collecting member 41 and the second magnetic flux collecting member 42.

[0024] (Operation of sensor device 1) In the sensor device 1 configured as described above, the sensor magnet 11 rotates integrally with the input shaft 3, and the magnetic yoke assembly 12 rotates integrally with the output shaft 5. When the driver operates the steering wheel, the torsion bar 4 twists and the input shaft 3 and output shaft 5 rotate relative to each other, changing the relative circumferential positions of the sensor magnet 11 and the magnetic yoke assembly 12. As a result, the magnetic flux flowing through the first yoke core 21 and the second yoke core 22 changes depending on the amount of twist of the torsion bar 4, i.e., the magnitude of the torque input by the driver. As a result, the magnetic flux flowing through the first magnetic flux collecting member 41 and the second magnetic flux collecting member 42 also changes depending on the change in the magnetic flux flowing through the first yoke core 21 and the second yoke core 22. The magnetic sensors 53a and 53b detect the magnetic flux flowing through the first magnetic flux collecting member 41 and the second magnetic flux collecting member 42 and generate a signal corresponding to this magnetic flux, i.e., a signal indicating torque.

[0025] (Waterproof structure of magnetic flux collector assembly 31) For example, assume that a liquid such as water enters the magnetic flux collecting assembly 31 through the housing 34. At this time, there is a risk that the liquid may reach the magnetic sensors 53a and 53b through the interface between the first magnetic flux collecting member 41 and the resin holder 43 and / or the interface between the second magnetic flux collecting member 42 and the resin holder 43. In particular, if there is a gap between the first magnetic flux collecting member 41 and the resin holder 43 and / or between the second magnetic flux collecting member 42 and the resin holder 43 on the inner circumferential surface of the resin holder 43, the liquid will be more likely to reach the magnetic sensors 53a and 53b.

[0026] Here, insert molding is a molding technique in which injection molding is performed with an insert placed inside a mold. For example, in the case of the magnetic flux collector assembly 31, injection molding is performed with the first magnetic flux collector member 41 and the second magnetic flux collector member 42 placed inside the mold. At this time, the first magnetic flux collector member 41 and the second magnetic flux collector member 42 are encapsulated, except for a portion, in molten resin injected into the mold. Then, this molten resin is cooled and solidified, forming the resin holder 43, which is a resin molded product.

[0027] When molten resin cools and solidifies, molding shrinkage typically occurs. This is a phenomenon in which the volume of molten resin filled inside a mold decreases as it cools and solidifies. Therefore, due to molding shrinkage, there is a possibility that small gaps will occur between the first magnetic field collecting member 41 and the second magnetic field collecting member 42 and the resin holder 43. In particular, if the resin holder 43 has a pointed shape, this pointed portion is more likely to separate from the first magnetic field collecting member 41 and the second magnetic field collecting member 42 than a flat portion, making it more likely that gaps will occur.

[0028] Specifically, as described above, the first claw 45a of the first magnetic flux collector 41 is bent from the first main body 44. Therefore, as shown in FIGS. 5A and 5B , when viewed locally near the connecting portion between the first main body 44 and the first claw 45a, the space filled by the resin holder 43 has a pointed shape. In other words, the resin holder 43 has a locally pointed shape near the connecting portion between the first main body 44 and the first claw 45a. As will be described later, the first magnetic flux collector 41 of this embodiment has a first recess 73a adjacent to the first claw 45a, which makes it easier for the shape of the resin holder 43 near the connecting portion between the first main body 44 and the first claw 45a to become even more pointed. The same applies to the connecting portion between the first main body 44 and the first claw 45a and the connecting portion between the second main body 46 and the second claws 47a, 47b of the second magnetic flux collector 42.

[0029] During insert molding, when molten resin 43x that constitutes resin holder 43 is injected into a mold as shown in Fig. 5A, the molten resin 43x closely surrounds and encases first magnetic flux collecting member 41. However, when the molten resin 43x cools and solidifies, a molding shrinkage phenomenon occurs as shown in Fig. 5B, causing the pointed portion of resin holder 43 to separate from first magnetic flux collecting member 41. As a result, a gap may be formed at the connecting portion between first main body portion 44 and first claw portion 45a.

