Proportional sequence valve with pressure amplification device
AssigneeParker-Hannifin Corporation
InventorsJarmo Antero Harsia, Germano Franzoni
Life of this patent
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Abstract
A valve member having a supply pressure and a method of controlling the supply pressure in the valve member includes a valve body having a fluid inlet, a fluid outlet, and a controlled port. The valve member includes a spool moveable within the valve body to fluidly connect at least one of the fluid inlet and the fluid outlet with the controlled port. The spool includes an end in fluid communication with a control pressure port and a pin received within the end of the spool that is moveable relative to the spool. Fluid flow through the control pressure port acts against a cross-sectional area of the pin and an annular area of the spool to modulate the supply pressure through the valve member.
Claims21
A valve member for supplying and discharging fluid flow, the valve member comprising:
- a valve body having a fluid passage, a supply port for supplying a flow of fluid to the valve member, a tank port for discharging the flow of fluid from the valve member, and a controlled port for supplying fluid to a hydraulic device;
- a spool moveable within the valve body, the spool having a first end, a second end opposite the first end, and a bore defined at the second end, wherein the second end is in fluid communication with the fluid passage;
- and
- a pin that is received within the bore of the spool and moveable relative to the spool, the pin and the spool being concentric and moveable along a common axis,
- wherein a fluid flow through the fluid passage acts against a cross-sectional area of the pin and an annular area of the spool at the second end of the spool to move the spool between:
- (i) a first position where the tank port is fluidly connected to the controlled port, (ii) a second position where the supply port is fluidly connected to the controlled port, and (iii) a third position where both the supply port and the tank port are fluidly connected to the controlled port.
A valve member for operating a hydraulic actuating device, the valve member comprising:
- a valve body defining a supply port, a tank port, and a controlled port fluidly connectable between the hydraulic actuating device and at least one of the supply port and the tank port;
- a pressure control port;
- a spool that is slideable and fluidly connecting the controlled port with at least one of the supply port and the tank port, wherein the spool has a first end, a second end, and a bore chamber extending between the first and second end;
- and
- a pin that is received within the bore chamber at the second end of the spool and is slideable relative to the spool,
- wherein the spool is biased in a first direction by a biasing force that acts on a cross-sectional area of the spool at the first end of the spool, and
- wherein the spool moves in a second direction opposite the first direction within the valve body in response to pressure from the pressure control port acting on an annular area of the spool and acting on a cross-sectional area of the pin at the second end of the spool, wherein the spool is moveable between (i) a first position where the tank port is fluidly connected to the controlled port, (ii) a second position where the supply port is fluidly connected to the controlled port, and (iii) a third position where both the supply port and the tank port are fluidly connected to the controlled port.
A method of controlling a supply pressure in a valve member having a fluid inlet, fluid outlet, and a controlled port, the method comprising:
- positioning a spool within the valve member, the spool having a first end and a second end opposite the first end;
- positioning a pin within the spool at the second end of the spool;
- applying a force by a spring on the first end of the spool;
- applying the supply pressure to an effective area of the spool equal to a cross-sectional area of the pin;
- applying a control pressure against:
- (i) an annular area of the spool, wherein the annular area of the spool comprises a cross-sectional area of the spool minus the cross-sectional area of the pin, and (ii) the cross-sectional area of the pin at the second end of the spool;
- moving the spool for fluidly connecting and disconnecting at least one of the fluid inlet and the fluid outlet with the controlled port;
- moving the pin relative to the spool to modulate the supply pressure in the valve member;
- and
- changing the supply pressure based on:
- (i) amplification of the control pressure by a ratio between the cross-sectional area of the spool and the cross-sectional area of the pin, and (ii) a ratio between the force of the spring and the cross-sectional area of the pin.
Dependencies are inferred from the claim text.