An injection molding machine includes an injection apparatus configured to perform an injection operation of a material and a mold clamping apparatus configured to mold the material injected from the injection apparatus. Here, the injection apparatus includes a screw, a piston connected to the screw, and a hydraulic apparatus configured to drive the piston in an axial direction. On the other hand, the mold clamping apparatus includes a movable platen to which a first mold can be attached, a fixed platen to which a second mold can be attached, and an electric drive unit configured to move the movable platen in a mold closing direction or a mold opening direction with respect to the fixed platen.

A configuration of oil hydraulic power unit is simplified. In the oil hydraulic power unit, a port B and a port C are communicated to each other. By this, the hydraulic oil supplied to the port B can also be supplied to the port C even in exclusion of the solenoid valve and the flow-rate control valve, and, as a result, the hydraulic oil supplied to the port C contacts a side surface of the piston, and therefore, a backward pressure can be applied to the side surface of the piston. Thus, according to the oil hydraulic power unit, the backward movement of the piston can be achieved even in the exclusion of the solenoid valve and the flow-rate control valve.

An injection apparatus of one embodiment includes a cylinder, a screw, and a drive mechanism configured to drive the screw. The drive mechanism includes a piston having a hollow piston rod, a connection rod having one end side inserted into the piston rod, the connection rod being rotatable with respect to the piston and movable integrally with the piston in a direction of a central axis of the piston rod, and a rotating body which is arranged around the connection rod and is driven to rotate around a central axis of the connection rod as a rotation axis. A plurality of external teeth are provided on the connection rod, and a plurality of internal teeth meshing with the external teeth are provided on the rotating body. Also, the screw is non-rotatably connected to the other end side of the connection rod protruding from the piston rod.

An injection device according to one embodiment of the present invention monitors the linear torque of a linear motor and the rotary torque of a rotary motor using a first detection unit for detecting the linear torque and a second detection unit for detecting the rotary torque while controlling the linear motor and the rotary motor so that a bush is spline-fitted to a screw.

An injection molding apparatus and method of fabricating a molded part are provided. The apparatus may include a barrel, a nozzle enclosing an end of the barrel and defining an opening in fluid communication with an inside of the barrel, and an extrusion screw positioned at least partially inside the barrel and rotatable relative to the barrel. The extrusion screw may include a screw tip. Relative axial movement between the barrel and the extrusion screw may open or close the opening of the nozzle to permit or prevent, respectively, material flow through the opening of the nozzle. The method may include clamping a mold, opening a nozzle, rotating the extrusion screw to pump a molten material into the mold until the mold is filled, closing the nozzle, and unclamping the mold to release a molded part.

There is provided a screw of an injection molding machine that can eliminate uneven distribution of reinforcing fibers without giving an excessive shear force to the reinforcing fibers. A screw is provided inside a heating cylinder of an injection molding machine to which a resin pellet is fed on an upstream side in a conveyance direction of resin and to which reinforcing fibers are fed on a downstream side therein, and includes: a first stage at which the resin pellet which is fed is melted; and a second stage that continues to the first stage, and at which molten resin and the reinforcing fibers are mixed with each other. A second flight provided at the second stage includes: a large-diameter flight with a relatively large outer diameter; and a small-diameter flight with a relatively small outer diameter.

There is provided a screw of an injection molding machine that can eliminate uneven distribution of reinforcing fibers without giving an excessive shear force to the reinforcing fibers. A screw is provided inside a heating cylinder of an injection molding machine to which a resin pellet is fed on an upstream side in a conveyance direction of resin and to which reinforcing fibers are fed on a downstream side therein, and includes: a first stage at which the resin pellet which is fed is melted; and a second stage that continues to the first stage, and at which molten resin and the reinforcing fibers are mixed with each other. A second flight provided at the second stage includes: a large-diameter flight with a relatively large outer diameter; and a small-diameter flight with a relatively small outer diameter.

In an injection device according to an embodiment, each of a plurality of outer peripheral protrusions of a screw is formed with an outer peripheral protrusion inclined surface, and each of a plurality of inner peripheral protrusions of a through-hole of a bush is formed with an inner peripheral protrusion inclined surface. The injection device advances the bush until a linear-motion torque exceeds a linear-motion torque threshold, and, if a rotation torque exceeds a rotation torque threshold before the linear-motion torque exceeds the linear-motion torque threshold, ends control processing when the linear-motion torque exceeds the linear-motion torque threshold.

In an injection device according to an embodiment, each of a plurality of outer peripheral protrusions of a screw is formed with an outer peripheral protrusion inclined surface, and each of a plurality of inner peripheral protrusions of a through-hole of a bush is formed with an inner peripheral protrusion inclined surface. The injection device advances the bush until a linear-motion torque exceeds a linear-motion torque threshold, and, if a rotation torque exceeds a rotation torque threshold before the linear-motion torque exceeds the linear-motion torque threshold, ends control processing when the linear-motion torque exceeds the linear-motion torque threshold.

A drive unit for a molding machine for longitudinally displacing a movable first machine component relative to a second machine component, includes a rotationally drivable spindle mounted in a linear movement-locking manner on the second machine component, a spindle nut arranged in a rotational movement-locking manner on the first machine component for positive-locking engagement with the spindle, and a fluid chamber which at least adjoins the spindle and/or the spindle nut, and contains a lubricant. A temperature control element for controlling the temperature of the lubricant is arranged in and/or on the fluid chamber at least in areas.