JP2023141619A - Rotation angle detector - Google Patents

Abstract

To provide a rotation angle detector which can be downsized.SOLUTION: A rotation angle detector 2 includes: a first rotary member 3 and a second rotary member 4 which rotate at different rates in association with rotation of a steering shaft 171; a first magnet 51 attached to the first rotary member 3; a second magnet 52 attached to the second rotary member 4; and a magnetic field detection element 6 for detecting a magnetic field of the first magnet 51 and a magnetic field of the second magnet 52. The magnetic field detection element 6 is disposed at a position where the rotation axial line O1 of the first rotary member 3 and the rotation axial line O2 of the second rotary member 4 intersect each other.SELECTED DRAWING: Figure 6

Description

The present invention relates to a rotation angle detection device that detects the angular position of a rotating shaft.

Conventionally, a rotation angle detection device that detects the angular position of a rotating shaft has been used, for example, to detect a steering angle in a steering device of a vehicle.

The rotation angle detection device described in Patent Document 1 includes a rotating body fixed to a steering shaft, a first detection body and a second detection body that rotate with the rotation of the rotation body, and a rotation angle detection device of the first detection body. It includes a first detection means for detecting rotation, and a second detection means for detecting rotation of the second detection body. Spur gear portions are formed on the outer peripheries of the side surfaces of the rotating body, the first detection body, and the second detection body, respectively. The spur gear portion of the first detection body meshes with the spur gear portion of the rotating body. The spur gear portion of the second detection body meshes with the spur gear portion of the first detection body. The rotation axis of the first detection body and the rotation axis of the second detection body are parallel. The number of teeth of the spur gear portion of the first detection body is different from the number of teeth of the spur gear portion of the second detection body. The first detection means includes a magnet placed in the center of the first detection body and a magnetic detection element placed opposite the magnet. The second detection means includes a magnet placed in the center of the second detection body and a magnetic detection element placed opposite the magnet. The magnetic detection element of the first detection means and the magnetic detection element of the second detection means are mounted on one wiring board arranged perpendicularly to the rotation axis of the first detection body and the second detection body. has been done.

Japanese Patent Application Publication No. 2010-112848

When the rotation angle detection device is used, for example, in a vehicle steering device, an important requirement is that the rotation angle detection device be small. In the rotation angle detection device described in Patent Document 1, the first detection body and the second detection body face the wiring board and are arranged in the radial direction, so there are restrictions on miniaturization of the wiring board. Therefore, an object of the present invention is to provide a rotation angle detection device that can be downsized.

In order to solve the above-mentioned problems, the present invention provides a rotation angle detection device for detecting the angular position of a rotating shaft, in which first and second rotations rotate at different speeds as the shaft rotates. a first magnet attached to the first rotating member, a second magnet attached to the second rotating member, a magnetic field of the first magnet, and a magnetic field of the second magnet. a rotation angle detection device, wherein the magnetic field detection element is arranged at a position where a rotation axis of the first rotation member and a rotation axis of the second rotation member intersect. I will provide a.

According to the present invention, it is possible to downsize the rotation angle detection device.

1 is a schematic diagram of a vehicle equipped with a steer-by-wire steering device including a rotation angle detection device according to a first embodiment of the present invention. FIG. 2 is a perspective view showing a detection section and a gear member of the rotation angle detection device together with a steering shaft. FIG. 3 is a cross-sectional view of the detection section taken along line AA in FIG. 2. FIG. (a) and (b) are perspective views showing a gear member, first and second rotating members, a magnetic field detection element, a substrate, and a connecting portion. (a) thru|or (c) are the figures which looked at the 1st rotating member, the 2nd rotating member, and the gear member from each axial direction. FIG. 3 is an explanatory diagram showing the positional relationship between first and second rotating members, first and second magnets, and a magnetic field detection element. It is a graph which shows an example of the strength of the magnetic field in the X-axis direction, the Y-axis direction, and the Z-axis direction detected by the magnetic field detection element when the steering shaft moves in the axial direction. FIG. 7 is an explanatory diagram showing the positional relationship between the first and second rotating members, the first and second magnets, and the magnetic field detection element according to the first modification. FIG. 7 is an explanatory diagram showing the positional relationship between the first and second rotating members, the first and second magnets, and the magnetic field detection element according to a second modification. FIG. 7 is an explanatory diagram showing the positional relationship between the first and second rotating members, the first and second magnets, and the magnetic field detection element according to a third modification. FIG. 12 is an explanatory diagram showing the positional relationship between the first and second rotating members, the first and second magnets, and the magnetic field detection element according to a fourth modification. FIG. 7 is a diagram of first and second rotating members and a gear member according to a second embodiment as viewed from their respective axial directions.

