JP2007271565A - Torque detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torque detector capable of satisfying a request of shortening an axial length, while detecting the rotation angle of a rotary shaft, together with the rotational torque applied to the rotary shaft. <P>SOLUTION: This torque detector is juxtaposed with a rotation angle detecting part 6, provided with a large-diametric internal gear 60 provided at the periphery of an extended part of a holding cylinder 32, small-diameter external gears 61, 62 meshed with the internal gear 60, and magnetic sensors 65, 66 for detecting the rotation angles thereof, on one side of a torque-detecting part 1, provided with yaw rings 3, 3 as rotating members fixed to the second shaft 1b as the rotary shaft via the resin holding cylinder 32. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a torque detection device for detecting a rotational torque applied to a rotation shaft, and more particularly to a torque detection device integrally including a rotation angle detection unit for detecting a rotation angle of the rotation shaft.

  In an electric power steering apparatus that drives a steering assist motor in accordance with a rotation operation of a steering member such as a steering wheel and assists steering by adding power of the motor to a steering mechanism, drive control of the steering assist motor It is necessary to detect the steering torque applied to the steering member to be used for this purpose. For this detection, a torque detection device disposed in the middle of the steering shaft that connects the steering member and the steering mechanism has been used. Yes.

  This torque detection device divides a steering shaft (rotating shaft) to be detected into a first shaft on the steering member side and a second shaft on the steering mechanism side, and these shafts are separated by a small-diameter torsion bar. The steering torque (rotational torque) applied to the steering shaft by rotating the steering member is detected by using the relative angular displacement generated between the first and second shafts as the torsion bar is twisted. It is constituted as follows.

  The detection of the relative angular displacement between the first and second axes has conventionally been realized by various configurations, and one of them is a cylindrical magnet that rotates integrally with one of the first axis and the second axis, A yoke ring that surrounds the outside of the cylindrical magnet and a yoke ring that rotates integrally with the other is provided as a rotating member, and changes in the magnetic circuit between the cylindrical magnet and the yoke ring are fixedly arranged so as to surround these outsides. There is a torque detection device configured to detect by a detection means (see, for example, Patent Document 1).

  The yoke ring is formed by arranging a plurality of magnetic pole claws extending in the axial direction on one side of a ring-shaped yoke body, and a set of two pieces each having the magnetic pole claws alternately positioned in the circumferential direction. It is fixed to the first shaft or the second shaft. The cylindrical magnet is a multipolar magnet in which the same number of pairs of magnetic poles as the magnetic pole claws of the yoke ring are arranged in the circumferential direction. The cylindrical magnet is fitted on the second shaft or the first shaft and is positioned inside the yoke ring. It is.

  Such a yoke ring and a cylindrical magnet have a boundary between the N and S poles where the former magnetic pole claws are arranged on the circumference of the latter in a neutral state where no relative angular displacement occurs between the first and second axes. It is positioned in the circumferential direction so as to align with the top. As a result, when a steering torque is applied to the steering shaft and a relative angular displacement occurs between the first and second shafts, the positional relationship in the circumferential direction between the magnetic pole claws of the two yoke rings and the magnetic pole of the cylindrical magnet is opposite to each other. Since the magnetic flux generated in the two yoke rings changes according to this position change, the steering torque can be known by detecting this magnetic flux change.

The two yoke rings are integrated by a resin holding cylinder that is molded while maintaining the positional relationship described above, and is integrally formed on the inner periphery of one end of the holding cylinder. In addition, a mounting structure is employed in which the first shaft or the second shaft is fitted and fixed to the connecting side end portion via a fixing collar. Similarly, in the cylindrical magnet, a plurality of strip-shaped magnet pieces constituting the respective magnetic poles are arranged in the circumferential direction and integrated by a molded resin holding cylinder, and the second shaft or the first shaft is integrated through the holding cylinder. It is fixed on the shaft.
JP 2005-98821 A

  Now, in the middle of the steering shaft where the torque detection device as described above is arranged, in order to know the steering angle (direction of the steering wheel) used for various control of the vehicle, a plurality of rotation angles of the steering shaft are set. In some cases, a rotation angle detection device for detecting the rotation is provided. When this type of rotation angle detection device is provided together with a torque detection device, the axial length that these devices occupy in the middle of the steering shaft. There is a problem that lengthens.

