PURPOSE: To enable flaw detection of a spring by using an oscillator detector which is normally installed to a structure and detects passively the expanding defect of the constituting material in the loading stage of active stress to the spring base material, i.e., setting.
CONSTITUTION: An oscillation detector which can detect the slight oscillation propagating in a material to be exampled according to the release of the sound generated in the material to be detected is preliminarily brought into contact directly or indirectly with the surface of the base material and the characteristic slight oscillation which is induced from the noise generated when the flaw existing on or in the base material is expanded by torsional stress or bending stress load and propagates in the base material is detected, by which the presence of the flaw is detected in the setting accomplished in the process of manufacturing a spring or loading of the torsion stress or bending stress to the base material. The constitution consisting of holding a sensor or guide in a supporting device which displaces in follow-up to the base material displacing according to the load applied thereto and bringing the sensor or the guide into press contact with the base material is incorporated in the stage of building the device into the process for manufacture.
IKUTA FUMIAKI
NAKAGAWA YOSHIKI
| JPS5223985A | 1977-02-23 |