[First embodiment]
FIG. 1 is a schematic diagram of a vehicle equipped with a steer-by-wire steering device 1 equipped with a rotation angle detection device 2 according to a first embodiment of the present invention.

As shown in FIG. 1, the steering device 1 includes a tie rod 12 connected to left and right rolling wheels 11 (front wheels), a rack shaft 13 to which the tie rod 12 is connected at both ends, and a cylindrical shaft that houses the rack shaft 13. The housing 14, the worm reduction mechanism 15 having a pinion gear 151 meshed with the gear teeth 131 of the rack shaft 13, the electric motor 16 that applies an axial movement force to the rack shaft 13 via the worm reduction mechanism 15, and the operation A steering wheel 17 that is operated by a person, a steering shaft 171 connected to the steering wheel 17, a torque sensor 18 that detects the steering torque applied to the steering shaft 171, and a reaction sensor 18 that applies a steering reaction force to the steering shaft 171. The power motor 19 includes a rotation angle detection device 2 that detects the steering angle of the steering wheel 17, which is the angular position of the steering shaft 171, and a control device 10 that controls the electric motor 16 and the reaction motor 19.

In FIG. 1, the housing 14 is shown in phantom lines. The rack shaft 13 is supported by a pair of rack bushes 141 attached to both ends of the housing 14. The worm reduction mechanism 15 has a worm wheel 152 and a worm gear 153, and a pinion gear 151 is fixed to the worm wheel 152. Worm gear 153 is fixed to motor shaft 161 of electric motor 16.

The electric motor 16 generates torque using a motor current supplied from the control device 10 and rotates the worm wheel 152 and pinion gear 151 via the worm gear 153. When the pinion gear 151 rotates, the rack shaft 13 moves forward and backward in its axial direction, and the left and right rolling wheels 11 are steered. The rack shaft 13 is movable to the right and left in the vehicle width direction within a predetermined range from a neutral position when the steering angle is zero. In FIG. 1, a range _R1 within which the rack shaft 13 can move in the axial direction is indicated by double-headed arrows.

Further, the control device 10 calculates a target value of the steering reaction force to be applied to the steering shaft 171 based on the steering angle detected by the rotation angle detection device 2, the steering torque detected by the torque sensor 18, and the vehicle speed, A motor current corresponding to this target value is supplied to the reaction force motor 19.

The rotation angle detection device 2 includes a detection section 21 non-rotatably attached to the vehicle body, a shaft-shaped gear member 22 fixed to a steering shaft 171, and calculates a steering angle according to a detection signal from the detection section 21. It is equipped with a calculation unit 23 that performs the following steps. The rotation angle detection device 2 detects the steering angle of the steering wheel 17 as the angular position of the gear member 22 with respect to the detection section 21, and the calculation section 23 outputs the detection result to the control device 10. The control device 10 controls the electric motor 16 so that the steering angle of the rolling wheels 11 corresponds to the steering angle detected by the rotation angle detection device 2.

FIG. 2 is a perspective view showing the detection unit 21, the gear member 22, and the steering shaft 171. FIG. 3 is a cross-sectional view of the detection unit 21 taken along line AA in FIG. The detection unit 21 includes first and second rotating members 3 and 4 that rotate at different speeds as the steering shaft 171 rotates, a first magnet 51 attached to the first rotating member 3, and a first magnet 51 attached to the first rotating member 3. a second magnet 52 attached to the second rotating member 4; a magnetic field detection element 6 that is a single IC (Integrated Circuit) that detects the magnetic field of the first magnet 51 and the magnetic field of the second magnet 52; It includes a substrate 7 on which a magnetic field detection element 6 is mounted, a case member 8 that accommodates them, and a connection part 9.

