WO2004044390A1

WO2004044390A1 - High speed solenoid valve

Info

Publication number: WO2004044390A1
Application number: PCT/AU2003/001323
Authority: WO
Inventors: Edward Wechner
Original assignee: Duckdive Pty. Limited
Priority date: 2002-11-12
Filing date: 2003-11-04
Publication date: 2004-05-27

Abstract

There is an electrically operated valve assembly for an internal combustion engine. The valve assembly includes a valve housing (15) with a valve member (1) and piston (3) which is movable relative to a valve seat (2) between open and closed positions in accordance with an electromagnetic force applied by a solenoid core (6). There are cavities (7, 8) for compression of a gas upon movement of the valve member (1) and piston (3) in one direction between the open and closed positions in order to store energy to subsequently assist movement of the valve member (1) in the opposite direction.

Description

HIGH SPEED SOLENOID VALVE FIELD OF THE INVENTION This invention relates to valves. More particularly although not exclusively it discloses an improved high speed solenoid valve of the type used in internal combustion engines for the purpose of variable air intake and exhaust control.

BACKGROUND OF THE INVENTION With prior art variable internal combustion solenoid valves such as described by Wolfgang Saiber, Hans Kemper, Frank van der Staav and Thomas Esch in a January 2001 paper entitled THE ELECTRO-MECHANICAL VALVE TRAIN - A SYSTEM MODULE FOR FUTURE POWERTRAIN CONCEPTS (published in the MTZ Motortechnische Zeitschrift 62 (2001) Heft/Vol . Fried. Viβ eg & Sohn Veriagsgesellschaft mbH, Wiesbaden, Germany) steel coil springs are used to store and release kinetic energy for the purpose of assisting the electromagnetic solenoid forces in accelerating the valve mass. While this technology significantly enhances the valve acceleration as compared to convention solenoid valves the additional mass of the coil springs adds to the total valve mass and thus reduces the maximum potentially achievable valve velocity.

While valve assemblies using gas springs are described in prior art patent specifications such as US patents 5,988,124 and 6,076,490 these use pistons separate from the solenoid which adds to the size and mass of the mechanism.

SUMMARY OF THE INVENTION It is therefore an object of this invention to ameliorate the aforementioned disadvantage and accordingly an electrically operated valve assembly is disclosed for an internal combustion engine, said valve assembly including a valve housing with a valve member and piston means which is movable relative *to a valve seat between open and closed positions in accordance with an electromagnetic force applied by at least one solenoid core and one or more cavities for compression therein of a gas upon movement of said valve member and piston means in one direction between said open and closed positions in order to store energy to subsequently assist movement of said valve member and piston means in an opposite direction.

Preferably said piston means is an armature plate located within the valve housing.

It is further preferred that there are two solenoid cores for applying forces to move said armature plate in said one direction and in said opposite direction respectively. It is further preferred that there are two cavities for compression of said gas to assist movement of said valve member in said one direction and in said opposite direction respectively.

It is further preferred that said valve assembly includes check valve means to make up any leakage of said gas.

It is further preferred that the cross-section of the armature plate is shaped to maximise the magnetic flux for a given mass of said plate.

It is further preferred that said valve member is a poppet valve.

BRIEF DESCRIPTION OF THE DRAWINGS The currently preferred embodiment of this invention will now be described with reference to the attached drawings in whic :- figure 1 shows a cross-sectional view of the valve in its closed position along the lines A-A of figure 4, figure 2 shows a cross-sectional view of the valve in its open position along the lines A-A of figure 4, figure 3 shows a view in the direction of arrow C of figure 1, and figure 4 shows a cross-sectional view of the valve along the line B-B of figure 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to figure 1 the main components of the device are a poppet valve 1, valve seat 2, armature plate 3, gas seal 4, opening solenoid coil 5, closing solenoid coil 6, opening gas spring cavity 7, closing gas spring cavity 8 and gas spring cylinder 9.

