MAGNETOSTRICTIVE TORQUE SENSOR AND METHOD FOR MANUFACTURING MAGNETOSTRICTIVE TORQUE SENSOR

A magnetostrictive torque sensor, configured to be mounted around a rotating shaft having a magnetostrictive effect and to detect torque applied to the rotating shaft, is provided with a support member having a cylindrical portion through which the rotating shaft is inserted; a flexible substrate arranged around an outer periphery of the cylindrical portion and having a plurality of coils composed of wiring patterns; and a tightening member that tightens the flexible substrate toward an outer peripheral surface of the cylindrical portion. The tightening member may be a tubular heat-shrinkable tube that shrinks upon heating. A method for manufacturing the magnetostrictive torque sensor includes placing the flexible substrate around the outer periphery of the cylindrical portion of the support member and placing the heat-shrinkable tube around an outer periphery of the flexible substrate; and tightening the flexible substrate toward the outer peripheral surface of the cylindrical portion by heating the heat-shrinkable tube to shrink the heat-shrinkable tube.

TECHNICAL FIELD

The present invention relates to a magnetostrictive torque sensor and a method for manufacturing a magnetostrictive torque sensor.

BACKGROUND ART

Conventionally, for example, magnetostrictive torque sensors are used to detect torque on an output rotating shaft of an automobile engine. The magnetostrictive type torque sensor utilizes the magnetostrictive effect, in which the magnetic permeability of the rotating shaft changes with stress, and is configured to detect torque applied to the rotating shaft based on the change in inductance of detection coils arranged around the rotating shaft. The Applicant has proposed a magnetostrictive torque sensor in which a flexible substrate on which a plurality of detection coils are formed is arranged around a rotating shaft and torque applied to the rotating shaft is detected based on changes in the inductance of the plurality of detection coils (see Patent Literature 1).

The magnetostrictive torque sensor described in Patent Literature 1 has a flexible substrate on which a plurality of first detection coils each having a first linear portion inclined at +45 degrees to an axial direction of a rotating shaft, a plurality of second detection coils each having a second linear portion inclined at −45 degrees to the axial direction of the rotating shaft are formed, and a magnetic ring composed of a hollow cylindrical ferromagnetic material coaxially arranged around the flexible substrate. The flexible substrate is adhesively fixed to an inner peripheral surface of the magnetic ring.

CITATION LIST

Patent Literatures

SUMMARY OF INVENTION

Technical Problem

The magnetostrictive torque sensor described in Patent Literature 1 is manufactured by adhesively fixing the flexible substrate to the inner peripheral surface of the hollow cylindrical magnetic ring as described above, so that it was necessary to wait until the adhesive applied to the inner peripheral surface of the magnetic ring or to one side surface of the flexible substrate facing the inner peripheral surface of the magnetic ring hardens. This was an obstacle to improving productivity.

Therefore, it is an object of the invention to provide a magnetostrictive torque sensor and a method for manufacturing a magnetostrictive torque sensor, which can improve productivity compared to the case where a flexible substrate with a plurality of coils is adhesively fixed to a hollow cylindrical magnetic ring to constitute a magnetostrictive torque sensor.

Solution to Problem

So as to solve the above problem, one aspect of the present invention provides a magnetostrictive torque sensor, configured to be mounted around a rotating shaft having a magnetostrictive effect and to detect torque applied to the rotating shaft, comprising: a support member having a cylindrical portion through which the rotating shaft is inserted; a flexible substrate arranged around an outer periphery of the cylindrical portion and having a plurality of coils composed of wiring patterns; and a tightening member that tightens the flexible substrate toward an outer peripheral surface of the cylindrical portion.

Further, so as to solve the above problem, another aspect of the present invention provides a method of manufacturing the magnetostrictive torque sensor described above, in which the tightening member is a tubular heat-shrinkable tube that shrinks by heating, comprising: a placing step of placing the flexible substrate around the outer periphery of the cylindrical portion of the support member and placing the heat-shrinkable tube around an outer periphery of the flexible substrate; and a tightening step of tightening the flexible substrate toward the outer peripheral surface of the cylindrical portion by heating the heat-shrinkable tube to shrink the heat-shrinkable tube.

Advantageous Effects of Invention

According to a magnetostrictive torque sensor and a method for manufacturing a magnetostrictive torque sensor of the present invention, it is possible to improve productivity compared to the case where a flexible substrate with a plurality of coils is adhesively fixed to a hollow cylindrical magnetic ring to constitute a magnetostrictive torque sensor.