The magnetic field detection element 6 is, for example, a GMR (Giant Magneto Resistive effect) element. Further, as the magnetic field detection element 6, an AMR (Anisotropic Magneto Resistive) element, a TMR (Tunneling Magneto Resistive) element, a Hall element, or the like can also be used. The gear member 22, the first and second rotating members 3 and 4, and the case member 8 are made of non-magnetic material so as not to affect the magnetic fields of the first magnet 51 and the second magnet 52 detected by the magnetic field detection element 6. is formed by. In this embodiment, the gear member 22, the first and second rotating members 3 and 4, and the case member 8 are made of injection molded resin.

The case member 8 has a case main body 81 and a case lid body 82. In FIG. 2, illustration of the case lid body 82 is omitted, and the inside of the case body 81 is illustrated. Both the first rotating member 3 and the second rotating member 4 are housed in a case body 81 and are pivotally supported by the case member 8 .

4A and 4B are perspective views showing the gear member 22, the first and second rotating members 3 and 4, the magnetic field detection element 6, the substrate 7, and the connection part 9. FIG. 5(a) is an axial view of the first rotating member 3 to which the first magnet 51 is attached. FIG. 5(b) is an axial view of the second rotating member 4 to which the second magnet 52 is attached. FIG. 5(c) is a diagram of the gear member 22 viewed from the axial direction. FIG. 6 is an explanatory diagram showing the positional relationship between the first and second rotating members 3 and 4, the first and second magnets 51 and 52, and the magnetic field detection element 6.

The board 7 is a printed circuit board on which a predetermined wiring pattern (not shown) is formed, and is fixed to the case member 8 . In addition to the magnetic field detection element 6, electronic components such as resistors, capacitors, and ICs for communication with the calculation unit 23 are mounted on the board 7, but illustration of these electronic components is omitted in each drawing. ing. Further, a plurality of mounting holes 70 for fixing to the case member 8 are formed in the board 7 . The case body 81 has a plurality of protrusions 811 (see FIG. 3) that fit into the mounting holes 70 of the substrate 7, and these protrusions 811 and the substrate 7 are fixed, for example, by adhesive.

The connecting portion 9 includes first to fourth connecting pins 91 to 94 and a connecting plate 95 that connects the first to fourth connecting pins 91 to 94. One end of each of the first to fourth connection pins 91 to 94 is connected to the substrate 7, and the other end projects to the outside of the case member 8. A cable connecting the detection section 21 and the calculation section 23 is connected to the other end of the first to fourth connection pins 91 to 94. Note that the first to fourth connection pins 91 to 94 may be connected to, for example, a printed circuit board on which circuit elements of the calculation section 23 are mounted. For the first to fourth connection pins 91 to 94, for example, the first connection pin 91 is a ground pin, the second connection pin 92 is a power supply pin that supplies operating power to the magnetic field detection element 6, The third and fourth connection pins 93 and 94 are signal pins for communicating with the calculation section 23.

The first rotating member 3 includes a disc-shaped gear part 31 in which a plurality of gear teeth 30 are formed along the circumferential direction on the outer periphery, and a cylindrical gear part 31 provided to protrude in the axial direction from the center of the gear part 31. This gear integrally includes a cylindrical portion 32 and a boss portion 33 supported by the case member 8. A first magnet 51 is housed in the cylindrical portion 32 . The first magnet 51 is a permanent magnet having an N pole 511 and an S pole 512, and is fixed to the bottom surface 32a of the cylindrical portion 32, for example, by adhesive. The north pole 511 and the south pole 512 are arranged in the radial direction of the cylindrical portion 32.

Similarly, the second rotating member 4 includes a disc-shaped gear part 41 having a plurality of gear teeth 40 formed along the circumferential direction on the outer periphery, and a disc-shaped gear part 41 that protrudes in the axial direction from the center of the gear part 41. This gear integrally includes a cylindrical tube portion 42 and a boss portion 43 supported by the case member 8. A second magnet 52 is housed in the cylindrical portion 42 . The second magnet 52 is a permanent magnet having an N pole 521 and an S pole 522, and is fixed to the bottom surface 42a of the cylindrical portion 42, for example, by adhesive. The north pole 521 and the south pole 522 are arranged in the radial direction of the cylindrical portion 42 .

