WO2013023765A1

WO2013023765A1 - Poppet valve with an improved flow path

Info

Publication number: WO2013023765A1
Application number: PCT/EP2012/003405
Authority: WO
Inventors: Vincent Tanari
Original assignee: Fluid Automation Systems S.A.
Priority date: 2011-08-15
Filing date: 2012-08-09
Publication date: 2013-02-21
Also published as: EP2745032A1

Abstract

A poppet valve (300) is provided. The poppet valve (300) includes a first fluid port (302) and a second fluid port (303). The poppet valve (300) further comprises a nozzle (304) including the first fluid port (302) at a first end and including a valve seat (307) at a second end. The poppet valve (300) can further include a poppet member (306) configured to move along a stroke axis (360) to selectively open a fluid communication path between the first and second fluid ports (302, 302). The poppet member (306) can further comprise a first portion (316) oriented generally perpendicular to the stroke axis (360) that is configured to form a substantially fluid- tight seal with the valve seat (307) and a second portion (317) comprising a protrusion extending from the first portion (316) towards the first fluid port (302).

Description

POPPET VALVE WITH AN IMPROVED FLOW PATH

TECHNICAL FIELD

The present invention relates to, valves, and more particularly, to a poppet valve with an improved flow path.

BACKGROUND OF THE INVENTION

Fluid control valves are used in a wide variety of applications to control the flow of a fluid. The fluid being controlled may comprise a gas, a liquid, or a combination thereof. In some situations, the fluid may also include suspended particulates. While fluid control valves vary widely in the specific configuration used to open and close a fluid communication path through the valve, one specific type of fluid control valve is a poppet valve. Poppet valves generally include one or more valve orifices and a poppet member that moves to contact and seal the valve orifice(s) in order to perform a valve function. Poppet valves can be actuated in a variety of different manners. For example, some poppet valves are actuated using a solenoid. Alternatively, the poppet valve can be actuated by a pilot fluid source. In solenoid-actuated poppet valves, the solenoid comprises an electric current that passes through a coil, with the coil typically formed around a magnetic core. The energized solenoid generates a magnetic field. The magnetic field operates on a movable armature connected to the poppet member. Typically, the poppet valve also includes a spring or other biasing member that generates a biasing force in opposition to the magnetic field. Therefore, in the absence of a magnetic field generated by the solenoid, the poppet member is moved into a normally open or a normally closed position.

Poppet valves have several advantages. Poppet valves can accommodate high flow rates. Poppet valves can accommodate varying flow rates. Poppet valves can form a highly reliable seal, even in the presence of moisture, dirt, debris, etc. Due to the benefits that poppet valves provide, they are very popular for industrial applications.

One problem faced with traditional poppet valves is the relatively large pressure loss and turbulence that occurs as the pressurized fluid flows through the valve. One of the largest sources of pressure loss is when the fluid exits the nozzle and impacts the face of the poppet member, which is generally flat. As the fluid impacts the poppet member, a substantial amount of the fluid's velocity is converted into pressure acting on the poppet member. Some of the energy cannot be recovered, thereby resulting in a substantial pressure loss through the valve.

FIG. 1 shows a prior art poppet valve 10 that suffers from a substantial pressure loss. The poppet valve 10 includes a fluid inlet 11, a fluid outlet 12, a fluid chamber 13, a valve seat 14, and a poppet member 15. The poppet member 15 is adapted to form a substantially fluid-tight seal with the valve seat 14. The poppet member 15 is coupled to a movable armature 16. The movable armature 16 moves in response to a magnetic field produced by an electromagnetic coil 18 and a magnetic core 19. When an electrical current is provided to the coil 18, a magnetic flux is created. The magnetic core 19 is provided to redirect the magnetic flux through the movable armature 16, thereby pulling the movable armature 16 and thus, the poppet member 15 towards the magnetic core 19. A biasing member 20 may also be provided that biases the poppet member 15 in a direction opposite the magnetic force. In the absence of the magnetic flux, the biasing member 20 can move the poppet member 15 in a direction opposite the magnetic force. The general operation of solenoid-actuated valves is known in the art and therefore, a more detailed discussion is omitted for brevity of the description.

