GB2145500A

GB2145500A - Pilot-operated valve

Info

Publication number: GB2145500A
Application number: GB08407646A
Authority: GB
Inventors: Felix Aranovich
Original assignee: Imperial Clevite Inc
Current assignee: Clevite Industries Inc
Priority date: 1983-08-24
Filing date: 1984-03-23
Publication date: 1985-03-27
Also published as: GB2145500B; SE8401821D0; IT8448742A0; GB8407646D0; SE8401821L; IT1208688B; DE3428096A1; JPS6060386A

Abstract

In a poppet valve 10 which includes a poppet 11 having an annular seat 12, the poppet is provided with a transfer passage 22 from the inlet 21 to a pressure space 20, and a through bore 15 extending from the pressure space 20 to a discharge space 14 and closable by a pilot valve 24, the through bore 15 being extended so that even when the valve is in open position the end 35 of the bore 15 is within the discharge space 14 downstream of the seat 12. As shown the extension 31 is threadedly secured to the poppet 11. <IMAGE>

Description

SPECIFICATION Pilot-operated valve Technical Field This invention relates to valves and in particular to pilot-operated valves.

Background Art In one form of fluid flow control valve, a poppet is seated against a valve seat to close the valve. The poppet is provided with a through bore which is selectively closed by a pilot valve. The poppet is spring-biased to the closed position with fluid pressure acting on opposite sides of the poppet so as to permit the spring biasing to maintain the poppet closed. When the pilot valve is raised from the valve seat, the fluid pressure behind the poppet is reiieved to the through bore, thus permitting the fluid pressure acting upwardly on the poppet to move the poppet from the valve seat and thereby permit flow through the valve.

In one form, the pilot valve is operated by a suitable solenoid having a plunger connected to the pilot valve for selective positioning thereof in effecting the desired fluid flow control.

Such valves are provided in a wide range of sizes depending on the flow capacity desired.

It is further conventional to provide such valves in the form of cartridges, including both the valve and the solenoid operator in a single assembly which, illustratively, may be connected to suitable ports by a threaded adapter portion thereof.

In U.S. Letters Patent 2,951,133 of James E. Davies et al, a hermetically sealed electromagnetic contactor and the like is disclosed wherein a drawn metal member is provided with a central opening through its upper end, which is encircled by an upstanding flange portion extending through an opening in a superjacent cupshaped housing member.

Arthur J. Foley et al, in U.S. Letters Patent 3,215,902, show a solenoid actuated mechanism wherein the electrical assembly is located between a flux plate and an upper flux plate, with central apertures of the three elements being aligned and mounted upon a cylindrical protruding portion of the core support.

In U.S. Patent 3,446,473, George E.

Barker shows a solenoid valve wherein the solenoid housing is threaded to the valve body.

Alfred J. Ludwig, in U.S. Letters Patent 3,593,241, discloses a solenoid valve having a slotted flux sleeve for nesting the winding leads. The magnetic flux path includes a portion established by a pair of magnetizable end members disposed adjacent the opposite end surfaces of the solenoid coil, with a magnetizable center leg defining the end plug.

The U.S. Letters Patent 3,818,398, William J. Barbier et al discloses an electromagnetic coil assembly wherein a T-shaped tubutar shroud formed of ferrous material is pressfitted into each end of the spool supporting the solenoid coil.

In U.S. Letters Patent 4,074,700 of Thomas H. Engle, a valve assembly is disclosed wherein the coil housing provides a flux return path extending toroidally from the coil through an upper portion of a plunger guide, through the plunger, across a working air gap, through a pole piece, through a coil support flange, and up through a coil housing. The coil housing includes an axially extending lip which is sized diametrically to fit closely to the plunger and axially to provide an increased area for flux transfer. The plunger guide is made as thin as practical so that magnetic losses are minimized.

Disclosure of Invention The present invention is concerned with the problem of decreased pressure differential acting across the poppet member as a result of a decreased pressure acting on the rear side of the poppet member as a result of dynamic fluid flow conditions adjacent the outlet end of the pilot valve bore.

More specifically, the present invention is concerned with a poppet valve having a poppet member removably seated on an annular valve seat opening to a discharge space and a through bore opening at one end to a pressure space at the rear of the poppet opposite the exhaust space and at its opposite end to the exhaust space, means defining an inlet space adjacent the poppet for conducting pressurized fluid transfer to the exhaust space when the poppet is spaced from the valve seat means defining a transfer passage from the inlet space to the pressure space, and a pilot valve means for selectively opening and closing the through bore.

