Electric heating – Metal heating – By arc
Patent
1996-10-28
1998-02-17
Walberg, Teresa J.
Electric heating
Metal heating
By arc
21912184, 21912185, 723425, B23K 2614, B21D 500, B21D 1100
Patent
active
057193746
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The subject of the invention is the method of bending and overbending of metal objects, in particular plates and shells of zero Gaussian curvature, along a straight line or along a set of straight lines.
2. Brief Description of the Background of the Invention Including Prior Art
Polish patent description no. 155358 teaches a method of bending metal objects characterized by the use of a "narrow beam", narrow as compared to the thickness of the metal bent. It allows bending of plates and shells of zero Gaussian curvature in such a way that on the side subject to be subjected to heat radiation a concavity is formed or enlarged. When, on the other hand, a shell of zero Gaussian curvature or an initially bent plate is being heated from the convex side, then this convexity will get diminished. The method of "narrow beam" has limited capacities of shaping the metal objects. It cannot be used to form closed cylindrical or conical surfaces of small internal diameters, since this would require introduction of the beam into the inside hollow space of these objects and then changing of the direction of the beam to the one perpendicular to the surface.
SUMMARY OF THE INVENTION
1. Purposes of the Invention
It is an object of the present invention to provide a method for forming closed cylindrical or conical surfaces having small inner diameters.
It is another object of the invention to increase the applicability of the method of bending metal objects with an energy beam.
It is yet another object of the present invention to provide a method for forming a bulging and a convexity on an irradiated side of a flat plate being irradiated and heated.
These and other objects and advantages of the present invention will become evident from the description which follows.
2. Brief Description of the Invention
The essence of the invention lies in the fact that the object shaped is subject to single or multiple local two-phase process of deep heating using the sufficiently broad energy beam along the straight line selected, and then cooling of the heated strip of metal in a natural manner or with the use of an external factor, in adequate distance behind the said beam. Consequently, the metal object undergoes permanent bending along the straight line and in particular when the flat plate is being heated a convexity is formed on the heated side, while when an initially bent plate or a shell with zero Gaussian curvature is heated then there will ensue the increase of the bending angle (increase of curvature), irrespective of the fact whether radiation was directed onto the convex or onto the concave side.
The energy beam, moving with velocity "V" along the straight line of bending (or overbending), heats the strip of width "a" and length "b" on the side to which heat radiation is applied, and on the other side it heats the strip of dimensions of at least one third of the width a and at least one third of the length b, to the temperature higher than the temperature "T.sub.1 ", taken from a schematic diagram illustrating temperature-dependent plastic properties of metals, above which the plastic properties of the metal are enhanced.
The strip, heated with the energy beam, is being cooled with the stream of liquid at the distance b behind the said beam to attain the temperature of the environment or the temperature lower than T.sub.1, with the cooling stream being directed onto the surface on the heated and/or non-heated side.
The minimum length b.sub.min of the heated strip cannot be smaller than its width taken two times.
For a flat plate the minimum width a.sub.min of the heated strip is equal at least seven times the thickness of the plate.
For the initially bent plate or shell, in which the depth "h" of the heated strip is smaller than half of the thickness "g" we can apply the same process of overbending as for the flat plates, with the minimum width a.sub.min of the heated strip calculated from the formula: a.sub.min
For the initially bent plate or shell in which the depth h
REFERENCES:
patent: 4120187 (1978-10-01), Mullen
patent: 5228324 (1993-07-01), Frackiewicz et al.
patent: 5359872 (1994-11-01), Nashiki
Frackiewicz Henryk
Gradon Ryszard
Kalita Wojciech
Mucha Zygmunt
Centrum Laserowych Technologii Metali Politechniki Swietokrzyski
Kasper Horst M.
Mills Gregory L.
Walberg Teresa J.
LandOfFree
Method of bending metal objects with an energy beam does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of bending metal objects with an energy beam, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of bending metal objects with an energy beam will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1785913