As shown in FIG. 1, the poppet member 15 of the prior art poppet valve 10 has a substantially flat face 21, which is exposed to the inlet 11 (the inlet 11 may comprise the outlet port if the flow is reversed). The substantially flat face 21 is oriented approximately perpendicular to the general movement of the poppet member 15 as indicated by a poppet member stroke axis 60. Consequently, when the valve 10 is opened and fluid enters the fluid chamber 13 from the inlet 11, the fluid is directed towards the flat face 21 of the poppet member 15 as shown by the arrows. According to Bernoulli's principle, the following holds:

PV²

P + + pgh = constant (1)

Where:

P is the fluid pressure;

p is the fluid density;

h is the height;

V is the fluid velocity; and

g is the gravitational constant. While there are numerous variations to this equation that compensate for various frictional losses, compressibility, etc., the basic equation is provided for simplicity. Based on equation (1), it can be appreciated that due to the substantially head-on impact with the flat face 21 of the poppet member 15, the velocity of the fluid drops to approximately zero as the fluid impacts the poppet member 15 with the decrease in fluid velocity causing an increase in the pressure. This assumes that the gravitational force acting on the fluid remains substantially constant, which is a valid assumption for most valves because of the small "h" term in the equation. Therefore, the term p*g*h has almost no effect. However, not all of the energy that is converted to pressure can be recovered and rather, a substantial amount of energy of the fluid is lost. This energy loss of the fluid through the valve is typically referred to as a loss coefficient of the valve. The loss coefficient can be defined as:

Where:

K_L is the loss coefficient;

H_L is the head loss;

V is the fluid velocity; and

g is the gravitational constant.

As can be appreciated, a higher loss coefficient is associated with a higher energy loss through the valve. The majority of the energy loss through the prior art valve 10 can be associated with at least two points of viscous energy loss. One is the fluid impact with the flat face 21 of the poppet member 15 as mentioned above. The second point of major energy loss is caused by the abrupt fluid separation from the nozzle 22 as the fluid flows through the nozzle 22 and enters the fluid chamber 13. If a gas is flowing through the valve, a large pressure difference between the inlet and outlet can cause a big loss in the shock wave. It should be appreciated that there may also be a thermal energy loss. As is generally known in the art, fluid cannot change directions abruptly without suffering a severe energy loss; therefore, when flowing fluid encounters an approximately ninety-degree turn, the fluid separates from the wall of the container creating a substantial amount of turbulence, as shown at point 24. In this case, the fluid separates from the wall of the nozzle 22. The fluid first separates from the wall of the nozzle 22 at point 24 where the cross-sectional width of the nozzle 22 suddenly decreases. The fluid also separates from the nozzle 22 at the approximately ninety- degree angle turn the fluid encounters as it exits the nozzle 22 near the valve seat 14 as indicated by 23.

As a result, the energy of the fluid at the outlet 12 is much lower than the energy of the fluid at the inlet 11 as some of the energy of the fluid is lost. Depending on the particular application the prior art poppet valve 10 is used for, the severe pressure loss may have serious consequences.

Numerous prior art designs have attempted to reduce the turbulence of the fluid as it flows through the valve. One example of a prior art attempt is illustrated in FIGS. 2a & 2b.

FIG. 2a shows a cross-sectional view of a prior art poppet member 30 with a prior art valve seat 34 formed at the end of the prior art nozzle 32. The remaining components of the prior art valve 10 are not shown in FIGS. 2a & 2b because the poppet member 30, the valve seat 34, and the nozzle 32 can easily be incorporated into the prior art valve 10 shown in FIG. 1 by replacing the poppet 15, the valve seat 14, and the nozzle 22. As shown in FIG. 2a, the poppet member 30 comprises a protrusion 40. The protrusion 40 extends from the flat face 41 of the poppet member 30. The protrusion can be provided to direct fluid flowing through the associated valve away from the flat face 41, thereby reducing the amount of fluid that impacts the poppet member 30 head- on. Therefore, the goal of the poppet member 30 is to reduce the energy loss of the fluid as it impacts the poppet member 30. While the prior art poppet member 30 makes an advance in the art with regard to the fluid flow, the prior art poppet 30 creates a substantially new problem, which is the adequate sealing between the poppet 30 and the valve seat 34. As shown in FIG. 2a and in better detail in FIG. 2b, the protrusion 40 of the poppet member 30 seals against the valve seat 34 rather than the flat face 41 sealing against the valve seat 34.

FIG. 2b shows the sealing between the protrusion 40 and the valve seat 34 in better detail. As shown in FIG. 2b, the protrusion 40 is at an angle a with respect to the vertical poppet member movement. Consequently, a given gap ε between the face of the protrusion 40 and the valve seat 34 requires a much greater movement of the poppet member 30 and thus, a greater movement of the plunger 16. This is because for a given gap ε, the required movement of the poppet member 30 is calculated as E/sin(ct) due to the angled surfaces. As an example, if a gap of 4 mm (0.16 inches) is desired between the poppet member 30 and the valve seat 34 for the fluid to flow between, the plunger 16 and the poppet member 30 are required to move approximately 5.66 mm (0.22 inches) if the angle a of the protrusion is 45°. Therefore, as illustrated, the poppet member 30 in this example is required to move approximately 42% further than the desired fluid flow gap ε. If the angle a is increased to 30°, the travel distance of the poppet member 30 increases to 100% of the desired gap ε. This increase in movement requires an increase in power to operate the prior art valve. Furthermore, as can be appreciated, the specific sealing point is not as well defined for an angled contact as for a flat contact because the poppet member 30 may move further into the nozzle 22 with a stronger biasing member 20 than with a weaker biasing member 20. Conversely, a higher fluid pressure may prevent the poppet member 30 from moving into the nozzle 22 a sufficient distance to create an adequate seal. Another problem is that with a stronger biasing member 20, once the poppet member 30 is closed, it may be more difficult to open.

