THREE-WAY DIRECT PILOT VALVE

Abstract

The present disclosure provides a method, apparatus, and system of an inline direct acting solenoid pilot valve. The valve has a solenoid assembly with a longitudinally moveable core assembly that shifts alternatively between sealing engagement on a lower first end of the core assembly with a pilot port formed in a poppet and sealing engagement on an opposite upper end with a stationary pilot exhaust port in the solenoid assembly. The core assembly can move in the same or opposite direction than the poppet and thus is independently moveable from the poppet to effect the various modes of operation. Because the movement is independent, the core assembly can advantageously operate within the solenoid with a shorter stroke to produce a higher overall force per length relative to a conventional core assembly stroke that is longer than the poppet stroke. The overall design allows a more compact and simplified design.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

While the inventions disclosed herein are susceptible to various modifications and alternative forms, only a few specific embodiments have been shown by way of example in the drawings and are described in detail below. The figures and detailed descriptions of these specific embodiments are not intended to limit the breadth or scope of the inventive concepts or the appended claims in any manner. Rather, the figures and detailed written descriptions are provided to illustrate the inventive concepts to a person of ordinary skill in the art as required by 35 U.S.C. § 112.

FIG. 1 is a perspective schematic view of an exemplary pilot valve according to the teachings in this disclosure.

FIG. 2 is a schematic assembly view of the exemplary pilot valve of FIG. 1.

FIG. 3 is a cross-sectional schematic diagram of the exemplary pilot valve in a de-energized state.

FIG. 4 is a cross-sectional schematic view of the solenoid base subassembly.

FIG. 5 is a prospective schematic view of the core assembly.

FIG. 6 is a top schematic view of the core assembly of FIG. 5.

FIG. 7 is a cross-sectional schematic view through FIG. 6 of the core assembly.

FIG. 8 is a cross-sectional schematic view of the poppet.

FIG. 9 is a cross-sectional schematic view of the wall seal.

FIG. 10 is a cross-sectional schematic view of the seat seal.

FIG. 11 is a cross-sectional schematic view of a seal support.

FIG. 12 is a top schematic view of the guide ring.

FIG. 13 is a top perspective schematic view of the guide ring.

FIG. 14 is a cross-sectional schematic diagram of the exemplary pilot valve in an energized state.

FIG. 15 is a cross-sectional schematic diagram of the exemplary pilot valve in a de-energizing state shown with the core assembly still adjacent the poppet seat.

Claims

1. A pilot valve, comprising: a body having an inlet port, a device port, and an outlet port formed in the body to establish one or more flow paths, the body further having a main flow opening having a first seat distal from the inlet port;a solenoid base subassembly coupled to the body comprising: a stopper having: a pilot exhaust port formed longitudinally through the stopper; anda bonnet having: a first opening formed longitudinally in the bonnet and aligned with the pilot exhaust port adjacent the pilot exhaust port seat; anda second opening aligned with the first opening, the second opening being formed in the bonnet and distal from the pilot exhaust port of the stopper; anda core tube adapted to couple the stopper and the bonnet with a gap formed between the stopper and bonnet;a core assembly slidably coupled to the solenoid base subassembly in the first and second openings, comprising: a core having a core opening formed longitudinally through the core and axially aligned with the body main flow opening;a first seal disc slidably disposed in the core opening toward the pilot exhaust port for sealing engagement with the exhaust port;a second seal disc slidably disposed in the core opening toward the body main flow opening and distal from the pilot exhaust port; anda spring disposed in the core opening between the first seal disc and the second seal disc;a solenoid assembly disposed around at least a portion of the solenoid base subassembly, the solenoid assembly having a toroidal coil adapted to be energized to create a magnetic field longitudinally through the solenoid base subassembly;a poppet slidably disposed in the second opening of the bonnet and the main flow opening of the body, the poppet being aligned with the main flow opening and the poppet having: a poppet piston slidably disposed in the second opening of the bonnet, the poppet piston having a port in communication between the inlet port and the core assembly, the port being aligned with the second seal disc of the core assembly for sealing engagement with the second seal disc; anda seat seal coupled to the poppet distal from the second opening and adapted to sealably engage the first seat on the main flow opening distal from the poppet piston relative to the main flow opening; anda second seat coupled to the body distal from the poppet piston and adapted to be engaged by the seat seal distal from the first seat, the poppet defining a stroke between the first seat and the second seat.

