A die cushion device includes four hydraulic cylinders that support a cushion pad, a die cushion load controller that controls each of the hydraulic cylinders and generates a die cushion load on the cushion pad, and a die cushion position controller that controls each of the hydraulic cylinders to control a position of the cushion pad. In a case where only a left part is produced with a left die by a press machine, the die cushion load controller performs die cushion load control on two hydraulic cylinders on the left side, and the die cushion position controller performs die cushion position control on two hydraulic cylinders on the right side.

A control apparatus of a machine tool includes: a slide position control unit configured to control a slide according to operation patterns; a pressure command generation unit configured to generate a pressure command for a die cushion according to the operation patterns; a pressure detection unit configured to detect an actual pressure of the die cushion; a die cushion speed control unit configured to control the die cushion, based on an error between the pressure command and the actual pressure; and a command reach determination unit configured to determine whether or not the error is greater than a pressure threshold, wherein the slide position control unit sets, based on a result of the determination by the command reach determination unit, a waiting period between the operation pattern at the time of the determination and the next operation pattern, wherein the slide is kept at its position during the waiting period.

A control apparatus of a machine tool includes: a slide position control unit configured to control a slide according to operation patterns; a pressure command generation unit configured to generate a pressure command for a die cushion according to the operation patterns; a pressure detection unit configured to detect an actual pressure of the die cushion; a die cushion speed control unit configured to control the die cushion, based on an error between the pressure command and the actual pressure; and a command reach determination unit configured to determine whether or not the error is greater than a pressure threshold, wherein the slide position control unit sets, based on a result of the determination by the command reach determination unit, a waiting period between the operation pattern at the time of the determination and the next operation pattern, wherein the slide is kept at its position during the waiting period.

Provided are: a method for producing a molded material comprising tubular body and a flange formed at an end portion of the body; and a molded material produced thereby, which can prevent the flange of the molded material becoming unnecessarily thick, avoid the generation of wrinkles and buckling, and allow weight reduction of the molded material and size reduction of a base metal sheet. When producing the molded material by molding processes including at least one drawing-out process and at least one drawing process performed after the drawing-out process, a first drawing process is carried out on a region corresponding to the body while opening a die and a drawing sleeve, and an ironing process is carried out on a region corresponding to the flange while keeping a constant interval of a mold gap between the die and the drawing sleeve.

Provided are: a method for producing a molded material comprising tubular body and a flange formed at an end portion of the body; and a molded material produced thereby, which can prevent the flange of the molded material becoming unnecessarily thick, avoid the generation of wrinkles and buckling, and allow weight reduction of the molded material and size reduction of a base metal sheet. When producing the molded material by molding processes including at least one drawing-out process and at least one drawing process performed after the drawing-out process, a first drawing process is carried out on a region corresponding to the body while opening a die and a drawing sleeve, and an ironing process is carried out on a region corresponding to the flange while keeping a constant interval of a mold gap between the die and the drawing sleeve.

Shock absorbers (33) are attached to a press apparatus (10). The press apparatus (10) has a lower die unit (11) and an upper die unit (21) that is movable in vertical directions; the lower die unit and the upper die unit are capable of cooperating with each other to perform press-forming on a blank (W). The upper die unit (21) has an upper forming die (22) that serves as a forming die to perform press-forming on the blank (W) and upper blank holders (25) that partially serve as blank holders. The shock absorbers (33) are respectively disposed between the upper forming die (22) and the upper blank holders (25), and when the upper die unit (21) is moved upward away from the lower die unit (11) to open the upper and lower forming dies after press-forming is performed on the blank (W), impact applied to the upper blank holders (25) by the upper forming die (22) are respectively absorbed by the shock absorbers (33).

Shock absorbers (33) are attached to a press apparatus (10). The press apparatus (10) has a lower die unit (11) and an upper die unit (21) that is movable in vertical directions; the lower die unit and the upper die unit are capable of cooperating with each other to perform press-forming on a blank (W). The upper die unit (21) has an upper forming die (22) that serves as a forming die to perform press-forming on the blank (W) and upper blank holders (25) that partially serve as blank holders. The shock absorbers (33) are respectively disposed between the upper forming die (22) and the upper blank holders (25), and when the upper die unit (21) is moved upward away from the lower die unit (11) to open the upper and lower forming dies after press-forming is performed on the blank (W), impact applied to the upper blank holders (25) by the upper forming die (22) are respectively absorbed by the shock absorbers (33).

A method of forming a finished stamped product includes positioning a blank on a blank holder between an upper die and a lower die, inserting a movable wedge block between the blank holder and the upper die to establish a first binder gap, and while the movable wedge block is inserted, performing a first strike of the blank by lowering the upper die a first distance to contact and partially form the blank, the movable wedge block limiting downward movement of the upper die relative to the lower die. After the first strike, withdrawing the movable wedge block to establish a second binder gap between the blank holder and the upper die, and while the movable wedge block is withdrawn, performing a second strike of the blank by lowering the upper die a second distance to finally form the blank into the finished product.

A die cushion control device for controlling a die cushion mechanism includes: a pressure command generation unit that outputs a first pressure command on pressure or force to be generated between the die cushion mechanism and a slide; a deviation prediction unit that predicts a pressure deviation that is the difference between the pressure or the force in the first pressure command and a detected pressure caused when the die cushion mechanism is controlled according to the first pressure command, and outputs the predicted pressure deviation as a correction pressure command; a pressure command correction unit that corrects the first pressure command with the correction pressure command to calculate a second pressure command; and a pressure control unit that calculates a speed command to cause the detected pressure to follow the second pressure command, and outputs the speed command to a speed control unit.

A die cushion control device for controlling a die cushion mechanism includes: a pressure command generation unit that outputs a first pressure command on pressure or force to be generated between the die cushion mechanism and a slide; a deviation prediction unit that predicts a pressure deviation that is the difference between the pressure or the force in the first pressure command and a detected pressure caused when the die cushion mechanism is controlled according to the first pressure command, and outputs the predicted pressure deviation as a correction pressure command; a pressure command correction unit that corrects the first pressure command with the correction pressure command to calculate a second pressure command; and a pressure control unit that calculates a speed command to cause the detected pressure to follow the second pressure command, and outputs the speed command to a speed control unit.