[0030] In consideration of this, the resin holder 43 holds the first magnetic flux collecting member 41 and the second magnetic flux collecting member 42 so that the connecting portion between the first main body portion 44 and the first claw portions 45a, 45b and the connecting portion between the second main body portion 46 and the second claw portions 47a, 47b are not exposed on the inner circumferential surface of the resin holder 43. The configurations of the resin holder 43, the first magnetic flux collecting member 41, and the second magnetic flux collecting member 42 will be described in detail below.

[0031] (Resin holder 43) 2 and 3, the resin holder 43 has a cylindrical holder main body 61 and a first support wall 62 and a second support wall 63 provided on the outer peripheral surface of the holder main body 61. In this embodiment, the holder main body 61 has a circular shape when viewed in the axial direction. The first support wall 62 protrudes radially outward from one axial end of the holder main body 61. The second support wall 63 protrudes radially outward from the other axial end of the holder main body 61. The first support wall 62 faces the second support wall 63 with an axial gap between them.

[0032] (First magnetic flux collecting member 41) 4 and 6, the first magnetic flux collecting member 41 is formed by bending a long metal plate made of a magnetic material. In other words, the first magnetic flux collecting member 41 is a one-piece product. The first main body portion 44 of the first magnetic flux collecting member 41 has a first arc portion 71 and a first protrusion portion 72.

[0033] The first arc portion 71 has an arc-shaped inner peripheral surface that coincides with the inner peripheral surface of the holder main body 61, i.e., the inner peripheral surface of the resin holder 43, when viewed in the axial direction. Here, a circle formed by extending the inner peripheral surface of the first arc portion 71 is defined as a first imaginary circle C1. In FIG. 6, the line indicating the first imaginary circle C1 coincides with the line indicating the inner peripheral surface of the resin holder 43.

[0034] The first protrusion 72 protrudes radially outward from, for example, the circumferential center of the first arc portion 71 so as to be disposed on the outer circumferential side of the first virtual circle C1. The first protrusion 72 has a connecting portion bent radially outward from an end of the first arc portion 71 and a straight portion extending linearly between the connecting portions. The first claw portions 45a, 45b are bent radially outward from the straight portion of the first protrusion 72 and protrude toward the outer circumferential side of the resin holder 43. First recesses 73a, 73b are provided on both sides of each of the first claw portions 45a, 45b in the first protrusion 72. That is, the first main body portion 44 has first recesses 73a, 73b on both circumferential sides of the resin holder 43 at each connecting portion with the first claw portions 45a, 45b. Each of the first recesses 73a and 73b extends linearly along the thickness direction of the first protruding portion 72 and opens to the inner and outer circumferential sides of the first main body portion 44.

[0035] As shown in FIGS. 6 and 7 , the first magnetic flux collector 41 of this embodiment is held by the resin holder 43 such that the entire inner circumferential surface of the first arc portion 71 is exposed to the inner circumferential surface of the resin holder 43 and the entire first protrusion 72 is embedded within the resin holder 43. In other embodiments, a portion of the inner circumferential surface of the first arc portion 71 may be embedded within the resin holder 43. Furthermore, although the inner circumferential surface of the first arc portion 71 of this embodiment is exposed without any step between it and the inner circumferential surface of the resin holder 43, for example, the inner circumferential surface of the first arc portion 71 may protrude toward the inner circumferential side of the resin holder 43. Furthermore, as long as the connecting portion between the first main body portion 44 and the first claw portions 45a and 45b is embedded within the resin holder 43, a portion of the first protrusion 72 may be exposed to the outside of the resin holder 43. As shown in FIG. 3 , the first claw portions 45a and 45b are exposed on the surface of the first support wall 62 facing the second support wall 63.

[0036] (Second magnetic flux collecting member 42) 4 and 6, the second magnetic flux collecting member 42 has the same shape as the first magnetic flux collecting member 41 and is formed by bending a long metal plate made of a magnetic material. In other words, the second magnetic flux collecting member 42 is a one-piece product. The second main body portion 46 of the second magnetic flux collecting member 42 has a second arc portion 81 and a second protrusion portion 82.