The present invention overcomes these and other problems and an advance in the art is achieved. The present invention provides a valve with an inlet nozzle shaped to reduce fluid separation, thereby lowering the pressure loss through the system. The present invention further provides a protrusion extending from the poppet member. The protrusion can direct a substantial amount of the fluid that impacts the poppet member in order to avoid a head-on impact with the flat portion of the poppet member. Similarly, when flow is reversed, the protrusion can aid in guiding the fluid into the nozzle, thereby avoiding fluid separation, thereby resulting in a smaller pressure loss. By diverting the fluid, the pressure loss through the valve is further reduced. However, rather than forming a seal between the protrusion and a valve seat, the present invention seals a flat portion of the poppet member against the valve seat, thereby minimizing the distance the poppet member is required to travel for a given fluid flow gap. SUMMARY OF THE INVENTION

A poppet valve is provided according to an embodiment of the invention. The poppet valve includes a first fluid port and a second fluid port. The poppet valve further comprises a nozzle including the first fluid port at a first end and including a valve seat at a second end. According to an embodiment of the invention, the poppet valve further includes a poppet member configured to move along a stroke axis to selectively open a fluid communication path between the first and second fluid ports. The poppet member can further comprise a first portion oriented generally perpendicular to the stroke axis that is configured to form a substantially fluid-tight seal with the valve seat and a second portion comprising a protrusion extending from the first portion towards the first fluid port.

A method for operating a poppet valve including a poppet member configured to move along a stroke axis, including a first portion oriented generally perpendicular to the stroke axis, and a second portion extending from the first portion towards a first fluid port is provided according to an embodiment of the invention. The method comprises a step of introducing a pressurized fluid into a nozzle through the first fluid port towards a poppet member. The method further comprises a step of actuating the poppet member to a first position. According to an embodiment of the invention, the method further comprises a step of directing the pressurized fluid out of the nozzle and into a fluid chamber using the protrusion formed on the poppet member so as to reduce head-on impacts between the fluid and the first portion of the poppet member.

A method for operating a poppet valve is provided according to an embodiment of the invention. The poppet valve includes a poppet member with a first portion oriented generally perpendicular to a stroke axis and a second portion extending from the first portion towards a first fluid port. According to an embodiment of the invention, the poppet member is configured to move along the stroke axis to selectively provide fluid communication between the first fluid port and a second fluid port. According to an embodiment of the invention, the method comprises a step of introducing a pressurized fluid into the second fluid port towards the poppet member. According to an embodiment of the invention, the method further comprises a step of actuating the poppet member to a first position. According to an embodiment of the invention, the method further comprises a step of directing the pressurized fluid past the poppet member and out of a nozzle towards the first fluid port using the protrusion formed on the poppet member to guide the pressurized fluid into the nozzle. A method of forming a poppet valve including a first fluid port and a second fluid port is provided according to an embodiment of the invention. According to an embodiment of the invention, the method comprises a step of forming the first fluid port on a first end of a nozzle and forming a valve seat on a second end of the nozzle. According to an embodiment of the invention, the method further comprises a step of positioning a poppet member between the first fluid port and the second fluid port such that the poppet member can move along a stroke axis to selectively open a fluid communication path between the first and second fluid ports. The method can further comprise a step of aligning a first portion of the poppet member generally perpendicular to the stroke axis such that the first portion can form a substantially fluid-tight seal with the valve seat. According to an embodiment of the invention, the method can also include a step of extending a second portion of the poppet member from the first portion towards the first fluid port. ASPECTS

According to an aspect of the invention, a poppet valve comprises:

a first fluid port and a second fluid port;

a nozzle including the first fluid port at a first end and including a valve seat at a second end; and

a poppet member configured to move along a stroke axis to selectively open a fluid communication path between the first and second fluid ports;

wherein the poppet member comprises a first portion oriented generally perpendicular to the stroke axis that is configured to form a substantially fluid-tight seal with the valve seat and a second portion comprising a protrusion extending from the first portion towards the first fluid port.

