Kabushiki Kaisha Toyota Chuo Kenkyusho

Hirofumi Komatsubara

Masaharu Takeuchi

Jun Sugiyama

Yutaka Nonomura

Keiichi Shimaoka

Takashi Takeuchi

A stress detector including an AC power source for generating an AC symmetrical wave form voltage, an exciting coil driven by the AC power source for alternatingly magnetizing at least a portion of a ferromagnetic material to be measured in a predetermined direction, a detecting coil for detecting a magnetic flux generated due to the alternating magnetization, and an adder circuit for taking out a part of a voltage applied to the exciting coil, setting an amplitude and a phase of a wave form of the taken-out part of the voltage to preset values, adding the voltage thus obtained to a voltage induced in the detecting coil. The detector gives an output signal representative of a value of stress applied to the material to be measured as a variation either in amplitude or phase depending on the preset phase.

Stress detector

A torque sensor for electrically detecting torque, such as the torque of an automobile engine, wherein a strain disk is provided in the path of torque transmission and the torque is magnetically detected in terms of the magnetostriction generated in the strain disk. The torque sensor comprises a magnetic rotating disk and a magnetic sensor disposed in the vicinity of and opposed to the strain disk. The magnetic sensor comprises a detection coil and an excitation coil oriented perpendicularly to each other with the excitation coil ordinarily being disposed outside of the detection coil. Supplying alternating current to the excitation coil causes an alternating field to be produced within the strain disk and the configuration of this alternating magnetic field is varied by the anisotropy of the strain caused within the strain disk by the transmitted torque. The variation in the configuration of the alternating magnetic field is noncontactingly detected by the detection coil, which outputs a corresponding electrical signal from which the torque can be determined with high accuracy.

Device for measuring torque of a rotary mechanism

A torque measuring apparatus for detecting torque in a noncontacting state on the basis of the magnetostrictive amount of a rotary magnetic member for transmitting the torque which is detected by means of a magnetic sensor. The measuring apparatus comprises: a timing signal generator for dividing the rotational angle of the rotary magnetic member into a given number of segments and outputting a predetermined timing signal every time a rotational angle of the rotary magnetic member passes each segment; an offset signal generator for setting in advance for each segment an offset signal to be output from the magnetic sensor depending upon the rotational angle of the rotary magnetic member, and subsequently outputting an offset signal which corresponds to a respective segment on the basis of the timing signal; and a subtractor for subtracting the offset signal from the detection signal of the magnetic sensor at each segment, whereby the transmitted torque of the rotary magnetic member is measured on the basis of the output of the subtractor.

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Aichi, Japan

Hirofumi Komatsubara