In the present embodiment, the first _and second rotating members 3 and 4 are spur gears, and the gear teeth ₃₀ and 40 are The tooth lines are parallel. Further, in the present embodiment, the pitch circle diameter _D1 of the gear portion 31 of the first rotating member 3 is formed larger than the pitch circle diameter D2 of the gear portion 41 of the second rotating member ₄ , and The number of gear teeth 30 in the gear portion 31 of the first rotating member 3 is greater than the number of gear teeth 40 in the gear portion 41 of the second rotating member 4. In the example shown in FIGS. 5A and 5B, the first rotating member 3 has 31 teeth, and the second rotating member 4 has 29 teeth.

The gear member 22 includes an annular base 220 fixed to the outer periphery of the steering shaft 171, a first gear part 221 with which the first rotating member 3 meshes, and a second gear part with which the second rotating member 4 meshes. 222. The base portion 220 is fixed to the steering shaft 171 by, for example, adhesive or bolt fastening. The first gear portion 221 has a plurality of first gear teeth 221 a that mesh with the gear teeth 30 of the first rotating member 3 . The second gear portion 222 has a plurality of second gear teeth 222a that mesh with the gear teeth 40 of the second rotating member 4.

The first gear tooth 221a and the second gear tooth 222a are formed to protrude from the base 220 in different directions, respectively. In this embodiment, first gear teeth 221a are provided on the outer periphery of base 220, and second gear teeth 222a are provided to protrude in the axial direction from the outer periphery side end of base 220. In this embodiment, the number of first gear teeth 221a in first gear portion 221 and the number of second gear teeth 222a in second gear portion 222 are both 40.

The rotation axis O of the gear member 22, the rotation axis O ₁ of the first rotation member 3, and the rotation axis O 2 of the second rotation member ₄ are included in one virtual plane. FIG. 6 shows cross sections of the gear member 22, the first rotating member 3, and the second rotating member 4 on this virtual plane. In this virtual plane, the rotational axis O of the gear member 22, the rotational axis _O1 of the first rotating member 3, and the rotational axis _O2 of the second rotating member are perpendicular to each other. In this embodiment, the rotation axis O ₁ of the first rotation member 3 is parallel to the rotation axis O of the gear member 22 .

As shown in FIG. 6, the magnetic field detection element 6 is arranged at a position where the rotational axis _O1 of the first rotating member 3 and the rotational axis _O2 of the second rotating member 4 intersect. The magnetic field detection element 6 is capable of detecting the strength of magnetic fields in three axial directions orthogonal to each other. Specifically, as shown in FIG. 6, the direction perpendicular to the above virtual plane is the X-axis direction, the direction parallel to the rotation axis _O1 of the first rotating member 3 is the Y-axis direction, and the second When the direction parallel to the rotation axis _O2 of the rotating member 4 is the Z-axis direction, the magnetic field detection element 6 detects the strength of the magnetic field in the X-axis direction, the strength of the magnetic field in the Y-axis direction, and the strength of the magnetic field in the Z-axis direction. can be detected individually.

In FIG. 6, the lines of magnetic force 51m of the first magnet 51 and the lines of magnetic force 52m of the second magnet 52 that intersect the magnetic field detection element 6 are shown by dashed lines. When the steering shaft 171 rotates and the first rotating member 3 rotates, the strength of the magnetic field in the X-axis direction and the Z-axis direction detected by the magnetic field detection element 6 changes, but the magnetic field line 51m of the first magnet 51 Since there is no component in the Y-axis direction, the strength of the magnetic field in the Y-axis direction does not change. Further, when the second rotating member 4 rotates, the strength of the magnetic field in the X-axis direction and the Y-axis direction detected by the magnetic field detection element 6 changes, but the magnetic field line 52m of the second magnet 52 has a component in the Z-axis direction. Since there is no magnetic field, the strength of the magnetic field in the Z-axis direction does not change.

FIG. 7 shows magnetic fields in the X-axis direction, Y-axis direction, and Z-axis direction detected by the magnetic field detection element 6 when the steering wheel 17 is steered from one maximum steering angle in the left-right direction to the other maximum steering angle. 3 is a graph showing an example of the intensity of . The horizontal axis of the graph in FIG. 7 indicates the steering angle, and the vertical axis indicates the strength of the magnetic field in each direction.

