JP2006046987A - Torque sensor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torque sensor for measuring large torque such as driving torque of car correctly and its manufacturing method excellent in torque detection precision with low hysteresis as well as realizing the manufacturing cost reduction. <P>SOLUTION: The torque sensor for detecting the magnitude of torque transmitted by the rotary shaft 1 supported rotatively is provided with: the magnetic sensing means provided with a magnetostriction function arranged on the rotary shaft 1; the coils 5a, 5b arranged around the magnetic sensing means for exciting the magnetic sensing means and detecting the change of strain generated on the surface of the rotary shaft 1 by the torque transmitted by the rotary shaft 1 via the change in the permutation of the magnetic sensing means as the change of self inductance. The magnetic sensing means is provided with metallic glass 2 exposed to all around of the surface at least a part in the axial direction of the rotary shaft 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a torque sensor used for non-contact detection of torque transmitted to a shaft to be measured, and particularly suitable for detecting torque of a high torque transmission shaft such as an axle of an automobile. And a manufacturing method thereof.

  Conventionally, as a torque detection technique using the applied magnetic effect, for example, an exciting coil in which an amorphous alloy ribbon having a magnetostrictive effect is bonded in the circumferential direction of the axis to be measured, and the permeability change due to the applied torque is installed near the axis. In addition to an amorphous alloy ribbon, a torque sensor using a permalloy having a magnetostrictive effect has been proposed.

  In the field of automobiles, with the recent increase in power steering and electrification, torque sensors that measure torque input to a steering shaft using a torsion beam have come to be widely used.

Japanese Patent Laid-Open No. 62-182630 JP 07-159257 A Proceedings of the IEEJ National Conference (No. 1277)

  However, in the case of a torque sensor made by bonding an amorphous alloy ribbon, etc., a process such as strain relief annealing is required to form the amorphous alloy ribbon, and a very thin amorphous alloy ribbon is used as the axis. Due to the fact that it adheres to the top, a special process is required for the adhesion itself and the application of the adhesive, resulting in a problem that the manufacturing cost is high.

  Further, in this torque sensor, since the amorphous ribbon is bonded to the rotating shaft, it is difficult to withstand the input of a large torque such as a driving torque of an automobile, and the level of vehicle motion performance and safety. There was a problem that it was impossible to accurately measure the driving torque, which is very useful information for vehicle motion control indispensable for up.

  On the other hand, a torque sensor using a torsion beam is hard to withstand a large torque input due to its structural reasons, and the drive torque is accurately measured in the same way as a torque sensor formed by bonding an amorphous alloy ribbon or the like. There is a problem that it cannot be done, and solving these problems has been a conventional problem.

  The present invention has been made by paying attention to the above-described conventional problems, and has realized low torque, high torque detection accuracy, and accurate measurement of large torque such as driving torque of an automobile after realizing reduction in manufacturing cost. It is an object of the present invention to provide a torque sensor that can be used and a manufacturing method thereof.

  The present invention relates to a torque sensor for detecting the magnitude of torque transmitted to a shaft to be measured that is rotatably supported, the magnetic sensor having a magnetostrictive function disposed on the shaft to be measured, and the surroundings of the magnetic sensor A strain detecting means for detecting a change in the strain generated on the surface of the shaft to be measured by torque transmitted to the shaft to be measured, wherein the magnetic sensing means is at least partially in the axial direction of the shaft to be measured. The present invention is characterized in that a metal glass exposed on the surface is provided, and the configuration of the torque sensor is used as a means for solving the above-described conventional problems.

  According to the present invention, since it is configured as described above, it is possible to obtain a very excellent effect that a large torque such as a driving torque of an automobile can be measured with low cost and high accuracy.

  When performing highly accurate torque measurement with a torque sensor equipped with a magnetic sensing means, it is important that the magnetic sensing means has low hysteresis, and in order to reduce hysteresis, the surface of the magnetic sensing means is important. It is necessary to increase the hardness and lower the magnetocrystalline anisotropy. For example, since the surface hardness of Fe-based metallic glass is as high as about 1000 Hv and there is no crystal magnetic anisotropy, accurate torque detection with low hysteresis is possible. It is desirable to use a metallic glass.