[0037] The second arc portion 81 has an arc-shaped inner peripheral surface that coincides with the inner peripheral surface of the resin holder 43 when viewed in the axial direction. The second arc portion 81 has the same shape as the first arc portion 71. Here, a circle formed by extending the inner peripheral surface of the second arc portion 81 is defined as a second imaginary circle C2. The second imaginary circle C2 coincides with the first imaginary circle C1.

[0038] The second protrusion 82 protrudes radially outward from, for example, the circumferential center of the second arc portion 81 so as to be disposed on the outer circumferential side of the second imaginary circle C2. The second protrusion 82 has a connecting portion bent radially outward from an end of the second arc portion 81 and a straight portion extending linearly between the connecting portions. The second claw portions 47a, 47b are bent radially outward from the straight portion of the second protrusion 82 and protrude toward the outer circumferential side of the resin holder 43. Second recesses 83a, 83b are provided on both sides of each of the second claw portions 47a, 47b in the second protrusion 82. That is, the second main body portion 46 has second recesses 83a, 83b on both circumferential sides of the resin holder 43 at each connecting portion with the second claw portions 47a, 47b. Each of the second recesses 83a and 83b extends linearly along the thickness direction of the second protruding portion 82 and opens to the inner and outer circumferential sides of the second main body portion 46.

[0039] 6 and 7 , the second magnetic flux collecting member 42 of this embodiment is held by the resin holder 43 in such a manner that the entire inner circumferential surface of the second arc portion 81 is exposed to the inner circumferential surface of the resin holder 43 and the entire second protruding portion 82 is embedded inside the resin holder 43. In other embodiments, a portion of the inner circumferential surface of the second arc portion 81 may be embedded inside the resin holder 43. Furthermore, although the inner circumferential surface of the second arc portion 81 of this embodiment is exposed so as not to form a step with the inner circumferential surface of the resin holder 43, for example, the inner circumferential surface of the second arc portion 81 may protrude toward the inner circumferential side of the resin holder 43. Furthermore, as long as the connecting portion between the second main body portion 46 and the second claw portions 47 a, 47 b is embedded inside the resin holder 43, a portion of the second protruding portion 82 may be exposed outside the resin holder 43. As shown in FIG. 3, the second claws 47a and 47b are exposed on a surface of the second support wall 63 that faces the first support wall 62 so as to face the first claws 45a and 45b in the axial direction.

[0040] Next, the operation and effects of this embodiment will be described. (1) The resin holder 43 holds the first magnetic flux collecting member 41 and the second magnetic flux collecting member 42 so that the connecting portion between the first main body portion 44 and the first claw portions 45a, 45b and the connecting portion between the second main body portion 46 and the second claw portions 47a, 47b are not exposed on the inner circumferential surface of the resin holder 43. Therefore, even if a gap occurs between the connecting portion of the first main body portion 44 with the first claw portion 45a and the resin holder 43 due to molding shrinkage, for example, a gap is unlikely to occur on the inner circumferential surface of the resin holder 43. As a result, even if liquid seeps into the resin holder 43, the liquid can be prevented from reaching the magnetic sensors 53a, 53b.

[0041] (2) The first main body portion 44 has a first arc portion 71 and a first protruding portion 72. A circle formed by extending the first arc portion 71 is a first imaginary circle C1. The first protruding portion 72 protrudes from the first arc portion 71 so as to be disposed on the outer circumferential side of the first imaginary circle C1. The first claw portions 45a, 45b protrude from the first protruding portion 72 toward the outer circumferential side of the resin holder 43. The resin holder 43 holds the first magnetic flux collecting member 41 so that the first arc portion 71 is exposed to the inner circumferential surface of the resin holder 43 and the first protruding portion 72 is embedded inside the resin holder 43.

[0042] According to the above configuration, the connecting portion between the first main body portion 44 and the first claw portions 45a, 45b is not exposed on the inner circumferential surface of the resin holder 43, and the first arc portion 71, which is a part of the first main body portion 44, can be exposed on the inner circumferential surface of the resin holder 43. Therefore, compared to when the entire first main body portion 44 is embedded inside the resin holder 43, for example, the first main body portion 44 can be disposed closer to the first yoke core 21, and a decrease in the magnetic flux flowing through the first magnetic flux collecting member 41 can be suppressed. This prevents the absolute value of the magnetic flux detected by the magnetic sensors 53a, 53b from becoming smaller, and suppresses a decrease in noise resistance performance.

