Kinked bellies

The buckling is a tensile compression forming according to DIN 8584, in which elongated hollow bodies of small wall thickness are widened or constricted on a length section by compressive forces applied in the longitudinal axis at their tangential circumference in the form of a convex (bulging) or concave (necking) shape.

use

The method can basically be used for thin-walled, elongated hollow bodies such as profiles , sheet metal housings . The main application is in the further processing of pipes . Workpieces made of a material that can be plastically deformed are required.
Because of the very simple deformation, the machine tools or devices required for the buckling are comparatively simple, inexpensive and flexible to use. The alternative production technique , the production of the widening or constriction already during the production of the starting material for the kink , would be much more complex and inflexible.

Distinction

The distinction is made according to the tangential direction of the deformation in:

Widening buckling or bulging

When expanding, the hollow body is stabilized by an inner punch that matches the original shape and then compressed in the longitudinal direction. As a result, the plastically deforming wall material can only deform tangentially outwards and a belly is created on the workpiece circumference.

Constricting kinked belly or necking

When constricting, the hollow body is stabilized by a holder that matches the outer shape and then compressed in the longitudinal direction. As a result, the plastically deforming wall material can only deform tangentially inwards and a belly is created on the inner workpiece surface.

Web links

• Wesling, Reiter: Fertigungstechnik II. (PDF) TU Clausthal, p. 28 ff. , Accessed on July 9, 2009 (8.37 MB).