Patent DE-102006026819-A1 (DE)
Title: Plasticizing and injecting device for producing micromechanical component or small medical parts by micro injection molding, comprises rotationally driven plasticizing screw revolvably arranged in a storage, and plasticizing cylinder
Inventor: WUERTELE MARTIN
IPC: B29C45/00
Filed: 2006-06-09
Abstract: The plasticizing and injecting device for the production of micromechanical component or small medical parts by micro injection molding, comprises rotationally driven plasticizing screw revolvably arranged in a storage (8) with which the plasticizing cylinder is connected in torque-proof manner. The plasticizing cylinder has an extension piece formed as injecting piston at its front end. A linear and rotating drive (1) is arranged for the plasticizing screw. The rear end of the screw and shaft drive of the drives are connected with one another over a coupling. The plasticizing and injecting device for the production of micromechanical component or small medical parts by micro injection molding, comprises rotationally driven plasticizing screw revolvably arranged in a storage (8) with which the plasticizing cylinder is connected in torque-proof manner. The plasticizing cylinder has an extension piece formed as injecting piston at its front end. A linear and rotating drive (1) is arranged for the plasticizing screw. The rear end of the screw and shaft drive of the drives are connected with one another over a coupling. Axial and radial bearings are arranged in the area of the coupling. The storage has a housing (3) in which the axial and radial bearings are arranged. The plasticizing screw is nonrelocatably arranged in the storage. The plasticizing cylinder is firmly connected with the housing. A backflow stop is arranged downstream of the screw. The front end of the plasticizing screw is formed as a valve body that is sealed with the interior wall of the cylinder. Mechanical, hydraulic and/or pneumatic prestressing means are arranged between the cylinder and the housing. The cylinder is prestressed from the storage deflection, so that the valve body of the screw forms a durable column with the interior wall of the cylinder during the dosing process and is pressed with its front end against the cylinder during the injecting process. The plasticizing cylinder is arranged to the storage, so that the cylinder is separated from the valve body during the dosing process through pump pressure by which the molten mass is conveyed into the cylinder. After termination of the dosing process, the plasticizing cylinder adjoins with its valve body at the interior wall of the cylinder and proceeds forward by the linear drive of the screw. The screw and the interior of the cylinder are conically formed. Adjusting screws are intended for adjusting the die gap between the screw and the interior wall of the cylinder. The outside diameter of the screw pitch continuously decreases and the diameter of the screw core remains constant over a section of the plasticizing screw in conveying direction. Two subsequently turned hollow shaft motors (4, 5) are intended as linear and rotatable drives. The injecting device is arranged on a stand by the linear drive at a nozzle disk or a form tool of molding machine. The cylinder and the housing are firmly connected with the stand. An independent claim is included for an injection molding machine.