The invention comprehends provision of extension means causing the one end of the through bore in the poppet member to extend to substantially beyond the plane of the annular valve seat when the poppet valve member is spaced from the valve seat.

Thus, the extension means in the present invention causes the pilot valve controlled bore to exhaust substantially downstream of the valve seat so as to provide a pressure through the bore which is effectively at exhaust pressure, thereby maximizing the pressure differential force urging the poppet to the open position.

Thus, the improved pilot valve bore extension means is efficacious in providing improved functioning of the poppet valve both where the poppet valve comprises a normally closed poppet and where the poppet valve comprises a normally open poppet valve.

In the illustrated embodiment, the extension means comprises an element fixedly secured to the poppet as by removable securing means.

In the illustrated embodiment, the extension means comprises a nozzle which tapers away from the poppet member.

In the illustrated embodiment, the discharge space is defined by a widening peripheral wall and the extension means causes the end of the poppet bore to open to the discharge space adjacent the wide end of the tapered portion.

In the illustrated embodiment, the extension means extends coaxially of the annular valve seat.

In the illustrated embodiment, the extension means is provided with a tool engagement peripheral surface for use in threadedly installing and removing the extension element as desired.

The extension means has a length preselected to open adjacent the wide end of the tapered portion of the discharge space when the poppet member is seated on the annular valve seat. In the open position of the valve, the end of the extension element is disposed within the tapered portion of the discharge space.

In the illustrated embodiment, the extension means comprises an extension on the poppet extending the outer end of the through bore in the poppet member to substantially beyond the plane of the annular valve seat when the poppet valve is spaced from the valve seat.

The extension defines an outer tapered surface narrowing away from the poppet member and centered in the discharge space to efffectively minimize turbulence of the fluid flowing past the extension from the inlet space.

In the illustrated embodiment, the inner surface of the poppet member is provided with a recess and the extension element is threadedly secured to the poppet member in the recess.

Brief Description of the Drawing Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing wherein: FIGURE 1 is a perspective view of a poppet valve embodying the invention; FIGURE 2 is an enlarged diametric section thereof taken substantially along the line 2-2 of Figure 1; and FIGURE 3 is an enlarged diametric section of a poppet valve embodying the invention, of the normally open type.

Best Mode for Carrying Out the Invention In the illustrative embodiment of the invention as disclosed in the drawing, a poppet valve generally designated 10 is shown to comprise a cartridge valve having a poppet member 11 arranged to seat on an annular valve seat 1 2 defined by a portion of a tubular valve body 1 3. The valve seat opens to a discharge space 14.

The poppet member is further provided with a through bore 1 5 opening at one end 1 6 through a recess 1 7 in the inner surface 1 8 of the poppet member to the discharge space 14.

The rear surface 1 9 of the poppet member opens to a pressure space 20.

Valve body 1 3 further defines an inlet space 21 adjacent the poppet for conducting pressurized fluid therefrom to the discharge space 14 when the poppet is spaced from the valve seat 1 2.

A transfer passage 22 is provided in the poppet member 11 for delivering pressurized fluid from the inlet space 21 to the pressure space 20.

Pilot valve means generally designated 23 are provided for controlling the disposition of the poppet member and includes a pilot valve 24 arranged for selectively closing and opening the through bore 1 5. In the illustrated embodiment, the pilot valve 24 is selectively positioned by operating means generally designated 25 including a magnetic coil 26 selectively acting on a magnetic member 27 connected to the pilot valve 24 for positioning the pilot valve as a function of energization of the coil 26.

In the embodiment of Figure 2, the poppet valve comprises a normally closed poppet valve, with a seating portion 28 of the pilot valve sealingly closing the end 1 6 of through bore 1 5 as a result of the magnetic member 27 acting downwardly on a reaction element 29 connected to the pilot valve.

In a modified embodiment of the invention, as illustrated in Figure 3, a normally open poppet valve generally designated 110 is shown to comprise a poppet valve similar to normally closed poppet valve 10, but wherein the pilot valve 1 24 is biased by a spring 1 30 to space the seating portion 1 28 of the poppet valve in spaced relationship to the through bore end 116.