  Further, in the torque sensor of the present invention, the change in distortion generated on the surface of the shaft to be measured due to the torque transmitted to the shaft to be measured by exciting the magnetic sensing device as the change in self-inductance through the change in the magnetic permeability of the magnetic sensing device. It is possible to adopt a configuration in which the coil to be detected is a strain detection means, and the metal glass provided in the magnetic sensing means is exposed on the surface over the entire circumference in at least a part of the axial direction of the axis to be measured.

  Furthermore, in the torque sensor of the present invention, a magnetoresistive element (MR element; Magneto-Resistance) that detects a change in the external magnetic field by approaching the outer periphery of the measured shaft, a ferromagnetic magnetoresistive element (GMR element; Giant Magneto). -Resistance) or magneto-impedance element (MI element; Magneto-Impedance) is used as a strain detection means, and the metallic glass provided in the magnetic sensing means is partly in the axial direction of the measured axis. It is possible to adopt a configuration in which a plurality are arranged at a predetermined interval in the circumferential direction. When any one of a magnetoresistive element, a ferromagnetic magnetoresistive element, and a magnetoimpedance element is used as the strain detection means, the number of arrangement may be one or more, and a slight change in magnetic field is detected with high accuracy. It is desirable to use a magneto-impedance element that can be used.

  Here, since the amount of change in the magnetic field when the same strain occurs is greatly different between the metallic glass as the magnetic sensing means and the material constituting the axis to be measured, a magnetoresistive element for detecting a change in the external magnetic field, When one of the ferromagnetic magnetoresistive element and the magneto-impedance element is used as the strain detection means, the signals detected by these elements are greatly different. As a result, the magnitude of the above signal is small. The rotational position and rotational speed of the shaft to be measured can be measured with high accuracy from the detection time interval.

  As described above, when any one of a magnetoresistive element, a ferromagnetic magnetoresistive element, and a magnetoimpedance element that detects a change in an external magnetic field is used as a strain detecting means, various controls are performed by driving a motor. It is no longer necessary to install a rotation detection device such as a resolver attached to the equipment to be performed or the vehicle, that is, it is not necessary to install a resolver separately from the torque sensor that detects the output torque of the motor. Reduction and space saving will be achieved.

  Furthermore, in the torque sensor of the present invention, it is possible to employ a configuration in which a slit that is inclined at a predetermined angle with respect to the axial direction of the axis to be measured is provided in the metallic glass of the magnetic sensing means. The inclination angle of this slit is ideally set to 45 ° in both the clockwise direction and the counterclockwise direction with respect to the axial direction of the axis to be measured. Even if an angle variation of about 2.5 ° occurs, there is no significant effect on performance. Note that the metallic glass itself of the magnetic sensing means may be inclined at a predetermined angle with respect to the axial direction of the axis to be measured without providing a slit in the metallic glass of the magnetic sensing means.

  At this time, from the viewpoint of the torque detection accuracy of the torque sensor, the metal glass of the magnetic sensing means applied to the portion where the slit is formed has a larger magnetic permeability change due to a minute input torque, that is, a minute distortion of the metal glass. In addition, the higher the magnetic permeability, the better the detection accuracy. Therefore, in the torque sensor of the present invention, the metal glass of the magnetic sensing means is Fe-Co-Ln-B-based metal glass.

  In the metal glass of the magnetic sensing means, a bulk material having a strength exceeding 1 GPa can be produced by SPS sintering of the metal glass powder. Therefore, in the present invention, the metallic glass layer of the magnetic sensing means is integrally formed on the surface of the shaft to be measured by the SPS sintering method of metallic glass powder. By such a manufacturing method, the shaft to be measured and the metallic glass are integrally formed, and without using a special process at the time of bonding, which is necessary for a torque sensor using a conventional amorphous alloy ribbon, It is possible to obtain a high-strength magnetic sensing means.

  Furthermore, in the torque sensor of the present invention, bulk metal glass can be bonded to the shaft to be measured. In this case, the bond between the bulk metal glass and the shaft to be measured is very strong, and the conventional amorphous alloy thin film is thin. Unlike a torque sensor with a band attached, it can be applied to detection of automobile axle torque, which could not be applied conventionally.

