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.

The present application provides a chamfer removing device for wheels. The device may be used for removing a bolt hole chamfer on flange side of back cavity of a wheel in hub machining process. Drill bits are spaced a certain height from the flange side of the wheel by adjusting the relative height of an external thread guiding sleeve in an internal thread guiding sleeve, a motor and gears drive the drill bits to rotate, and a cylinder and a sliding box drive the drill bits to move up and down so as to realize chamfer removing function.

An improved electro-hydraulic clinching system involves generating, through a high potential electric shock, a forceful wave in a fluid such as water, and applying the force of the wave to a sheet of metal. The force of the wave results in deforming the sheet and making the sheet material move through a hole in a second sheet adjacent to the first sheet, thus joining the two sheets. In an alternative implementation, in which neither sheet includes an opening, the force of the wave moves both sheets simultaneously, thereby causing them to join together at the point of impact.

An improved electro-hydraulic clinching system involves generating, through a high potential electric shock, a forceful wave in a fluid such as water, and applying the force of the wave to a sheet of metal. The force of the wave results in deforming the sheet and making the sheet material move through a hole in a second sheet adjacent to the first sheet, thus joining the two sheets. In an alternative implementation, in which neither sheet includes an opening, the force of the wave moves both sheets simultaneously, thereby causing them to join together at the point of impact.

A pneumatic drilling device comprising: an impact manifold or cylinder in fluid communication with a rotary air manifold or gear box; and a single air inlet. The single air inlet may be in fluid communication with the impact manifold or cylinder.

A pneumatic drilling device comprising: an impact manifold or cylinder in fluid communication with a rotary air manifold or gear box; and a single air inlet. The single air inlet may be in fluid communication with the impact manifold or cylinder.