  In particular, in the middle of the steering shaft, there is a case where an energy absorbing mechanism is provided that absorbs impact energy applied during a frontal collision of the vehicle by shortening to telescopic under a substantially constant resistance over a predetermined stroke. In this case, in order to ensure a long shortening stroke of the steering shaft that contributes to energy absorption, it is required to reduce the axial lengths of the torque detection device and the rotation angle detection device as much as possible.

  The present invention has been made in view of such circumstances, and a rotation angle detector is provided side by side using some of the components of the torque detection device that detects the rotation torque of the rotation shaft, and the rotation angle together with the rotation torque is provided. It is an object of the present invention to provide a torque detection device that can respond to a request for shortening the axial length while making it possible to detect.

  According to a first aspect of the present invention, there is provided a torque detection device that detects a rotating member fixed to a rotating shaft via a resin-made holding cylinder by detecting means fixedly disposed outside the rotating member, and the rotating shaft In the torque detection device for obtaining a rotational torque applied to the internal cylinder, an internal gear provided around one extension of the holding cylinder, an external gear meshing with the internal gear, and detection of a rotation angle of the external gear And a rotation angle detector for obtaining the rotation angle of the rotation shaft based on the detection result of the detection means.

  A torque detector according to a second aspect of the present invention is characterized in that the internal gear in the first aspect is integrally formed with the holding cylinder.

  In the torque detection device according to the first aspect of the present invention, the resin holding cylinder of the rotating member fixed to the rotating shaft to be detected for torque is extended to one side, and the internal gear is provided around the extended portion. Since the rotation angle detection unit for detecting the rotation angle of the rotation shaft through the rotation of the external gear meshing with the rotation gear is provided, the rotation angle is detected together with the rotation torque by a compact configuration with the axial length minimized. Is possible.

  In the torque detection device according to the second aspect of the invention, since the internal gear constituting the rotation angle detection unit is integrally formed with the resin holding cylinder, it is possible to reduce the number of parts and the assembly man-hour. The present invention has an excellent effect.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. FIG. 1 is a longitudinal sectional view of a torque detection device according to the present invention. The torque detection device according to the present invention includes two shafts (first shaft 1a and second shaft) that are coaxially connected via a torsion bar 10. A torque detection unit 1 for detecting torque applied to the shaft 1b) is provided. On one side of the torque detection unit 1, a rotation angle detection configured as described below with the rotation angle of the second shaft 1b as a detection target is provided. Part 6 is provided.

  The torque detection device according to the present invention includes a torque detection unit 1 that detects torque applied to two shafts (first shaft 1a and second shaft 1b) that are coaxially connected via a torsion bar 10. On one side of the torque detection unit 1, a rotation angle detection unit 6 configured as described later with the rotation angle of the second shaft 1b as a detection target is provided.

  The torque detector 1 includes a cylindrical magnet 2 that rotates integrally with the first shaft 1a, and a set of two yoke rings 3, 3 that rotate integrally with the second shaft 1b. The magnetic flux collecting rings 4 and 4 for collecting the magnetic flux generated in the magnetic flux collecting medium 4 and the two magnetic sensors 5 and 5 disposed between the magnetic flux collecting rings 4 and 4 are provided. FIG. 2 is an exploded perspective view of the constituent members of the torque detector 1.

  The torsion bar 10 includes large-diameter and short-sized connecting portions 11 and 11 for connecting the first and second shafts 1a and 2a to both ends of a small-diameter round bar as a torsion spring. The first shaft 1a and the second shaft 1b are fitted into the connecting holes 11 and 11 at both ends of the torsion bar 10 in the connecting holes formed in the shaft center portions, respectively, and after positioning in the circumferential direction as described later, Another connecting pin 12, 12 is driven and connected. When a rotational torque is applied to the first shaft 1a and the second shaft 1b connected in this way, the torsion bar 10 is twisted and deformed by the action of the rotational torque, and the first shaft 1a and the second shaft 1b are deformed. In the meantime, a relative angular displacement having a magnitude corresponding to the rotational torque occurs. In FIG. 1, only the connecting portion between the torsion bar 10 and the second shaft 1b is shown.