Since the pitch circle diameter _D1 of the first rotating member 3 is larger than the pitch circle diameter D2 of the second rotating member 4, the rotation of the first rotating member ₃ when the steering shaft 171 rotates at a constant speed The speed is slower than the rotational speed of the second rotating member 4, and the period of change in magnetic field strength in the Z-axis direction is longer than the period of change in magnetic field strength in the Y-axis direction. Further, the least common multiple of the number of teeth of the first rotating member 3 and the number of teeth of the second rotating member 4 is the number of teeth of the first gear teeth 221a of the first gear portion 221 and the number of teeth of the second gear portion 222. Since the number of teeth is larger than the number of teeth of the second gear teeth 222a, the combined pattern of the magnetic field strengths in the Y-axis direction and the Z-axis direction from the maximum steering angle of one side to the maximum steering angle of the other side in the left-right direction of the steering wheel 17 is It cannot appear in multiple locations. Therefore, the rotation angle detection device 2 can uniquely detect the absolute angular position of the steering shaft 171.

Further, the rotation angle detection device 2 can detect the angular position of the steering shaft 171 even when the steering shaft 171 rotates one rotation (360°) or more. In other words, the rotation angle detection device 2 is capable of detecting the absolute angular position of multiple rotations of the steering shaft 171, which is the detection target.

In this embodiment, since the magnetic field detection element 6 is capable of detecting the strength of the magnetic field in the X-axis direction, even if it becomes unable to detect the strength of the magnetic field in the Y-axis direction or the Z-axis direction due to some kind of failure. In this case, the strength of the magnetic field in the direction that can no longer be detected can be calculated by using the strength of the magnetic field in the X-axis direction, and it becomes possible to continue functioning the steering device 1. In other words, the strength of the magnetic fields in the X-axis direction, Y-axis direction, and Z-axis direction has a predetermined correlation, so when this correlation is no longer satisfied, it is possible to detect the occurrence of a failure, and also to detect any Even if the intensity of the magnetic field in the direction cannot be detected, the intensity of the magnetic field in the direction that can no longer be detected can be determined by calculation based on the intensity of the magnetic field in the other two directions.

(Operations and effects of the first embodiment)
According to the rotation angle detection device 2 according to the first embodiment described above, the rotation axis O ₁ of the first rotation member 3 and the rotation axis O ₂ of the second rotation member 4 intersect with each other. Since the two magnetic field detection elements 6 are arranged and can detect the strength of the magnetic field in each direction, the substrate 7 can be made smaller, and thus the rotation angle detection device 2 can be made smaller. Furthermore, since there is no need to use a plurality of magnetic field detection elements, it can also contribute to cost reduction.

[Modification of the first embodiment]
Next, four modified examples of the first embodiment will be described with reference to FIGS. 8 to 11. In the first embodiment described above, the first and second rotating members 3 and 4 are spur gears, but in the modified examples shown in FIGS. 8 to 11, the first and second rotating members One or both of 3 and 4 are bevel gears. In the first to fourth modifications, the pitch circle diameter of the first rotating member 3 is larger than the pitch circle diameter of the second rotating member 4, and the number of teeth of the first rotating member 3 is larger than that of the second rotating member 4. More teeth than 4.

In the first modification shown in FIG. 8, both the first and second rotating members 3 and 4 are bevel gears, and in the second modification shown in FIG. 9, the second rotating member 4 is a bevel gear. be. In the third modification shown in FIG. 10, the first and second rotating members 3 and 4 are both bevel gears as in the first modification, but the first and second rotational members 3 and 4 are bevel gears. The angles of the rotational axes O ₁ and O ₂ of the two rotating members 3 and 4 are different from each other, and the rotational axes O ₁ and O ₂ are inclined at 45 degrees with respect to the rotational axis O. In the first to third modified examples, similarly to the first embodiment, the rotation axis O ₁ of the first rotation member 3 and the rotation axis O ₂ of the second rotation member 4 intersect at right angles, and this intersection point A magnetic field detection element 6 is arranged in the portion.

In the fourth modification shown in FIG. 11, the rotation axis O ₁ of the first rotation member 3 and the rotation axis O ₂ of the second rotation member 4 are not at right angles but intersect at an angle of about 60°. are doing. Even in such a case, since the magnetic field detection element 6 disposed at the intersection of the rotation axis O ₁ and the rotation axis O ₂ can detect the strength of the magnetic field in the three orthogonal axes directions, the steering The rotation angle of the shaft 171 can be determined.

