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US 2014/0345355 A1Published application
Point forming processes
AssigneeThe National Machinery Company
InventorsThomas E. Hay, Donald E. Krintzline
Life of this patent
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AssigneeThe National Machinery Company
InventorsThomas E. Hay, Donald E. Krintzline
Estimating the term…
A set of tooling for a progressive forming machine comprising die and tool units having internal complementary cavity portions for receiving a workpiece, one of said units being arranged to slide a limited distance along its axis and to be biased by a spring force towards the other unit when the units are mounted in the forming machine, the units each having an end face with a smooth surface finish adapted to press against the smooth surface finish of the end face of the other unit, the end face area of one of the units being relatively small compared to its major cross-sectional area whereby a high contact pressure between the end faces is obtained for a given spring bias force such that extrusion/cooling oil coating a workpiece received in the cavity portions is restrained from leakage from the cavity portions across said end faces during a hydrostatic trapped extrusion of the workpiece in the die and tool units whereby the die and tool units are capable of shaping the workpiece to a degree beyond limits of conventional cold-forming processes.
1-6. (canceled)
A method of cold-forming with high reduction in area comprising operating a cold-forming machine with a die breast and a slide that reciprocates towards and away from the die breast, mounting a die on the die breast for limited sliding movement along a direction parallel to the slide motion, biasing the die with a spring towards the slide whereby the end faces of the die and cooperating tool are held together for a distance in the final portion of the advance stroke of the slide for a trap extrusion, inserting a cylindrical workpiece in the die, before insertion of the workpiece, flooding it with extrusion/cooling oil and maintaining a kickout pin at the entrance to the die to exclude appreciable volume of oil apart from that coating the workpiece, the force of the spring being sufficiently high in relation to the contact area of the die and tool end faces and the finish of these end faces being effective to seal against significant leakage of oil across these faces such that a trapped extrusion of the workpiece into the tool is augmented by a hydrostatic extrusion effect of the oil to achieve a high reduction of area of the workpiece exceeding 55% in the tool.
8-9. (canceled)
In a multi-station cold-forming machine having a die breast and a slide reciprocal towards and away from the die breast, a plurality of workstations, the die breast carrying dies at respective workstations and the slide carrying tools at respective workstations, the die and tool of at least one workstation being arranged to perform a hydrostatic large change in cross-sectional area of a workpiece such that hydrostatic pressure of liquid lubricant in a workpiece forming space surrounding the workpiece across a plane of separation of the tool and die when the workpiece is fully trapped in said space whereby an area reduction exceeding 55% is obtained on a workpiece, the die and tool of the one workstation having mutually engageable surfaces of limited size and adequate finish such that when engaged, during a forming stroke, provide sufficient contact pressure and sealing to maintain such hydrostatic pressure.
In a multi-die cold-forming machine having a die breast and a slide that reciprocates towards and away from the die breast, a plurality of workstations on the die breast and slide, the die breast supporting dies at its workstations and the slide supporting tools at its workstations, the die and tool units of one workstation being arranged to perform a large change in cross-section of a workpiece by consequent hydrostatic forming with hydraulic pressure imposed by extrusion/cooling oil on the workpiece in a cavity formed by the die and tool units, a dispenser for coating the workpiece with extrusion/cooling oil before it is fully received in the cavity, the die and tool units having opposed end faces, one of the tool and die units being supported for limited sliding movement on its support and being biased by a spring towards the other one of the tool and die units, the tool end face closing on the die end face to trap a workpiece prior to completion of an advance stroke of the slide, the spring allowing said one tooling part to recede in its sliding movement relative to its support while maintaining a high contact force between said end faces, the end faces being arranged such that the area of contact between said end faces is relatively small compared to the profile of either the die or tool units so that the spring is capable of developing sufficient contact pressure between the die and tool end faces under hydrostatic forming pressures developed in the cavity during the final advancing movement of the slide, whereby an area reduction exceeding 55% is obtained on a workpiece.
In a multi-die cold-forming machine having a die breast and slide that reciprocates in a direction towards and away from the die breast, a plurality of workstations on the die breast and slide, the die breast supporting dies at its workstations and the slide supporting tools at its workstations, the die and tool of one workstation being configured to trap extrude a relatively long workpiece to effect a high reduction in area in the tool by consequent hydrostatic forming with hydraulic pressure imposed by extrusion/cooling oil on the workpiece in a cavity mutually formed by the die and tool, a dispenser for coating the workpiece with extrusion/cooling oil before it is fully received in the cavity, a die kickout pin capable of excluding a detrimental volume of oil from the die prior to entry of the workpiece into the die, the die and tool having opposed end faces, the die being supported on the die breast for limited sliding movement in a direction along the direction of reciprocation of the slide, a spring biasing the die towards the tool, the tool end face closing on the die end face prior to completion of the advance stroke of the slide, the spring allowing the die to recede relative to the die breast while maintaining a high contact force between the end faces, the end faces being highly finished and arranged such that the area of contact between them is relatively small compared to the profile of either of the die or tool so that the spring is capable of developing sufficient contact pressure between the end faces to prevent escape of extrusion/cooling oil across the end faces under hydrostatic forming pressures developed in the cavity during a reduction in area exceeding 55% during the final advancing movement of the slide.
A progressive forming machine comprising a die breast and a slide arranged to reciprocate towards and away from the die breast, the die breast and slide each serving as a carrier for complementary opposing tools at respective workstations, one of said workstations having a slidable tool mounted for limited sliding movement relative to its carrier, a force lever operated by a spring biasing said slidable tool towards its opposing tool, said slidable tool and its opposing tool being arranged to simultaneously laterally trap and extrude a workpiece at said one workstation during the forward stroke of the slide.
A method of achieving a high reduction of area on a workpiece at a workstation in a progressive forming machine having a die breast and a slide arranged to reciprocate towards and away from the die breast, the die breast and slide each being arranged to serve as a carrier for a mutually complementary opposing tool at respective workstations, at one station mounting one of the tools for limited movement relative to its carrier, biasing said one tool against its opposing tool with a spring through a force multiplying lever so that the workpiece is simultaneously laterally trapped and extruded by the tools at said one workstation during the forward stroke of the slide.
Dependencies are inferred from the claim text.