A SHOCK ABSORBER FOR PROTECTING A TEST PIECE FROM RECEIVING A SECOND IMPACT

摘要

The present invention relates to a shock absorber for preventing a test piece from receiving a secondary impact which can prevent the secondary impact applied to the test piece by efficiently controlling a state where a moving block for fixing one side of the front end of the metallic test piece returns forward by impact repulsive power while pulling back by impact hitting power applied to a high-speed impact tensile test device. The present invention provides the shock absorber for preventing the test piece from receiving the secondary impact comprising a hydraulic cylinder for position adjustment (161) connected to an external hydraulic source; a cylinder rod (162) with a rear end coupled to the hydraulic cylinder for position adjustment; a hydraulic cylinder for shock absorption (163) to which the front side of the cylinder rod is coupled; a check valve (164) mounted on a hydraulic passage arranged inside the rear side of the hydraulic cylinder for shock absorption; a variable safety valve (166) communicating with the hydraulic passage of the hydraulic cylinder for shock absorption, and having an orifice inside thereof; and a bypass valve (165) mounted on a bypass line (165a) for connecting a front hydraulic passage (163a) and a rear hydraulic passage (163b) in the hydraulic cylinder for shock absorption.