|Publication number||USRE41262 E1|
|Application number||US 11/121,330|
|Publication date||Apr 27, 2010|
|Filing date||May 4, 2005|
|Priority date||Feb 23, 2001|
|Also published as||CA2372298A1, CA2372298C, DE60201764D1, DE60201764T2, DE60208439D1, DE60208439T2, EP1234974A2, EP1234974A3, EP1234974B1, EP1452718A1, EP1452718B1, US6666193, US20020117156|
|Publication number||11121330, 121330, US RE41262 E1, US RE41262E1, US-E1-RE41262, USRE41262 E1, USRE41262E1|
|Original Assignee||Crf Societa Consortile Per Azioni|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (28), Referenced by (1), Classifications (19), Legal Events (3)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The invention relates to gas injection systems, particularly of methane, for internal combustion engines, for the type comprising:
The on-off solenoid valve complies with standards in force and ensures the possibility of hermetically closing the reservoir in any emergency condition, for example in the case of an accident entailing leakage of gas into the tubes located downstream to the reservoir.
The on-off valves used to date in systems of the type specified above use a deformable metallic material valve member, typically made of synthetic rubber, with consequent problems of tightness when cold. The use of plastic material valve members is consequently not advantageous, because there is the risk of the material forming the valve member being cut or sheared consequent to the pressure with which it is pressed against the corresponding valve seat, which again causes problems of tightness.
The object of the invention is to realise an on-off valve of the perfected type for use in gas injection systems of the type described above, which guarantees good tightness quality in all conditions of operation and particularly at all operating temperatures.
To obtain this object, the invention relates to a system of the type described in the preamble, characterised in that said on-off valve comprises a metallic material valve member, co-operating with a valve seat, also made of metallic material, and a solenoid to recall the valve member to an open condition against the action of elastic means.
The use of the metal-to-metal contact of the valve according to the invention ensures a fixed geometry of the valve in all operative conditions and, particularly, and at any operating temperature and pressure value.
In a practical embodiment of the invention, said valve member presents a ball conformation and the co-operating valve seat presents an impression defining an annular portion of spherical surface formed in a tapered portion of a gas outflow conduit.
According to an additional characteristic of the invention, the valve member is recalled to the closed condition by a spring tending to push it in the same direction as the flow of gas from reservoir.
The impression forming the valve seat can be obtained by coinage in the metallic side of said conduit for by machining with a hard metal rotary tool.
The valve geometry can be predetermined so that the valve also acts as a flow limiting valve for automatically cutting off the flow of gas if the delivery tends to increase over a certain value following a leak downstream to the reservoir, for example, due to the breakage of a tube caused by an accident. For this purpose, the solenoid valve is suited to apply a force of attraction on the valve member which is higher in a first phase, in order to cause the detachment of the valve member from its seat, and lower in a second subsequent phase to keep the valve member open. During this phase, a flow of gas exceeding a predetermined threshold is thus capable of overcoming the relatively low attraction of the solenoid. Said result can be obtain by varying the power current of the solenoid and/or by suitably shaping the windings in the various areas of the solenoid.
Additional characteristics and advantages of the invention will now be described, by the way of example only, with reference to the accompanying drawings wherein:
With reference to
Despite that the example herein illustrated is referred to the system previously proposed by the Applicant, it must be stressed that the invention is applicable in general to any electronic gas injection system for an internal combustion engine, and consequently to diffuse systems from the one described in the Applicant's present Patent Application.
Specifically, the system 1 also comprises a second technique known per se, i.e. an on-off valve 12, which is also controlled by the control unit 6 to entirely cut off the output of the reservoir 5 in emergency conditions.
A cylindrical piston 17 of metallic material with a spherical surface end nose 18, forming the valve member of the valve, is slidingly mounted in the cavity 14. The valve member 18, which is made of metallic material (typically steel), co-operates with a valve seat also made of steel, formed in a tapered position 19 of a conduit putting the cavity 14 into communication with the output passage 16.
As appears in the detail in
The valve member 18 is pressed against the seat of the valve 20 by a coil spring 21 operatively interposed between the piston 17 and an end element 22, which defines the input passage 15, presenting a circumferential groove acting as a seat for the solenoid 23 of the solenoid valve. When the solenoid 23 is energised, the piston 17 is pushed into contact with an end surface 24 of the element 22 against the action of the spring 21. In this condition, the input gas in the passage 15 flows in the output passage 16 through an axial hole 25 in the piston 17, from where several holes 26 lead into a chamber 27, delimited by a piston 17 communicating with the output passage 16.
In the example shown, the portion of the body 13 where the sliding cavity 14 of the piston 17 is formed is made of a separate element 28, in which the output passage 16 is also formed. The element 28 is withheld against the element 22 by an annular lid 29, which is screwed onto the element 22 so that the solenoid 23 remains locked in the circumferential groove of the element 22 by the element 28. Obviously, the construction details are herein provided by the way of a non-limiting example and do not restrict the scope protection of the invention.
As appears in the description above, the basic concept of the invention is that of an on-off valve for an electronic gas injection system, in which both the valve member 18 and the co-operating valve seat 20 are made of metallic material elements. The metal-to-metal contact ensures the good quality of the tightness in any operative condition, thanks to the stability of its geometry in any temperature and pressure value.
As illustrated above, the annular groove 20 forming the valve seat can be made by coinage or by machining by means of a hard metal rotary tool.
