| 摘要 |
<p>PROBLEM TO BE SOLVED: To surely restrain the loading of a plant within an allowable value by changing a limit value of servo current so as to narrow the limit width at the positive side of a servo current limit means according to the condition whose detected loading approaches a setting loading allowable value. SOLUTION: A loading deviation signal output means 10 outputs a loading deviation signal 10A corresponding to the obtd. value subtracting a loading present value 4A from the loading allowable value 9A. When the loading deviation signal 10A is large, i.e., the loading is sufficiently smaller than the allowable value, the large servo current limit value is outputted and reversely, when the loading deviation signal 10A is small, i.e., the loading approaches the allowable value, the small value is outputted, and further, when the loading equals to the allowable value, the servo current limit value 11A of zero is outputted, with a servo current limit value arithmetic means 11.</p> |
