Apparatus for measuring injection speeds of die casting machines

Claim 1

Apparatus for measuring injection speeds of a die casting machine comprising means for detecting injection times at low and high speed injection strokes, respectively, means for arithmetically calculating low and high injection speeds by dividing said low and high injection strokes by said injection times, and means for displaying said low and high injection speeds as average injection speeds, said injection time detecting means comprising an elongated member provided with a plurality of axially spaced portions having different magnetic characteristics, means responsive to said different magnetic characteristics for generating a pulse signal havig a period corresponding to the injection speed of the die casting machine, low and high speed injection limit switches operated by said elongated member for generating signals when low speed injection is started and when the injection speed is switched from low to high, a signal generator, an AND gate circuit with one input connected to said low speed injection limit switch and the other input connected to receive an output of said signal generator, first determining means responsive to the output of said AND gate circuit for determining the low speed injection time and stroke, means for discriminating the period of the signal generated by said pulse signal generating means, and second determining means responsive to the signal generated by said high speed injection limit switch, to the output of said discriminating means and to the output of said AND gate circuit for determining the high speed injection time and stroke.