  Here, when joining the bulk metal glass and the shaft to be measured, if there is a large heat input during the joining and the temperature of the bulk metal glass and the shaft to be measured rises, the structure of the bulk metal glass will be broken. Therefore, it is necessary to perform bonding with the lowest possible heat input. From such a viewpoint, it is desirable to use any one of friction welding, friction stir welding, electron beam welding, and laser welding as a bonding method used for bonding.

  Furthermore, as a manufacturing method of the bulk metallic glass to be joined, in addition to the above-described SPS sintering method, a casting method, for example, a molten metal forging method may be mentioned. In addition to the integral molding and joining as described above, as a method for firmly fixing the bulk metal glass and the shaft to be measured, metal glass powder may be welded on the shaft to be measured.

  As described above, since the bulk metal glass is very hard, performing a removal process such as a cutting process when forming a plurality of slits increases the cost. Therefore, as a method of forming a plurality of slits at a low cost, in addition to the method of integrally forming when bulk metal glass is cast and formed, it is utilized that metal glass exhibits complete Newtonian viscous flow in the supercooled liquid region. Then, the bulk metallic glass produced by the casting method or the SPS sintering method is reheated to a temperature range that becomes a supercooled liquid region, and a plurality of slits are formed by superplastic deformation by die pressurization such as forging at that temperature. It is also possible.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example.

[Example 1]
FIG. 1 shows an embodiment of the torque sensor of the present invention.

  As shown in FIG. 1, this torque sensor is disposed around a metallic glass 2 as a magnetic sensing means having a magnetostrictive function disposed on a rotating shaft (measurement shaft) 1 made of steel, and around the metallic glass 2. Excitation and detection coils 5a and 5b for exciting a metallic glass 2 and detecting a change in distortion generated on the surface of the rotary shaft 1 by a torque transmitted to the rotary shaft 1 as a change in self-inductance through a change in magnetic permeability of the magnetic sensing means. I have.

  The metallic glass 2 as the magnetic sensing means is joined to the surface of the rotating shaft 1 over the entire circumference at two locations in the axial direction. The metal glass 2 located on the left side of the metal glass 2 is formed with a plurality of slits 3 inclined at 45 ° clockwise relative to the axial direction, and is located on the right side of the metal glass 2 in the figure. The metallic glass 2 is formed with a plurality of slits 3 that are inclined 45 ° counterclockwise with respect to the axial direction.

  The rotating shaft 1 to which the metal glass 2 is bonded as described above is rotatably mounted via ball bearings 4 provided at both ends of the housing 7, and is disposed on the rotating shaft 1 in the housing 7. The excitation and detection coils 5 a and 5 b are mounted concentrically with the rotary shaft 1 at positions facing the individual metal glasses 2 and 2. A magnetic yoke 6 is attached outside the excitation / detection coils 5a and 5b.

  In the torque sensor having the above-described configuration, when torque is applied to the rotating shaft 1, distortion occurs in the metal glasses 2 and 2 bonded to the two axial directions of the rotating shaft 1, and the clockwise direction with respect to the axial direction. The magnetic permeability of the left and right metallic glasses 2 and 2 in which the plurality of slits 3 inclined 45 ° and the plurality of slits 3 inclined 45 ° counterclockwise with respect to the axial direction are respectively changed. As a result, the self-inductances of the left and right excitation / detection coils 5a and 5b change, so that the magnitude of the torque can be detected from the difference between the left and right self-inductances.

[Example 2]
FIG. 2 shows another embodiment of the torque sensor of the present invention.

  As shown in FIG. 2, the rotating shaft 11 is formed by integrally molding metallic glass as a magnetic sensing means by SPS sintering of metallic glass powder. The strength as a strength member and the magnetic characteristics as the magnetic sensing means. Have both.

  The metallic glass rotary shaft 11 having magnetic characteristics as the magnetic sensing means is formed with a plurality of slits 3 inclined at 45 ° in the clockwise direction with respect to the axial direction at two locations in the axial direction. In addition, the metal glass 2 positioned on the right side of the metal glass 2 is formed with a plurality of slits 3 that are inclined 45 ° counterclockwise with respect to the axial direction.

