METHOD FOR QUALITY JUDGEMENT OF WELDED PRODUCT BY FRICTIONAL WELDING AND ITS APPARATUS

摘要

PURPOSE:To judge the quality of welded part during the course of welding process without any inspection process, by measuring the time required for stopping the frictional movement from the beginning to the end in the process of frictional welding. CONSTITUTION:In the process of frictional welding with a frictional welding machine in which the frictional movement is produced by the rotation of a rotary shaft 4, the stopping time of the frictional movement is the main factor to occurrences of inferior goods. Because of this, for example, a frame 4' of a stopping time ts measuring device and a leaf spring 32 are fixed to the shaft 4 so that an inertia body 31 moves freely. When the shaft 4 is being stopped, accelerated, or constantly rotated, the inertia body 31 is connected to a switch S2 and a condenser C is charged by a DC power source DC. The voltage in the condenser C soon becomes the same as that of the power source. On the other hand, when a stopping acceleration is applied to th shaft 4 (the period during which the acceleration is being applied is proportional to the time ts), the inertia body 31 closes and opens switches S1 and S2, respectively, and discharges the electricity in the condenser C so that the voltage in the condenser is dropped. Therefore, when this voltage is measured with a voltmeter V, the time ts can be known. When the time ts is larger than a prescribed value, the welded product is judged as inferior.