Injection device and axial-center position adjusting method

An axial-center position adjusting method of adjusting axial-center positions of a spline shaft and a spline nut of an injection device, the injection device including the spline shaft configured to rotate a screw inserted into a cylinder, and the spline nut fitted on the spline shaft, wherein:

• the injection device further includes:
• a first supporting member attached to a pressure plate that supports the screw rotatably but immovably in an axial direction, and configured to support the spline shaft or the spline nut rotatably but immovably in the axial direction;
• a second supporting member attached to a fixed plate that supports an injection motor and receives a reaction force of the pressure plate, the injection motor being configured to move the pressure plate in the axial direction, and configured to support the spline nut or the spline shaft rotatably but immovably in the axial direction;
• a rotary motor attached to the fixed plate and configured to rotate the screw via the spline shaft and the spline nut;
• a first torque transmitting mechanism configured to transmit a torque of the rotary motor to the spline nut or the spline shaft supported by the second supporting member attached to the fixed plate;
• and
• a second torque transmitting mechanism configured to transmit a torque that is generated on the spline shaft or the spline nut supported by the first supporting member attached to the pressure plate, to the screw,
• the first supporting member is provided with a first positioning mechanism configured to adjust a mounting position of the first supporting member with respect to the pressure plate,
• the second supporting member is provided with a second positioning mechanism configured to adjust a mounting position of the second supporting member with respect to the fixed plate,
• the first supporting member and the second supporting member include holes formed therein for axial-center checking, rods being inserted through the holes, and
• the holes are formed in a manner that the rods smoothly pass through the holes when an axial center of the spline nut and an axial center of the spline shaft coincide with each other, and the rods do not smoothly pass through the holes when the axial center of the spline nut and the axial center of the spline shaft do not coincide with each other,
• the method comprising the step of:
• in mounting the first supporting member and the second supporting member, adjusting the mounting positions of the first supporting member and the second supporting member by use of the first positioning mechanism and the second positioning mechanism in a manner that the rods are inserted through the holes formed in the first supporting member and the second supporting member.