  The torque detection apparatus shown in FIG. 1 is configured as a detection means for steering torque applied to a steering shaft that connects a steering member such as a steering wheel and a steering mechanism in an electric power steering apparatus. The first shaft 1a is connected to the steering member, and the lower second shaft 1b is connected to the steering mechanism so that a steering torque applied to the steering member for steering is applied to the first shaft 1a and the second shaft 1b. It is.

  The second shaft 1b is supported at both ends by two upper and lower bearings 80 and 81 in a housing 8 partially shown in FIG. 1, and a worm wheel 82 fitted and fixed between these bearings 80 and 81 is provided. I have. The worm wheel 82 is engaged with a worm at the output end of a steering assist motor (not shown). When the steering assist motor is driven, the power of the motor is decelerated and transmitted to the worm wheel 82. A steering assist force is applied to the steering mechanism via the shaft 1b.

  The second shaft 1b is provided with a cylindrical connecting tube 13 that is connected to a position above the support portion of the bearing 80, and the lower end of the first shaft 1a is inserted inside the connecting tube 13. It is supported by the bush 14 fitted in the connecting cylinder 13 while maintaining the same axis.

  As shown in FIG. 2, the cylindrical magnet 2 that rotates integrally with the first shaft 1a has a plurality of magnetic poles (a plurality of N poles 20, 20,... And S poles 21, 21,...) Arranged in parallel in the circumferential direction. A multi-pole magnet, which is formed by integrating a plurality of strip-shaped magnet pieces in the circumferential direction and integrated with a molded resin holding cylinder 22, as shown in FIG. The first shaft 1a is externally fitted and fixed.

  As shown in FIG. 2, the yoke rings 3, 3 that rotate integrally with the second shaft 1b are provided with a plurality of magnetic pole claws 31, 31,... Extending in the circumferential direction on the inner periphery of the ring-shaped yoke body 30 in the circumferential direction. It is a ring made of soft magnetic material that is arranged in a regular manner. The magnetic pole claws 31, 31... Have a triangular shape with a reduced width toward the extended end, and the two yoke rings 3, 3 face the protruding side of the magnetic pole claws 31, 31. In addition, they are positioned in a state where they are alternately arranged in the circumferential direction, and are integrated by a holding cylinder 32 made of resin that is molded into a cylindrical shape so as to cover the outside. Further, a fixing collar 33 made of a nonmagnetic metal is integrally fixed to the inner periphery of one end portion of the holding cylinder 32. The collar 33 can be integrated with the yoke rings 3 and 3 when the holding cylinder 32 is molded.

  The yoke rings 3 and 3 configured in this way are coaxial with the second shaft 1b by fitting the holding tube 32 to the connecting tube 13 at the upper end of the second shaft 1b via the collar 33 on one side. As shown in FIG. 1, it is opposed to the outer peripheral surface of the cylindrical magnet 2 fitted and fixed to the first shaft 1a with a slight air gap therebetween, so that the following positional relationship is obtained in the circumferential direction. It is assembled.

  FIG. 3 is an explanatory diagram of the positional relationship in the circumferential direction between the yoke rings 3 and 3 and the cylindrical magnet 2. FIG. 3B shows the positional relationship at the time of assembly. The yoke rings 3, 3 and the cylindrical magnet 2 are composed of the former magnetic pole claws 31, 31,. They are positioned and assembled in the circumferential direction so as to coincide with the boundary with the S pole 21. In this state, the magnetic pole claws 31, 31... Of the two yoke rings 3, 3 are the same in the magnetic field formed between the N pole 20 and the S pole 21 adjacent to each other on the circumference of the cylindrical magnet 2. The magnetic fluxes generated in the yoke bodies 30, 30 that connect the base portions of the magnetic pole claws 31, 31,... Are the same.

  The positional relationship between the magnetic pole claws 31, 31... And the N pole 20 and the S pole 21 is such that the first shaft 1a to which the cylindrical magnet 2 is fixed and the second shaft 1b to which the yoke rings 3 and 3 are fixed. In accordance with the relative angular displacement caused by the torsion of the torsion bar 10 between the two, they change in opposite directions as shown in FIG. 3 (a) or FIG. 3 (c). When this change occurs, magnetic field lines 31, 31... Of one yoke ring 3 and magnetic line claws 31, 31. Positive and negative magnetic fluxes are generated in the main bodies 30 and 30. The sign of the magnetic flux generated at this time is determined according to the direction of the relative angular displacement generated between the cylindrical magnet 2 and the yoke rings 3 and 3, that is, between the first shaft 1a and the second shaft 1b. Since the density corresponds to the magnitude of the relative angular displacement, by detecting this magnetic flux, the relative angular displacement between the first axis 1a and the second axis 1b, that is, the first, second axis 1a, The rotational torque (steering torque) applied to 1b can be known.

