Title: In-tube solenoid gas valve
Abstract: A solenoid gas valve having a solenoid assembly and inlet and outlet fittings is installed inside a tube. The opening and closing of the valve is operated by the pressure difference with an aid of the magnetic field. A compression spring is attached to the support cylindrical body and held against the inlet end fitting while a moving solenoid assembly is located inside the support cylindrical body. The moving solenoid assembly that consists of a stop, a flange, a sleeve and an electrical coil, is held by a second compression spring that is attached to the inside of the support cylindrical body. A small moving magnetic rod, slides inside the sleeve of the solenoid assembly. Acted by a third compression spring, the magnetic rod seals the gas outlet through the bleed orifice on the flange of the solenoid assembly.
Patent Number: 6,994,308 Issued on 02/07/2006 to Wang, et al.
| Inventors:
|
Wang; Wei-Ching (1791 Branchwood Park, Mississauga, Ontario, CA);
Wang; Chia-Ping (1791 Branchwood Park, Mississauga, Ontario, CA)
|
| Appl. No.:
|
924789 |
| Filed:
|
August 25, 2004 |
| Current U.S. Class: |
251/30.04; 251/129.21 |
| Current Intern'l Class: |
F16K 31/02 (20060101) |
| Field of Search: |
251/3003,300.4,129.21
|
References Cited [Referenced By]
U.S. Patent Documents
Primary Examiner: Bastianelli; John
Attorney, Agent or Firm: Hammond; Peter R., Ridout & Maybee LLP
Claims
We claim:
1. An in-tube solenoid gas valve, comprising:
a valve tube defining a gas inlet passage, a gas outlet passage and a cavity;
an inlet fitting with an axial hole threading into said inlet passage of said valve
tube to connect to the in-line tube of piping system;
an outlet fitting provides a seal seat and an axial hole threading into said
outlet passage of said valve tube to connect to the inline tube of piping system;
a support cylindrical body with a chamber is pushed by a compression spring,
against said inlet fitting, inserting into said outlet fitting;
a solenoid assembly comprising a flange, an electrical coil, a stop, and a sleeve,
able to slide in said chamber of said support cylindrical body;
said solenoid assembly comprising an O-ring located in said flange for segregating
said chamber to a front side chamber and a back side chamber;
said flange provides a small seal seat, a bleed orifice, and an axial hole;
a plastic insert with a center hole, is molded onto said flange, to provide seal.
2. The in-tube solenoid gas valve as defined in claim 1; a minuscule hole on
said support cylindrical body acts a restricting gas conduit, limiting the amount
of gas of cavity flow into said front side chamber of said support cylindrical body.
3. The in-tube solenoid gas valve as defined in claim 1; having a gas conduit
for passing the gas from said front side chamber of said support cylindrical body
to a hollow space of said solenoid assembly, via an eccentric axial small hole
on said stop.
4. The in-tube solenoid gas valve as defined in claim 1; having a gas conduit
for passing the gas from said hollow space of said solenoid assembly, via said
axial hole of said flange; said minuscule hole having a diameter smaller than that
of both said eccentric axial small hole and said bleed orifice of said flange of
said solenoid assembly.
5. An in-tube solenoid gas valve as defined in claim 1; holes, on said support
cylindrical body peripherally, locating at the side of inserting into said outlet
fitting, provide gas conduits for passing the gas in said cavity flow into said
back side chamber.
6. An in-tube solenoid gas valve as defined in claim 1; said solenoid assembly
being spring biased by a compression spring onto said seal seat of said outlet
fitting, to a closed position.
7. An in-tube solenoid gas valve as defined in claim 1; a magnetic rod, able
to slide inside said sleeve in said hollow space of said solenoid assembly, is
biased by a compression spring and pushed onto said small seal seat of said flange
to a closed position; a rubber insert with an axial hole, is molded onto said magnetic
rod, to provide seal.
8. An in-tube solenoid gas valve as defined in claim 1; said electrical coil
associated with said stop, said sleeve, said flange of said solenoid assembly and
said support cylindrical body, provides a magnetic field for movements of said
magnetic rod and said flange incorporating within said solenoid assembly, so that
when the electrical current in said electrical coil is diminished, said magnetic
rod closes said bleed orifice of said flange and causes a pressure equalization,
allowing said compression spring to push said solenoid assembly to close the valve
and when said electrical coil means is energized, said magnetic rod opens said
bleed orifice to release the gas in said hollow space of said solenoid assembly
and lowers the pressure in said front side chamber which causes pushing of said
solenoid assembly to open the valve.
