Extended range proportional valve
AssigneeASCO Controls, LP
InventorsPaul W. Freisinger, John J. Haller, Peter A. Holborow
Life of this patent
Estimating the term…
Abstract
An extended range proportional valve which can control rates of mass flow over continuous low, intermediate and high ranges has a pilot member mounted on an armature of a solenoid which can be dithered onto and off of a pilot opening in a main valve member which seals a main valve opening to control mass flow rates over the low range by varying the duty cycle and/or frequency of a pulse width modulated current in the solenoid coil. Intermediate and high flow rates are achieved by dithering the pilot valve member with a duty cycle and/or frequency sufficient to raise the main valve member relatively short and relatively long respective distances from the main valve seat.
Claims5
A flow valve comprising:
- a main valve body defining an inlet port, and outlet port, and a main reservoir;
- a movable element positioned within the main reservoir including a diaphragm positioned across the main reservoir, and a member defining a pilot passage through the movable element;
- a pilot sealing member,
- a movable control element comprising a solenoid actuator having a solenoid core coupled to the pilot sealing member, wherein the solenoid core has a narrowed portion near the location where the core is coupled to the pilot sealing member.
The flow valve of claim 3 where the mass of the material removed by machining comprises at least 28% of the mass of the non-machined solenoid core.
A fluid flow system comprising:
- a controller that receives a fluid flow command and generates in response signals represent a desired pulse width modulation frequency and a desired duty cycle;
- a power circuit coupled to the controller that receives the signals representing the desired pulse width modulation frequency and duty cycle and generates a fixed frequency pulse width modulated signal having an active duty cycle corresponding to the desired duty cycle;
- a flow valve that includes a solenoid actuator that receives the fixed frequency pulse width modulated signal from the power circuit to control the flow of fluid passing through the valve, wherein the valve comprises a valve seat and a flow-shaping element positioned within the valve seat, and wherein the flow shaping element is constructed such that the flow of fluid through the valve at a first fixed pulse width modulated frequency and first duty cycle is substantially equal to the flow of fluid through the valve at a second sized pulse width modulated frequency with the first duty cycle.
A flow valve comprising:
- a main valve body defining an inlet port, and outlet port, and a main reservoir;
- a valve sealing tube positioned with in the main reservoir, the valve sealing tube having an outer diameter;
- a movable element positioned within the valve sealing tube, the movable member including a diaphragm positioned across the main reservoir, and an upper retaining member that contacts the diaphragm in the side opposite the main reservoir where the outer diameter of the upper retaining member is less than or equal to the outer diameter of the valve sealing tube.
Dependencies are inferred from the claim text.