JP2018017597A - Torque detector and electric power steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque detector that suppresses the effect of static electricity on a magnetic sensor and has improved detection reliability.SOLUTION: A magnetism collection unit 7d is arranged at a position facing a notch part 40 on a peripheral wall 22 of a second housing. When the notch part 40 is seen from the outside of a portion of the peripheral wall 22 facing a circuit main face 62b, the magnetism collection unit 7d is arranged so that the magnetism collection unit 7d is visible from the notch part 40. Magnetism collection units 7c, 7d are arranged so that they face two magnetic sensors 64 of a magnetic sensor circuit 60, respectively. Between the magnetism collection unit 7c and the magnetic sensor 64 and between the magnetism collection unit 7d and the magnetic sensor 64, there are formed spaces D5 each having an equal size. The magnetism collection unit 7d and a substrate 62 are arranged with a distance D6 therebetween. The distance D6 is set to be shorter than the spaces D5 and longer than a radial space between a magnetic yoke and a magnetism collecting ring.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a torque detection device and an electric power steering device.

  Conventionally, Patent Document 1 discloses a torque detection device having a first unit and a second unit. The first unit includes a pair of magnetism collecting rings. Each of the pair of magnetism collecting rings has two claw pieces. The two claw pieces in one magnetic flux collecting ring and the two claw pieces in the other magnetic flux collecting ring are opposed to each other via a gap in the axial direction. The pair of magnetism collecting rings is molded with a synthetic resin.

  The second unit has two magnetic sensors. These magnetic sensors are molded of synthetic resin. The first unit and the second unit are fixed to the sensor housing with a magnetic sensor interposed between the claw portions facing each other in the axial direction.

JP2008-249598

  However, in the torque detection device, static electricity is transmitted through the surface of the synthetic resin covering the magnetic sensor in the second unit, and the transmitted static electricity may be applied to the magnetic sensor. In this case, there is a concern that the detection reliability of the magnetic sensor is lowered.

  An object of the present invention is to provide a torque detection device that suppresses the influence of static electricity on a magnetic sensor and improves detection reliability.

  A torque detecting device capable of achieving the above object is a multi-pole magnet, a permanent magnet having magnetic poles arranged in a circumferential direction, and a relative rotation between the permanent magnet and a permanent magnet arranged in a magnetic field formed by the permanent magnet. A pair of magnetic flux collectors, each of which has a pair of magnetic yokes whose positions change, and magnetic flux collecting portions of the magnetic yoke, which have magnetic flux collecting portions facing each other in the axial direction, are provided with a gap on the outer side in the radial direction of the magnetic yoke. A magnetic sensor circuit provided between the ring and the magnetic flux collector, and having a magnetic sensor for detecting the magnetic flux between the magnetic flux collectors in the axial direction; It is assumed that a first housing and a second housing, which are resin housings that house the magnetism collecting portion therein, are provided. The resin housing has a penetrating portion provided at a portion facing the magnetism collecting portion so that the outside and the inside of the resin housing communicate with each other.

  Generally, it is known that static electricity tends to enter the nearest conductor through the surface of an insulating object. Therefore, when a magnetic sensor circuit having a magnetic sensor is accommodated in a resin housing configured by assembling the first housing and the second housing, when static electricity is applied to the surface of the resin housing, the magnetic sensor circuit can be The static electricity is transmitted to the magnetic sensor circuit, and the transmitted static electricity is applied to the magnetic sensor, so that the detection reliability of the magnetic sensor may be lowered.

  In that respect, in the above-described configuration, a through portion that connects the outside and the inside of the resin housing is provided in a portion of the resin housing that faces the magnetism collecting portion. Therefore, even if static electricity is applied to the resin housing surface, the static electricity is transmitted from the penetrating part to the conductive magnetism collecting ring through the magnetism collecting part. For this reason, it can suppress that static electricity is transmitted to a magnetic sensor via a magnetic sensor circuit. Therefore, the influence of static electricity on the magnetic sensor can be suppressed, and the detection reliability of the torque detector can be improved.

