Motor drive apparatus for an injection molding machine

• US 6,333,611 B1
• Filed: 11/05/1999
• Issued: 12/25/2001
• Est. Priority Date: 11/05/1998
• Status: Expired due to Term

• Current Assignee: Moog Japan Ltd. (Moog, Inc. (California))
• Original Assignee: Nissei Plastic Industrial Co., Ltd., Nisso Electric Company
• Inventors: Nishida, Satoshi, Shibuya, Hiroshi, Yamaura, Hiroshi, Koide, Atsushi
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US09/434,466
• Time in Patent Office: 781 Days
• Field of Search: 318/370-389, 318/393, 318/700-832, 318/490, 187/105-119, 363/124, 320/14, 320/15, 361/18-24, 264/40.1, 264/40.5, 264/40.7, 264/328.1, 425/135, 425/145, 425/149, 425/451.2, 425/451.4, 425/451.7
• US Class Current: 318/370
• CPC Class Codes: B29C 2045/1792 Machine parts driven by an electric motor, e.g. electric servomotor
• CPC Class Codes: B29C 2045/7673 Recovering energy or power from drive motors
• CPC Class Codes: B29C 2945/76033 Electric current or voltage
• CPC Class Codes: B29C 2945/76214 drive means
• CPC Class Codes: B29C 2945/7623 clamping or closing drive means
• CPC Class Codes: B29C 2945/76247 drive means thereof
• CPC Class Codes: B29C 2945/76525 Electric current or voltage
• CPC Class Codes: B29C 2945/76692 drive means
• CPC Class Codes: B29C 2945/76709 clamping or closing drive means
• CPC Class Codes: B29C 2945/76725 drive means thereof
• CPC Class Codes: B29C 2945/76943 compare with thresholds
• CPC Class Codes: B29C 45/7666 of power or energy, e.g. integral function of force
• CPC Class Codes: H02P 23/06 Controlling the motor in four quadrants
• CPC Class Codes: Y02P 70/10 Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

Abstract

A motor drive apparatus is provided in an injection molding machine in order to supply electrical energy to a motor. The motor drive apparatus includes an electricity accumulation unit for accumulating electrical energy; and an electricity accumulation circuit for accumulating in the electricity accumulation unit electrical energy regenerated from the motor during a deceleration period of the motor and for supplying the electrical energy accumulated in the electricity accumulation unit to the motor during an acceleration period of the motor. By virtue of the above-described structure, when a heavy member such as a screw of an injection apparatus or a movable platen of a mold clamping apparatus is moved at high speed in each molding cycle, at the beginning of movement or during an acceleration period of the motor, the electricity accumulation circuit adds the electrical energy accumulated in the accumulation unit to electrical energy that is supplied from a power source to the motor, and during a deceleration period of the motor, electrical energy regenerated from the motor is accumulated in the accumulation unit.

Claims

1. A motor drive apparatus provided in an injection molding machine and adapted to supply electrical energy to a motor, said motor drive apparatus comprising:

an electricity accumulation unit for accumulating electrical energy; and

an electricity accumulation circuit for accumulating into said electricity accumulation unit electrical energy regenerated from said motor during a deceleration period of said motor and for supplying the electrical energy accumulated in said electricity accumulation unit to said motor during an acceleration period of said motor,

wherein said electricity accumulation circuit comprises a charge circuit for charging said electricity accumulation unit to an electricity accumulation voltage higher than a drive voltage of said motor.

2. A motor drive apparatus according to claim 1, wherein said electricity accumulation circuit comprises a charge control function section which causes said charge circuit to charge said electricity accumulation unit to said electricity accumulation voltage when said motor drive apparatus is turned on.

3. A motor drive apparatus according to claim 2, wherein said electricity accumulation circuit comprises a charge control function section which causes said charge circuit to charge said electricity accumulation unit to said electricity accumulated voltage before said motor enters an acceleration period.

4. A motor drive apparatus according to claim 1, wherein said electricity accumulation circuit comprises a supply control function section which supplies the accumulated electrical energy to said motor only in an acceleration period of said motor.

5. A motor drive apparatus according to claim 1, wherein said electricity accumulation unit comprises a capacitor.