[0043] (3) The second main body portion 46 has a second arc portion 81 and a second protruding portion 82. A circle formed by extending the second arc portion 81 is a second imaginary circle C2. The second protruding portion 82 protrudes from the second arc portion 81 so as to be disposed on the outer circumferential side of the second imaginary circle C2. The second claw portions 47a, 47b protrude from the second protruding portion 82 toward the outer circumferential side of the resin holder 43. The resin holder 43 holds the second magnetic flux collecting member 42 so that the second arc portion 81 is exposed to the inner circumferential surface of the resin holder 43 and the second protruding portion 82 is embedded inside the resin holder 43.

[0044] According to the above configuration, the same effect as that of (2) above can be said to be obtained for the second magnetic flux collecting member 42. This prevents the absolute value of the magnetic flux detected by the magnetic sensors 53a and 53b from decreasing, thereby preventing a decrease in noise resistance performance.

[0045] (4) Each of the first magnetic flux collecting member 41 and the second magnetic flux collecting member 42 is an integral part, which reduces the number of parts compared to when a magnetic flux collecting member is formed by joining multiple parts together.

[0046] (5) The first main body portion 44 has first recesses 73a, 73b on both circumferential sides of the resin holder 43 at the connection portions with the first claw portions 45a, 45b. The second main body portion 46 has second recesses 83a, 83b on both circumferential sides of the resin holder 43 at the connection portions with the second claw portions 47a, 47b.

[0047] In the above configuration, the first recesses 73a, 73b are provided in the first main body portion 44 (strictly speaking, the first protrusion 72), so when the first claws 45a, 45b are bent, the first main body portion 44 can be prevented from being pulled by the first claws 45a, 45b and bending. This makes it easier to bend the first claws 45a, 45b. Similarly, it makes it easier to bend the second claws 47a, 47b.

[0048] However, since the first magnetic flux collecting member 41 has the first recesses 73a, 73b, the shape of the resin holder 43 near the connecting portions between the first main body portion 44 and the first claw portions 45a, 45b tends to become even sharper (see FIGS. 5A and 5B). The same can be said for the second magnetic flux collecting member 42. Therefore, it is very effective to adopt a configuration in which the connecting portions between the first main body portion 44 and the first claw portions 45a, 45b and the connecting portions between the second main body portion 46 and the second claw portions 47a, 47b are not exposed on the inner circumferential surface of the resin holder 43.

[0049] (6) The first magnetic flux collecting member 41 has the same shape as the second magnetic flux collecting member 42. Therefore, the manufacturing costs can be reduced compared to when the first magnetic flux collecting member 41 has a different shape from the second magnetic flux collecting member 42.

[0050] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. The first magnetic flux collecting member 41 may not have the first recesses 73a and 73b. Similarly, the second magnetic flux collecting member 42 may not have the second recesses 83a and 83b.

[0051] The first magnetic flux collecting member 41 does not have to be an integral part. For example, the members constituting the first claws 45a, 45b may be separately joined to the member constituting the first main body 44. Similarly, the second magnetic flux collecting member 42 does not have to be an integral part.

[0052] The shape of the first main body portion 44 can be modified as appropriate. For example, the first main body portion 44 may have only the first arc portion 71 without the first protruding portion 72. In this case, for example, the resin holder 43 may hold the first magnetic flux collecting member 41 in a state eccentric to the axis L, so that the connecting portion between the first main body portion 44 (first arc portion 71) and the first claw portions 45a, 45b is not exposed on the inner circumferential surface of the resin holder 43. Furthermore, the first arc portion 71 may have an arc-shaped inner circumferential surface that does not coincide with the inner circumferential surface of the resin holder 43 when viewed in the axial direction. Furthermore, the first protruding portion 72 may not have a straight portion, and the entire first protruding portion 72 may be curved. Similarly, the shape of the second main body portion 46 can be modified as appropriate.

[0053] The first magnetic flux collecting member 41 may have only one first claw, and similarly, the second magnetic flux collecting member 42 may have only one second claw. The first magnetic flux collecting member 41 may have a different shape from the second magnetic flux collecting member 42.