The gap between the magnetic yoke and the pair of magnetism collecting rings is preferably set smaller than the shortest distance between the magnetism collecting unit and the magnetic sensor circuit.
Since static electricity is likely to be transmitted to a closer conductor, when static electricity is transmitted through the penetrating portion and applied to the magnetism collecting ring, the next place where static electricity is likely to be applied is the magnetic sensor circuit or the magnetic yoke.

  In the above configuration, the radial gap between the magnetic flux collecting ring and the magnetic yoke is set smaller than the shortest distance between the magnetic flux collecting portion and the magnetic sensor circuit. For this reason, static electricity is easily transmitted by the magnetic yoke. For this reason, it is possible to suppress static electricity from being directly transmitted to the magnetic sensor.

  When the shortest distance between the magnetic sensor circuit and the resin housing is different in the direction orthogonal to the pair of circuit main surfaces of the magnetic sensor circuit, the shortest distance between the magnetic sensor circuit and the resin housing is smaller It is preferable that the through portion is provided in a portion of the resin housing where the magnetism collecting portion faces.

  In the manufacture of the torque detection device, there is a possibility that the magnetic sensor circuit is manufactured near one of the surfaces of the resin housing facing the pair of circuit main surfaces inside the resin housing. Therefore, there is a possibility that static electricity is likely to be transmitted from the resin housing having the shortest distance between the magnetic sensor circuit and the resin housing to the magnetic sensor circuit in the direction orthogonal to the pair of circuit main surfaces of the magnetic sensor circuit.

  In that respect, in the above-described configuration, the resin housing has a portion where the magnetism collecting portion of the resin housing in the direction where the shortest distance between the magnetic sensor circuit and the resin housing is opposite in the direction orthogonal to the pair of circuit main surfaces of the magnetic sensor circuit. A penetrating portion that communicates between the outside and the inside of the housing is provided. By doing in this way, it can suppress more that the static electricity which propagates the surface of the resin housing is transmitted to a magnetic sensor circuit.

  When the shortest distance between the magnetic sensor circuit and the resin housing is equal in a direction orthogonal to a pair of circuit main surfaces of the magnetic sensor circuit, a portion of the resin housing in which one of the magnetism collecting portions is opposed, and the resin It is preferable that the penetrating portion is provided in both portions of the housing facing the other magnetic flux collecting portion.

  In the manufacture of the torque detection device, the magnetic sensor circuit may be manufactured with the same distance between the pair of circuit main surfaces and the surface of the resin housing facing the inside of the resin housing. Therefore, there is a possibility that static electricity is likely to be transmitted to the magnetic sensor circuit from all directions of the resin housing.

  In that respect, in the above-described configuration, a penetrating portion that communicates the outside and the inside of the resin housing is provided in all of the portions of the resin housing where the magnetism collecting portions face each other. By doing in this way, it can suppress more that the static electricity which propagates the surface of the resin housing is transmitted to a magnetic sensor circuit.

  The above torque detection device is suitable for an electric power steering device. By applying the torque detection device to the electric power steering device, an electric power steering device with improved torque detection reliability can be provided.

  According to the torque detection device and the electric power steering device of the present invention, it is possible to suppress the influence of static electricity on the magnetic sensor and improve the detection reliability.

1 is a schematic diagram of an electric power steering device in an embodiment. FIG. Schematic of the torque detection apparatus in an embodiment. The perspective view of the sensor assembly in an embodiment. Sectional drawing of the sensor assembly in 1st Embodiment. Sectional drawing which showed the 2nd housing inside of the torque detection apparatus in 1st Embodiment. Sectional drawing which showed the inside of the 2nd housing of the torque detection apparatus in 2nd Embodiment.

<First Embodiment>
Hereinafter, a first embodiment in which the torque detection device of the present invention is applied to an electric power steering device will be described.