9. An in-tube solenoid gas valve as defined in claim 1; extend lead wires of
said electrical coil pass through the hole of an internal pass-through plug which
is inserted into said support cylindrical body, to said cavity of said valve tube.
10. An in-tube solenoid gas valve as defined in claim 9, is soldered on terminals
of an external pass-through connector at one end; external wires which is from
a power supply, through a threaded metal plug with a center hole, is soldered on
terminals of said external pass-through connector at the other end; electrical
current pass through said external wires from said power supply, said external
pass-through connector, to said lead wires of said electrical coil, to provide
a said magnetic field for movements of said magnetic rod and said solenoid assembly.
11. An in-tube solenoid gas valve, defined in claim 1; said external pass-through
connector comprising an o-ring for sealing internal pressure gas in said cavity
of said valve tube; said thread metal plug thread into said inlet fitting, to hold
said external pass-through connector in said inlet fitting.
Description
BACKGROUND OF THE INVENTION
The configuration of piping systems is complex in alternative fuel vehicles.
The fuel, either natural gas or hydrogen, is normally stored in a high pressure
tank, controlled by solenoid gas valves when it is in operation. Generally, the
space in a vehicle is limited; hence a small size of valves and piping systems
is desired. In addition, having an in-line inlet and outlet ports would simplify
the arrangement of piping systems.
Valves are used to control the flow rate of the fuel under a specified inlet
pressure. Because of the inlet pressure restrictions and temperature variations,
it is difficult to design an appropriate valve that meets all the requirements
for the piping systems. Solenoids of a reasonable size can typically produce a
pulling force that is approximately only 1/100 of the force necessary to unseat
a valve that is being forced shut by the high-pressure gases. To overcome this,
most of the gas valves adopt a two-stage process in which a small "bleed" orifice
is first opened, allowing the high-pressure gas from the storage tank to flow into
a downstream outlet passage way through the "bleed" orifice that leads to the engine.
As the downstream outlet passage way filled with gas, the pressure will increase,
subsequently reducing the force necessary gradually to unseat the closed valve.
Eventually, the differential pressure between the upstream and downstream passage
ways becomes infinite small to allow the valve to be opened by a relatively weak
pull of the solenoid valve, thus resulting in the flow of high-pressure gas from
the storage tank to the vehicle engine.
In a typical two-stage valve assembly, two pistons were required in the operation
solenoid assembly, namely primary piston and main piston. The primary piston is
located on top of the main piston. When in operation, the primary piston is first
opened to allow gas flow through a small bleed orifice located on the main piston
to create a pressure difference between the front and back sides of the main piston.
This difference in pressure causes the valve to open to gain full gas flow. Since
the movement of both pistons affects one another, the opening stroke (distance)
of the primary piston must be equal to or larger than that of the main piston to
give required operations. Since an electrical coil is utilized to generate magnetic
field to cause the primary piston to open, the longer the primary piston has to
travel, the less magnetic force the piston experiences. This becomes problematic
if the pressure of the inlet is increased. Hence, to increase the magnetic attraction
force that the primary piston experiences, the magnetic field strength has to be
increased. To increase the magnetic strength, the number of turns of the electrical
coil has to be increased if the input current stays the same. An increase in number
of turns in a coil also increases the size of the solenoid assembly, which is undesirable.
In the current design, described hereafter, the equivalent main piston will move
with a solenoid assembly while the movement of equivalent small piston does not
affect the movement of the main piston. It can reasonably reduce the size of valve
and/or increase the gas flow rate.
SUMMARY OF THE INVENTION
The newly designed solenoid valve can be used in a high gas flow and high pressure
application. It is most applicable where a small-sized solenoid gas valve with
the ability to control high gas flow rate.
It is the object of the present invention to provide an in-tube solenoid gas
valve
of the above mentioned general types which avoid the disadvantages of and improve
the performance of the prior art.
It is also the object of the present invention to provide a solenoid gas valve
which has intrinsic ability to reduce the opening stroke (distance) of a magnetic
rod to either alleviate the electrical power required or to reduce the size of
the valve. The movement of solenoid assembly is caused by the spring force and
gas pressure; therefore, the opening distance of said solenoid assembly is not
limited by magnitude of magnetic force generated by electrical power via electrical
coil. So that, the present invention can reasonably increase gas flow rate.
