Patent attributes
The invention provides an injection molding machine injection unit that eliminates adverse effects on the load cell of belt tension due to belt drive. A load cell that detects resin pressure is mounted on a pusher plate and a rotation-transmitting member, on which an injection screw is fixedly mounted, is axially supported by an inner annular part of the load cell. The shaft of a pulley is axially supported on the pusher plate and coupled by splines to the rotation-transmitting member. A screw rotation motor is mounted on motor mounts of a housing mounted on the rear surface of the pusher plate. Tension on a belt run between the pulley and a pulley mounted on the motor output shaft concentrates a force at the base of the motor mounts. However, the housing is separate from the pusher plate and fixedly mounted on the pusher plate at a location other than that occupied by the base of the motor mounts. Therefore, the belt tension does not adversely affect the load cell, thus enabling high-accuracy resin pressure detection.