As shown in FIG. 1, the electric power steering device (hereinafter referred to as “EPS”) 1 includes a steering mechanism 2, an assist force applying mechanism 3, a torque detection device 4, and a control device 9.
The steering mechanism 2 turns the steered wheels 15 based on the operation of the steering wheel 10 by the user. The steering mechanism 2 includes a steering wheel 10 and a steering shaft 11 that rotates integrally with the steering wheel 10. The steering shaft 11 includes a column shaft 11a, an intermediate shaft 11b, and a pinion shaft 11c. The column shaft 11a has an input shaft INS, an output shaft OUT, and a torsion bar TB. An upper end portion of the input shaft INS is connected to the steering wheel 10. A lower end portion of the input shaft INS and an upper end portion of the output shaft OUT are connected to each other via a torsion bar TB so as to be relatively rotatable. The torsion bar TB is twisted according to the torque difference applied to the input shaft INS and the output shaft OUT. The lower end portion of the output shaft OUT is connected to the upper end portion of the intermediate shaft 11b. The lower end portion of the intermediate shaft 11b is connected to the upper end portion of the pinion shaft 11c. A lower end portion of the pinion shaft 11 c is connected to a rack shaft 12 as a steered shaft via a rack and pinion mechanism 13.

  Therefore, the rotational movement of the steering shaft 11 is caused in the axial direction of the rack shaft 12 via the rack and pinion mechanism 13 composed of a portion provided with pinion teeth on the pinion shaft 11 c and a portion provided with rack teeth on the rack shaft 12 ( It is converted into a reciprocating linear motion in the left-right direction in FIG. The reciprocating linear motion is transmitted to the left and right steered wheels 15 via the tie rods 14 respectively connected to both ends of the rack shaft 12, whereby the steered angle of the steered wheels 15 changes.

  The assist force application mechanism 3 includes a speed reduction mechanism 3c provided on the column shaft 11a and a motor 3a having a rotation shaft 3b. The rotational force of the rotating shaft 3b of the motor 3a is transmitted to the column shaft 11a via the speed reduction mechanism 3c. The motor 3 a is used as a generation source of assist force that assists the operation of the steering wheel 10. The assist force is power for the steering mechanism 2 that changes the turning angle of the steered wheels 15.

  The torque detection device 4 is provided in a portion between the steering wheel 10 and the assist force applying mechanism 3 in the column shaft 11a. The torque detection device 4 is configured by attaching a sensor assembly SA having a second housing 20 as a resin housing containing a magnetic sensor circuit 60 to a first housing 70 containing a magnetic flux output device 5. The magnetic flux output device 5 outputs a magnetic flux corresponding to the torsion of the torsion bar TB connected to the input shaft INS that rotates together with the steering wheel 10. The sensor assembly SA detects the magnetic flux output from the magnetic flux output device 5 by the magnetic sensor circuit 60, and outputs an output signal corresponding to the magnetic flux to the control device 9 that controls the driving of the motor 3a.

  As shown in FIG. 2, the magnetic flux output device 5 includes magnetic yokes 6a and 6b, magnetism collecting rings 7a and 7b, and a cylindrical permanent magnet 8 connected to the input shaft INS. The permanent magnet 8 has N poles and S poles alternately arranged at equal intervals in the circumferential direction. The magnetic yokes 6a and 6b are respectively provided with teeth 6c and 6d at equal intervals along the circumferential direction. The number of teeth 6c and 6d is equal to the number of N poles (the number of S poles) of the permanent magnet 8, respectively. The magnetism collecting rings 7a and 7b are cylindrical members, and two magnetism collecting portions 7c and 7d are provided on the outer peripheral surfaces of the magnetism collecting rings 7a and 7b, respectively.