Preferably, the nozzle comprises a first cross-sectional width proximate the first fluid port and a second cross-sectional width proximate the valve seat, wherein D_t > D₂.

Preferably, the poppet valve further comprises a transition portion between the first cross-sectional width and the second cross-sectional width.

Preferably, the poppet valve further comprises an opening adapted to removably receive at least a portion of the second portion.

Preferably, the second portion extends into the nozzle. Preferably, the poppet valve further comprises a second poppet member configured to selectively open a fluid communication path between a third and a fourth fluid port;

wherein the second poppet member comprises a first portion oriented generally perpendicular to the stroke axis that is configured to form a substantially fluid-tight seal with a valve seat and a second portion comprising a protrusion extending from the first portion towards the third fluid port.

According to another aspect of the invention, a method for operating a poppet valve including a poppet member configured to move along a stroke axis and including a first portion oriented generally perpendicular to the stroke axis and a second portion extending from the first portion towards a first fluid port, the method comprises steps of:

introducing a pressurized fluid into a nozzle through the first fluid port towards a poppet member;

actuating the poppet member to a first position; and

directing the pressurized fluid out of the nozzle and into a fluid chamber using the protrusion formed on the poppet member so as to reduce head- on impacts between the fluid and the first portion of the poppet member. Preferably, the method further comprises a step of actuating the poppet member to a second position, wherein in the second position, the first portion of the poppet member forms a substantially fluid-tight seal with a valve seat formed on the nozzle.

Preferably, the step of actuating the poppet member to the second position further comprises a step of inserting the second portion at least partially into the nozzle.

According to another aspect of the invention, a method for operating a poppet valve including a poppet member with a first portion oriented generally perpendicular to a stroke axis and a second portion extending from the first portion towards a first fluid port, the poppet member being configured to move along the stroke axis to selectively provide fluid communication between the first fluid port and a second fluid port the method comprises steps of:

introducing a pressurized fluid into the second fluid port towards the poppet member;

actuating the poppet member to a first position; and directing the pressurized fluid past the poppet member and out of a nozzle towards the first fluid port using the protrusion formed on the poppet member to guide the pressurized fluid into the nozzle.

According to another aspect of the invention, a method of forming a poppet valve including a first fluid port and a second fluid port comprises steps of:

forming the first fluid port on a first end of a nozzle and forming a valve seat on a second end of the nozzle;

positioning a poppet member between the first fluid port and the second fluid port such that the poppet member can move along a stroke axis to selectively open a fluid communication path between the first and second fluid ports;

aligning a first portion of the poppet member generally perpendicular to the stroke axis such that the first portion can form a substantially fluid-tight seal with the valve seat; and

extending a second portion of the poppet member from the first portion towards the first fluid port.

Preferably, the method further comprises steps of:

forming the nozzle with a first cross-sectional width proximate the first fluid port; and

forming the nozzle with a second cross-sectional width proximate the valve seat, wherein the second cross-sectional width is less than the first cross- sectional width.

Preferably, the method further comprises a step of forming a transitional portion between the first and second cross-sectional widths.

Preferably, the method further comprises a step of forming an opening in the poppet member adapted to removably receive at least a portion of the second portion.

Preferably, the second portion extends into the nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional view of a prior art poppet valve.

FIG. 2a shows a cross-sectional view of a prior art poppet member. FIG. 2b shows an enlarged view of a seal created between the prior art poppet member and the valve seat.

FIG. 3 shows a cross-sectional view of a valve according to an embodiment of the invention.

FIG, 4 shows an enlarged view of the poppet member and the valve seat according to an embodiment of the invention.

FIG. 5 shows a cross-sectional view of the valve according to another embodiment of the invention.

FIG. 6 shows a cross-sectional view of the valve according to another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 3 - 6 and the following description depict specific examples to teach those skilled in the art how to make and use the best mode of the invention. For the purpose of teaching inventive principles, some conventional aspects have been simplified or omitted. Those skilled in the art will appreciate variations from these examples that fall within the scope of the invention. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the invention. As a result, the invention is not limited to the specific examples described below, but only by the claims and their equivalents.

FIG. 3 shows a cross-sectional view of a poppet valve 300 according to an embodiment of the invention. According to an embodiment of the invention, the poppet valve 300 comprises a housing 301, a first fluid port 302, a second fluid port 303, a fluid nozzle 304, a fluid chamber 305, a poppet member 306, and a valve seat 307. The fluid nozzle 304 includes the first fluid port 302 at a first end and the valve seat 307 at a second end. According to the embodiment shown, the housing 301 is separated into a first housing section 301a, and a second housing section 301b. A sealing member 320 can be provided to form a substantially fluid-tight seal between the two housing sections 301a, 301b. It should be appreciated that in other embodiments, the housing 301 may be formed from a single component.

