초록 ▼

A slide driving device employs a variable-displacement pump/motor for driving a rotating element of the slide driving device. The displacement volume of the variable-displacement pump/motor, whose output drives the slide, is varied in response to deviation of measured driver parameters from commande

A slide driving device employs a variable-displacement pump/motor for driving a rotating element of the slide driving device. The displacement volume of the variable-displacement pump/motor, whose output drives the slide, is varied in response to deviation of measured driver parameters from commanded driver parameters. An energy storage device temporarily absorbs excess energy during a portion of a molding cycle, and returns the energy to the system for re-use. In one embodiment, the energy storage device is an accumulator. In a second embodiment, the energy storage device is a flywheel. The combination of variable displacement volume and energy storage maintains the fluid pressure substantially constant during a cycle of the slide driving device.

대표청구항 ▼

[ What is claimed is:] [1.] A slide driving device for a press comprising:means for generating pressure in a hydraulic fluid;said means for generating pressure includes an accumulator;means for controlling said pressure to maintain said pressure within said accumulator within a prescribed range;said

[ What is claimed is:] [1.] A slide driving device for a press comprising:means for generating pressure in a hydraulic fluid;said means for generating pressure includes an accumulator;means for controlling said pressure to maintain said pressure within said accumulator within a prescribed range;said pressure being substantially constant during changes in a load on said press;rotating means, responsive to said pressure, for converting energy from said hydraulic fluid into rotational power;said rotating means including means for absorbing rotational drive force from said slide through said means for applying rotational power, and for converting said rotational drive force into stored energy for said hydraulic fluid, said stored energy being stored temporarily in said accumulator;said rotating means includes at least one variable displacement pump/motors and at least one fixed volume pump/motors;means for applying said rotational power to a slide driving mechanism of said press;means for varying a displacement volume of said rotating means; andmeans for controlling said displacement volume, thereby controlling a drive torque applied to said slide driving mechanism.