[Second embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. 12(a) to 12(c). FIG. 12(a) is a diagram of the first rotating member 3 according to the second embodiment viewed from the axial direction. FIG. 12(b) is an axial view of the second rotating member 4 according to the second embodiment. FIG. 12(c) is an axial view of the gear member 22 according to the second embodiment. Like the first embodiment, the first rotating member 3 and the second rotating member 4 mesh with the gear member 22 so that the rotation axes O ₁ and O ₂ are orthogonal to each other, and the rotation axes O ₁ and O ₂ The magnetic field detection element 6 is arranged at a position where the two intersect.

In the first embodiment and the first to fourth modifications described above, the pitch circle diameter D ₁ of the gear portion 31 of the first rotating member 3 is the same as that of the gear portion 41 of the gear portion 41 of the second rotating member 4. Although the case has been described in which the pitch circle diameter D is larger than ₂ and the first rotating member 3 rotates slower than the second rotating member 4, in the second embodiment, the first gear of the gear member 22 The number of teeth of the first gear teeth 221a in the section 221 is different from the number of teeth of the second gear teeth 222a in the second gear section 222, and the number of teeth of the first gear teeth 221a is different from the number of teeth of the second gear teeth 222a. Due to the smaller number, the first rotating member 3 rotates slower than the second rotating member 4. Further, in this embodiment, the number of teeth and pitch circle diameters D ₁ and D ₂ of the first rotating member 3 and the second rotating member 4 are the same. In the example shown in FIG. 12(c), the number of first gear teeth 221a in the first gear portion 221 is 38, and the number of second gear teeth 222a in the second gear portion 222 is 40. be.

According to this embodiment as well, it is possible to downsize the rotation angle detection device 2 similarly to the first embodiment. Moreover, since the number of teeth and the pitch circle diameters D ₁ and D ₂ of the first rotating member 3 and the second rotating member 4 are the same, the first rotating member 3 and the second rotating member 4 are made of the same metal. It can be molded using a mold, reducing mold costs.

(Summary of embodiments)
Next, technical ideas understood from the embodiments described above will be described using reference numerals and the like in the embodiments. However, each reference numeral in the following description does not limit the constituent elements in the scope of the claims to those specifically shown in the embodiments.

[1] A rotation angle detection device (2) that detects the angular position of a rotating shaft (steering shaft 171), wherein first and second rotations rotate at different speeds as the shaft (13) rotates. members (3, 4), a first magnet (51) attached to the first rotating member (3), and a second magnet (52) attached to the second rotating member (4). and a magnetic field detection element (6) that detects the magnetic field of the first magnet (51) and the magnetic field of the second magnet (52), and the magnetic field detection element (6) is configured to detect the magnetic field of the first magnet (51) and the second magnet (52). A rotation angle detection device (2) arranged at a position where the rotation axis (O ₁ ) of the member (3) and the rotation axis (O ₂ ) of the second rotation member (4) intersect.

[2] The rotation axis (O) of the shaft (171), the rotation axis (O 1 ) of the first rotation member (3), and the rotation axis (O ₂ ) of the second rotation member ( ₄ ) are included in one virtual plane, in which the rotation axis (O 1 ) of the first rotation member (3) and the rotation axis (O ₂ ) of the second rotation member ( ₄ ) are orthogonal; The rotation angle detection device (2) according to [1] above.

[3] The direction perpendicular to the virtual plane is the X-axis direction, the direction parallel to the axis of rotation (O ₁ ) of the first rotating member (3) is the Y-axis direction, and the direction perpendicular to the virtual plane is the Y-axis direction. ) is defined as the Z-axis direction, and the magnetic field detection element ( ₆ ) detects the strength of the magnetic field in the X-axis direction, the strength of the magnetic field in the Y-axis direction, and the Z-axis direction. The rotation angle detection device (2) according to [2] above, which is capable of detecting the strength of the magnetic field in the axial direction.

[4] The first and second rotating members (3, 4) are members (gear members 22) fixed to the shaft (171) or gears that mesh with and rotate the shaft (171); The rotation angle detection device (2) according to [3] above, wherein the number of teeth of the first rotating member (3) and the number of teeth of the second rotating member (4) are different.

[5] The first rotating member (3) rotates by meshing with a member (22) fixed to the shaft (171) or a first gear portion (221) formed on the shaft (13). The second rotating member (4) is a gear and rotates by meshing with a member (22) fixed to the shaft (171) or a second gear part (222) formed on the shaft (171). The first gear part (221) and the second gear part (222) have different numbers of teeth, and the first rotating member (3) and the second rotating member (4) have different numbers of teeth. ) The rotation angle detection device (2) according to the above [3], having the same number of teeth and the same pitch diameter (D ₁ , D ₂ ) as the rotation angle detection device (2).

