Direct-pressure type mold clamping mechanism
AssigneeFanuc Corporation
InventorsYoshiharu Inaba, Fumio Mitoguchi, Hiromasa Yamashita
Life of this patent
Estimating the term…
Abstract
A motor-operated, direct-pressure type mold clamping apparatus is capable of high-speed mold closing and opening operations and of producing a required mold clamping force, without the use of a large-sized motor. In the mold opening and closing operations, a ball screw, in engagement with a ball nut which is movable in one with a moving platen, is rotated at high speed by a motor through gears and a clutch, so that a die is opened and closed at high speed. In a mold clamping operation, the ball screw is driven with a large rotatory force transmitted through a clutch and gears which, having a high reduction ratio, serve to increase the rotatory force of the motor. Thus, dies are clamped with a large clamping force.
Claims8
A direct-pressure mold clamping apparatus for an injection-molding machine having a moving platen, comprising:
- conversion means including a rotating member and a rectilinear motion member movable in unison with the moving platen, said conversion means for converting rotary motion of said rotating member into rectilinear motion of said rectilinear motion member;
- a feed table movably supporting said moving platen;
- a motor having a drive shaft for driving the rotating member of said conversion means;
- a transmission coupled to the motor;
- a first ball screw/nut mechanism for course-adjustment having a course-adjustment nut coupled to said feed table and a course-adjustment ball screw driven by said motor through said transmission for moving the moving platen under a relatively high speed, low torque condition;
- a second ball screw/nut mechanism for fine adjustment having a fine-adjustment nut fixedly coupled to said moving platen and a fine-adjustment ball screw spline-coupled to a speed reducer and being driven by said motor for moving the moving platen under a relatively low speed, high torque condition;
- said transmission transmitting the rotation of said motor drive shaft to said course-adjustment ball screw;
- said speed reducer for reducing the rotational speed of said fine-adjustment ball screw while increasing the rotary force of said motor, and transmitting the rotary force of said motor to said fine-adjustment ball screw;
- and
- switching means for alternatively connecting said motor to said fine-adjustment ball screw and said course-adjustment ball screw through said transmission and said speed reducer, respectively.
A mold clamping apparatus having a movable die fixed to a movable platen and a stationary platen, the apparatus comprising:
- a motor having a rotary power output shaft;
- a feed table movably supporting the movable platen;
- a first ball nut supported on the feed table;
- a first ball screw threadedly engaging the first ball nut and having a rotatably supported integrally formed shaft driven by the motor to move the movable platen and the feed table in unison under a relatively high speed, low torque condition;
- a second ball nut fixedly connected to the movable platen;
- a second ball screw threadedly engaging the ball nut and having a rotatably supported integrally formed shaft driven by the motor for moving the movable platen relative to the feed table under a relatively low speed, high torque condition;
- a transmission for transmitting power from the motor shaft to the first ball screw shaft;
- a speed reducer for transmitting power from the motor shaft to the second ball screw shaft at a reduced rotational speed and increased torque;
- and
- switching means for alternatively connecting the transmission and the speed reducer to the motor shaft.
Dependencies are inferred from the claim text.