DESCRIPTION OF EMBODIMENT

Embodiment

FIG.1is a perspective view of a magnetostrictive torque sensor according to an embodiment of the present invention.FIG.2is a cross-sectional view of the magnetostrictive torque sensor at line A-A inFIG.1together with a rotating shaft on which torque is to be detected.FIG.3is a cross-sectional view showing an enlarged part of the magnetostrictive torque sensor.

A magnetostrictive torque sensor1is mounted around a rotating shaft8and is used to detect torque applied to the rotating shaft8. The rotating shaft8is a shaft that transmits the driving force of a drive source, such as an automobile engine, for example. The torque detection results obtained by the magnetostrictive torque sensor1are used to control the drive source, automatic transmission, or the like.

The magnetostrictive torque sensor1includes a support member2having an inner cylindrical portion21into which the rotating shaft8is inserted at the center, a cover member3having an outer cylindrical portion31arranged around the outer periphery of the inner cylindrical portion21of the support member2, a sealing member4made of molded resin covering at least a portion of each of the support member2and the cover member3, a flexible substrate5arranged around the outer periphery of the inner cylindrical portion21of the support member2, and a heat-shrinkable tube6as a tightening member (i.e., clamping member) that tightens the flexible substrate5toward an outer peripheral surface21bof the inner cylindrical portion21of the support member2, and a cable7having multiple wires configured to be connected to the flexible substrate5. The support member2and the cover member3are injection-molded resin members, and together with the sealing member4constitute a housing10made of a resin.

A rotating shaft8is a ferromagnetic material having a magnetostrictive effect and rotates around a rotation axis O to transmit torque. Here, the magnetostrictive effect is a phenomenon in which a distortion (strain) appears in the shape of a ferromagnetic material when a magnetic field is applied to the ferromagnetic material to magnetize it. By utilizing this phenomenon in reverse, the magnetostrictive torque sensor1can detect the torque applied to the rotating shaft8by detecting the magnetic field generated by the shape distortion. As the rotating shaft8, for example, a shaft-like body made of chromium-containing steel such as chrome steel, chrome molybdenum steel, or nickel-chromium molybdenum steel that has been carburized and tempered, and then shot peened can be suitably used. Hereafter, the direction parallel to the rotation axis O of the rotating shaft8is referred to as the axial direction.

FIG.4is a perspective view showing the support member2.FIG.5is a configuration diagram showing the flexible substrate5and the cable7assembled with the support member2in an axial view. The cable7has first to fourth wires71-74and a sheath75that collectively covers the first to fourth wires71-74. The first to fourth wires71-74are insulated wires in which core wires711,721,731,741made of good electrically conductive metal are covered by insulating sheaths712,722,732,742made of electrically insulating material, respectively.

The support member2integrally comprises the inner cylindrical portion21, an annular-shaped flange22provided around an outer periphery of one axial end of the inner cylindrical portion21, a bottom wall23provided around an outer periphery of the other axial end of the inner cylindrical portion21and axially opposite to the flange22, and a cable support portion24for supporting the cable7. The inner cylindrical portion21has an inner peripheral surface21afacing an outer peripheral surface8aof the rotating shaft8and the flexible substrate5contacting the outer peripheral surface21b. The inner cylindrical portion21corresponds to the “cylindrical portion” of the present invention. As shown inFIG.3, the flange22has a trapezoidal shape in cross-section along the axial direction, and a part of the flange22is a protrusion221protruding on the opposite side from the flexible substrate5-side. An annular recess20is formed between the protrusion221and the inner cylindrical portion21.

The cable support portion24is provided protruding radially outward from the other axial end of the inner cylindrical portion21. The cable support portion24has first to third wall portions241-243that divide and support each of the first to fourth wires71-74at predetermined intervals, a sheath holding portion244that holds the sheath75, and a pedestal portion245that supports a protruding piece500(described below) of the flexible substrate5. The pedestal portion245is provided with a pair of protrusions245a,245bas a fixing portion to fix the protruding piece500.

The cover member3integrally comprises an outer cylindrical portion31, an annular lid portion32provided around an inner periphery of one axial end of an outer cylindrical portion31, and a cable holding portion33that sandwiches the cable7between itself and the cable support portion24of the support member2. The other axial end of the outer cylindrical portion31is butted against the bottom wall23of the support member2. The outer cylindrical portion31forms an annular housing space100that houses the flexible substrate5and the heat-shrinkable tube6between itself and the inner cylindrical portion21of the support member2. At an end of an inner diameter side of the lid portion32, there is a protrusion321that is axially aligned with the flange22of the support member2. The protrusion321fits into the recess20between the protrusion221and the inner cylindrical portion21of the flange22.

