Title:
STRAIN DETECTING DEVICE
Document Type and Number:
Japanese Patent JPH05281059
Kind Code:
A
Abstract:
PURPOSE:To reduce dispersion being due to the temperature of a product in output by using a raw material approximate to a shaft material in the coefficient of thermal expansion for a bobbin material in which a detecting coil is set. CONSTITUTION:A bobbin 5A is formed of liquid crystal polymer having the coefficient of thermal expansion approximate to that of material for a driven shaft 1A. When their temperature changes, magnetic layers 3,4 adhering onto the driven shaft 1 are displaced in their absolute positions in the same direction by the thermal expansion of the driven shaft 1A mainly in the direction of a central shaft 2. Since the bobbin 5A expands thermally mainly in the same direction as that of the driven shaft 1A, detecting coils 10, 11 wound on the bobbin 5A are displaced in their absolute positions in the same direction as that of the bobbin 5A. Since the driven shaft 1A and the bobbin 5A are mutually approximate in the coefficient of thermal expansion, the magnetic layers 3,4 and the detecting coils 10, 11 are almost the same in the quantity and direction of displacement, and a relative position between the magnetic layer 3 and the detecting coil 10 and that between the magnetic layer 4 and the detecting coil 11 scarcely change even when their temperatures increase. Thus dispersion caused by the temperature of a product in output is little.
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Inventors:
Hiromasa Ozawa
Application Number:
JP7955392A
Publication Date:
October 29, 1993
Filing Date:
April 01, 1992
Export Citation:
Assignee:
Mitsubishi Electric Corporation
International Classes:
G01L3/10; (IPC1-7): G01L3/10
Attorney, Agent or Firm:
Takada Mamoru