Clinching (metalworking)

Clinching (synonyms: clinching, clinching or press Joining after a patent owner also toxing ) is a method for joining metal sheets without using a filler metal. It can be expected, both of the joining methods as well as to the forming method, since the connection is achieved by deformation of the material.

A subgroup of joining is according to DIN 8593 joining by forming. Joining is again divided into joining by forming wire-like body with sheet metal, pipe and profile parts and riveting. According to DIN 8593 is the joining by forming with sheet metal, pipe and profile parts in addition to crushing and pressing, among other things, clinching, also called clinching assigned. An advantage of the clinching is that no Vorlochvorgang is performed.

The static strength in the range of about 2/3 up to 1.5 times that of a comparable spot weld. The fatigue strength is due to the lack of stress concentration higher (for non-intersecting connections) and non-existent heat affected zone than in spot welds. Especially when different sheet thicknesses have to be connected, clinching offers great potential. If the mating direction " Dick in thin " is maintained, are static strengths that exceed a half times the strength of a spot weld possible. A further advantage is that various materials and / or coated sheets can be assembled.

A clinching tool consists of a punch and a die. The sheets to be joined are pressed by the punch similarly to the deep-drawing under plastic deformation in the die. By a special design of the die results in a push button -like shape, the form and force -locking connected with each other, the sheets. Depending on the system causes either a depression in the bottom of a movable die segments Starrmatrize or yielding that the plates form an overlap. Distinguished here include the circular point at which the ram a round gastight recess leaves (see cross-sectional view ), and the square point at which the connection is cut at two sites, and so the gas-tightness can not be given. For even higher-strength materials can be joined together in this method.

Procedure ( die with movable die segments ):

Procedure ( Starrmatrize ):

A special form of clinching the hydraulic pressure jointing, in which a high-pressure fluid acts as a stamp replacement.

Clinching is often used in automotive manufacturing to connect body parts together. The method here replaced partially spot welding. Often the clinching is also used to secure the components in the adhesive compounds to cure the adhesive.