In keeping with these objects and with others which will became apparent hereinafter,
features of present invention reside, briefly stated in a solenoid gas valve which
has a valve tube defining a gas inlet passage with an inlet fitting, a gas outlet
passage with a outlet fitting, and a cavity; a support cylindrical body, inserting
onto outlet fitting, held by a compression spring against to inlet fitting. A solenoid
assembly comprising with flange, electrical coil, stop, and sleeve, movable axially
in the chamber of said support cylindrical body, pushed by a compression spring
against on the seat of said outlet fitting to close gas flow. An o-ring on said
flange of said solenoid assembly segregates the chamber of said support cylindrical
body into front side chamber and back side chamber.
There are two gas conduits to the outlet passage. The main gas flows through
holes on said support cylindrical body peripherally, locating at the side of attaching
to outlet fitting, into the back side chamber in support cylindrical body. Another
gas conduit, the gas flow goes through the minuscule hole in said support cylindrical
body, then, via the eccentric axial small hole in the said stop to the hollow space
of said solenoid assembly.
A magnetic rod, able to slide in said hollow space of said solenoid assembly,
is
pushed by a compression spring against on the bleed orifice of said flange of said
solenoid assembly to close gas flow. A said electrical coil means associated with
said stop, said sleeve, said flange, and said support cylindrical body to provide
a magnetic field for movements of said magnetic rod, so that when said electrical
coil is de-energized, said magnetic cylindrical rod closes said bleed orifice to
seal gas flow and causes a pressure equalization, allowing said compression spring
to push said solenoid assembly to close the valve. When said electrical coil is
energized said magnetic rod opens said bleed orifice to let gas flow to said outlet
passage and lowers a pressure which causes a pressure difference between front
and back side of said solenoid assembly, pushing of said main piston to open the valve.
The lead wires of said electrical coil extend to the external pass-through connector
for powering via the internal chamber in said support cylindrical body, internal
pass-through plug, inside said cavity of said valve tube.
Hence, in the current design, described hereafter, the stroke of the movement
of magnetic rod is not affected by the required stroke of that of the solenoid
assembly. The stroke of the magnetic rod is minimized and the stroke of the solenoid
assembly is maximized to result in a reduction of the electrical coil size and
an increase in maximum flow rate under the same conditions of the same inlet pressure
and the same power supply.
When the solenoid gas valve is designed in accordance with the present invention,
it avoids the disadvantages of the prior art and provide for the above-specified advantages.
The novel features which are considered as characteristic for the present invention
are set forth in particular in the appended claims. The invention itself, however,
both as to its construction and its method of operation, together with additional
objects and advantages thereof, will be best understood from the following description
of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
One embodiment of this invention is illustrated in the accompanying drawings,
in which like numerals denote like parts throughout the several views, and in which:
FIG. 1 is an axial sectional view through a valve constructed in accordance
with this invention, showing the valve in a "closed" state;
FIG. 2 is a detailed view of FIG. 1 through a valve constructed in accordance
with this invention, showing the valve in a "closed" state;
FIG. 3 is a detailed view, similar to that of FIG. 2, showing the small piston
opens the bleed orifice with an active magnetic field;
FIG. 4 is a detailed view, similar to that of FIG. 2, showing the main piston
opens the outlet passage with an active magnetic field. The valve is in a "fully
open" state;
FIG. 5 is a detailed view, similar to that of FIG. 2, showing the small piston
closes the bleed orifice after the magnetic field diminishes.
DESCRIPTION OF PREFERRED EMBODIMENTS
Attention is first directed to FIG. 1 and FIG. 2, which shows an in-tube
solenoid gas valve in section view. The valve tube
1 has a hollow hole with
internal threads at both ends, to accept both inlet fitting
2 and outlet
fitting
3. Both fittings have an axial hole
34 with internal threads
for connecting adaptive fittings of piping system. A support cylindrical body
4,
pushed by a compression spring
5 against said outlet fitting
3, having
a chamber
7, provides the space for movements of the solenoid assembly
6
which comprises of a hollow sleeve
8, a stop
9, a flange
10
and an electrical coil
11.
A compression spring
12 pushes said solenoid assembly
6 to the
seal
seat
13 of said outlet fitting
3 at "closed" state. A plastic insert
14 is molded onto said flange
10 to provide seal. A magnetic rod
15 moveable axially in the hollow space
16 of said solenoid assembly
6, while a compression spring
17 pushes said magnetic rod
15
against the small seal seat
18 of said flange
10 at "closed" state.