  The magnetic yokes 6 a and 6 b are opposed to the outer side in the radial direction of the permanent magnet 8. The magnetic yoke 6a faces the magnetism collecting ring 7a, and the magnetic yoke 6b faces the magnetism collecting ring 7b with a predetermined gap D1 in the radial direction. Magnetic yokes 6a and 6b and magnetism collecting rings 7a and 7b are arranged coaxially with the input shaft INS. A gap D2 having such a size that the magnetic sensor circuit 60 can be disposed so as not to contact the magnetism collecting portions 7c and 7d is formed between the magnetism collecting portions 7c and 7d of the magnetism collecting rings 7a and 7b in the axial direction. It is configured. The magnetic yokes 6a and 6b and the magnetism collecting rings 7a and 7b are fixed to the output shaft OUT provided at the end opposite to the input shaft INS via the torsion bar TB. The teeth 6c of the magnetic yoke 6a and the teeth 6d of the magnetic yoke 6b are arranged so as to be displaced from each other in the circumferential direction.

  The magnetic flux generated in the magnetic yoke 6a is collected in the magnetic collecting part 7c through the magnetic collecting ring 7a, and the magnetic flux generated in the magnetic yoke 6b is collected in the magnetic collecting part 7d through the magnetic collecting ring 7b. The magnetic flux density in the gap D2 between the magnetic flux collector 7c and the magnetic flux collector 7d facing each other in the axial direction varies depending on the relative rotational positional relationship between the permanent magnet 8 and the magnetic yokes 6a and 6b. Since the permanent magnet 8 is fixed to the input shaft INS and the magnetic yokes 6a and 6b are fixed to the output shaft OUT, the relative rotational positional relationship between the permanent magnet 8 and the magnetic yokes 6a and 6b is torsional. It changes according to the twist degree of the bar TB. That is, the relative rotational positional relationship between the permanent magnet 8 and the magnetic yokes 6a and 6b changes according to the torque input to the input shaft INS. For this reason, the magnetic flux density in the gap D2 in the axial direction between the magnetism collecting portion 7c and the magnetism collecting portion 7d changes according to the torque input to the input shaft INS. The magnetic flux output device 5 outputs a magnetic flux according to the torque input to the input shaft INS from the gap D2 between the magnetic flux collector 7c and the magnetic flux collector 7d facing each other in the axial direction.

As shown in FIG. 3, the sensor assembly SA includes a second housing 20, a flange portion 23, a harness 30, and a magnetic sensor circuit 60.
The magnetic sensor circuit 60 has two magnetic sensors 64 and a substrate 62 on which they are mounted. The second housing 20 accommodates the magnetic sensor circuit 60. The flange portion 23 is erected from the side surface of the second housing 20 so as to be orthogonal to the entire circumference. The harness 30 outputs an output signal corresponding to the magnetic flux detected by the magnetic sensor circuit 60 to the control device 9. The magnetic sensor 64 is provided on the circuit main surface 62 a of the substrate 62. The substrate 62 has a cutout hole 62c that penetrates a portion where the magnetic sensor 64 is provided in the thickness direction. The notch 62c is provided to directly oppose the magnetism collecting portions 7c and 7d of the magnetic flux output device 5 and the magnetic detection element of the magnetic sensor 64 when the sensor assembly SA is assembled to the first housing 70. Two holes 26 are provided in the flange portion 23. After the sensor assembly SA is attached to the first housing 70, a bolt is inserted into the hole 26.

  As shown in FIG. 4, the second housing 20 has a main body 21 and a peripheral wall 22. The main body 21 accommodates a part of the magnetic sensor circuit 60. The peripheral wall 22 is erected so as to surround the protruding portion of the magnetic sensor circuit 60 at the periphery of the surface 21a of the main body portion 21 from which the magnetic sensor circuit 60 protrudes, and has a rectangular tube shape. The magnetic sensor circuit 60 has a circuit main surface 62b opposite to the circuit main surface 62a of the magnetic sensor circuit 60 on the inner peripheral surface of the peripheral wall 22 with reference to the midpoint in the length L in the direction orthogonal to the substrate 62 of the surface 21a. It is close to the surface opposite. The magnetic sensor 64 is provided at the midpoint of the length L in the direction orthogonal to the substrate of the surface 21a. The gap D3 formed between the magnetic sensor 64 of the magnetic sensor circuit 60 and the surface of the inner peripheral surface of the peripheral wall 22 facing the circuit main surface 62a, the circuit main surface 62b of the magnetic sensor circuit 60, and the circuit main surface 62b. When the gap D4 formed between the surfaces facing each other is compared, the gap D3 is set larger than the gap D4.