[6] A case member (8) that accommodates the first rotating member (3) and the second rotating member (4), the first rotating member (3) and the second rotating member ( 4) is pivotally supported by the case member (8), and the board (7) on which the magnetic field detection element (6) is mounted is fixed to the case member (8). 5]. The rotation angle detection device (2) according to any one of [5].

[7] The rotation angle detection device according to any one of [1] to [6] above, wherein the shaft is a steering shaft (171) connected to the steering wheel (17) of (1) of a steering device of a vehicle. (2).

Although the first and second embodiments and modifications of the present invention have been described above, the embodiments and modifications described above do not limit the invention according to the claims. Furthermore, it should be noted that not all combinations of features described in the embodiments and modified examples are essential for solving the problems of the invention. Furthermore, the present invention can be implemented with appropriate modifications without departing from the spirit thereof, and for example, the following modifications are also possible.

In the first and second embodiments and modifications described above, when the first and second rotating members 3 and 4 mesh with the gear teeth 221a and 222a formed on the gear member 22 fixed to the steering shaft 171 Although described above, the present invention is not limited to this, and the steering shaft 171 may have gear teeth that mesh with the first and second rotating members 3 and 4.

Further, in the above embodiment, the case where the present invention is applied to the rotation angle detection device 2 of the steering device 1 of a vehicle has been described, but the rotation angle detection device of the present invention can also be applied to applications other than the steering device of a vehicle. Applicable.

2... Rotation angle detection device 221... First gear part 221a... First gear tooth 222... Second gear part 222a... Second gear tooth 3... First rotating member 4... Second rotating member 51... First magnet 52...Second magnet 6...Magnetic field detection element 7...Substrate 8...Case member _O1 , _O2 ...Rotation axis _D1 , _D2 ...Pitch circle diameter _P1 , _P2 ...Pitch

Claims (7)

A rotation angle detection device that detects the angular position of a rotating shaft,
first and second rotating members that rotate at different speeds as the shaft rotates;
a first magnet attached to the first rotating member;
a second magnet attached to the second rotating member;
comprising a magnetic field detection element that detects the magnetic field of the first magnet and the magnetic field of the second magnet,
The magnetic field detection element is arranged at a position where the rotational axis of the first rotating member and the rotational axis of the second rotating member intersect.
Rotation angle detection device. A rotation axis of the shaft, a rotation axis of the first rotation member, and a rotation axis of the second rotation member are included in one virtual plane,
The rotational axis of the first rotating member and the rotational axis of the second rotating member are orthogonal to each other in the virtual plane.
The rotation angle detection device according to claim 1. The direction perpendicular to the virtual plane is the X-axis direction, the direction parallel to the rotational axis of the first rotating member is the Y-axis direction, and the direction parallel to the rotational axis of the second rotating member is the Z-axis direction. When I did,
The magnetic field detection element is capable of detecting the strength of the magnetic field in the X-axis direction, the strength of the magnetic field in the Y-axis direction, and the strength of the magnetic field in the Z-axis direction, respectively.
The rotation angle detection device according to claim 2. The first and second rotating members are members fixed to the shaft or gears that mesh with and rotate the shaft,
the number of teeth of the first rotating member and the number of teeth of the second rotating member are different;
The rotation angle detection device according to claim 3. The first rotating member is a member fixed to the shaft or a gear that rotates by meshing with a first gear portion formed on the shaft,
The second rotating member is a member fixed to the shaft or a gear that rotates by meshing with a second gear portion formed on the shaft,
The first gear part and the second gear part have different numbers of teeth,
The number of teeth and pitch diameter of the first rotating member and the second rotating member are the same,
The rotation angle detection device according to claim 3. comprising a case member that accommodates the first rotating member and the second rotating member,
The first rotating member and the second rotating member are pivotally supported by the case member,
a substrate on which the magnetic field detection element is mounted is fixed to the case member;
The rotation angle detection device according to any one of claims 1 to 5. the shaft is a steering shaft connected to a steering wheel of a steering device of a vehicle;
The rotation angle detection device according to any one of claims 1 to 6.

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