Injection moulding machines

• US 3,911,677 A
• Filed: 06/21/1974
• Issued: 10/14/1975
• Est. Priority Date: 12/28/1971
• Status: Expired due to Term

• Current Assignee: George T. Collins
• Original Assignee: George T. Collins
• Inventors: Collins, George T.
• Primary Examiner(s): Geoghegan, Edgar W.
• Application Number:
  US05/482,029
• Time in Patent Office: 480 Days
• Field of Search: 60/DIG.2,368,369,383,390,428,486 91/35,37,39 425/135,149
• US Class Current: 60/368
• CPC Class Codes: B29C 45/76 Measuring, controlling or regulating measuring in general G01; controlling or regulating in general G05
• CPC Class Codes: Y10S 60/911 Fluid motor system incorporating electrical system

Abstract

A hydraulically operated injection moulding machine for the moulding of synthetic resin materials including hydraulic pumping means for supplying power to the machine and comprising a variable speed electric motor driving the hydraulic pumping means, the electric motor being arranged and adapted to be operated at speeds and torques each varied directly in accordance with the hydraulic requirements of the machine during an injection moulding cycle. In a preferred embodiment the speeds and torques of the motor are controlled by an electronic variable-speed drive controllable by its response to signals received from the motor, torque and speed reference setting devices and an electronic sequence control system on the machine.

Claims

1. An injection moulding machine for the moulding of synthetic resin materials, said machine being operated by hydraulic power and including hydraulic pumping means for supplying the power and a variable speed electric motor for driving the hydraulic pumping means, electronic controller means for controlling the electrical power supply to said variable speed electric motor, said electronic controller having selectively adjustable speed reference means and torque reference means adjustable respectively in accordance with predetermined hydraulic flow and pressure requirements of tHe machine during an injection moulding cycle, said electronic controller selectively controlling the electrical power supply to said variable speed electric motor in accordance with the settings of said speed reference means and said torque reference means.

2. An injection moulding machine in accordance with claim 1 including a plurality of speed and torque reference means and further including sequencer means responsive to successive portions of a cycle of said injection moulding machine for successively controlling the electrical power supply to said variable speed electric motor in accordance with a predetermined sequence among said plurality of speed and torque reference means.

3. An injection moulding machine for the moulding of synthetic resin materials, said machine being operated by hydraulic power and including hydraulic pumping means for supplying the power and a variable speed electric motor for driving the hydraulic pumping means, electronic controller means for controlling the electrical power supply to said variable speed electric motor, said electronic controller having selectively adjustable speed reference means and torque reference means adjustable respectively in accordance with predetermined hydraulic flow and pressure requirements of the machine during an injection moulding cycle, means for feeding back a signal representative of actual motor speed to said controller, means for feeding back a signal representative of actual motor torque to said controller, said controller including means for performing a comparison between the signals fed back which are representative of actual motor speed and torque to said speed and torque reference means, respectively, said controller adjusting the electric power supply to said electric motor in accordance with said comparison.

4. An injection moulding machine in accordance with claim 3 in which said means for feeding back a signal representative of actual motor speed comprises a tachometer coupled to said motor.

5. An injection moulding machine in accordance with claim 4 in which said means for feeding back a signal representative of actual motor torque comprises means for feeding back a signal representative of motor armature current.

6. An injection moulding machine in accordance with claim 3 including a plurality of speed and torque reference means and further including sequencer means responsive to successive portions of a cycle of said moulding machine for selecting appropriate speed and torque reference means for said comparison.

7. An injection moulding machine in accordance with claim 3 in which said means for feeding back a signal representative of actual motor torque comprises at least one pressure transducer mounted to said injection moulding machine for feeding back a signal representative of the actual pressure developed in said machine.