In accordance with the currently preferred embodiment of the invention the armature plate 3 acts as a piston in the cylinder 9 for compressing both the opening gas spring cavity 7 and the closing gas spring cavity 8. This novel arrangement enables the valve assembly to be of reduced size and mass compared with prior art gas spring valve assemblies which use separate external pistons.

As in prior art solenoid valves, by energising the opening solenoid coil 5 the armature plate 3 is pulled by electromagnetic force toward the iron core 10 so that it opens the poppet valve 1.

As the armature plate 3 moves toward the iron core 10 the gas contained in the closing gas spring cavity 8 is compressed by the exponentially increasing electromagnetic force between the solenoid armature plate 3 and the iron core 10. This stores the electromagnetic energy of the solenoid coil 5 in the form of thermodynamic gas energy in the closing gas spring cavity 8. When the closing solenoid coil 6 is energised for the purpose of closing the poppet valve 1 the armature plate 3 will be pulled toward the iron core 11 and the stored energy in the closing gas spring cavity 8 will exert a force onto the armature plate 3 in the same direction as the electromagnetic force of the closing solenoid coil 6. This assists in closing the poppet valve 1 more rapidly.

Similarly, when opening the poppet valve 1 the thermodynamic energy stored during the previous closing cycle in the opening gas spring cavity 7 will assist the electromagetic force between the armature plate 3 and the iron core 10 to open the poppet valve 1 more rapidly.

For convenience air is used as the spring gas in the preferred embodiment and one way check valves 12, 13 are provided to make up for any gas leakage through the piston (armature plate) gas seal 4 and the rod seals 14. Alternatively any other suitable gas may be used in a hermetically closed system.

Although in the described embodiment of the invention the armature plate preferably has a circular shape alternative shapes such as oval or rectangular may also be used. These can be used to reduce the overall width of the valve housing 15 in one direction so that adjacent valves can be mounted closer together. The cross-section of the armature plate 3 is preferably also shaped so as to maximise the magnetic flux density for a given minimum plate mass.

Other components shown in the representations are the valve guide sleeve 16, top mounting plate 17 with cooling fins 18, mounting bolts 19, heat insulation plate 20 and valve nut 21.

It will thus be appreciated that this invention at least in the form of the embodiment described provides a novel and improved high speed solenoid valve for use in internal combustion engines. Clearly however the example disclosed is only the currently preferred form of the invention and a variety of modifications may be made which would be apparent to a person skilled in the art. For example the shape and conf guration of the valve member, gas cavities and armature plates may be changed according to design preference.

Claims

The claims defining the invention are as follows:

1. An electrically operated valve assembly for an internal combustion engine, said valve assembly including a valve housing with a valve member and piston means which is movable relative to a valve seat between open and. closed positions in accordance with an electromagnetic force applied by at least one solenoid core and one or more cavities for compression therein of a gas upon movement of said valve member and piston means in one direction between said open and closed positions in order to store energy to subsequently assist movement of said valve member and pistoh means in an opposite direction.

2. The electrically operated valve assembly as claimed in claim 1 wherein the piston means is an armature plate.

3. The electrically operated valve assembly as claimed in claim 2 wherein the armature plate is located within the valve housing.

4. The electrically operated valve assembly as claimed in claim 3 wherein said armature plate has a cross-section shaped to maximise magnetic flux for a given mass of said pl te

5. The electrically operated valve assembly as claimed in claim 4 wherein said assembly includes one or more check valves to make up any leakage of said gas.

6. The electrically operated valve assembly as claimed in claim 5 wherein the armature plate has an oval or rectangular shape to reduce the width of the valve housing whereby another valve assembly can be mounted closely adjacent thereto.

7. The electrically operated valve assembly as claimed in claim 6 wherein there are two solenoid coils for applying said electromagnetic force to move said armature plate in said one direction and in said opposite direction respectively.

8. The electrically operated valve assembly as claimed in claim 7 wherein there are two cavities for compression of said gas to assist movement of said valve member in said one direction and in said opposite direction respectively.

9. The electrically operated valve assembly as claimed in claim 8 wherein said valve member is a poppet valve.

10. An internal combustion engine when fitted with a valve assembly as claimed in claim 1.