A pneumatic chamber 20 is configured to include a first pneumatic chamber 21 pressurizing a first piston 11 and a second pneumatic chamber 22 pressurizing a second piston 12. The first pneumatic chamber 21 and the second pneumatic chamber 22 communicate with each other through a communication hole 87 formed via the inside of a retaining bolt 17. The second pneumatic chamber 22 is formed in a hydraulic pressure generating unit 55 moving in a thrust direction in a cylinder 2 and is separable from the first pneumatic chamber 21. In addition, the communication hole 87 is also separated into a communication hole 87a and a communication hole 87b with the corresponding separation, a rod portion 50 of the first piston 11 is also separated into a rod portion 50a and a rod portion 50b, and the communication hole 87b and the rod portion 50b are formed to be movable along with the hydraulic pressure generating unit 55 in the thrust direction.

The present disclosure provides an impact hydroforming mold and an impact hydroforming method with integration of blank holder and feeding, belonging to the technical field of metal forming. The hydroforming mold includes: a lower concave mold, a blank holder ring, and a working sleeve assembly. A working sleeve has a liquid chamber for containing liquid medium and a stamping acceleration channel; a throttling flow channel is formed between working sleeve and blank holder ring; the liquid medium can be throttled and depressurized through the throttling flow channel and then contacted with side face of the sheet. Under the action of intensity of pressure, the edge of the sheet pressed by the blank holder ring can be allowed in a mutually adaptive way to realize feeding in a downward forming process when the middle area of the sheet suffers impact, so forming quality of a target component can be effectively improved.

In the proposed hydro ironing method, through an innovative arrangement of loads and using a novel configuration for the die components, the thickness reduction in one stage of ironing is almost equal to twice the common approaches.

Provided is a door for a refrigerator. The door includes an outer door manufactured by pressing and deforming a metal sheet. The outer door includes a first surface, second to fifth surfaces extending from the first surface, and a plurality of flanges extending from the second to fifth surfaces. The first to fifth surfaces are integrated with each other and defined based on the pressing and deforming of the metal sheet. A door liner is coupled to surfaces of the plurality of flanges of the outer door, and an insulation material is disposed in a space defined between the door liner and the outer door.

In the proposed hydro ironing method, through an innovative arrangement of loads and using a novel configuration for the die components, the thickness reduction in one stage of ironing is almost equal to twice the common approaches.

Disclosed are an apparatus and a method for deep drawing of large-sized thin-wall curved surface parts with servo reverse bulging, which pertain to the technical field of drawing of a thin-wall curved surface part. The apparatus includes a forming die, a jacking unit, and a power unit, wherein the forming die includes an upper die, a lower die, and a blank holder. The upper die and the blank holder are connected to a press machine, the blank holder is disposed above the lower die, and a blank to be drawn is placed between the lower die and the blank holder; the jacking unit is disposed inside the lower die and adapted to move along a moving direction of the upper die, enabling the blank to be drawn to deform by with reverse bulging. The method can inhibit defects of wrinkling and cracking in drawing processes effectively.