According to one embodiment of the invention, the first fluid port 302 comprises an inlet port while the second fluid port 303 comprises an outlet port. However, it should be appreciated that the fluid flow through the valve 300 could be reversed. It should further be appreciated that the valve 300 may comprise more than two fluid ports. For example, a first and second fluid port may control a first pressurized fluid while a third and fourth fluid port could control a second pressurized fluid (See FIG. 6). Therefore, the particular embodiment shown in the figures should in no way limit the scope of the present invention.

The valve 300 shown in FIG. 3 also includes an electromagnetic coil 319 located in a sleeve 308. Positioned within the coil 319 is a magnetic core 309. The magnetic core 309 may be formed from a magnetic material or a material with a high magnetic permeability. The magnetic core 309 can be provided to direct and focus the magnetic flux produced by the coil 319. According to an embodiment of the invention, the valve 300 further comprises a movable armature 310. As can be appreciated, as the electromagnetic coil 319 is energized as is known in the art, a magnetic flux is created through the housing 301, the magnetic core 309, and the movable armature 310 in order to bias the movable armature 310 in a first direction. Therefore, the housing 301, the magnetic core 309, and the movable armature 310 may all be formed from a magnetic material or a material with a high magnetic permeability to increase the magnetic properties of the valve 300. According to an embodiment of the invention, the valve 300 further comprises a biasing member 311. The biasing member 311 can provide a biasing force on the movable armature 310 in a second direction that is substantially opposite the first direction. The biasing member 311 is shown in FIG. 3 as comprising a plate spring; however, it should be appreciated that biasing members having other configurations can certainly be used without departing from the scope of the present invention. Further, while the valve 300 is described as comprising a solenoid-actuated valve, it should be appreciated that the valve 300 may be actuated according to other known methods without departing from the scope of the present invention. For example, the valve 300 may comprise a pilot-actuated valve that is supplied a pilot pressure in order to move the movable armature 310.

According to an embodiment of the invention, the movable armature 310 can be coupled to the poppet member 306. The movable armature 310 may be coupled to the poppet member 306 according to known methods such as brazing, welding, adhesives, mechanical fasteners, etc. Therefore, as the movable armature 310 moves in response to the biasing member 311 or the magnetic flux, the poppet member 306 also moves to either open or seal against the valve seat 307 formed on the nozzle 304 to close the fluid flow path between the first and second ports 302, 303.

According to an embodiment of the invention, the poppet member 306 comprises a first portion 316 and a second portion 317. The first portion 316 can comprise a flat portion aligned generally perpendicular to the motion of the poppet member 306. The second portion 317 can comprise a protrusion that extends from the first portion 316 towards the first fluid port 302. In the embodiment shown in FIG. 3, the protrusion 317 comes to a point that can be positioned at least partially within the nozzle 304. According to an embodiment of the invention, the first portion 316 can substantially surround an outer radius of the second portion 317 as shown in the Figures. Advantageously, when the poppet member 306 is actuated to a first position, i.e., away from the valve seat 307, the protrusion 317 can direct fluid from the nozzle 304 away from the center of the poppet member 306 and into the fluid chamber 305 (See FIG. 5). The protrusion 317 therefore substantially reduces the fluid that impacts the first portion 316 of the poppet member 306 head-on, leading to a substantial pressure loss through the valve 300. Rather, with the protrusion 317 extending from the first portion 316, the pressure losses are substantially reduced.

Therefore, according to an embodiment of the invention, the protrusion 317 can improve the flow, and thereby reduce the overall pressure loss of the fluid. According to an embodiment of the invention, the protrusion 317 extends at an angle Θ with respect to the first portion 316. The angle Θ may be between 0° and 90°. In the embodiment shown, the angle Θ comprises approximately forty-five degrees. However, it should be appreciated that the angle should not be limited to forty-five degrees and other angles may be utilized while remaining within the scope of the present invention. It should also be appreciated that as the angle Θ varies, the drag and separation of the fluid from the protrusion 317 will vary. While the angle Θ is described with respect to the first portion 316, FIG. 3 also shows the angle a, which is comparable to the angle shown in FIGS. 2a & 2b. Therefore, the angle a is the angle of the protrusion 317 with respect to a stroke axis 360 of the poppet member 306. As can be appreciated, in embodiments where the first portion 316 is substantially perpendicular to the stroke axis 360, Θ + a = 90°. According to an embodiment of the invention, while the protrusion 317 can extend into the nozzle 304, the first portion 316 of the poppet 306 forms the substantially fluid-tight seal with the valve seat 307. As mentioned briefly above, the first portion 316 is generally perpendicular to the stroke axis 360 along which the poppet member 306 travels during actuation and de-actuation of the valve 300. By providing a substantially fluid-tight seal with the first portion 316 rather than with the protrusion 317, an accurate and shorter stroke distance can be ensured for a predetermined valve opening. This is shown in FIG. 4.

