Cold forming equipment for metal hardware, fasteners and component parts production
return to main page equipment for cold heading
Cold heading equipment for metal hardware, fasteners and component parts production
(for reference)
Single-stroke machines
Designed for heading parts with heads formed at one stroke in one matrix (one position) and by one head (punch). Machines have high performance of up to 650 pieces per minute. In some cases, the single- stroke machines can be used for finishing previously headed blanks with intermediate annealing and additional surface preparation. Sometimes a single-stroke machines are used when the final calibration is performed for achieving high purity and accuracy of the finished part.
Single-stroke machines are widely used for the manufacture of rivets with round, oval heads, blanks for for screws and similar parts.
Two- stroke single-station machines
Function and construction of two- stroke single-station machines is that the parts are formed in a matrix (in one position) by two heads (punches), provisional and final.Thus, only after the second stroke the part is completely formed. On machines with a solid matrix at the same time with heading it is possible to carry out the single reduction of the rod (for the thread rolling), as well as to perform direct or reverse extrusion, forming projections, recesses. On machines with split matrix at the same time with heading it is possible to carry out flattening and bending the rod blank, squeezing the longitudinal grooves, reverse extrusion, reducing and puncheon. With one machine design punch unit moves in the vertical direction with help of lug, in others - punch unit performs a wobbling movement. Two-stroke single station machines are widely used for the manufacture of rivets, screws with flat or cross slots and semi-circular or oval head, screws, self-tappers and similar parts.
Two-station machines
In recent years, two-position machines were created, on which rod parts are stamped in two or three stages. In Two-stroke two-station machines each matrix has its own punch. The transport system conveys the blank from the first to the second matrix. Thus, it is possible to make not only the standard, but also special parts. Machines may be used to manufacture the stepped parts.
Machines equipped with two matrices (two positions) and three punches (heads).
While the first punch is always working only in the first matrix, and in most cases performs reducing (or squeezing), two other punches alternately operate in the second matrix. Thus the part head is formed by the preliminary and final heading or polygon heading and cutting. With these machines it is advisable to make core parts with large head and rod areas, in particular bolts with large heads and articles of hard steels and alloys.
Some machine tool companies manufacture machines composed of two matrices and four punches. They are designed specifically for the manufacture of original parts that can not be deformed in multi-position machines. Introduction of the fourth punch has no influence on the rate and allows to manufacture a wide range of parts with special configurations and complex form.
Kinematic schemes of two-stage machines are much simpler than schemes of multiposition machines, they are easier and cheaper. Thus, two-station two-three-four-stroke machines are essentially the transition from single-position to multi-position machines.
Multi-position machines
Broader technological abilities of multi-positional machines can be explained by alternation of various technological operations (headings, reducing, forward, backward or combined extrusion, contour cutting, bending, stamping, etc.), concentrated in one machine.
The higher performance of these machines is achieved by the stamped blank passes through all stages of plastic forming in one machine and in one stroke of the ram. This ensures high process stability, the part stamped on the previous position, once transferred to the next position. Multi-position machines can be designed with a number of formative positions: three, four, five, six or more.
Machines can be used for the manufacture of bolts with square, hexagon, bi-hexagon head, E-TORX head, without flange, with flange, with internal hexagon, bi-hexagon, T-TORX recess, other special parts that require consistent core elements shaping.
Three-position machines
Is used as a rule, for short rod parts stamping. The main application- is the production of standard short bolts with hexagon head and the length of the rod up to five blank diameter.
Four-position machines
Bolts with polygon head and similar core parts, shaping of which is possible at least in four heading positions, are headed on four-position machines. Structurally, the machines are made with horizontal and a vertical arrangement of stamping positions.
Five -position machines
Most industries need different kinds of nuts, it causes massive production of this type of product. Five-position process of making the nuts is less energy-intensive than four-position process. Therefore, minimum expansion cracks falls on parts made at five-position stamping machine, and maximum – at four-position. Machines can be used for the manufacture of the hexagon nuts of normal height, low, high, with flange, with cylindrical belt for polymer insert rolling or crimped on the ellipse , castellated, as well as special designs of plugs and other similar items.
For the manufacture of complex parts with an extremely high degree of deformation line of the three machines with two-stage pre-treatment is often used…