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US 12,188,493 B2Granted
Control system for actuating lifting function
AssigneeDanfoss Power Solutions Inc.
InventorsAaron Darnell, Zhekang Du, Simon Nielsen
Life of this patent
Estimating the term…
Abstract
A hydraulic control system for linear actuation that provides a bypass flow during startup of a lifting command, provides a split flow between a cylinder and a reservoir once a minimum operating speed of a pump has been reached, and provides complete flow to a cylinder after the minimum operating speed of the pump has been reached. This is achieved through control of a flow control valve and a proportional flow control valve by a processor.
Claims20
A hydraulic control system for linear actuation, comprising:
- an electric motor connected to a hydraulic pump;
- a hydraulic cylinder connected to the pump via a flow line;
- a pressure transducer, a pressure control valve, and a check valve connected to the flow line between the pump and the cylinder;
- a tank connected to the pump and to the cylinder via a return line;
- a control valve connected to the flow line between the check valve 24 and the pump and also connected to the return line;
- a proportional control valve connected to the flow line between the check valve and the pressure control valve and also connected to the return line;
- and
- the proportional control valve connected to a processor having software to control the system state during startup of lifting command and during operation at commanded lifting speeds requiring pump speeds less than the minimum pump operating speed;
- wherein the software of the processor, before energizing the proportional flow control valve to close, provides instructions to increase pump speed to a level corresponding to a greater value of a command cylinder extension rate or a minimum allowed pump speed.
6 more elements
A hydraulic control system for linear actuation, comprising:
- an electric motor connected to a hydraulic pump;
- a hydraulic cylinder connected to the pump via a flow line;
- a pressure transducer, a pressure control valve, and a check valve connected to the flow line between the pump and the cylinder;
- a tank connected to the pump and to the cylinder via a return line;
- a control valve connected to the flow line between the check valve and the pump and also connected to the return line;
- a proportional control valve connected to the flow line between the check valve and the pressure control valve and also connected to the return line;
- and
- the proportional control valve connected to a processor having software to control the system state during startup of lifting command and during operation at commanded lifting speeds requiring pump speeds less than the minimum pump operating speed;
- wherein the software of the processor provides instruction for all flow to be bypassed to the tank during startup through the proportional flow control valve.
6 more elements
A hydraulic control system for linear actuation, comprising:
- an electric motor connected to a hydraulic pump;
- a hydraulic cylinder connected to the pump via a flow line;
- a pressure transducer, a pressure control valve, and a check valve connected to the flow line between the pump and the cylinder;
- a tank connected to the pump and to the cylinder via a return line;
- a control valve connected to the flow line between the check valve and the pump and also connected to the return line;
- a proportional control valve connected to the flow line between the check valve and the pressure control valve and also connected to the return line;
- and
- the proportional control valve connected to a processor having software to control the system state during startup of lifting command and during operation at commanded lifting speeds requiring pump speeds less than the minimum pump operating speed;
- wherein the software of the processor, at commanded speeds requiring speeds less than a minimum operating speed of the pump, provides instructions to apply flow regardless of whether speed needs to be ramped up or ramped down.
6 more elements
A hydraulic control system for linear actuation, comprising:
- an electric motor connected to a hydraulic pump;
- a hydraulic cylinder connected to the pump via a flow line;
- a pressure transducer, a pressure control valve, and a check valve connected to the flow line between the pump and the cylinder;
- a tank connected to the pump and to the cylinder via a return line;
- a control valve connected to the flow line between the check valve and the pump and also connected to the return line;
- a proportional control valve connected to the flow line between the check valve and the pressure control valve and also connected to the return line;
- and
- the proportional control valve connected to a processor having software to control the system state during startup of lifting command and during operation at commanded lifting speeds requiring pump speeds less than the minimum pump operating speed;
- wherein the software of the processor, once an operating speed for the pump has been reached, provides instructions to energize the proportional control valve to become partially opened to a position that bypasses a fraction of the pump flow away from the cylinder directly to the tank.
6 more elements
Dependencies are inferred from the claim text.