2. The valve of claim 1, further comprising a recess formed around the pilot exhaust port in the stopper to receive the core assembly when the valve is energized.

3. The valve of claim 1, wherein the poppet comprises a poppet guide disposed distal from the poppet piston and the valve further comprises a guide ring wherein the poppet guide is adapted to be slidably engaged with the guide ring to guide the poppet along the poppet stroke.

4. The valve of claim 1, wherein the pilot exhaust port communicates with a cross opening to allow pilot exhaust to escape from the pilot exhaust port through the cross opening and a seal is flexibly disposed around the cross opening.

5. The valve of claim 1, wherein the core assembly is biased toward the poppet.

6. The valve of claim 1, wherein the poppet assembly is biased toward the core assembly.

7. The valve of claim 1, further comprising a wall seal coupled to the poppet and slidably disposed in the second opening of the bonnet.

8. The valve of claim 1, further comprising a seal support radially disposed around the seat seal.

9. The valve of claim 1, further comprising an outlet fitting coupled to the body distal from the solenoid base subassembly, the outlet fitting establishing the second seat for engagement by the seat seal.

10. The valve of claim 1, wherein the core assembly can move independently in the same or different direction as the poppet to operate the valve between an energized state and a de-energized state.

11. The valve of claim 1, wherein the core assembly has a core stroke and the poppet has a poppet stroke and the core stroke is shorter than the poppet stroke.

12. A pilot valve, comprising: a body having an inlet port, a device port, and an outlet port formed in the body to establish one or more flow paths;a solenoid base subassembly;a solenoid assembly disposed around at least a portion of the solenoid base subassembly, the solenoid assembly having a toroidal coil adapted to be energized to create a magnetic field longitudinally through the solenoid base subassembly;a core assembly slidably coupled to the solenoid base subassembly, the core assembly having a core stroke;a poppet slidably disposed in the valve body, the poppet having a poppet stroke;wherein the core assembly can move independently in the same or different direction as the poppet to operate the valve between an energized state and a de-energized state.

13. The valve of claim 12, wherein the core stroke is shorter than the poppet stroke.

14. The valve of claim 13, wherein the core assembly has a higher average pulling force per length of core assembly movement compared to a core assembly that can only move in the same direction as the poppet and has a longer core stroke than the poppet stroke.

15. A pilot valve, comprising: a body having an inlet port, a device port, and an outlet port formed in the body to establish one or more flow paths, the body further having a main flow opening having a first seat distal from the inlet port;a solenoid base subassembly coupled to the body comprising: a stopper having a pilot exhaust port formed longitudinally through the stopper;a bonnet coupled to the stopper having a first opening formed longitudinally in the bonnet and aligned with the pilot exhaust port; anda core assembly slidably coupled to the solenoid base subassembly in at least the first opening, the core assembly having a first end and a second end and a sealing surface disposed on each end;a solenoid assembly disposed around at least a portion of the solenoid base subassembly, the solenoid assembly having a coil adapted to be energized to create a magnetic field longitudinally through the solenoid base subassembly;a poppet slidably disposed in the second opening of the bonnet and the main flow opening of the body and aligned with the main flow opening, the poppet having: a poppet piston slidably disposed at least partially in the bonnet, the poppet piston having a pilot port in communication between the inlet port and the core assembly, the port being aligned with a least one of the sealing surfaces of the core assembly for sealing engagement; anda seat seal coupled to the poppet distal from the bonnet and adapted to sealably engage the first seat of the main flow opening distal from the poppet piston; anda second seat coupled to the body distal from the poppet piston and the first seat and adapted to be engaged by the seat seal distal from the first seat, the poppet having a stroke between the first seat and the second seat.

