Patent ID: 8209863
Filing Date: 2012-07-03
Classification: H02K,Y10T

Abstract:
1. A method of manufacturing a rotor core for a motor-driven valve that is arranged in a central portion of a rotor of the motor-driven valve having a valve body linearly moving by rotation of the rotor of an electric motor, said rotor core composed of: a cylindrical sleeve entirely formed of synthetic resin with a valve closing limit stopper for restricting, in a fully-closed state of the valve, the rotor from further moving in a direction that the valve closes; and a bushing with a female screw on an internal circumference thereof and integrally fixed on an internal circumference of the sleeve so as to be coaxial with the sleeve, said method comprising the steps of: using an openable/closable die device defining a molding recess for the sleeve; forming to the die device a molding recess for the valve closing limit stopper and a first positioning portion positionally corresponding to said molding recess of the valve closing limit stopper in a rotational direction about a central axis of the sleeve that is to be formed; forming to the bushing a second positioning portion such that when said second positioning portion coincides with the first positioning portion a thread-cut leading end of the female screw and the molding recess for the valve closing limit stopper are positionally corresponding to each other in a rotational direction about a central axis of the bushing; mounting the bushing directly to the die device such that said second positioning portion is aligned with the first positioning portion; and closing the die device and casting molten resin into the molding recess to manufacture the rotor core for the motor-driven valve.