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US 6,257,859 B1Granted
Hydraulic circuit of an injection molding machine
AssigneeNissei Plastic Industrial Co., Ltd.
InventorsToshiyasu Koda, Mamoru Miyagawa
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AssigneeNissei Plastic Industrial Co., Ltd.
InventorsToshiyasu Koda, Mamoru Miyagawa
Estimating the term…
A hydraulic circuit of an injection molding machine includes a 4-port servo valve having A, B, P, and T ports and adapted to drive and control an injection cylinder. The A and B ports are connected respectively to the front and rear oil chambers of the injection cylinder. The P port is connected to a hydraulic power unit. The T port is connected to an oil tank via a shutoff valve for selecting a regular mode or a differential mode. The T port is connected to the rear oil chamber via the logic valve. Alternatively, the rear oil chamber is connected to a hydraulic power unit side via the servo valve; the front oil chamber is connected to an oil tank via the shutoff valve; and the front oil chamber is connected to the P port of the servo valve via the logic valve. The above configuration eliminates or simplifies an additional braking circuit. Also, proper and accurate braking control can be performed.
A hydraulic circuit of an injection molding machine permitting selection of either a regular mode, in which all drain oil ejected from a front oil chamber of an injection cylinder during injection is returned to an oil tank, or a differential mode, in which all or a portion of the drain oil is supplied to a rear oil chamber of said injection cylinder during injection, said hydraulic circuit comprising:
A hydraulic circuit of an injection molding machine permitting selection of either a regular mode, in which all drain oil ejected from a front oil chamber of an injection cylinder during injection is returned to an oil tank, or a differential mode, in which all or a portion of the drain oil is supplied to a rear oil chamber of said injection cylinder during injection, said hydraulic circuit comprising:
A hydraulic circuit of an injection molding machine permitting selection of either a regular mode, in which all drain oil ejected from a front oil chamber of an injection cylinder during injection is returned to an oil tank, or a differential mode, in which all or a portion of the drain oil is supplied to a rear oil chamber of said injection cylinder during injection, said hydraulic circuit comprising:
Dependencies are inferred from the claim text.