16. The valve of claim 15, further comprising a pilot exhaust port seat formed in one end of the stopper around the pilot exhaust port.

17. The valve of claim 15, further comprising a second opening formed in the bonnet and aligned with the first opening, the second opening being formed in the bonnet distal from the pilot exhaust port of the stopper and wherein at least a portion of the poppet piston is disposed in the second opening.

18. The valve of claim 15, wherein the solenoid base subassembly further comprises a core tube adapted to couple the stopper and the bonnet.

19. The valve of claim 15, wherein the core assembly comprises a core opening formed longitudinally through the core, further comprising: a first seal disc slidably disposed in the core opening toward the pilot exhaust port;a second seal disc slidably disposed in the core opening toward the body main flow opening and distal from the pilot exhaust port; anda spring disposed in the core opening between the first seal disc and the second seal disc.

20. The valve of claim 15, wherein the poppet comprises a poppet guide disposed distal from the poppet piston and the valve further comprises a guide ring wherein the poppet guide is adapted to be slidably engaged with the guide ring to guide the poppet along the poppet stroke.

21. The valve of claim 15, wherein pilot exhaust port communicates with a cross opening to allow pilot exhaust to escape from the exhaust pilot port through the cross opening and a seal is flexibly disposed around the cross opening.

22. The valve of claim 15, wherein the core assembly is biased toward the poppet.

23. The valve of claim 15, wherein the poppet assembly is biased toward the core assembly.

24. The valve of claim 15, further comprising a wall seal coupled to the poppet and slidably disposed in the bonnet.

25. The valve of claim 15, further comprising a seal support radially disposed around the seat seal.

26. The valve of claim 15, further comprising an outlet fitting coupled to the body distal from the solenoid base subassembly, the outlet fitting establishing the second seat for engagement by the seat seal.

27. A method of operating the valve of claim 10, comprising: energizing the coil to provide a force on the core assembly directed toward the stopper and away from the poppet;moving the core assembly away from the poppet piston having the pilot port to allow pressurized fluid to enter the opening in the bonnet on a portion of the poppet piston disposed in the opening to counteract pressure on the poppet piston on a distal portion of the poppet piston;applying the pressurized fluid to the seat seal and forcing the poppet piston away from the first seat of the main flow opening toward the second seat and away from the core assembly to open a flow path between the inlet port and the device port.

28. The method of claim 27, wherein moving the core assembly away from the pilot port overcomes a bias in an opposite direction of a core assembly return spring.

29. The method of claim 27, further comprising moving the core assembly into a sealing engagement with the pilot exhaust port.

30. The method of claim 27, further comprising: de-energizing the coil;allowing the core assembly to move toward the poppet piston and engage the poppet port;exhausting pressurized fluid from the opening in the bonnet;moving the poppet piston away from the second seat and toward the first seat and the poppet piston to open a flow path between the device port and the outlet port.

31. A method of operating a pilot valve having an inlet port, a device port, and a outlet port defining at least two flow paths, comprising: pressurizing an inlet port of a de-energized valve;energizing a coil of a solenoid assembly coupled to a portion of the valve and surrounding a movable core assembly of the valve to pull the core assembly toward a stationary stopper having a pilot exhaust port distal from the inlet port;sealing the pilot exhaust port with a seal coupled to the core assembly;flowing pressurized fluid from the inlet port through a pilot port in a piston of a slidable poppet to create a first force on a portion of the poppet piston distal from the inlet port; andforcing with the first force the poppet piston, axially aligned with the poppet, toward a main flow opening in the valve and away from the core assembly, to move a biased seat seal axially coupled with the poppet from a first main seat to a second main seat to open a flow path between the inlet port and the device port.