Apparatus for applying a multi-component viscous material to workpieces

An apparatus for applying a multi-component viscous material to workpieces, having a metering unit (12) that has a number of metering valves that corresponds to the number of components of the viscous material, as well as a coupling device (16), and having a mixing unit (20), which has a material inlet (28), and a coupling part (26) releasably connected to the coupling device (16) at a first end (24), and, at a second end (32), a mixing tube (22) that has an exit opening (34) for the viscous material, as well as a mixing structure (36) arranged in the mixing tube (22), for mixing the components as they are passed through the mixing tube (22) from the material inlet (28) to the exit opening (34), the apparatus further comprising a needle valve (40) for releasing and closing the exit opening (34), wherein the needle valve has a valve needle (42) that extends in a longitudinal direction (38) that runs from the material inlet (28) to the exit opening (34), wherein the valve needle releases the exit opening (34) in a release position, and closes the exit opening in a closed position, by making contact with a valve seat (46),

• wherein the mixing structure (36) has an inner tube (48), which is arranged in the mixing tube (22), and through which tube the valve needle (42) extends, and from which tube a mixing spiral (50) projects away radially, and
• wherein the valve needle (42) projects out of the inner tube (48) at a front end (52) of the inner tube, wherein the front end faces the valve seat (46), and is conducted to be sealed off at the front end (52), by means of a sealing element (54).