  The gap D3 is formed between the magnetic sensor 64 and the inner peripheral surface of the peripheral wall 22 facing the circuit main surface 62a. However, since the thickness of the magnetic sensor 64 is very small, the gap D3 is the circuit main. The distance between the surface 62a and the surface facing the circuit main surface 62a on the inner peripheral surface of the peripheral wall 22 is substantially equal. Therefore, the gap D3 is larger than the gap D4. The gaps D3 and D4 are sized so that the magnetism collecting portions 7c and 7d of the magnetism collecting rings 7a and 7b are not in contact with the magnetic sensor circuit 60 and the peripheral wall 22.

  As shown in FIG. 3, in the peripheral wall 22, two notch portions 40 as penetrating portions that communicate the outside and the inside of the second housing 20 are formed in a portion facing the circuit main surface 62 b of the magnetic sensor circuit 60. Is provided. The notch 40 is provided at the tip edge of the peripheral wall 22 on the side opposite to the main body 21. The notch 40 is provided on the peripheral wall 22 so as to be disposed at a position corresponding to the two magnetic flux collectors 7d of the magnetic flux output device 5 when the sensor assembly SA is assembled to the first housing 70. ing.

Next, a method for assembling the sensor assembly SA to the first housing 70 will be described.
When the sensor assembly SA is attached to the attachment portion of the first housing 70 from the radial direction, the position of the sensor assembly SA is first aligned with the attachment portion of the first housing 70. In the axial direction of the first housing 70, the magnetic sensor circuit 60 of the sensor assembly SA is provided with respect to the gap D2 formed by the magnetic collection parts 7c and 7d in the magnetic flux output device 5, and the magnetic collection part is provided with respect to the gap D3 in the sensor assembly SA. 7c is arranged in such a manner that the magnetism collecting portion 7d corresponds to the gap D4. Further, in the circumferential direction of the first housing 70, the two magnetism collecting portions 7d in the magnetic flux output device 5 are arranged so as to correspond to the two notch portions 40 of the sensor assembly SA. In this state, the sensor assembly SA is brought close to the first housing 70 with the opening formed by the peripheral wall 22 of the sensor assembly SA facing the first housing 70. At this time, the magnetic sensor circuit 60 is gradually inserted into the gap D2 so as not to contact the magnetic flux collectors 7c and 7d. Further, the magnetic flux collectors 7c and 7d are gradually inserted into the gaps D3 and D4 so as not to contact the magnetic sensor circuit 60 and the inner peripheral surface of the peripheral wall 22. The sensor assembly SA is inserted into the first housing 70 until the flange portion 23 of the sensor assembly SA contacts the first housing 70. At this time, the magnetism collecting portions 7c and 7d do not contact the surface 21a of the main body portion 21 of the second housing. The first housing 70 and the sensor assembly SA are fixed to each other by inserting and tightening bolts into the hole portions 26 of the flange portion 23. The assembly of the sensor assembly SA to the first housing 70 is completed.

  As shown in FIG. 5, in the state where the sensor assembly SA is assembled to the first housing 70, the two magnetism collecting portions 7 d of the magnetic flux output device 5 are two notch portions 40 in the peripheral wall 22 of the second housing 20. And facing each other in a direction orthogonal to the mounting direction. At this time, the magnetism collecting portion 7d is arranged so that the magnetism collecting portion 7d can be seen through the notch portion 40 when the notch portion 40 is viewed from the circuit main surface 62b side in the direction orthogonal to the substrate 62. . The magnetism collecting portions 7c and 7d are opposed to the two magnetic sensors 64 of the magnetic sensor circuit 60 in directions orthogonal to the mounting direction. At this time, gaps D <b> 5 having the same size are formed between the magnetic flux collector 7 c and the magnetic sensor 64 and between the magnetic flux collector 7 d and the magnetic sensor 64. Further, the magnetism collecting portion 7d and the substrate 62 of the magnetic sensor circuit 60 are separated by a distance D6. Here, the distance D6 is set shorter than the gap D5. The shortest distance from the magnetic flux collector 7d to the magnetic sensor circuit 60 is a distance D6. The distance D6 is set to be longer than the gap D1 in the radial direction between the magnetic yokes 6a and 6b and the magnetism collecting rings 7a and 7b.

