Tension impact test machine for the sudden stressing of tensile specimens, preferably made of plastics

摘要

Tension impact tests on tensile specimens are preferably carried out using pendulum-type impact testing machines or hydraulic tensile testing machines. In doing so, a mass - pendulum or piston - is accelerated to a defined extension rate which is given by the construction or can be set, is linked to a follower attached to the free part of the specimen, and as a result the specimen is stretched or ruptured. The linking action often gives rise to rebounds which are superimposed on the force signal and make accurate analysis impossible. This drawback is overcome by the tension impact test machine filed, by the piston (10) of the tension impact test machine being designed so as to be extremely light and being linked directly to the specimen (14) without a follower, Fig. 1. The piston (10) is accelerated by a proportioning piston (5) which at a preset speed penetrates a pressure chamber (8) arranged above the piston (10), shuts off said pressure chamber abruptly, thereby generating a sudden pressure rise, and thus accelerates the piston (10) in the fraction of a millisecond without rebound to a speed proportional to the proportioning piston (5) and thus stretches or ruptures the specimen (14). IMAGE