Pressure measuring device in an injection moulding machine

摘要

An elastically deformable load detector(14) between the plasticizing screw and its drive unit forms an integral component of a stroke force transmitting member(3,9) of the screw stroke drive unit. The load detector comprises a deformable zone(15) with reduced cross-section and a sensor(22) which measures reductions in cross-section of the deformable zone. The deformable zone(15) comprises a reduced diameter cylindrical section(16) of the screw shaft(3) between the plasticizing screw(5) and drive shaft bearing(10). Alternatively the deformable zone comprises a reduced diameter cylindrical section of the stroke force transmitting member of the spindle drive system. Shaft shape changes in the deforming zone are detected by a contactless sensor(18,19,22). The sensor can be either a laser scanner which measures length and/or thickness changes or an inductive transducer.