Nsk Corporation

Proterial, Ltd.

Honda Motor Co., Ltd.

Hitachi Metals, Ltd.

Kota Fukuda

Teruyuki Nakamura

Masahiro Kobayashi

Junji Ono

Takahiro Odera

Yuta Sugiyama

Naoki Futakuchi

Hisayoshi Fukui

Hiroki Nishii

Toshirou Toyoda

Yiming Jin

Shinji Okada

Takashi Onimoto

Yuya Daikoku

Seigou Urakami

Ken Okuyama

Akitoshi Fujimori

Toshihiro Saito

Yuka Kaneko

Yoshinori Kubo

Haruhiko Tanno

The torque measuring device includes: a casing made of a magnetic metal; a rotating shaft rotatably arranged inside the casing and having a magnetostrictive effect section whose magnetic permeability changes according to torque to be transmitted; and a torque sensor arranged around the magnetostrictive effect section and supported by the casing, the torque sensor including a coil unit formed in a cylindrical shape using a flexible substrate having a detection coil that changes voltage in response to changes in the magnetic permeability of the magnetostrictive effect section, and a holder made of rubber or synthetic resin, covering an outer peripheral surface of the coil unit, and having a portion that protrudes from the coil unit on both sides in an axial direction; and the torque sensor supported by the casing with an outer peripheral surface of the holder fitted into an inner peripheral surface of the casing.

Torque measuring device

A torque measuring device includes a bridge circuit in which four detection coils arranged around a magnetostrictive effect section of a rotating shaft are arranged on four sides; and the bridge circuit includes a resistance element connected to at least one of the four sides for adjusting a resistance value of the side.

A torque measuring device includes: a coil unit having a detection coil configured to change a voltage in response to a change in magnetic permeability of a magnetostrictive effect section of a rotating shaft; a back yoke arranged coaxially around the coil unit; a holder configured to hold the coil unit and the back yoke; and an electronic circuit including the detection coil and configured to generate an output voltage according to a voltage of the detection coil, a clearance in a radial direction is provided between an outer peripheral surface of the coil unit and an inner peripheral surface of the back yoke, and a range of change in the clearance that accompanies temperature change during use is regulated to a range in which a change in the output voltage is linear with respect to the change in the clearance.

The manufacturing method includes: performing testing of samples having the same configuration as the torque measuring device to be manufactured to find a coil balance Cthat is a ratio (R1×R3)/(R2×R4) of a product R1×R3 of resistance values R1 and R3 of one pair of opposite sides of the four sides of a bridge circuit, and a product R2×R4 of resistance values R2 and R4 of another pair of opposite sides of the four sides, and a temperature change rate Vof output voltage Vo of a sensor portion, and acquiring a relationship X between the coil balance Cand the temperature change rate Vfrom the test results; and measuring the resistance values R1, R2, R3, R4 of the four sides to find the coil balance Cto find the temperature change rate Vfrom the relationship X for the torque measuring device to be manufactured.

Torque measuring device and manufacturing method thereof

A method of manufacturing a magnetostrictive torque sensor shaft () to which a sensor portion () of a magnetostrictive torque sensor () is mounted. The method includes heat treatment step of subjecting an iron-based shaft member to a carburizing, quenching, and tempering process, and a shot peening step of performing shot peening using a boron-free zirconia shot media having a Vickers hardness at least equal to 1100 and at most equal to 1300, at least in a position on the shaft member, after the heat treatment step, to which the sensor portion is to be attached. The surface of the shaft member, after shot peening, has a total error, including hysteresis error and angle error, of not more than 3%.

Method of manufacturing magnetostrictive torque sensor shaft

A magnetostrictive torque sensor includes detection coils formed around a magnetostrictive material made of chrome steel or chrome molybdenum steel, a magnetic ring configured to cover around the detection coils, and a drive unit for providing alternating current excitation to the detection coils at an excitation frequency of 50 kHz or more and 333 kHz or less. A torque applied to the magnetostrictive material is detected based on a change in inductance of the detection coils. The magnetic ring is configured by wrapping around the detection coils with an amorphous tape made of amorphous soft magnetic material in a tape shape. The thickness of the magnetic ring is 1.455 times or more as thick as a skin effect thickness of the magnetostrictive material and less than 1.000 mm.