FIG. 4 shows an enlarged view of the first portion 316 proximate the valve seat 307 according to an embodiment of the invention. As shown in FIG. 4, the first portion 16 of the poppet member 306 seals against the valve seat 307 rather than the second portion 317. Consequently, in order to create a gap ε for the fluid to flow through the valve 300, the poppet member 306 is only required to move a distance equivalent to the fluid flow gap ε. As can be appreciated, this distance is substantially less than the distance required to create the same sized gap ε in the prior art poppet 30 illustrated in FIGS. 2a & 2b. FIG. 4 also shows a line 460, which is substantially parallel to the stroke axis 360 and is shown merely to illustrate the angle a as the stroke axis 360 is not visible in FIG. 4.

Returning to FIG. 3, in addition to the advantages provided by the improved poppet member 306, according to an embodiment of the invention, the fluid flow through the valve 300 is further optimized by providing an improved port 302. More specifically, the present invention provides an improved nozzle 304 formed in the port 302. While the prior art nozzle 22 shown in FIG. 1 comprised a substantially straight and uniform flow path with abrupt changes in the cross-sectional width, the nozzle 304 of the present invention comprises a flow path having at least two cross-sectional widths with a substantially continuous transition connecting the two cross-sectional widths. Although the nozzle 304 is explained in terms of cross-sectional "widths", it should be appreciated that the use of cross-sectional widths can be used interchangeably with cross-sectional "areas" if different shaped nozzles are used. According to an embodiment of the invention, fluid enters the nozzle 304 at the inlet port 302. The nozzle 304 proximate the inlet port 302 is shown comprising a first cross-sectional width Di. According to an embodiment of the invention, the nozzle 304 comprises a transitional portion 308. The transitional portion 308 gradually reduces the cross- sectional width of the nozzle from the first cross-sectional width at the inlet 302 to a second cross-sectional width D₂ proximate the valve seat 307. According to an embodiment of the invention, the transitional portion 308 is substantially continuous, i.e., the transitional portion 308 does not include abrupt changes in cross-sectional width, which would lead to the generation of eddies in the fluid flow. According to an embodiment of the invention, the second cross-sectional width D₂ is less than the first cross-sectional width Di.

According to an embodiment of the invention, by decreasing the cross-sectional width of the nozzle 304, the area of the poppet member 306 exposed to the pressurized fluid while the poppet member 306 is actuated to a second position and sealed against the valve seat 307, i.e., the valve 300 is closed, is substantially reduced. The reduction in exposed area of the poppet member 306 reduces the force created by the pressurized fluid acting on the poppet member 306 for a predetermined fluid pressure. Similarly, when the valve is open, for a fixed input/output pressure, the reduced exposed area does not reduce the mass flow because, by comparison, for a given surface, the pressure losses are smaller than in prior art valves due to the improved flow. Further, as can be appreciated, with the poppet member 306 closed the majority of the pressurized fluid acts on the second section 317. Therefore, a much smaller portion of the pressurized fluid is acting to push the poppet member 306 away from the valve seat 307. By reducing the force created by the pressurized fluid, a weaker biasing force is required by the biasing member 311 (assuming the valve is a normally closed valve). With a weaker biasing force provided by the biasing member 311, less force is required by the solenoid 309 during actuation. Advantageously, reducing the cross-sectional width of the nozzle 304 results in a reduction in power required to actuate the valve 300.

While the protrusion 317 is shown in FIG. 3 as comprising a substantially integral component of the poppet member 306. According to other embodiments, the protrusion 317 may comprise a separate component that is coupled to the poppet member 306.

FIG. 5 shows the valve 300 according to another embodiment of the invention.

While the poppet member 306 described in the previous embodiments comprise first and second portions 316, 317 that are integrally formed, in the embodiment shown in FIG. 5, the protrusion 317 comprises a separate component that is removably received by an opening 517 formed in the poppet member 306. Advantageously, various protrusions 317 having different angles Θ may be interchanged in order to alter the flow characteristics of the valve 300. Alternatively, a different angle Θ may be desired depending on the anticipated fluid pressure fluid flow rate. The angle Θ is typically chosen such that the transition from the second part 317 to the first part 316 changes slowly, thereby minimizing pressure loss. Another advantage of providing the protrusion 317 as a separate component is that the first and second parts 316, 317 may be formed from different materials. For example, the first part 316 may be formed from a material with good sealing characteristics, such as rubber, cork, etc. while the second part 317 can be formed from different material such as metal, plastic, etc. that typically would not be used to form a fluid-tight seal. Therefore, the remainder of the valve 300 may remain substantially the same in order to reduce the number of different types of valves that need to be stored. Rather, different protrusions may be stored that are adapted to fit into the same opening 317 in a modular manner.

