Hydraulic device for supplying a hydraulic driving unit
First Claim
1. A hydraulic device for supplying a hydraulic driving unit in an injection molding machine for processing synthetic materials comprisingat least one variable capacity pump,a main line extending from said variable capacity pump to said driving unit,at least one control valve arranged in said main line and adapted to determine a quantity and a pressure of hydraulic fluid in said main line,a controlling mechanism connected with said variable capacity pump for control of said pressure,a control conduit which connects said controlling mechanism of said variable capacity pump with said main line downstream of said control valve,at least one pressure transducing means arranged for transducing an actual pressure value downstream of said control valve;
- comparing means for comparing said actual pressure value with a nominal pressure value and supplying a first correcting variable for said controlling mechanism in dependency of result of said comparing means,said variable capacity pump being driven by a rotary current motor which is connected to a current source, and a speed of rotation of said rotary current motors being regulated via a frequency converter arranged between said current source and said rotary current motor.
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Accused Products
Abstract
In a hydraulic device a variable capacity pump adapted to record a differential pressure via a control valve is actuated in such a way that a constant operational pressure gradient is maintained. Since the variable capacity pump is driven by a rotary current motor, which is connected to a current source by a frequency converter and is regulable with regard to its speed, it is possible to control hydraulic consumers in an energy-saving manner at a reasonable price.
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Citations
5 Claims
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1. A hydraulic device for supplying a hydraulic driving unit in an injection molding machine for processing synthetic materials comprising
at least one variable capacity pump, a main line extending from said variable capacity pump to said driving unit, at least one control valve arranged in said main line and adapted to determine a quantity and a pressure of hydraulic fluid in said main line, a controlling mechanism connected with said variable capacity pump for control of said pressure, a control conduit which connects said controlling mechanism of said variable capacity pump with said main line downstream of said control valve, at least one pressure transducing means arranged for transducing an actual pressure value downstream of said control valve; - comparing means for comparing said actual pressure value with a nominal pressure value and supplying a first correcting variable for said controlling mechanism in dependency of result of said comparing means,
said variable capacity pump being driven by a rotary current motor which is connected to a current source, and a speed of rotation of said rotary current motors being regulated via a frequency converter arranged between said current source and said rotary current motor. - View Dependent Claims (2, 3, 4, 5)
- comparing means for comparing said actual pressure value with a nominal pressure value and supplying a first correcting variable for said controlling mechanism in dependency of result of said comparing means,
Specification