Furthermore, as previously indicated, the valve can be predisposed so that the solenoid 23 applies an attraction force to the valve member 18 which is higher in a first interval of determined time to allow the detachment of the valve member in its seat and lower during a second phase only to keep the valve member open. In this way, if the flow of gas through the open valve exceeds a predetermined threshold valve, for example due to leakage of the tubes downstream to the valve, the geometry of the valve will generate a drop of pressure through the passage 19 which overcomes the attraction of the solenoid and causes the valve to close again. In this way, the valve according to the invention also acts as a flow limiting valve. This effect can be obtained also because the spring 21 pushes the valve member in the same direction of flow of the gas from the reservoir.
Moreover, numerous changes can be implemented to the construction and embodiments of the invention herein envisaged without departing from the scope of the present invention, as defined by the following claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2693929||May 2, 1951||Nov 9, 1954||Hart Charles W||Solenoid-operated valve|
|US3796409||Aug 13, 1971||Mar 12, 1974||Daimler Benz Ag||Rapidly shifting leakage-proof electromagnetically actuated valve|
|US4399944||Jul 21, 1981||Aug 23, 1983||Robert Bosch Gmbh||Electromagnetic fuel injection valve and process to manufacture an electromagnetic fuel injection valve|
|US5150690 *||Apr 20, 1990||Sep 29, 1992||Ortech Corporation||Flow control system|
|US5531199 *||May 10, 1993||Jul 2, 1996||United Fuels Limited||Internal combustion engines|
|US5546908 *||Jan 7, 1994||Aug 20, 1996||Stokes; Richard A.||Plural fuel system for internal combustion engine|
|US5584467 *||Sep 2, 1994||Dec 17, 1996||Echlin Inc.||Linear gaseous fuel flow controller|
|US5615655 *||Jun 26, 1995||Apr 1, 1997||Honda Giken Kogyo K.K.||Control system for internal combustion engines|
|US5623907 *||Jun 9, 1995||Apr 29, 1997||Walbro Corporation||Liquid propane fuel delivery system|
|US5632250 *||Sep 19, 1995||May 27, 1997||Honda Giken Kogyo Kabushiki Kaisha||Gas fuel supply system for vehicle|
|US5671711 *||Dec 7, 1995||Sep 30, 1997||Ford Global Technologies, Inc.||Low pressure LPG vapor fuel injection|
|US5738076 *||Sep 27, 1995||Apr 14, 1998||Daewoo Motor Co., Ltd.||Compressed natural gas engine|
|US5899194 *||Nov 24, 1997||May 4, 1999||Toyota Jidosha Kabushiki Kaisha||Method and apparatus for supplying fuel|
|US6289930 *||Jul 24, 2000||Sep 18, 2001||Ward J. Simon||Refrigerant expansion device having combined piston orifice valve and solenoid-actuated closure|
|US6298833 *||Apr 7, 2000||Oct 9, 2001||Westport Research Inc.||Fluid seal apparatus and method for dynamically controlling sealing-fluid pressure|
|US6427670 *||Apr 20, 2001||Aug 6, 2002||Honda Giken Kogyo Kabushiki Kaisha||Fuel gas feeding system|
|US6578560 *||Nov 26, 2001||Jun 17, 2003||Crf Societa Consortile Per Azioni||Gas injection system, particularly of methane, for internal combustion engines, and pressure regulating valve comprised in said system|
|US6666193 *||Feb 22, 2002||Dec 23, 2003||C.R.F. Societa Consortile Per Azioni||On-off valve for a gas injection system, particularly of methane, for internal combustion engines|
|US6792920 *||Nov 27, 2002||Sep 21, 2004||Honda Giken Kogyo Kabushiki Kaisha||Fuel injection apparatus for an engine|
|US7036491 *||Feb 10, 2005||May 2, 2006||C.R.F. Societa Consortile Per Azioni||Internal combustion engine gas feeding system|
|US7069917 *||Feb 10, 2005||Jul 4, 2006||C.R.F. Societa Consortile Per Azioni||Gas feeding system for an internal combustion engine, having a pressure reducing valve and a pressure regulating solenoid valve|
|US7073490 *||Feb 10, 2005||Jul 11, 2006||C.R.F. Societa Consortile Per Azioni||Gas feeding system for an internal combustion engine, having an improved pressure reducing valve|
|US7100581 *||Feb 10, 2005||Sep 5, 2006||C.R.F. Societa Consortile Per Azioni||Gas feeding system for an internal combustion engine, having a pressure reducing valve connected to the intake manifold|
|US7140354 *||Aug 30, 2005||Nov 28, 2006||Ford Global Technologies, Llc||Compressed gaseous fuel system for internal combustion engine|
|DE4205887A1||Feb 26, 1992||Sep 2, 1993||Bosch Gmbh Robert||Injection device for fuel gas mixture - has elastomer sealing ring between injection valve end and facing gas sleeve base surface|
|GB2060827A *||Title not available|
|GB2136499A||Title not available|
|SU507704A2 *||Title not available|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US20130340861 *||Jun 20, 2012||Dec 26, 2013||Caterpillar Inc||Check valve of fuel system|
|U.S. Classification||123/527, 123/458, 123/529, 123/511|
|International Classification||F02M21/02, F02M57/06|
|Cooperative Classification||F02D19/024, F02D19/027, F02M21/0266, F02M21/0221, F02M21/0233, F02M21/0296, F02M21/0245, F02M21/0254, F02M21/0209, Y02T10/32, F02M21/0242|
|European Classification||F02M21/02S10, F02M21/02|
|May 2, 2011||FPAY||Fee payment|
Year of fee payment: 8
|Sep 8, 2011||AS||Assignment|
Owner name: METATRON S.R.L., ITALY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:C.R.F. SOCIETA CONSORTILE PER AZIONI;REEL/FRAME:026872/0369
Effective date: 20110902
|Jun 5, 2015||FPAY||Fee payment|
Year of fee payment: 12