Patent ID: 6109161
Filing Date: 2000-08-29
Classification: B30B,F15B

Abstract:
A hydraulic driven tool controlling apparatus for driving upward and downward movements of a ram in a cylinder with the use of hydraulic power and punching out holes in a workpiece with a punch attached to the lower end of the ram, comprising:a lower limit detecting means for detecting the lower limit of a movement of the ram;a directional valve controlling means responsive to a detection signal from the lower limit detecting means for shifting a flow of hydraulic oil which acts on the ram from the downward movement to the upward movement; anda pause period generating means for providing a pause period of a predetermined length in a switching action between the downward movement and the upward movement, wherein the directional valve controlling means includes first and second solenoids and first and second pushrods driven by the first and second solenoids, respectively, and located on both sides of a directional valve so that the flow of hydraulic oil acting on the ram can be shifted from the downward movement to the upward movement by driving the pushrods to switch the directional valve between first and second positions.