Patent ID: 6012321
Filing Date: 2000-01-11
Classification: B30B

Abstract:
A driving device for a pressing machine, comprising:a press system that converts a rotational movement into a linear movement and causes a punch tool to carry out a reciprocating movement;a rotation transmission system that transmits said rotational movement by a servomotor to said press system;a variable transmission means arranged on said rotation transmission system, wherein said variable transmission means includes a plurality of rotation transmission ratios including at least a high rotation transmission ratio for low load processing and a low rotation transmission ratio for high load processing;a process type specific exchange control means for exchanging a rotation transmission ratio of said variable transmission means corresponding to a type of processing based on a comparison between characteristics of a tool to be used in a process and predetermined data, wherein said process type specific exchange control means carries out, for each specific process type, a selection of a single transmission ratio among said plurality of rotation transmission ratios; andan exchange operation means, operably coupled to said variable transmission means and said process type specific exchange control means, for receiving electrical signals representing said single transmission ratio corresponding to said specific process type from said process type specific exchange control means, and for setting said variable transmission means to said single transmission ratio.