  Thus, the magnetic fluxes generated in the yoke rings 3 and 3 are collected by the corresponding magnetic flux collecting rings 4 and 4 and detected by the magnetic sensors 5 and 5. The magnetism collecting rings 4 and 4 are circular rings made of a soft magnetic material having an inner diameter slightly larger than the outer diameter of the yoke bodies 30 and 30 of the yoke rings 3 and 3, and as shown in FIG. A pair of magnetism collecting portions 40, 40 extending in the direction and having their tips bent outward at substantially right angles are provided at corresponding positions in the circumferential direction. The magnetic flux collecting rings 4 and 4 are arranged coaxially with the extended sides of the magnetic flux collecting portions 40 and 40 facing each other, and the tip ends of the corresponding magnetic flux collecting portions 40 and 40 are predetermined in the axial direction. They are positioned so as to face each other with a gap, and these outsides are covered and integrated by a resin holding cylinder 41 molded in a cylindrical shape.

  The magnetic sensors 5 and 5 use magnetic sensing elements such as Hall elements, and are arranged between the opposing portions of the pair of magnetic collecting portions 40 and 40 of the magnetic collecting rings 4 and 4, respectively, as shown in FIG. It is. The arrangement of the magnetic sensors 5 and 5 can be correctly realized by integrating the magnetism collecting rings 4 and 4 when the holding cylinder 41 is molded.

  As shown in FIG. 1, the holding cylinder 41 for holding the magnetic flux collecting rings 4 and 4 and the magnetic sensors 5 and 5 is configured so that each of the magnetic flux collecting rings 4 and 4 exposed on the inner surface is outside the yoke rings 3 and 3, respectively. Is fitted in and fixed to the housing 8 so as to face each other. As a result, magnetic fluxes generated in the yoke rings 3 and 3 adjacent to the inner sides of the magnetic flux collecting rings 4 and 4 are induced, and the respective induced magnetic fluxes are focused on the pair of magnetic flux collecting portions 40 and 40 to be opposed to each other. It leaks in between and is detected by the magnetic sensors 5 and 5. Since the magnetic flux generated in the yoke rings 3 and 3 corresponds to the relative angular displacement between the first shaft 1a and the second shaft 1b as described above, the first shaft is based on the output change of the magnetic sensors 5 and 5. The rotational torque applied to 1a and the second shaft 1b can be obtained.

  The pair of magnetism collecting projections 40 and 40 are provided on the magnetism collecting rings 4 and 4 and the magnetic sensors 5 and 5 are arranged between the opposing portions, one for torque detection and the other for fail. This is for determination. This fail determination is performed by, for example, comparing the outputs of the two magnetic sensors 5 and 5 over time, and when there is a clear difference between the two, the magnetic sensor 7 showing an unsteady output change before and after the difference. This is performed by a known procedure for determining that the state is in a fail state.

  As shown in FIG. 1, the holding cylinder 32 of the yoke rings 3 and 3 constituting the torque detecting unit 1 is extended upward for an appropriate length as shown in FIG. A large-diameter disk-shaped internal gear 60 having an inner circumference is integrally provided. The internal gear 60 can be integrally formed when the holding cylinder 32 is molded, but a separate gear may be externally fitted to the end of the holding cylinder 32 and integrated by means such as adhesion. . In FIG. 2, the extension of the holding cylinder 32 and the internal gear 60 provided at the extension end are not shown in order to show the shape of the internal yoke rings 3 and 3.

  The internal gear 60 faces a gear chamber 83 formed by projecting a part of the peripheral wall of the housing 8 outwardly above the magnetism collecting rings 4 and 4 and the holding cylinder 41 of the magnetic sensors 5 and 5. The gear chamber 83 is provided with two external gears 61 and 62 (only one is shown in FIG. 1) so as to be rotatable around an axis parallel to the first shaft 1a. 4 is a cross-sectional view taken along the line IV-IV in FIG. 1, and shows the positional relationship between the internal gear 60 and the external gears 61 and 62. FIG.