The sealing member4covers the outer cylindrical portion31, the lid portion32, and the cable holding portion33of the cover member3, as well as the axial ends of the inner cylindrical portion21, the bottom wall23, and the cable support portion24of the support member2, to prevent moisture and the like from entering the housing space100. The sealing member4is formed by injecting molten liquid mold resin into a mold in which the support member2and the cover member3are arranged. The mold resin is injected through a plurality of injection holes provided at a portion facing the end surface32aon the opposite side of the housing space100-side in the lid portion32of the cover member3.

As shown inFIG.1, three injection marks41to43of mold resin are formed on the sealing member4. The injection marks41to43are traces of mold resin that remained in the injection holes of the mold. As shown inFIG.3, a small gap is formed between the support member2and the cover member3, but because this gap is formed into a labyrinth shape with a Z-shaped cross-section by the interlocking of the protrusions221,321, which prevents the molten mold resin from entering the housing space100and coming into contact with the flexible substrate5and heat-shrinkable tube6. In other words, the housing space10is configured by the cover member3to prevent the mold resin from contacting the flexible substrate5and the heat-shrinkable tube6.

FIG.6is a plan view of the flexible substrate5.FIG.7is a cross-sectional view of the flexible substrate5. The flexible substrate5has a strip portion (band-shape portion)50extending in a longitudinal direction (left and right direction inFIG.6) and a protruding piece500extended from the strip portion50along a shortitudinal direction perpendicular to the longitudinal direction. First to fourth terminals501to504are provided at the tip of the protruding piece500. The first to fourth terminals501to504are connected to the respective core wires711,721,731,741of the first to fourth wires71to74supported on the cable support portion24of the support member2by soldering or welding.

The protruding piece500has mating holes500a,500b, into which a pair of protrusions245a,245bprovided on the pedestal portion245in the cable support portion24fit. The mating holes500a,500bpenetrate the protruding piece500in a thickness direction. The protruding piece500is fixed to the cable support portion24by fitting the pair of protrusions245a,245binto the mating holes500a,500b.

The flexible substrate5has a multilayer structure with the first to fourth wiring layers51to54, and is arranged in a cylindrical curved shape to surround the inner cylindrical portion21of the support member2from the outside. The flexible substrate5is composed of a coverlay film551, an adhesive layer561, a first wiring layer51, a first base film571, a second wiring layer52, an adhesive layer562, a coverlay film552, a double-sided tape58, a coverlay film553, an adhesive layer563, a third wiring layer53, a second base film572, a fourth wiring layer54, an adhesive layer564, and a coverlay film554that are laminated in this order, from one side5a, which is outside the curve, to the other side surface5b, which is inside the curve.

The first wiring layer51and the second wiring layer52are wiring patterns formed by etching copper foil and are formed on a front surface571aand a back surface571bof the first base film571, respectively. Similarly, the third wiring layer53and the fourth wiring layer54are wiring patterns formed by etching copper foil and are formed on a front surface572aand a back surface572bof the second base film572, respectively. The coverlay films551,552,553,554are protective films attached to the first to fourth wiring layers51to54by means of the adhesive layers561,562,563,564. The first and second base films571,572, and the coverlay films551,552,553,554are composed of insulating resin such as polyimide. The double-sided tape58is, e.g., an acrylic tape.

FIG.8Ais a plan view showing the wiring pattern of the first wiring layer51formed on the front surface571aof the first base film571.FIG.8Bis a plan view showing the wiring pattern of the second wiring layer52viewed from the front surface571aof the first base film571.FIG.8Cis a plan view showing the wiring pattern of the third wiring layer53formed on the front surface572aof the second base film572.FIG.8Dis a plan view showing the wiring pattern of the fourth wiring layer54as viewed from the front surface572aside of the second base film572.

In the first wiring layer51, first to ninth coils511to519are formed by wiring patterns that are aligned in the longitudinal direction of the strip portion50. The first and ninth coils511,519are triangular in shape, and the second to eighth coils512to518are parallelogram-shaped. Similarly, in the second wiring layer52, first to ninth coils521to529, which are aligned in the longitudinal direction of the strip portion50, are formed by wiring patterns. The first and ninth coils521,529are triangular in shape, and the second to eighth coils522to528are parallelogram-shaped.