As described above in detail, according to the EPS 1 and the torque detection device 4 according to the present embodiment, the following operations and effects can be obtained.
(1) In the torque detector 4 described above, the magnetic sensor 64 of the magnetic sensor circuit 60, the gap D3 formed between the inner peripheral surface of the peripheral wall 22 facing the circuit main surface 62a, and the circuit of the magnetic sensor circuit 60 When comparing the main surface 62b and the gap D4 formed between the inner peripheral surface of the peripheral wall 22 facing the circuit main surface 62b, the gap D3 is set larger than the gap D4. That is, the shortest distance from the surface facing the circuit main surfaces 62a, 62b of the magnetic sensor circuit 60 on the inner peripheral surface of the peripheral wall 22 to the magnetic sensor circuit 60 is different. The magnetic sensor circuit 60 has an inner periphery formed by the peripheral wall 22. The surface is close to the surface facing the circuit main surface 62b. Generally, it is known that static electricity tends to enter the nearest conductor through the surface of an insulating object. For this reason, when static electricity is applied to the surfaces of the first housing 70 and the second housing 20, static electricity is likely to be applied from the surface facing the circuit main surface 62 b on the inner peripheral surface of the peripheral wall 22. In this state, static electricity may be applied to the magnetic sensor 64 through the substrate 62 or directly to the magnetic sensor 64 from the gap between the first housing 70 and the second housing 20.

  In that respect, in the above-described configuration, the notch 40 is provided in the portion of the inner peripheral surface of the peripheral wall 22 of the second housing 20 that faces the magnetism collecting portion 7d so that the outside and the inside of the peripheral wall 22 communicate with each other. Therefore, even if static electricity is applied to the surfaces of the first housing 70 and the second housing 20, the static electricity is transmitted from the cutout portion 40 to the conductive magnetism collecting ring 7b through the magnetism collecting portion 7d. That is, it is possible to suppress static electricity from being transmitted to the magnetic sensor 64. Therefore, the influence of static electricity on the magnetic sensor 64 can be suppressed, and the detection reliability of the torque detection device 4 can be improved.

  (2) When static electricity is applied to the magnetism collecting ring 7b (exactly the magnetism collecting portion 7d) through the notch 40, the static electricity is likely to be transmitted to a closer conductor. The place where it is easy to be done is the magnetic sensor circuit 60 or the magnetic yoke 6b.

  In the above configuration, the gap D1 provided between the magnetism collecting ring 7b and the magnetic yoke 6b in the radial direction is a distance D6 between the magnetism collecting portion 7d and the magnetic sensor circuit 60 (more precisely, the magnetism collecting portion 7d and the substrate 62). Is set smaller than the shortest distance). Therefore, it is possible to suppress the static electricity from being transmitted to the magnetic sensor 64 via the magnetism collecting ring 7b (more precisely, the magnetism collecting portion 7d).

  (3) By applying the torque detection device 4 described above to EPS1, it is possible to improve the torque detection reliability of EPS1. Therefore, a more appropriate assist force corresponding to the steering torque can be applied to the column shaft 11a.

