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.

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.

In a press machine having a die cushion device which supports a cushion pad and which generates a die cushion force when a slide of the press machine is lowered, the wrinkle generation detection device includes: a slide position detector which detects a height position of the slide; a cushion pad position detector which detects a height position of the cushion pad; and a computing unit which consecutively calculates a deviation between the height position of the slide detected by the slide position detector and the height position of the cushion pad detected by the cushion pad position detector, during a time period from the start of forming of a material by the slide lowering to the end of the forming, wherein a wrinkle generated in the material is detected based on an increase of the deviation consecutively calculated by the computing unit.

In a press machine having a die cushion device which supports a cushion pad and which generates a die cushion force when a slide of the press machine is lowered, the wrinkle generation detection device includes: a slide position detector which detects a height position of the slide; a cushion pad position detector which detects a height position of the cushion pad; and a computing unit which consecutively calculates a deviation between the height position of the slide detected by the slide position detector and the height position of the cushion pad detected by the cushion pad position detector, during a time period from the start of forming of a material by the slide lowering to the end of the forming, wherein a wrinkle generated in the material is detected based on an increase of the deviation consecutively calculated by the computing unit.

A device for forming a sheet-metal blank, the device including: a press frame; a tool top part including an outer die and an inner die; a tool base part including a punch and a sheet-metal holder; at least one drive assigned to the tool top part and/or the tool base part; and an annular sheet-metal holder surrounding the punch and having a support face; wherein one drive is in each case assigned to the inner die on the one hand, and to the outer die and the sheet metal holder on the other hand, and the one drive displaces the inner die and the outer die at different speeds in the drawing direction. A method of forming a sheet-metal blank including: using the device during a starting period, an intermediate phase, and a final phase where the movement and/or direction of the two dies vary.

A device for forming a sheet-metal blank, the device including: a press frame; a tool top part including an outer die and an inner die; a tool base part including a punch and a sheet-metal holder; at least one drive assigned to the tool top part and/or the tool base part; and an annular sheet-metal holder surrounding the punch and having a support face; wherein one drive is in each case assigned to the inner die on the one hand, and to the outer die and the sheet metal holder on the other hand, and the one drive displaces the inner die and the outer die at different speeds in the drawing direction. A method of forming a sheet-metal blank including: using the device during a starting period, an intermediate phase, and a final phase where the movement and/or direction of the two dies vary.

A method of manufacturing a press-formed product includes: capturing the sheet thickness of a sheet B; and using a die 6, a punch 7, and a movable mold part capable of moving relative to both the die 6 and punch 7 to press-form the sheet B into a press-formed product. During press-forming, the initial position of the movable mold part relative to the die 6 or punch 7 is controlled depending on the sheet thickness of the sheet B.

A cushion pin pressure equalizing device that can absorb a variation in height of a plurality of cushion pins and control a die cushion load highly accurately, a die cushion device, and a cushion pin pressure equalizing method are provided. An initial pressure in ascending-side pressurizing chambers of a pressure equalizing hydraulic cylinder group for absorbing a variation in height of cushion pins is controlled so as to be an appropriate pressure. The variation in height of the plurality of cushion pins can be absorbed within a shortest stroke of a slide after the slide comes into collision with a cushion pad so as to equalize die cushion loads that are applied individually to the cushion pins and a target die cushion load can be generated within the shortest stroke of the slide, whereby a response to application of the die cushion load can be stabilized without excessive delay.

A cushion pin pressure equalizing device that can absorb a variation in height of a plurality of cushion pins and control a die cushion load highly accurately, a die cushion device, and a cushion pin pressure equalizing method are provided. An initial pressure in ascending-side pressurizing chambers of a pressure equalizing hydraulic cylinder group for absorbing a variation in height of cushion pins is controlled so as to be an appropriate pressure. The variation in height of the plurality of cushion pins can be absorbed within a shortest stroke of a slide after the slide comes into collision with a cushion pad so as to equalize die cushion loads that are applied individually to the cushion pins and a target die cushion load can be generated within the shortest stroke of the slide, whereby a response to application of the die cushion load can be stabilized without excessive delay.

A cushion pin device for a press having a cushion pad in which a blank holder is seated on the top thereof outside a lower mold, and locks a blank holder to an upper mold while pressurizing an edge of a molded panel, includes: a cushion support disposed below the cushion pad, a cushion cylinder connected with a lower part of the cushion pad to move up or down the cushion pad from the cushion support, a linear scale mounted between the cushion pad and the cushion support to measure the position of the cushion pad, a main pressure control unit that keeps internal pressure of each cushion cylinder similarly, and a sub pressure control unit that is interconnected with the main pressure control unit so as to control the locking position of the cushion pad when each cushion cylinder operates.