  The rotating shaft 11 is rotatably mounted via ball bearings 4 provided at both ends of the housing 7, and is located at positions facing the slits 3 and 3 disposed at two locations of the rotating shaft 1 in the housing 7. Excitation and detection coils 5a and 5b are mounted concentrically with the rotary shaft 1. A magnetic yoke 6 is attached outside the excitation / detection coils 5a and 5b.

  In the torque sensor having the above-described configuration, when torque is applied to the rotating shaft 11, distortion occurs in the slits 3 and 3 provided at two locations in the axial direction of the rotating shaft 11, and the clockwise direction relative to the axial direction is generated. The permeability of the plurality of slits 3 inclined by 45 ° and the portions of the plurality of slits 3 inclined 45 ° counterclockwise with respect to the axial direction change. As a result, the self-inductances of the left and right excitation / detection coils 5a and 5b change, so that the magnitude of the torque can be detected from the difference between the left and right self-inductances.

[Example 3]
FIG. 3 shows still another embodiment of the torque sensor of the present invention.

  As shown in FIG. 3, this torque sensor is disposed around a metallic glass 2 as a magnetic sensing means having a magnetostrictive function disposed on a rotating shaft (measurement shaft) 21 made of steel, and around the metallic glass 2. An excitation / detection coil 5 is provided that excites the metallic glass 2 and detects a change in distortion generated on the surface of the rotating shaft 21 by a torque transmitted to the rotating shaft 1 as a change in self-inductance through a change in permeability of the magnetic sensing means. Yes.

  The metallic glass 2 as the magnetic sensing means is joined to the surface of the rotating shaft 21 over the entire circumference at one place in the axial direction. The metal glass 2 is formed with a plurality of slits 3 inclined at 45 ° counterclockwise (or clockwise) with respect to the axial direction.

  The rotating shaft 21 to which the metal glass 2 is bonded as described above is rotatably mounted via ball bearings 4 provided at both ends of the housing 7, and the metal disposed on the rotating shaft 21 in the housing 7. The excitation and detection coil 5 is mounted concentrically with the rotating shaft 21 at a position facing the glass 2. A magnetic yoke 6 is attached outside the excitation / detection coil 5.

  In the torque sensor having the above-described configuration, when torque is applied to the rotating shaft 21, distortion occurs in the metallic glass 2 bonded to one axial position of the rotating shaft 21, and the counterclockwise direction is relative to the axial direction. The permeability of the metallic glass 2 in which the plurality of slits 3 inclined by 45 ° (or clockwise direction) is formed changes. As a result, since the self-inductance of the excitation / detection coil 5 changes, the magnitude of the torque can be detected from the difference between the self-inductance at this time and the self-inductance at zero torque.

[Example 4]
FIG. 4 shows still another embodiment of the torque sensor of the present invention.

  As shown in FIG. 4, the rotating shaft 31 is formed by integrally molding metallic glass as a magnetic sensing means by SPS sintering of metallic glass powder, and strength as a strength member and magnetic characteristics as a magnetic sensing means. Have both.

  The metallic glass rotary shaft 31 having magnetic characteristics as the magnetic sensing means is inclined 45 ° counterclockwise (or clockwise) with respect to the axial direction at one axial position. A plurality of slits 3 are formed.

  The rotating shaft 31 is rotatably mounted via ball bearings 4 provided at both ends of the housing 7, and is excited at a position facing the slit 3 disposed at one location of the rotating shaft 1 in the housing 7. The cum detection coil 5 is mounted concentrically with the rotating shaft 31. A magnetic yoke 6 is attached outside the excitation / detection coil 5.

  In the torque sensor having the above-described configuration, when torque is applied to the rotating shaft 31, distortion occurs in the slit 3 provided at one position in the axial direction of the rotating shaft 31, and the counterclockwise direction with respect to the axial direction ( Alternatively, the magnetic permeability of the portions of the plurality of slits 3 inclined 45 ° (clockwise) changes. As a result, the self-inductances of the left and right excitation / detection coils 5 change, so that the magnitude of the torque can be detected from the difference between the self-inductance at this time and the self-inductance at zero torque.