  The external gears 61 and 62 schematically shown as disks in FIG. 4 have an outer diameter that is smaller than that of the internal gear 60, and have a different number of teeth formed on the outer periphery. The internal gear 60 is meshed at different positions in the circumferential direction. The number of teeth is determined so that there is only one combination of rotation angles of both gears 61 and 62 while the internal gear 60 rotates over a plurality of rotations. Magnets 63 and 64 are embedded in one surface of the external gears 61 and 62 as indicated by broken lines in FIGS. 1 and 4, and these magnets 63 and 64 are magnetized by being divided into two in the circumferential direction. In addition, it is a two-pole magnetized magnet.

  As shown in FIG. 1, magnetic sensors 65 and 66 are fixed on the side surface of the gear chamber 83 so as to face the magnetized surfaces of the magnets 63 and 64 embedded in the external gears 61 and 62, respectively. The rotation angle detector 6 includes the internal sensors 60, the external gears 61 and 62, and the magnets 63 and 64 as constituent elements.

  As described above, the internal gear 60 is provided around the holding cylinder 32 fitted and fixed to the second shaft 1b, and rotates in accordance with the rotation of the second shaft 1b. This rotation is transmitted to two external gears 61 and 62 meshing with the internal gear 60, and these external gears 61 and 62 rotate together with magnets 63 and 64 fixed thereto, respectively. The magnetic sensors 65 and 66 arranged to face the magnetized surface generate an output that periodically changes as the external gears 61 and 62 rotate.

  Since the external gears 61 and 62 have the number of teeth set as described above, the outputs of the magnetic sensors 65 and 66 are transmitted over a plurality of rotations of the internal gear 60, that is, a plurality of rotations of the second shaft 1b. Thus, the outputs change at different periods without overlapping each other, and by combining these outputs, the rotation angle of the second shaft 1b can be uniquely determined over a plurality of rotations.

  In the torque detector shown in the above embodiment, the resin holding cylinder 32 of the yoke rings 3 and 3 that rotate integrally with the second shaft 1b as the rotating shaft is extended to one side, and is provided around the extended portion. Since the rotation angle detection unit 6 that can determine the rotation angle of the second shaft 1b by detecting the rotation angle of the external gears 61 and 62 meshing with the internal gear 60 is configured, the occupation length in the axial direction is minimized. It is possible to detect the rotational angle of the second shaft 1b together with the rotational torque applied to the first shaft 1a and the second shaft 2b while limiting to the limit. For example, torque detection interposed in the middle of the steering shaft of the vehicle When used as a device, it is possible to meet the demand for shortening the axial length for securing the shock energy absorption stroke.

  The internal gear 60 provided around the holding cylinder 32 of the yoke rings 3 and 3 can be integrally formed when the holding cylinder 32 for positioning and holding the yoke rings 3 and 3 is molded, and an internal gear as a separate part. Since 60 is unnecessary, it is possible to reduce the number of parts and the number of assembly steps.

  FIG. 5 is a longitudinal sectional view showing another embodiment of the torque detection device according to the present invention. Similar to the embodiment shown in FIG. 1, the torque detection device shown in this embodiment includes a rotation angle detection unit 6 arranged in parallel on one side of the torque detection unit 1. The configuration and operation of the torque detection unit 1 are the same as those in the embodiment shown in FIG. 1, and the same reference numerals as those in FIG.

  Similarly to the embodiment shown in FIG. 1, the torque detector 6 also includes an internal gear 60, external gears 61 and 62, and magnets 63 and 64, and magnets 63 and 64 embedded in the external gears 61 and 62, respectively. Unlike the embodiment shown in FIG. 1, the holding cylinder 22 of the cylindrical magnet 2 that rotates integrally with the first shaft 1a is extended upward. An internal gear 60 is integrally provided around the extended end and meshed with external gears 61 and 62 attached to the side surface of the gear chamber 83. According to this configuration, since the internal gear 60 rotates integrally with the first shaft 1a, the rotation angle of the first shaft 1a can be obtained over a plurality of rotations by combining the outputs of the magnetic sensors 65 and 66.

