The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 18, 1997
Filed:
Nov. 27, 1995
Toshiyasu Koda, Nagano, JP;
Tsuyoshi Arai, Nagano, JP;
Nissei Plastic Industries, Ltd., Nagano-ken, JP;
Abstract
A drive control apparatus connects a hydraulic source 4 and an oil tank 5 to an injection cylinder 2 through a servo valve 3 and controls the injection cylinder 2 by the servo valve 3. A first change-over valve 6 which is connected between the hydraulic source 4 and the servo valve 3 and has a large capacity. A flow limiting circuit 9 connects a throttle valve 7 to a second change-over valve 8 having a small capacity in series and is connected to the first change-over valve 6 in parallel. A change-over valve control portion 10 opens both the first change-over valve 6 and the second change-over valve 8 when controlling a large rate of flow in an injection process or the like and controls to close the first change-over valve 6 when controlling a small rate of flow in a pressure maintenance process or the like. As a result, the first change-over valve 6 having a large capacity and the second change-over valve 8 (which is connected to the throttle valve 7 in series and has a small capacity) are opened so that the control suitable for the large rate of flow is performed when controlling the large rate of flow. When the first change-over valve 6 having a large capacity is closed, control of a small rate of flow is carried out.