[Example 5]
FIG. 5 shows still another embodiment of the torque sensor of the present invention.

  As shown in FIG. 5 (a), the torque sensor includes a metallic glass 42 as a magnetosensitive function having a magnetostrictive function disposed on a rotating shaft (measurement shaft) 41 made of steel, and around the metallic glass 42. A magnetoresistive element 45 is provided as a strain detecting means that is disposed and detects a change in the external magnetic field by approaching the outer periphery of the rotating shaft 41.

  As shown in FIG. 5B, four metal glasses 42 as magnetic sensing means are bonded to the surface of the rotating shaft 41 at 90 ° intervals at one axial position. Each of these metallic glasses 42 is formed with one slit 43 that is inclined 45 ° clockwise (or counterclockwise) with respect to the axial direction.

  As shown in FIG. 6, the rotating shaft 41 to which the metal glass 42 is bonded as described above is rotatably attached via ball bearings 44 provided at both ends of the housing 47. The magnetoresistive element 45 is mounted on the housing 47 so as to sandwich the metal glass 42 located outside the housing 47 of the rotating shaft 41 from above and below. In FIG. 6, reference numeral 48 denotes a rotor, and reference numeral 49 denotes a stator.

  In the torque sensor having the above-described configuration, when torque is applied to the rotating shaft 41, distortion occurs in the four metal glasses 42 bonded to the rotating shaft 41, and the clockwise direction (or counterclockwise) with respect to the axial direction. The magnetic field of the metallic glass 42 in which the slits 43 inclined by 45 ° are changed. As a result, the electrical signal output from the magnetoresistive element 45 for detecting a change in the external magnetic field changes, and the magnitude of the torque can be detected from the magnitude of this electrical signal.

  At this time, since the magnitude of the magnetic field is different between the rotating shaft 41 and the metal glass 42, the magnitude of the signal output from the magnetoresistive element 45 comes to draw the waveform shown in FIG. And the number of the magnetoresistive elements 45 disposed, the rotational speed can be obtained. FIG. 2 shows a case where the applied torque gradually increases.

[Example 6]
FIG. 8 shows still another embodiment of the torque sensor of the present invention.

  As shown in FIG. 8, this torque sensor includes two metal glasses 52 as magnetosensitive means having a magnetostriction function and one magnetoresistive element 55 as strain detection means. Two 52 are joined to the surface of the rotating shaft 51 at an interval of 180 ° at one axial position.

  Also in this torque sensor, it is possible to detect the torque and the rotational speed by the same mechanism as the torque sensor of the fifth embodiment. Thus, the number is not limited as long as the number of magnetic sensing means and the number of strain detection means are one or more.

  In each of the above-described embodiments, the slits 3, 43, 53 are provided in the metal glasses 2, 42, 52 of the magnetic sensing means, but the slits 3, 43, 53 are provided in the metal glasses 2, 42, 52. It is good also as a structure which inclines the metal glass 2,42,52 itself of a magnetic sensing means by a predetermined angle with respect to the axial direction of a rotating shaft, without providing.

  Moreover, as a material used for the metal glass as the magnetic sensing means in each of the above-described embodiments, an Fe—Co—Ln—B-based metal glass is preferable from the viewpoint of a large magnetostriction constant. Further, the type of steel used for the rotating shaft as the shaft to be measured is not particularly limited, such as structural carbon steel, structural low-alloy high-strength steel, structural alloy steel, and the like. Furthermore, the material used for the magnetic yoke is not particularly limited in its kind, such as pure iron, low carbon steel, Fe-Si alloy, permalloy and the like. In addition, although the housing 7 has been described as being configured exclusively for the torque sensor in the first to fourth embodiments, it is not limited to such a configuration.

  The strain detecting means for detecting the change in the magnetic field can be held using the motor housing 47 as in the fifth embodiment, and similarly held in the case or housing of the engine or transmission. It is also possible to attach it using a dedicated holder.