Also shown in FIG. 5 is the general flow path through the valve 300. As can be seen, the fluid remains in contact with the nozzle 304 until exiting the nozzle 304 adjacent the valve seat 307. Upon exiting the valve seat 307, the fluid is directed into the chamber 305 via the protrusion 317. Advantageously, the flow is improved. Further, the fluid maintains contact with the valve seat 307 for a longer distance due to the curved edges of the valve seat 307. Therefore, the development of eddies is substantially reduced.

In use, pressurized fluid can be introduced into the valve 300 via the first fluid port 302 formed at the first end of the nozzle 304. The fluid can flow through the nozzle 304 towards the poppet member 306. If the poppet member 306 is actuated to a first position, i.e., the valve 300 is opened, the pressurized fluid can exit the nozzle 304. As the fluid exits the nozzle 304, the fluid is directed into the fluid chamber 305 using the protrusion 317. The protrusion directs the fluid away from the poppet member 306, thereby reducing the amount of fluid that impacts the first portion 316 of the poppet member 306 head-on. Therefore, the pressure loss of the fluid experienced as the fluid exits the nozzle 304 and enters the fluid chamber 305 is substantially reduced compared to the pressure loss experienced by the prior art valve 10. The fluid can then exit the valve 300 through the second fluid port 303.

In another embodiment of the invention, the pressurized fluid can be introduced into the valve 300 via the second fluid port 303. The fluid can flow into the fluid chamber 305 and towards the poppet member 306. If the valve is opened, the pressurized fluid can flow past the protrusion 317 and into the nozzle 304 and exit the valve 300 through the first fluid port 302. As explained above, the protrusion 317 improves the flow by reducing the fluid separation and can also acts to guide the fluid into the nozzle 304. The transitional portion 308 can gradually increase the cross- sectional area of the nozzle.

In order to close the valve 300, the poppet member 306 can be actuated to a second position where the first portion 316 forms a substantially fluid-tight seal with the valve seat 307.

FIG. 6 shows a portion of the valve 300 according to another embodiment of the invention. The embodiment shown in FIG. 6 differs in that the valve 300 further includes third fluid ports 602. According to an embodiment of the invention, the poppet member 306 includes a second protrusion 617. The poppet member 306 may be coupled to the movable armature 310 (not shown in FIG. 6) in order to move the poppet member 306 in a manner similar to that described above. The movable armature 310 and electromagnetic coil 319 along with other components are omitted from FIG. 6 in order to simplify the drawing. According to an embodiment, the electromagnetic coil 319 may be energized with a first current to open up the fluid flow path between the first and second fluid ports 302, 303. With the fluid flow path opened between the first and second fluid ports 302, 303, the portion 616 formed adjacent the protrusion 617 can seal against the valve seat 607. According to an embodiment of the invention, the electromagnetic coil 319 may be energized with a second current to open up the fluid flow path between the second and third fluid ports 303, 602. With the fluid flow path opened between the second and third fluid ports 303, 602, the portion 316 can seal against the valve seat 307. In other embodiments, a biasing member (not shown) may be provided to bias the movable armature 310 into a first position to open the fluid flow path between the second fluid port 303 and one of the first or third fluid ports 302, 602. In this embodiment, upon energizing the electromagnetic coil 317, the movable armature 310 can move to a second position to open the fluid communication path between the second fluid port 303 and the other one of the first or third fluid ports 302, 602. The embodiment shown in FIG. 6 is merely provided to illustrate that the valve 300 may be provided with more than two fluid ports and the particular configuration shown should in no way limit the scope of the present invention.

The present invention as described above provides a poppet valve with an improved fluid flow path. The fluid flow path through the valve is improved by providing a poppet member 306 with a first portion 316 that is generally perpendicular to a stroke axis of the poppet member 306 and a second portion 317 that extends from the first portion 316 at an angle towards the fluid port 302. The protrusion formed by the second portion 317 can advantageously direct fluid away from the center of the poppet member 306 and into the fluid chamber 305, where the fluid can exit the valve 300 through the outlet port 303. The protrusion 317 therefore decreases the amount of fluid that impacts the first portion 316 head-on, which results in substantial energy losses as the fluid converts substantially all of its velocity into pressure, much of which cannot be recovered. As mentioned above, the protrusion 317 also improves the flow and therefore prevents mass flow losses for a fixed input/output pressure.