[0054] The first main body portion 44 may be opposed to the first yoke core 21 in the axial direction. In this case, the first main body portion 44 may be, for example, flat, and its shape may be changed as appropriate. Similarly, the second magnetic flux collecting member 42 may be opposed to the second yoke core 22 in the axial direction.

[0055] The resin holder 43 may have only the holder body 61 without having the first support wall 62 and the second support wall 63 . The rotating shaft 2 may be a shaft other than a pinion shaft, such as a column shaft. In other words, the sensor device 1 may be provided around the column shaft, for example.

[0056] The sensor device 1 does not have to include the outer case 32. Furthermore, as long as the sensor device 1 includes the magnetic sensors 53a and 53b, it does not have to include the circuit board 33. Furthermore, the sensor device 1 may include only one magnetic sensor.

[0057] The sensor device 1 may be configured to detect the rotation angle of the rotating shaft 2 in addition to the torque. In this case, the sensor device 1 further includes, for example, a driving gear provided on the magnetic yoke assembly 12 and one or more driven gears that mesh with the driving gear. The rotation angle of the rotating shaft 2 can then be detected based on the rotation angle of the driven gears.

[0058] Although the sensor magnet 11 is fixed to the input shaft 3 and the magnetic yoke assembly 12 is fixed to the output shaft 5 in the above embodiment, the sensor magnet 11 may be fixed to the output shaft 5 and the magnetic yoke assembly 12 may be fixed to the input shaft 3.

Claims

1. a sensor magnet configured to rotate integrally with the first shaft; a first yoke core and a second yoke core configured to rotate integrally with a second shaft connected to the first shaft via a torsion bar; a magnetic flux collecting assembly including a first magnetic flux collecting member disposed with a gap between it and the first yoke core, a second magnetic flux collecting member disposed with a gap between it and the second yoke core, and a cylindrical resin holder; a magnetic sensor that generates a signal according to magnetic flux flowing through the first magnetic flux collecting member and the second magnetic flux collecting member, the first magnetic flux collecting member has a first main body portion facing the first yoke core and a first claw portion bent from the first main body portion and protruding toward an outer periphery of the resin holder, the second magnetic flux collecting member has a second main body portion facing the second yoke core and a second claw portion bent from the second main body portion and protruding toward an outer periphery of the resin holder, the magnetic sensor is disposed on an outer circumferential side of the resin holder between the first claw portion and the second claw portion, the resin holder holds the first magnetic flux collecting member and the second magnetic flux collecting member such that at least a connecting portion between the first main body portion and the first claw portion and a connecting portion between the second main body portion and the second claw portion are not exposed on an inner circumferential surface of the resin holder, the first main body portion has a first arc portion and a first protrusion, a circle formed by extending the inner circumferential surface of the first arc portion is a first virtual circle, the first protrusion protrudes from the first arc portion so as to be disposed on an outer circumferential side of the first virtual circle; the first claw portion protrudes from the first protruding portion toward the outer periphery of the resin holder, The resin holder holds the first magnetic collecting member so that the first arc portion is exposed on the inner surface of the resin holder and the connecting portion between the first protrusion portion and the first claw portion is embedded inside the resin holder so that it is not exposed.

2. The sensor device according to claim 1, the second main body portion has a second arc portion and a second protrusion portion, a circle formed by extending the inner circumferential surface of the second arc portion is a second virtual circle, the second protruding portion protrudes from the second arc portion so as to be disposed on an outer circumferential side of the second virtual circle, the second claw portion protrudes from the second protruding portion toward the outer periphery of the resin holder, The resin holder holds the second magnetic flux collecting member so that the second arc portion is exposed to an inner circumferential surface of the resin holder and the second protrusion portion is embedded inside the resin holder.

3. 3. The sensor device according to claim 1, The sensor device, wherein the first magnetic flux collecting member and the second magnetic flux collecting member are each an integral part.

4. The sensor device according to any one of claims 1 to 3, the first main body portion has first recesses on both sides in the circumferential direction of the resin holder at a connecting portion with the first claw portion, The second main body portion has second recesses on both sides in the circumferential direction of the resin holder at a connecting portion with the second claw portion.

Images