Thus, in the normally closed valve 10, fluid pressure delivered through transfer passage 22 to the pressure space 20 acts downwardly on the poppet member so as to maintain the poppet member seated on valve seat 1 2 as long as the pilot valve is closed, as shown in Figure 2, with the seating portion 28 closing the through bore end portion 1 6. In poppet valve 110, the poppet member 111 is normally spaced from the valve 11 2 as a result of fluid pressure delivered through transfer passage 1 22 to the pressure space 1 20 being relieved in the pressure space by the opening of the through bore end 11 6 by the spaced relationship of the pilot valve seating portion 1 28 thereto, thereby maintaining the poppet valve in spaced relation to the main seat 11 2.

The present invention is concerned with the problem that arises as a result of the fluid flow from the inlet space 21 in the normally closed valve, and 121 in the normally open valve, to the discharge space 14, 114. In the prior art valves, wherein the poppet member through valve opened substantially directly through the inner surface 118 thereof, pressure conditions, such as due to turbulence and the like, adjacent the inner surface 18, 118, caused the pressure transmitted through the through bore 1 5 to the pressure space 20 to be somewhat higher than the discharge space pressure downstream of the valve.

Thus, less differential pressure force was available to move and hold the poppet valve in the open position. Thus, the decreased pressure differential caused an undesirable limit on the capacity of the valve as providing a fluid flow through the valve greater than a preselected amount tended to weaken the pressure differential force sufficiently so as to cause unstable operation.

The present invention overcomes this vexatious problem and permits substantially increased rates of flow through the same size valve by providing an extension means generally designated 31 for causing end 1 6 of the through bore 1 5 of the poppet member to extend to substantially beyond the plane of the annular valve seat 1 2 when the poppet valve member is spaced from the valve seat.

In the illustrated embodiment, the extension means comprises an extension element 32 having a through bore 33 having an inner end 34 opening inwardly through a distal surface 35 of the element. The outer end 36 of bore 33 opens to the through bore end 1 6 of the poppet member.

The extension element further defines a threaded portion 37 removably threaded to a threaded portion 38 of a recess 39 in poppet member surface 1 8 opening inwardly to the discharge space 14.

The extension element further defines an enlarged portion 40 arranged to abut the poppet member when the threaded portion 37 is fully threaded into poppet member portion 38. Portion 40 further defines a tool engagement peripheral surface 41 for use in threadedly installing and removing the extension element relative to the poppet member as desired.

As shown in Figure 2, in the closed position of the poppet member, i.e. when the poppet member is seated on the valve seat 12, distal end 35 of extension element 32 is disposed adjacent the outer end of a widening portion 42 of the discharge space 1 4 extending away from valve seat 1 2. In the open position of the poppet member, distal surface 35, as shown in broken lines in Figure 2, is disposed within the outwardly widening portion of the discharge space 1 4 in substantially spaced relationship to the plane of the annular valve seat 1 2. As seen in Figure 3, in the normally open valve 110, the distal surface of the extension element 1 32 is selectively similarly disposed as a function of the seated and unseated disposition of the poppet member.

It has been unexpectedly found that by the addition of the extension means 31, 131, a substantial improvement in the functioning of the valve is obtained over the prior art structures as the result of the extension means causing the pilot valve inner end portion 1 6 to be disposed substantially downstream of the entrance to the discharge space 14, 114 defined by the valve seat 12, 11 2. Thus, the pressure at the distal end 35, 135 of the extension element has been found to be substantially the discharge pressure downstream of the valve so that a substantial increase in the pressure differential acting across the poppet valve member is obtained providing a more positive opening of the valve 10 and more positive retention of the poppet member in the open position in each of the valves 10 and 110.

As further seen in Figures 2 and 3, the extension element is provided with a tapered outer surface portion 43, 143 narrowing away from the enlarged portion 40 and tending to guide the fluid flow along the surface of the extension member with reduced turbulence, thereby more smoothly causing a transition of the flow adjacent the distal end 35, 1 35 and further serving to provide an increased diffferential between the pressure space 20, 1 20 and the inlet space 21, 121, in the open condition of the valve.

As shown in Figure 2, the tapered surface portion 43 is arranged to extend from the plane of the inner surface 1 8 of the poppet member as a result of the enlarged portion 40 of the extension element being received in the recess 39.