  In the torque detection device shown in FIG. 5 as well, an internal gear 60 is provided around the extension of the resin holding cylinder 22 of the cylindrical magnet 2 that rotates integrally with the first shaft 1a as the rotation shaft, and this internal gear 60 is configured. Since the torque detector 6 included as a part is arranged side by side, the rotational torque applied to the first shaft 1a and the second shaft 2b and the rotation angle of the first shaft 1a while minimizing the axial length are minimized. It is possible to detect them together. The internal gear 60 provided around the holding cylinder 22 can also be integrally formed when the holding cylinder 22 is molded, so that the number of parts and the number of assembly steps can be reduced.

  In the above embodiment, the holding cylinder 32 of the yoke rings 3 and 3 or the holding cylinder 22 of the cylindrical magnet 2 is extended upward, and the internal gear 60 is provided in the extended portion. A cylinder 22 is extended downward, an internal gear 60 is provided in the extended portion, and the rotation detector 6 including the internal gear 60, the external gears 61 and 62, the magnets 63 and 64, and the magnetic sensors 65 and 66, You may make it distribute | arrange below the torque detection part 1 provided with the rings 4 and 4 and the magnetic sensors 5 and 5. FIG. Further, the internal gear 60 can be provided at an appropriate position within the length range of the holding cylinder 32, such as both end portions of the holding cylinder 32 and the central portion of the holding cylinder 32.

  In the above embodiment, the magnets 63 and 64 are fixed to the external gears 61 and 62. For example, the rotation shafts of the external gears 61 and 62 are appropriately extended, and a rotary plate provided at the extended end. The magnets 63 and 64 may be fixed to each other so that the magnets 63 and 64 rotate integrally with the external gears 61 and 62. In this case, the magnets 63 and 64 and the magnetic sensors 65 and 66 can be arranged away from the torque detector 1 while responding to the shortening of the axial length dimension, and magnetic mutual interference with the torque detector 1 can be prevented. This eliminates the possibility of stable detection of rotational torque and rotational angle.

  In the above embodiment, the internal gear 60 is a large-diameter gear and the external gears 61 and 62 are small-diameter gears. Conversely, the internal gear 60 is a small-diameter gear and the external gears 61 and 62 are As described above, the internal gear 60 and the external gears 61 and 62 may be a combination of rotation angles of the gears 61 and 62 while the internal gear 60 rotates over a plurality of rotations. It is only necessary to determine the number of teeth that exist only.

  Further, in the above-described embodiments, the application examples as the means for detecting the steering torque applied to the steering shaft that connects the steering member and the steering mechanism have been described. However, the torque detection device according to the present invention is applied to the rotating shaft. The present invention can be applied to all applications requiring detection of the rotation angle of the rotating shaft together with the rotational torque, and can be implemented in various modifications within the scope of the matters described in the claims. Needless to say.

It is a longitudinal cross-sectional view of the torque detection apparatus which concerns on this invention. It is a disassembled perspective view of the structural member of a torque detection part. It is explanatory drawing of the positional relationship of the circumferential direction of a yoke ring and a cylindrical magnet. It is a cross-sectional view by the IV-IV line of FIG. It is a longitudinal cross-sectional view which shows other embodiment of the torque detection apparatus which concerns on this invention.

Explanation of symbols

1a 1st axis (rotating axis), 1b 2nd axis (rotating axis), 2 cylindrical magnet (rotating member), 3 yoke ring (rotating member), 4 magnetism collecting ring (detecting means), 5 magnetic sensor (detecting means) ,
6 Rotation angle detector, 60 Internal gear, 61, 62 External gear, 65, 66 Magnetic sensor (detection means)

Claims (2)

In a torque detection device, wherein a rotation member fixed to a rotation shaft via a resin-made holding cylinder is detected by detection means fixedly disposed outside the rotation member, and a rotation torque applied to the rotation shaft is obtained. ,
An internal gear provided around an extension of one side of the holding cylinder, an external gear meshing with the internal gear, and a detecting means for detecting the rotation angle of the external gear, based on the detection result of the detecting means And a rotational angle detector for determining the rotational angle of the rotational shaft. The torque detection device according to claim 1, wherein the internal gear is integrally formed with the holding cylinder.

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