According to an embodiment of the invention, the poppet valve 300 also improves the nozzle of the valve by reducing the cross-sectional width from a first width D_! to a second width D₂ that is less than the first width Di. According to an embodiment of the invention, the nozzle is reduced from the first width D_! to the second width D₂ through the transitional portion 308. As explained above, the transitional portion 308 gradually reduces the cross-sectional width of the nozzle from the first cross-sectional width Di at the inlet 302 to a second cross-sectional width D₂ proximate the valve seat 307. By decreasing the width of the nozzle, a smaller area of the poppet member 306 is exposed to the pressurized fluid. Advantageously, less force is required to hold the poppet member 306 closed resulting in less force required to open the valve. Therefore, the decrease in cross-sectional width of the nozzle 304 creates a valve with lower power requirements to operate.

The detailed descriptions of the above embodiments are not exhaustive descriptions of all embodiments contemplated by the inventors to be within the scope of the invention. Indeed, persons skilled in the art will recognize that certain elements of the above-described embodiments may variously be combined or eliminated to create further embodiments, and such further embodiments fall within the scope and teachings of the invention. It will also be apparent to those of ordinary skill in the art that the above-described embodiments may be combined in whole or in part to create additional embodiments within the scope and teachings of the invention.

Thus, although specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. The teachings provided herein can be applied to other valves, and not just to the embodiments described above and shown in the accompanying figures. Accordingly, the scope of the invention should be determined from the following claims.

Claims

CLAIMS We claim:

1. A poppet valve (300), comprising:

a first fluid port (302) and a second fluid port (303);

a nozzle (304) including the first fluid port (302) at a first end and including a valve seat (307) at a second end; and

a poppet member (306) configured to move along a stroke axis (360) to selectively open a fluid communication path between the first and second fluid ports (302, 303);

wherein the poppet member (306) comprises a first portion (316) oriented generally perpendicular to the stroke axis (360) that is configured to form a substantially fluid-tight seal with the valve seat (307) and a second portion (317) comprising a protrusion extending from the first portion (316) towards the first fluid port (302).

2. The poppet valve (300) of claim 1, wherein the nozzle (304) comprises a first cross-sectional width (Di) proximate the first fluid port (302) and a second cross- sectional width (D₂) proximate the valve seat (307), wherein D_! > D₂.

3. The poppet valve (300) of claim 2, further comprising a transition portion (308) between the first cross-sectional width (D and the second cross-sectional width (D₂).

4. The poppet valve (300) of claim 1, further comprising an opening (517) adapted to removably receive at least a portion of the second portion (317).

5. The poppet valve (300) of claim 1, wherein the second portion (317) extends into the nozzle (304).

6. The poppet valve (300) of claim 1, further comprising a second poppet member (606) configured to selectively open a fluid communication path between a second and a third fluid port (303, 602); wherein the second poppet member (606) comprises a first portion (616) oriented generally perpendicular to the stroke axis (360) that is configured to form a substantially fluid-tight seal with a valve seat (607) and a second portion (617) comprising a protrusion extending from the first portion (616) towards the third fluid port (602).

7. A method for operating a poppet valve including a poppet member configured to move along a stroke axis and including a first portion oriented generally perpendicular to the stroke axis and a second portion extending from the first portion towards a first fluid port, the method comprising steps of:

introducing a pressurized fluid into a nozzle through the first fluid port towards the poppet member;

actuating the poppet member to a first position; and

directing the pressurized fluid out of the nozzle and into a fluid chamber using the protrusion formed on the poppet member so as to reduce head- on impacts between the fluid and the first portion of the poppet member.

8. The method of claim 7, further comprising a step of actuating the poppet member to a second position, wherein in the second position, the first portion of the poppet member forms a substantially fluid-tight seal with a valve seat formed on the nozzle.

9. The method of claim 8, wherein the step of actuating the poppet member to the second position further comprises a step of inserting the second portion at least partially into the nozzle.

10. A method for operating a poppet valve including a poppet member with a first portion oriented generally perpendicular to a stroke axis and a second portion extending from the first portion towards a first fluid port, the poppet member being configured to move along the stroke axis to selectively provide fluid communication between the first fluid port and a second fluid port, the method comprising steps of:

11. A method of forming a poppet valve including a first fluid port and a second fluid port, comprising steps of:

12. The method of claim 11, further comprising steps of:

13. The method of claim 12, further comprising a step of forming a transitional portion between the first and second cross-sectional widths.

14. The method of claim 11, further comprising a step of forming an opening in the poppet member adapted to removably receive at least a portion of the second portion.

15. The method of claim 11 , wherein the second portion extends into the nozzle.