[Example 7]
FIG. 9 shows a cross section along the axial direction of the rotating shaft 61 to which the metallic glass 2 as the magnetic sensing means in the torque sensor of the present invention is joined.

  In this embodiment, after forming a semi-ring (or ¼ ring) metallic glass part 2A by a casting method or SPS sintering method, the metallic glass part 2A is placed in a groove 61a provided in advance on the rotary shaft 41. The rotating shaft in which the ring-shaped bulk metallic glass 2 as a magnetic sensing means is integrated by joining the butt outer peripheral portion 8 using an electron beam welding method, a laser welding method, or a friction stir welding method. 61 can be obtained.

  Here, the case where the ring-shaped bulk metal glass 2 is formed by combining the half ring-shaped (or ¼ ring-shaped) metal glass component 2A has been described as an example, but the ring-shaped bulk metal glass is described. The number of divisions of 2 does not need to be 2 or 4, and even 3 or 5 or more is no problem.

[Example 8]
FIG. 10 shows a cross section along the axial direction of the rotating shaft 71 to which the metallic glass 2 as the magnetic sensing means in the torque sensor of the present invention is joined.

  In this embodiment, after forming the disk-shaped or columnar metallic glass part 2 by a casting method or SPS sintering method, it is installed between the steel parts 71A, 71A constituting the rotary shaft 71 divided in advance, Thereafter, the butt outer peripheral portion 8 is bonded using an electron beam welding method, a laser welding method, or a friction stir welding method, or the contact surface 9 between the metal glass 2 and the steel part 71A is bonded using a friction bonding method. By doing so, it becomes possible to obtain the rotating shaft 71 integrated with the bulk metallic glass 2 as the magnetic sensing means.

[Example 9]
FIG. 11 shows a cross section along the axial direction of the rotating shaft 81 to which the metallic glass 2 as the magnetic sensing means in the torque sensor of the present invention is joined.

  In this embodiment, the metallic glass part 2 can be inserted into the end face of the steel part 81A constituting the rotary shaft 81 divided in advance after the metallic glass part 2 is formed into a predetermined shape by casting or SPS sintering. After the metal glass part 2 is inserted into the processed end face, the other steel part 81B constituting the rotary shaft 81 divided into two parts is put together so that the metal glass part 2 is sandwiched, and then the butt is joined. The outer peripheral portion 8 is joined using an electron beam welding method, a laser welding method, or a friction stir welding method. Thereby, it is possible to obtain the rotating shaft 81 in which the bulk metallic glass as magnetic sensing means is integrated. If the contact surface 9 between the metallic glass part 2 and the steel part 81A is joined by an electron beam welding method, a laser welding method or a friction stir welding method, a rotating shaft 81 with higher strength can be obtained.

  As described above, the torque sensor of the present invention is capable of detecting high torque with high accuracy, low cost, high strength and high torque. The present invention can be applied to detection and detection of output shaft torque of various control motors for automobiles, and can also be applied to detection of output shaft torque of a spindle of a machine tool.

It is a section explanatory view showing one example of a torque sensor of the present invention. (Example 1) It is sectional explanatory drawing which shows the other Example of the torque sensor of this invention. (Example 2) It is sectional explanatory drawing which shows other Example of the torque sensor of this invention. Example 3 It is sectional explanatory drawing which shows other Example of the torque sensor of this invention. Example 4 It is the perspective explanatory drawing (a) and cross-sectional explanatory drawing of the rotating shaft which show other Example of the torque sensor of this invention. (Example 5) FIG. 6 is an explanatory sectional view showing a state where the torque sensor of FIG. 5 is mounted on a motor. (Example 5) It is a graph which shows the change of the electrical signal output from a magnetoresistive element when a torque is gradually loaded on the torque sensor of FIG. (Example 5) It is the perspective explanatory drawing (a) and cross-sectional explanatory drawing of the rotating shaft which show other Example of the torque sensor of this invention. (Example 6) It is sectional explanatory drawing which shows the other joining example of the metal glass in the torque sensor of this invention. (Example 7) It is sectional explanatory drawing which shows the other joining example of the metal glass in the torque sensor of this invention. (Example 8) It is sectional explanatory drawing which shows the other joining example of the metal glass in the torque sensor of this invention. Example 9

