| 摘要 |
<P>PROBLEM TO BE SOLVED: To control the pressure with good accuracy irrespective of period of the frequency signal when an electric voltage value in accordance with the pressure is converted to the frequency signal and the pressure is controlled in accordance with the period of the frequency signal. <P>SOLUTION: The pressure at a predetermined position of an injection molding machine is detected as an electric voltage value by a strain gauge 1, and the electric voltage value is converted into a frequency signal by a V/F converter 3 to output it, and the period of the frequency signal is measured by a counter 4. In a controlling and operating apparatus 5, when the frequency of the frequency signal output from the V/F converter 3 is at most a threshold value, a time by a clock from a rising edge of the frequency signal to the next rising edge is made to be a period of the frequency signal, and in addition, when the frequency of the frequency signal output from the V/F converter 3 is higher than the threshold value, a value obtained by dividing a definite time by the number of pulse within the definite time by a clock of the frequency signal is made to be a period of the frequency signal, and based on this period, the pressure controlling in the injection molding machine is performed. <P>COPYRIGHT: (C)2012,JPO&INPIT |