<Second Embodiment>
Hereinafter, a second embodiment of the electric power steering apparatus will be described. In the present embodiment, the shortest distance from the magnetic sensor circuit 60 to the surface of the inner peripheral surface of the peripheral wall 22 that faces the circuit main surfaces 62a and 62b of the substrate 62, the number of notches as penetrating portions, and magnetism collection It differs from the first embodiment in the shape of the magnetic flux collectors 7c and 7d in the rings 7a and 7b. For this reason, about the thing corresponding to the structure similar to 1st Embodiment, the same code | symbol is attached | subjected for convenience and detailed description is omitted.

  As shown in FIG. 6, in a state where the sensor assembly SA is assembled to the first housing 70, the magnetic sensor 64 of the magnetic sensor circuit 60 and the inner peripheral surface of the peripheral wall 22 between the surface facing the circuit main surface 62a. When the gap D3 formed is compared with the gap D4 formed between the circuit main surface 62b of the magnetic sensor circuit 60 and the surface facing the circuit main surface 62b on the inner peripheral surface of the peripheral wall 22, the gap D3 and The gap D4 has the same size. That is, the shortest distances from the magnetic sensor circuit 60 to the surfaces facing the circuit main surfaces 62a and 62b on the inner peripheral surface of the peripheral wall 22 are equal to each other.

  All of the two wall portions in which the magnetic flux collecting portions 7c and 7d in the peripheral wall 22 face each other in the direction orthogonal to the substrate 62 and the two wall portions in which the magnetic flux collecting portions 7c and 7d in the peripheral wall 22 face each other in the direction parallel to the substrate 62 The second housing 20 is provided with notches 40, 41, 43, and 44 as penetrating portions that allow the outside and the inside of the second housing 20 to communicate with each other.

  The magnetism collecting portions 7 c and 7 d closer to the notch 43 extend toward the notch 43 along the direction parallel to the substrate 62. Further, the magnetism collecting portions 7 c and 7 d closer to the notch 44 extend toward the notch 44 along the direction parallel to the substrate 62. The substrate 62 of the magnetism collecting portions 7c and 7d is arranged such that the side portions extending toward the cutout portions 43 and 44 of the magnetism collecting portions 7c and 7d are closer to the inner peripheral surface of the peripheral wall 22 than the side portions of the substrate 62. The width in the parallel direction is set.

  In the present embodiment, since the gaps D3 and D4 are equal in size, static electricity may be applied to the magnetic sensor circuit 60 from any location on the peripheral wall 22 of the second housing 20.

  However, in that respect, the peripheral wall 22 is provided with notches 40, 41, 43, 44, and the magnetic flux collecting portions 7c, 7d closer to the notches 43, 44 are arranged in a direction parallel to the substrate 62. It extends toward the notches 43 and 44.

  By setting it as such a structure, in addition to the effect of (1)-(3) of 1st Embodiment, the following effect is acquired. That is, static electricity transmitted from a surface orthogonal to the substrate 62 in the peripheral wall 22 is also transmitted through the cutout portion 43 or the cutout portion 44, and the magnetic flux collecting ring 7a or the magnetic flux collector having conductivity through the magnetic flux collecting portion 7c or the magnetic flux collecting portion 7d. It is transmitted to the ring 7b. For this reason, application of static electricity to the magnetic sensor circuit 60 can be suppressed.

Note that the first embodiment and the second embodiment may be modified as follows within a range where no technical contradiction occurs.
-In 1st Embodiment and 2nd Embodiment, although the notch parts 40, 41, 43, and 44 were provided in the surrounding wall 22 of the 2nd housing 20, it is not restricted to this. For example, it may be a through-hole in which the outside and the inside of the peripheral wall 22 communicate with each other. However, when the inside of the second housing 20 is viewed from the outside of the second housing 20 through the through hole, it is preferable that the magnetism collecting portions 7c and 7d be seen from the through hole.