Explanation of symbols

1, 11, 21, 31, 41, 51, 61, 71, 81 Rotating axis (axis to be measured)
2, 42, 52 Metal glass as magnetic sensing means 3, 43, 53 Slit 5, 5a, 5b Excitation / detection coil 45, 55 as strain detection means Magnetoresistive element as strain detection means

Claims (16)

  A torque sensor for detecting a magnitude of torque transmitted to a shaft to be measured that is rotatably supported, the magnetic sensor having a magnetostrictive function disposed on the shaft to be measured, and disposed around the magnetic sensor. Strain detecting means for detecting a change in strain generated on the surface of the shaft to be measured by torque transmitted to the shaft to be measured is provided, and the magnetic sensing means is exposed on the surface in at least a part of the axial direction of the shaft to be measured. A torque sensor comprising a metallic glass.   A coil that detects the change in strain generated on the surface of the shaft to be measured as a self-inductance change through the change in permeability of the shaft to be measured by exciting the magnetic sensing device and the torque transmitted to the shaft to be measured is used as the strain detecting means. 2. The torque sensor according to claim 1, wherein the metallic glass provided in the magnetic sensing means is exposed on the surface over the entire circumference in at least a part of the axial direction of the axis to be measured.   Any one of a magnetoresistive element, a ferromagnetic magnetoresistive element, and a magnetoimpedance element that detects a change in an external magnetic field by approaching the outer circumference of the shaft to be measured is used as a strain detecting means, and a magnetic sensitive means is provided. The torque sensor according to claim 1, wherein a plurality of metallic glasses are arranged at predetermined intervals in the circumferential direction in a part of the axial direction of the shaft to be measured.   The torque sensor according to any one of claims 1 to 3, wherein the metal glass of the magnetic sensing means is Fe-Co-Ln-B-based metal glass.   The torque sensor according to any one of claims 1 to 4, wherein the metallic glass of the magnetic sensing means is provided with a slit inclined at a predetermined angle with respect to the axial direction of the axis to be measured.   The slit provided in the metal glass of the magnetic sensing means is 42.5 to 47.5 ° in at least one of the clockwise direction and the counterclockwise direction with respect to the axial direction of the measured axis. The torque sensor according to claim 5 which is inclined.   The torque sensor according to claim 6, wherein an inclination angle of the slit provided in the metal glass of the magnetic sensing means is 45 °.   The torque sensor according to any one of claims 1 to 7, which is applied to detection of an output shaft torque of an automobile, an axial torque of a power steering, and an output shaft torque of various control motors of the automobile.   When manufacturing the torque sensor according to any one of claims 5 to 8, the metal glass layer of the magnetic sensing means is integrally formed on the shaft to be measured by the SPS sintering method of the metal glass powder. A manufacturing method of a torque sensor.   When manufacturing the torque sensor according to any one of claims 5 to 8, a bulk metallic glass is joined to the shaft to be measured, thereby forming a metal glass layer of magnetic sensing means on the surface of the shaft to be measured. A manufacturing method of a torque sensor characterized by the above.   The method for producing a torque sensor according to claim 10, wherein the bulk metallic glass is joined to the surface of the shaft to be measured by any one of friction welding, friction stir welding, electron beam welding, and laser welding.   The method for manufacturing a torque sensor according to claim 10 or 11, wherein the bulk metallic glass is formed by a casting method or an SPS sintering method.   The method for manufacturing a torque sensor according to claim 12, wherein the casting method of the bulk metallic glass is a molten metal forging method.   The method for manufacturing a torque sensor according to any one of claims 9 to 13, wherein the slits are integrally formed when the metal glass layer is formed.   14. After forming the metallic glass layer, the metallic glass layer is heated to a temperature range where it becomes a supercooled liquid, and the slit is integrally formed by mold pressing in this region. A method for manufacturing the torque sensor according to the item.   The method of manufacturing a torque sensor according to claim 10, wherein a metal glass material is welded on the surface of the shaft to be measured at a joint portion between the bulk metallic glass and the shaft to be measured.

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