III. Structure and Characteristics of Cold Extrusion Press (upset forging machine)
It can be used for extruding the end of bar steel with diameter 12 ~ 40mm. With the characteristics of high efficiency, simple structure, small volume, light weight and easy operation, this kind of machine is the flexible, movable and suitable architecture mechanical equipment. The female mould is integrated with the holding device with better centering to ensure the quality of product. With electrical-control limit and adjust travel, it operates in safety and reliability.
IV. Prerequisite for Production of End Extrusion Upset
The end surface should be vertical to the axial line of steel bar, if necessary, it can be machined smoothly.
The end of steel bar should be flat and straight without flexure.
The end should be free of burr
The end has not any defects.
V. Inspection of Semi-finished End
The size of end shall be inspected according to the stipulations shown in the Table - 1
The concentricity between the end and steel bar < 0.3 ~ 1
Out-of-roundness of end, circumference <1/3, unfilled corner 3 x 1.5
Loss of end (middle, root), circumference <1/3, unfilled corner 5 x 1
The axial crack in end is allowable, no more than 3 strips
No transverse crack is permitted.
VI. Cold Extrusion Press Operating Rule
1. The male and female moulds of cold extrusion machine and the distance in the plane are equal. The degree of balance in four corners is 0.5 mm in allowance. They move on the four stopper columns.
The fit clearance between male mould and female mould is 0.4 ~ 0.8
The male mound is assembled reasonably on the base. No cuttings and deposits exist on the contact surface. The cover must be firmly capped. After every 10 ~ 15 pieces are extruded in male mould, the cover must be capped again.
When extruding, it needs to try best to press the extrusion die on the transverse ribs of the reinforcing bars so as to achieve the connection with best performance.
4. The female mould is operated on the slide plate. It slides smoothly, symmetrically and cleanly . It is necessary to be dismounted for cleaning. No hard articles are permitted in it.
