Abstract: The press machine includes: a hydraulic cylinder configured to drive a slide; a plurality of hydraulic pumps/motors; a first port of each of which is connected to a first pressurizing chamber of the hydraulic cylinder; a plurality of servomotors axially connected to rotating shafts of the respective hydraulic pumps/motors respectively; a low-pressure accumulator to which second ports of the hydraulic pumps/motors are each connected; a high-pressure accumulator connected to a second pressurizing chamber of the hydraulic cylinder; and a slide position controller configured to control the servomotors so that a position of the slide matches a position corresponding to a slide position command signal based on the slide position command signal from a slide position commander and a slide position signal from a slide position detector.

Abstract: A double-blank detecting apparatus for a press machine that is provided with a die cushion apparatus and is configured to form blanks one by one automatically and repeatedly. The double-blank detecting apparatus includes: a position signal acquiring unit configured to acquire a slide position signal indicating a position of a slide of the press machine; a load signal acquiring unit configured to acquire a die cushion load signal indicating a die cushion load generated on a cushion pad of the die cushion apparatus; and a double-blank detector configured to detect a state in which a plurality of blanks are stacked as a double blank based on the slide position signal acquired by the position signal acquiring unit and the die cushion load signal acquired by the load signal acquiring unit.

Abstract: The press machine includes: a hydraulic cylinder configured to drive a slide; a plurality of hydraulic pumps/motors; a first port of each of which is connected to a first pressurizing chamber of the hydraulic cylinder; a plurality of servomotors axially connected to rotating shafts of the respective hydraulic pumps/motors respectively; a low-pressure accumulator to which second ports of the hydraulic pumps/motors are each connected; a high-pressure accumulator connected to a second pressurizing chamber of the hydraulic cylinder; and a slide position controller configured to control the servomotors so that a position of the slide matches a position corresponding to a slide position command signal based on the slide position command signal from a slide position commander and a slide position signal from a slide position detector.

Abstract: A double-blank detecting apparatus for a press machine that is provided with a die cushion apparatus and is configured to form blanks one by one automatically and repeatedly. The double-blank detecting apparatus includes: a position signal acquiring unit configured to acquire a slide position signal indicating a position of a slide of the press machine; a load signal acquiring unit configured to acquire a die cushion load signal indicating a die cushion load generated on a cushion pad of the die cushion apparatus; and a double-blank detector configured to detect a state in which a plurality of blanks are stacked as a double blank based on the slide position signal acquired by the position signal acquiring unit and the die cushion load signal acquired by the load signal acquiring unit.

Abstract: According to the die cushion apparatus of a press machine and the die cushion controlling method of the present invention, in holding the cushion pad on standby at a desired standby position, it is possible to hold the cushion pad on standby in parallel with the lower faces of the dies mounted to the slide, and if the lower faces of the dies are inclined, it is possible to hold the cushion pad on standby in the state of being inclined. Through this configuration, it is possible to easily allow the material to come into contact with the lower faces of the dies from the beginning of the die cushion force control (beginning of the collision), and also possible to smoothen the die cushion action in the plane, thereby enhancing the formability.

Abstract: There is provided a press machine which can apply a large compression force to a mold as well as impart smooth vibration only in a rectilinear advancing direction to the mold, and thereby can improve the press-formability. A main slide and a sub-slide constitute a slide and at the same time a cylinder-piston mechanism. During press-forming, a compression force is transmitted to the sub-slide (an upper mold) through hydraulic pressure applied interlockingly with driving of the main slide, and the sub-slide is vibrated with the hydraulic pressure being periodically changed. Favorable press-forming can be performed even under relatively difficult press-forming conditions, by controlling the vibration such that a vibration frequency of the sub-slide (the upper mold) becomes 9 Hz or higher but 33.3 Hz or lower and a vibration amplitude of the sub-slide becomes 0.05 mm or larger but 0.5 mm or smaller.

Abstract: According to the die cushion apparatus of a press machine and the die cushion controlling method of the present invention, in holding the cushion pad on standby at a desired standby position, it is possible to hold the cushion pad on standby in parallel with the lower faces of the dies mounted to the slide, and if the lower faces of the dies are inclined, it is possible to hold the cushion pad on standby in the state of being inclined. Through this configuration, it is possible to easily allow the material to come into contact with the lower faces of the dies from the beginning of the die cushion force control (beginning of the collision), and also possible to smoothen the die cushion action in the plane, thereby enhancing the formability.

Abstract: The present invention provides a servo press system and a drawing method using the servo press system. The drawing method according to the aspect of the present invention includes: a stopping step of stopping the slide for a first period in a course of a stroke for performing drawing; a keeping step of reducing the die cushion force to below a predetermined die cushion force and keeping the die cushion force for a second period within the first period for which the slide is stopped; and a restarting step of restarting the slide after keeping the die cushion force for the second period, wherein drawing including the stopping step, the keeping step, and the restarting step is performed at least one time in the course of the stroke for performing drawing.

Abstract: According to the die cushion apparatus of a press machine and the die cushion controlling method of the present invention, in holding the cushion pad on standby at a desired standby position, it is possible to hold the cushion pad on standby in parallel with the lower faces of the dies mounted to the slide, and if the lower faces of the dies are inclined, it is possible to hold the cushion pad on standby in the state of being inclined. Through this configuration, it is possible to easily allow the material to come into contact with the lower faces of the dies from the beginning of the die cushion force control (beginning of the collision), and also possible to smoothen the die cushion action in the plane, thereby enhancing the formability.

Abstract: The present invention provides a servo press system and a drawing method using the servo press system. The drawing method according to the aspect of the present invention includes: a stopping step of stopping the slide for a first period in a course of a stroke for performing drawing; a keeping step of reducing the die cushion force to below a predetermined die cushion force and keeping the die cushion force for a second period within the first period for which the slide is stopped; and a restarting step of restarting the slide after keeping the die cushion force for the second period, wherein drawing including the stopping step, the keeping step, and the restarting step is performed at least one time in the course of the stroke for performing drawing.

Abstract: There is provided a press machine which can apply a large compression force to a mold as well as impart smooth vibration only in a rectilinear advancing direction to the mold, and thereby can improve the press-formability. A main slide and a sub-slide constitute a slide and at the same time a cylinder-piston mechanism. During press-forming, a compression force is transmitted to the sub-slide (an upper mold) through hydraulic pressure applied interlockingly with driving of the main slide, and the sub-slide is vibrated with the hydraulic pressure being periodically changed. Favorable press-forming can be performed even under relatively difficult press-forming conditions, by controlling the vibration such that a vibration frequency of the sub-slide (the upper mold) becomes 9 Hz or higher but 33.3 Hz or lower and a vibration amplitude of the sub-slide becomes 0.05 mm or larger but 0.5 mm or smaller.

Abstract: According to the die cushion apparatus of a press machine and the die cushion controlling method of the present invention, in holding the cushion pad on standby at a desired standby position, it is possible to hold the cushion pad on standby in parallel with the lower faces of the dies mounted to the slide, and if the lower faces of the dies are inclined, it is possible to hold the cushion pad on standby in the state of being inclined. Through this configuration, it is possible to easily allow the material to come into contact with the lower faces of the dies from the beginning of the die cushion force control (beginning of the collision), and also possible to smoothen the die cushion action in the plane, thereby enhancing the formability.