In the third wiring layer53, the first to ninth coils531to539are formed by wiring patterns that are aligned in the longitudinal direction of the strip portion50. The first and ninth coils531,539are triangular in shape, and the second to eighth coils532to538are parallelogram-shaped. Similarly, in the fourth wiring layer54, first to ninth coils541to549, which are aligned in the longitudinal direction of the strip portion50, are formed by wiring patterns. The first and ninth coils541,549are triangular in shape, and the second to eighth coils542to548are parallelogram-shaped.

The first to ninth coils511to519of the first wiring layer51and the first to ninth coils541to549of the fourth wiring layer54have straight portions511ato519aand541ato549a, respectively, inclined at a predetermined angle (+45°) on one side to the shortitudinal direction of the strip portion50. The first to ninth coils521to529of the second wiring layer52and the first to ninth coils531to539of the third wiring layer53have straight portions521ato529aand531ato539a, respectively, inclined at a predetermined angle (−45°) on the other side with respect to the shortitudinal direction of the strip portion50. The straight portions521ato529a,531ato539ahave straight portions521ato529a,531ato539a, respectively.

FIG.9is a circuit diagram schematically showing an example configuration of an electric circuit composed of the flexible substrate5, the cable7, an oscillator91, and a voltmeter92. The first to ninth coils511to519of the first wiring layer51are directly connected to form a first inductive load510, and the first to ninth coils521to529of the second wiring layer52are directly connected to form the second inductive load520. The first to ninth coils531to539of the third wiring layer53are directly connected to form the third inductive load530, and the first to ninth coils541to549of the fourth wiring layer54are directly connected to form the fourth inductive load540.

The first inductive load510and the third inductive load530, and the second inductive load520and the fourth inductive load540are connected in series between the first terminal501and the second terminal502, respectively. A connecting line591connecting the first inductive load510and the third inductive load530is connected to the third terminal503, and a connecting line592connecting the second inductive load520and the fourth inductive load540is connected to the fourth terminal504. The oscillator91applies an alternating voltage between the first terminal501and the second terminal502. The voltmeter92measures the voltage between the third terminal503and the fourth terminal504.

When torque is applied to the rotating shaft8, the magnetic permeability in the direction of +45 degrees to the axial direction decreases (or increases) and the magnetic permeability in the direction of −45 degrees to the axial direction increases (or decreases). Therefore, when torque is applied to the rotating shaft8with AC voltage applied from the oscillator91, the inductance of the first inductive load510and the fourth inductive load540decreases (or increases), and the inductance of the second inductive load520and the third inductive load530increases (or decreases). As a result, the voltage measured by the voltmeter92changes, and the torque applied to the rotating shaft8can be detected based on this voltage change.

InFIGS.8A to8D, the wiring patterns of the portions of the first to fourth wiring layers51to54that connect the first to ninth coils511to519,521to529,531to539,541to549in series, and the wiring patterns between the connecting lines591,592and the circuit elements thereof and the first to fourth terminals501to504are omitted from the illustration.

The flexible substrate5is tightened toward the outer peripheral surface21bof the inner cylindrical portion21of the support member2by the heat-shrinkable tube6, which shrinks upon heating. In the present embodiment, hot melt adhesive61(seeFIG.3) is applied to an inner surface6aof the heat-shrinkable tube6. The hot melt adhesive61melts due to heat when shrinking the heat-shrinkable tube6and is interposed between one side surface5aof the flexible substrate5and the inner surface6aof the heat-shrinkable tube6to bond the flexible substrate5and the heat-shrinkable tube6. The other side surface5bof the flexible substrate5adheres to the outer peripheral surface21bof the inner cylindrical portion21without any gap. The heat-shrinkable tube6is made of a resin material such as polyolefin or polyvinyl chloride, for example, and shrinks at temperatures of 150° C. or higher.

An axial width of the heat-shrinkable tube6is wider than a shortitudinal width of the strip portion50of the flexible substrate5, and both ends in the shortitudinal direction of the strip portion50are covered by the heat-shrinkable tube6. Both axial ends of the heat-shrinkable tube6are bonded to the outer peripheral surface21bof the inner cylindrical portion21of the support member2by the hot melt adhesive61. This fixes the position of the flexible substrate5with respect to the support member2.