Magnetostrictive torque sensor and design method of thickness of magnetic ring for magnetostrictive torque sensor

A method for manufacturing a magnetostrictive torque sensor shaft () to which a sensor portion () of a magnetostrictive torque sensor () is to be attached includes: a heat treatment step of subjecting an iron-based shaft member to a carburizing, quenching, and tempering process; a shot peening step of performing shot peening using a steel shot media having a Vickers hardness at least equal to 1100 and at most equal to 1300, at least in a position on the shaft member, after the heat treatment step, to which the sensor portion () is to be attached; and a surface polishing step of subjecting the shaft member after the shot peening to surface polishing.

Method for manufacturing magnetostrictive torque sensor shaft

A torque measurement device includes a case that does not rotate even during use; a rotating shaft rotatably supported to the case and having a magnetostrictive effect part whose magnetic permeability changes according to a transmitted torque; and a magnetostrictive sensor having a detection part arranged closely adjacent to the magnetostrictive effect part so that a voltage changes according to change of the magnetic permeability of the magnetostrictive effect part, and being supported to the case; and the torque measurement device has a rotation-preventing construction configured to prevent the magnetostrictive sensor from rotating with respect to the case.

Torque measurement device

A torque load member has a detected surface which is configured to face a magnetostrictive torque sensor. The detected surface is a shot peened surface whose magnetic anisotropy directed in a specific direction has been reduced by performing shot peening thereto at an arc height value of 0.31 mmA or more.

Torque load member and method for manufacturing same, and torque measuring device

A torque measuring device includes: a magnetostrictive sensor having a ring-shaped holder arranged around a magnetostrictively affected section of a rotating shaft, a detecting section embedded in the holder and that changing a voltage according to a change in magnetic permeability of the magnetostrictively affected section; and a sensor-side engaging section; and a fixed member having a fixed-side engaging section, the fixed member not rotating even during operation. One of the sensor-side engaging portion and the fixed-side engaging section is a convex section and the other is a concave section. With the sensor-side engaging section and the fixed-side engaging section engaged with a concave-convex engagement, shifting of the position of the magnetostrictive sensor in the direction of rotation and the radial direction with respect to the substrate is prevented.

A detection circuit for a magnetostrictive torque sensor is configured to detect a torque applied to a magnetostrictive material treated by shot peening. The detection circuit includes a detection coil provided around the magnetostrictive material, and a drive unit for providing alternating current excitation to the detection coil. The torque applied to the magnetostrictive material is detected based on a change in inductance of the detection coil, and the drive unit provides alternating current excitation at a frequency at which a skin effect thickness is not more than an effective depth of the shot peening.

Detection circuit and detection method for magnetostrictive torque sensor

The reverse input shutoff clutch includes: an input member, an output member coaxially arranged with the input member, a pressed member having a pressed surface, and an engaging element. The engaging element, when rotational torque is inputted to the input member, moves in a direction away from the pressed surface due to engagement with the input member and transmits the rotational torque to the output member, and when rotational torque is reversely inputted to the output member, moves in a direction toward the pressed surface due to engagement with the output member, and prevents or suppresses relative rotation between the output member and the pressed member.

Reverse input shutoff clutch, electric valve timing adjustment device, variable compression ratio device, and electric power steering device

Fletching wear caused by elastic deformation in the axial direction of an input-side diskdue to thrust force of a pressure device is prevented. A female-spline sectionformed around the middle section in the axial direction of the inner-circumferential surface of a center holein the input-side diskand a male-spline sectionformed around the outer-circumferential surface of one end section in the axial direction of an input rotating shaftengage with a spline engagement. A disk-side fitting surface sectionformed around a portion of the inner-circumferential surface of the center holein the input-side diskthat is adjacent to the other end side of the female-spline sectionand a shaft-side fitting surface sectionformed around a portion of the outer-circumferential surface of the input rotating shaftthat is adjacent to the other end side of the male spline sectionare fitted together with an interference fit.

Growing community of inventors

Shizuoka, Japan

Kota Fukuda