Torque detection sensor

Abstract

The invention provides a self-excitation type torque detection sensor, which can be miniaturized and mass-produced at low cost, and can detect the compression stress and tensile stress generated at the whole periphery of a detected body without reducing detection sensitivity. The self-excitation type torque detection sensor comprises a plurality of first pole teeth (3a) and second pole teeth (3b) which are provided so as to protrude in a comb-tooth arrangement in the circumferential direction of an annular core (2); and a plurality of energizing circuits (6a, 6b) connected in series to a first coil (5a) and a second coil (5b) wound around the first pole tooth (3a) and the second pole tooth (3b) in different winding directions, wherein a plurality of magnetic circuits having an inclination of + 45 degrees and a plurality of magnetic circuits having an inclination of -45 degrees with respect to the axial direction formed by the object to be detected are respectively formed between the first pole tooth (3a) and the second pole tooth (3b) by energizing the plurality of energizing circuits (6a, 6b).

Description

technical field [0001] The invention relates to a self-excitation torque detection sensor. Background technique [0002] There is a magnetostrictive torque detection device as a method of detecting torque acting on an object to be detected such as a rotating shaft without contact. For example, torque is detected by measuring the magnetostrictive effect by applying a surface treatment (for example, plating or grooving) to the surface of a shaft (shaft portion) that is a subject to detect strain to increase magnetostrictive properties. The magnetostrictive effect is measured by arranging a coil wound coaxially with the shaft and reading a change in the magnetic permeability of the shaft due to the Villari effect based on the magnitude of impedance. [0003] As a torque detection device, the applicant proposes a magnetostrictive torque detection sensor, which increases the torque detection sensitivity by increasing the magnetic circuits formed between the object to be detected...

AI Technical Summary

Problems solved by technology

[0008] Therefore, since the detection coil and the core need to be buried using the radial thickness of the insulating cylinder, the sensor tends to be enlarged in the radial and axial directions

In addition, since the end surfaces of the legs on both sides constituting the core are set to face the object to be detected, it is necessary to form the end surfaces into an arc-shaped curved surface rather than a flat surface, which increases the processing cost

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