Next, the manufacturing method of the magnetostrictive torque sensor1is described with reference toFIGS.10to12. The method of manufacturing the magnetostrictive torque sensor1includes the following step: a placing step of placing the flexible substrate5around the outer periphery of the inner cylindrical portion21of the support member2and placing the heat-shrinkable tube6around the outer periphery of the flexible substrate5, a tightening step of heating the heat-shrinkable tube6to shrink the flexible substrate5toward the outer peripheral surface21bof the inner cylindrical portion21, an assembling step of assembling the cover member3and the cable7to the support member2to which the flexible substrate5is fixed by the heat-shrinkable tube6, and a molding step of molding the sealing member4.

FIG.10is a perspective view showing the support member2and the flexible substrate5arranged around the outer periphery of the inner cylindrical portion21of the support member2, together with the heat-shrinkable tube6with hot melt adhesive61applied to the inner surface6a. InFIG.10, the heat-shrinkable tube6before shrinkage by heating is shown axially aligned with the inner cylindrical portion21of the support member2. The inner diameter of the heat-shrinkable tube6before shrinkage is larger than the outer diameter of the flange22of the support member2, and the heat-shrinkable tube6can pass through the outer periphery side of the flange22by relative movement in the axial direction of the support member2and the heat-shrinkable tube6.

FIG.11is a perspective view showing the state in which the heat-shrinkable tube6is placed around the outer periphery of the flexible substrate5before shrinking and the placing step is completed.FIG.12is a perspective view showing the completed state of the tightening step, in which the heat-shrinkable tube6is heated and contracted from the state shown inFIG.11, and the flexible substrate5is tightened. The method of heating the heat-shrinkable tube6is not limited, but for example, the heat-shrinkable tube6can be heated by blowing hot air or by irradiating infrared rays. The temperature of the heat-shrinkable tube6heated in the tightening step is lower than the temperature of the molten resin in the molding step (e.g., 300° C.).

The cover member3has the function of protecting the flexible substrate5and the heat-shrinkable tube6from the heat of the molten resin in the molding step. The radial thickness of the outer cylindrical portion31is a dimension that can prevent molten resin from flowing into the housing space100even when subjected to heat and pressure of the molten resin in the molding step, and is, e.g., 1.2 mm or more and 2.7 mm or less. If the thickness of the outer cylindrical portion31is less than 1.2 mm, the outer cylindrical portion31may melt during the molding step and molten resin may flow into the housing space100, and if the thickness of the outer cylindrical portion31exceeds 2.7 mm, the magnetostrictive torque sensor1will be larger than necessary.

At the completion of the tightening step, the flexible substrate5is tightened by the heat-shrinkable tube6and fixed to the inner cylindrical portion21of the support member2so that the assembling and molding steps can be performed immediately, even before the hot melt adhesive61is solidified.

Functions and Effects of the Embodiment

The following functions and effects can be obtained according to the embodiment described above.

Since the flexible substrate5, in which the first to ninth coils511to519,521to529,531to539,541to549of the first to fourth wiring layers51to54are formed by the wiring patterns, is fastened to the inner cylindrical portion21of the support member2by the heat-shrinkable tube6, for example, the flexible substrate5can be fixed more quickly than when the flexible substrate5is fixed to the inner cylindrical portion21by only using, for example, an adhesive. This makes it possible to improve productivity.

Since the flexible substrate5is fixed to the inner cylindrical portion21of the support member2made of resin, peeling of the flexible substrate5due to the difference in thermal expansion coefficient with the support member2is unlikely to occur. Also, since the flexible substrate5is fixed to the inner cylindrical portion21of the support member2by tightening the flexible substrate5with the heat-shrinkable tube6, the flexible substrate5is not easily peeled off from the inner cylindrical portion21by this tightening.

Since both ends in the shortitudinal direction of the strip portion50of the flexible substrate5are covered by the heat-shrinkable tube6, the flexible substrate5can be held airtight, and moisture absorption by the flexible substrate5can be prevented. Furthermore, since the hot melt adhesive61is applied to the inside of the heat-shrinkable tube6, the flexible substrate5can be held airtight more securely, and the position of the flexible substrate5within the housing space100can be prevented from being shifted.

Since the flexible substrate5has the protruding piece500that is disposed outside the heat-shrinkable tube6and the first to fourth terminals501to504are provided on the protruding piece500, it is easier to make connections with the first to fourth wires71to74of the cable7. In addition, the cable support portion24of the support member2is provided with protrusions245a,245bfor fixing the protruding piece500, making it even easier to make connections with the first to fourth wires71to74.