  -In 1st Embodiment, although the notch 40 was provided only in the surface facing the circuit main surface 62b of the magnetic sensor circuit 60 in the internal peripheral surface of the surrounding wall 22, it is not restricted to this. For example, a notch portion may be provided in a portion of the peripheral wall 22 where the magnetism collecting portion 7 d faces in the direction parallel to the substrate 62. Further, as in the second embodiment, the magnetic flux collecting portions 7c and 7d on the peripheral wall 22 face each other in the direction orthogonal to the substrate 62, and the magnetic flux collecting portions 7c and 7d on the peripheral wall 22 are parallel to the substrate 62. You may provide the notch which connects the exterior and the inside of the 2nd housing 20 in all the opposing parts. Even if it does in this way, the effect similar to 1st Embodiment and 2nd Embodiment is acquired.

  In the first embodiment and the second embodiment, the torque detection device 4 is configured by assembling the sensor assembly SA to the first housing 70, but is not limited thereto. For example, an annular cover housing containing the magnetism collecting ring 7a and an annular resin housing containing the magnetism collecting ring 7b and the magnetic sensor circuit 60 are assembled in the axial direction of the magnetism collecting rings 7a and 7b, and after the assembly A torque detection device configured by arranging the permanent magnet 8 and the magnetic yokes 6a and 6b coaxially with the magnetism collecting rings 7a and 7b in the formed cylindrical space may be used. Even in this case, it is preferable to provide a through portion in which the outside and the inside of the housing communicate with each other in the portions where the magnetism collecting portions 7c and 7d of the magnetism collecting rings 7a and 7b in the cover housing and the resin housing face each other. By doing in this way, the effect similar to 1st Embodiment and 2nd Embodiment is acquired.

DESCRIPTION OF SYMBOLS 1 ... EPS, 4 ... Torque detection apparatus, 5 ... Magnetic flux output apparatus, 6a, 6b ... Magnetic yoke, 7a, 7b ... Magnetic collection ring, 7c, 7d ... Magnetic collection part, 8 ... Permanent magnet, 20 ... 2nd housing , 21 ... body part, 22 ... peripheral wall, 40, 41, 43, 44 ... notch part, 60 ... magnetic sensor circuit, 62 ... substrate, 62a, 62b ... circuit main surface, 64 ... magnetic sensor, 70 ... first Housing, D1, D2, D3, D4, D5 ... Gap, D6 ... Distance, SA ... Sensor assembly.

Claims (5)

A permanent magnet which is a multipolar magnet and has magnetic poles arranged in the circumferential direction;
A pair of magnetic yokes arranged in a magnetic field formed by the permanent magnet and changing a rotational position relative to the permanent magnet;
A pair of magnetic flux collecting rings that collect magnetic flux of the magnetic yoke and have magnetic flux collecting portions opposed to each other in the axial direction, and are provided with a gap on the radially outer side of the magnetic yoke;
A magnetic sensor circuit having a magnetic sensor provided to be sandwiched between the magnetic flux collectors and detecting a magnetic flux between the magnetic flux collectors in the axial direction;
In a torque detection device comprising: a first housing and a second housing, which are resin housings that house the magnetic sensor circuit and the magnetism collecting portion by assembling each other;
A torque detection device having a penetration part provided so that the outside and the inside of the resin housing communicate with each other at a portion where the magnetism collecting part of the resin housing faces.   The torque detection device according to claim 1, wherein the gap between the magnetic yoke and the pair of magnetism collecting rings is set to be smaller than a shortest distance between the magnetism collecting unit and the magnetic sensor circuit.   When the shortest distance between the magnetic sensor circuit and the resin housing is different in the direction orthogonal to the pair of circuit main surfaces of the magnetic sensor circuit, the shortest distance between the magnetic sensor circuit and the resin housing is smaller The torque detection device according to claim 1, wherein the through portion is provided in a portion of the resin housing where the magnetism collecting portion faces.   When the shortest distance between the magnetic sensor circuit and the resin housing is equal in a direction orthogonal to a pair of circuit main surfaces of the magnetic sensor circuit, a portion of the resin housing in which one of the magnetism collecting portions is opposed, and the resin The torque detection device according to claim 1, wherein the penetrating portion is provided in both portions of the housing facing the other magnetism collecting portion.   An electric power steering device having the torque detection device according to any one of claims 1 to 4.

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