As discussed above, the use of the extension means permits the valve to handle substantially greater volumetric flow of the fluid, and in one illustrative 40-gallon per minute valve, it was found that the use of the extension means 31, 1 31 permitted the valve to be operated as a 70-gallon per minute valve, with equal stability. Thus, the invention permits an unexpected minimization of the valve size in handling fluid flow in an extremely simple and novel manner.

The foregoing disclosure of specific embodiments is illustrative of the broad inventive concepts comprehended by the invention.

Claims

1. In a poppet valve having a poppet member removably seated on an annular valve seat opening to a discharge space and a through bore opening at one end to a pressure space at the rear of the poppet opposite said exhaust space and at its opposite end to said exhaust space, means defining an inlet space adjacent said poppet for conducting pressur ized fluid therefrom to said exhaust space when the poppet is spaced from the valve seat, means defining a transfer passage from said inlet space to said pressure space, and pilot valve means for selectively opening and closing said through bore, the improvement comprising extension means for causing said one end of the through bore in said poppet member to extend to substantially beyond the plane of the annular valve seat when the poppet valve member is spaced from said valve seat.

2. The poppet valve of Claim 1 wherein said extension means comprises an element fixedly secured to said poppet.

3. The poppet valve of Claim 1 wherein said extension means comprises a nozzle fixedly secured to said poppet.

4. The poppet valve of Claim 1 wherein said extension means comprises a nozzle fixedly secured to said poppet exteriorly tapered away from said poppet member.

5. The poppet valve of Claim 1 wherein said extension means comprises an element removably secured to said poppet.

6. The poppet valve of Claim 1 wherein said extension means comprises an element threaded to said poppet.

7. The poppet valve of Claim 1 wherein said discharge space widens from said valve seat to a position spaced substantially therefrom, and said extension means causes said one end of the poppet bore to open to said discharge space adjacent the wide end thereof when the poppet is seated in said valve seat.

8. The poppet valve of Claim 1 wherein said extension means extends coaxially of said annular valve seat.

9. The poppet valve of Claim 1 wherein said valve comprises a normally closed valve, biasing means are provided for urging said pilot valve to close said through bore, and operator means are provided for forcibly moving said pilot valve against the action of said biasing means to open said through bore.

10. The poppet valve of Claim 1 wherein said valve comprises a normally open valve, biasing means are provided for urging said pilot valve to open said through bore, and operator means are provided for forcibly moving said pilot valve against the action of said biasing means to close said through bore.

11. The poppet valve of Claim 1 wherein said extension means comprises an element threaded to said poppet and is provided with a tool-engagement peripheral surface for use in installing and removing the extension element as desired.

12. In a poppet valve having a poppet member removably seated on an annular valve seat opening to a discharge space and a through bore opening at one end to a pressure space at the rear of the poppet opposite said exhaust space and at its opposite end to said exhaust space, means defining an inlet space adjacent said poppet for conducting pressurized fluid therefrom to said exhaust space when the poppet is spaced from the valve seat, means defining a transfer passage from said inlet space to said pressure space.

and a pilot valve means for selectively opening and closing said through bore, the improvement comprising an extension on said poppet extending said one end of the through bore in said poppet member to substantially beyond the plane of the annular valve seat when the poppet valve member is spaced from said valve seat, said extension defining an outer tapered surface narrowing away from said poppet member and centered in said discharge space to effectively minimize turbulence of the fluid flowing past said extension from said inlet space.

1 3. The poppet valve of Claim 1 2 wherein said discharge space widens from said valve seat to a position spaced substantially therefrom, and said extension means causes said one end of the poppet bore to open to said discharge space adjacent the wide end thereof when the poppet is seated in said valve seat.

1 4. The poppet valve of Claim 1 2 wherein said poppet member defines an inner surface through which said extension extends.

1 5. The poppet valve of Claim 1 2 wherein said poppet member defines an inner surface having a recess opening toward said discharge space, and said extension comprises an extension element having a securing portion secured to said poppet member in said recess.

1 6. The poppet valve of Claim 12 wherein said poppet member defines an inner surface having a recess opening toward said discharge space, and said extension comprises an extension element having a securing portion threadedly secured to said poppet member in said recess.

1 7. The poppet valve as substantially described herein.