The combination of the support member2with the cover member3prevents molten resin from contacting the flexible substrate5and the heat-shrinkable tube6in the molding step, thus preventing heat damage to the flexible substrate5and the heat-shrinkable tube6.

The heat-shrinkable tube6is preferably transparent or translucent, because if the heat-shrinkable tube6is transparent or translucent, the position and posture of the flexible substrate5can be visually checked from outside the heat-shrinkable tube6to detect defective products.

Summary of Embodiment

Next, the technical concepts that can be grasped from the above-described embodiment will be described with the aid of the codes, etc. in the embodiment. However, each code in the following description does not limit the components in the scope of the claims to the parts, etc. specifically shown in the embodiment.

According to the feature [1], a magnetostrictive torque sensor1, configured to be mounted around a rotating shaft8having a magnetostrictive effect and to detect torque applied to the rotating shaft8, includes a support member2having a cylindrical portion (inner cylindrical portion21) through which the rotating shaft8is inserted; a flexible substrate5arranged around an outer periphery of the cylindrical portion21and having a plurality of coils511to519,521to529,531to539,541to549composed of wiring patterns; and a tightening member (heat-shrinkable tube6) that tightens the flexible substrate5toward an outer peripheral surface21bof the cylindrical portion21.

According to the feature [2], in the magnetostrictive torque sensor1described by the feature [1], the tightening member6is a tubular heat-shrinkable tube6that shrinks upon heating.

According to the feature [3], in the magnetostrictive torque sensor1described by the feature [1] or [2], the flexible substrate5has a strip portion50in which the plurality of coils511to519,521to529,531to539,541to549are arranged side by side in a longitudinal direction and both ends in a shortitudinal direction of the strip portion50are covered by the tightening member6.

According to the feature [4], in the magnetostrictive torque sensor1described by the feature [3], a hot melt adhesive61is applied to an inner surface6aof the tightening member6.

According to the feature [5], in the magnetostrictive torque sensor1described by the feature [3] or [4], the flexible substrate5has a protruding piece500extending in the shortitudinal direction from the strip portion50and disposed outside the tightening member6, a plurality of terminals501to504provided on the protruding piece500, and a cable7having a plurality of wires71to74connected to the plurality of terminals501to504, respectively.

According to the feature [6], in the magnetostrictive torque sensor1described by the feature [5], the support member2is provided with a cable support portion24for supporting the cable7projecting radially outward from the cylindrical portion21, and the cable support portion24is provided with a fixing portion protrusion245a,245bfor fixing the protruding piece500.

According to the feature [7], the magnetostrictive torque sensor1described by any one of the features [1] to [6], further includes a cover member3constituting a housing space100to accommodate the flexible substrate5between the cylindrical portion21of the support member2, and a sealing member4composed of a mold resin molded to cover at least a portion of each of the support member2and the cover member3, wherein the cover member3is configured to prevent the mold resin from contacting the flexible substrate5and the tightening member6.

According to the feature [8], a method for manufacturing the magnetostrictive torque sensor1described by the feature [2] includes a placing step of placing the flexible substrate5around the outer periphery of the cylindrical portion21of the support member2and placing the heat-shrinkable tube6around an outer periphery of the flexible substrate5; and a tightening step of tightening the flexible substrate5toward the outer peripheral surface21bof the cylindrical portion21by heating the heat-shrinkable tube6to shrink the heat-shrinkable tube6.

APPENDIX

The above description of the embodiment of the invention does not limit the invention as claimed above. It should also be noted that not all of the combinations of features described in the embodiment are essential for the invention to solve the problems of the invention.

Further, the present invention can be implemented with appropriate modifications. For example, in the above embodiment, the case where the magnetostrictive torque sensor1has the cover member3and the sealing member4was described, but depending on the environment of the site where the magnetostrictive torque sensor is installed, the cover member3and the sealing member4may be absent. In addition, in the above embodiment, the case where the tightening member is a heat-shrinkable tube6was described, but it is not limited to this. If the member is capable of tightening the flexible substrate5, for example, a cylindrical elastic body may be used as a tightening member, or an adhesive tape with an adhesive layer formed on one side of a base material made of band-shaped resin may be used.

INDUSTRIAL APPLICABILITY

According to a magnetostrictive torque sensor and a method for manufacturing a magnetostrictive torque sensor of the present invention, it is possible to improve productivity compared to the case where a flexible substrate with a plurality of coils is adhesively fixed to a hollow cylindrical magnetic ring to constitute a magnetostrictive torque sensor.

REFERENCE SIGNS LIST