A rubber insert
19 is molded onto said magnetic rod
15 to provide seal.
An internal pass-through plug
20, inserting into the support cylindrical
body
4, provides the strain relief of lead wires of coil
21 which
extends from said electrical coil
11, through said support cylindrical body
4, to the cavity
22 of said valve tube
1. Said lead wires
of coil
21 are soldered onto the terminals of an external pass-through connector
23 at the bottom of the said connector
23 as shown in the drawing.
The said external pass-through connector
23 is placed in said inlet fitting
2 with an o-ring
24 that seals high pressure gas. Because of the
high pressure in said valve tube
1, a metal plug
25 with a center
hole is threaded into said inlet fitting
2 to hold said external pass-through
connector
23.
The high pressure gas passes through said inlet fitting
2 from upstream
piping system to said cavity
22 of said valve tube
1. Gas penetrates
into the front inside chamber
26 of said support cylindrical body
4
through a miniscule hole
27 and an o-ring
28 divides said chamber
7 of said support cylindrical body
4 into two chambers, said front
inside chamber
26 and said back inside chamber
29. Gas from said
valve tube
1 flows through holes
30 locating peripherally into said
back inside chamber
29 of said support cylindrical body
4. The gas
in said front inside chamber
26 fills said hollow space l
6 of said
solenoid assembly
6 through the eccentric axial small hole
31.
At "closed" state, as shown in FIG. 2, both said magnetic rod
15 and said
solenoid assembly
6 are pushed by said compression spring
17 and
said compression spring
12 respectively. Since the seal material is molded
onto both said magnetic rod
15 and said flange
10, both the spring
force and the high pressure gas push the seal against to said small seal seat
18
and seal seat
13, therefore blocks the gas to flow to the outlet passage.
Wires from power supply
32, through said thread metal plug
25,
are soldered onto the terminals of said external pass-through connector
23
at the outer of said valve tube
1, providing the channel for input electrical
current to said electrical coil
11 which is incorporated with said solenoid
assembly
6 to provide a magnetic field for movements of said magnetic rod
15 and said solenoid assembly
6 of the valve. The appropriate materials
should be selected for stop
9, sleeve
8, support cylindrical body
4, and flange
10 so that these components form a magnetic loop. At
the first stage of opening, the solenoid is energized, as shown in FIG. 3, said
magnetic rod
15 is pulled up by the magnetic force to allow the gas flow
in said hollow space
16 flow through bleed orifice
33 and axial hole
35 in said flange
10. Because the diameter of said minuscule hole
27 is smaller than that of said bleed orifice
33, so that, the amount
of gas supply into said hollow space
16 is less than that of gas released;
the pressure difference between the front and back side of magnetic rod
15
is equal. The magnetic force created by said electrical coil
11 causes said
magnetic rod
15 to slide and remains in "open state".
Since the diameter of said miniscule hole
27 is much smaller than that
of said through hole
30 and said o-ring
28 segregates said chamber
7 into said front inside chamber
26 and said back inside chamber
29, the gas pressure in said front chamber
26 is less than that of
said back inside chamber
29, causes a pressure difference between front
and back sides of said solenoid assembly
6. Said solenoid assembly
6
moves, as shown in FIG. 4, allowing flow through said outlet fitting
3.
When said electrical coil
11 is de-energized, as shown in FIG. 5, said
magnetic rod
15 moves against the small seal seat
18 pushed by the
compression spring
17. While high pressure gas enters the hollow space
16
through a minuscule hole
27 and a eccentric axial small hole
31,
builds up the gas pressure in said hollow space
16 of said solenoid assembly
6. The pressure in said hollow space
16 compresses the rubber insert
19 onto the magnetic rod
15 to close the bleed orifice
33.
The increasing gas pressure in said front inside chamber
26 causes pressure
equalization, results in said compression spring
12 pushes said solenoid
assembly
6 against the seal seat
13. This causes the amount of gas
leak to the outlet passage to be less than that of flows into the chamber
7
of the support cylindrical body
4. Because of the difference in projected
surface area between front and back side of said solenoid assembly
6, the
force of the front side chamber
26 is larger than that of the back side
chamber
29. Hence, the plastic insert
14 of said flange
10
is compressed onto the seal seat
13 to cease the gas flow. This is the "closed"
state, as shown in FIG. 1.
*
