GB2124430A - An electromgnetic fuel injector with a plate-type armature - Google Patents

An electromgnetic fuel injector with a plate-type armature Download PDF

Info

Publication number
GB2124430A
GB2124430A GB08319322A GB8319322A GB2124430A GB 2124430 A GB2124430 A GB 2124430A GB 08319322 A GB08319322 A GB 08319322A GB 8319322 A GB8319322 A GB 8319322A GB 2124430 A GB2124430 A GB 2124430A
Authority
GB
United Kingdom
Prior art keywords
injector
spacer
armature
electromagnet
fuel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB08319322A
Other versions
GB8319322D0 (en
Inventor
John Herbert Kenning
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ZF International UK Ltd
Original Assignee
Lucas Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lucas Industries Ltd filed Critical Lucas Industries Ltd
Priority to GB08319322A priority Critical patent/GB2124430A/en
Publication of GB8319322D0 publication Critical patent/GB8319322D0/en
Publication of GB2124430A publication Critical patent/GB2124430A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details
    • G01N29/222—Constructional or flow details for analysing fluids
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M51/00—Fuel-injection apparatus characterised by being operated electrically
    • F02M51/06—Injectors peculiar thereto with means directly operating the valve needle
    • F02M51/061—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means
    • F02M51/0625—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means characterised by arrangement of mobile armatures
    • F02M51/0635—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means characterised by arrangement of mobile armatures having a plate-shaped or undulated armature not entering the winding
    • F02M51/0639—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means characterised by arrangement of mobile armatures having a plate-shaped or undulated armature not entering the winding the armature acting as a valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M51/00—Fuel-injection apparatus characterised by being operated electrically
    • F02M51/06—Injectors peculiar thereto with means directly operating the valve needle
    • F02M51/08—Injectors peculiar thereto with means directly operating the valve needle specially for low-pressure fuel-injection
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/02—Analysing fluids
    • G01N29/024—Analysing fluids by measuring propagation velocity or propagation time of acoustic waves
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
    • H01F7/16—Rectilinearly-movable armatures
    • H01F7/1638—Armatures not entering the winding
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
    • F02M2200/07—Fuel-injection apparatus having means for avoiding sticking of valve or armature, e.g. preventing hydraulic or magnetic sticking of parts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
    • F02M2200/90—Selection of particular materials
    • F02M2200/9015—Elastomeric or plastic materials
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/02—Indexing codes associated with the analysed material
    • G01N2291/021—Gases
    • G01N2291/0212—Binary gases
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/10—Number of transducers
    • G01N2291/101—Number of transducers one transducer

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Electromagnetism (AREA)
  • Acoustics & Sound (AREA)
  • Analytical Chemistry (AREA)
  • General Engineering & Computer Science (AREA)
  • Pathology (AREA)
  • Combustion & Propulsion (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Power Engineering (AREA)
  • Fuel-Injection Apparatus (AREA)

Abstract

An electromagnetic fuel injector comprises a spacer (27) against which an armature (24) of the electromagnet abuts, said spacer (27) being formed from a material which is non- magnetic, resistant to attack by fuel, electrically insulating and dimensionally stable when subject to, and able to withstand, repeated impact loading by the armature of the electromagnet. <IMAGE>

Description

SPECIFICATION Plate type fuel injectors This invention relates to plate-type electromagnetically operated fuel injectors for internal combustion engines.
In a plate-type electromagnetic fuel injector the closure member is in the form of a plate or disc formed in a material such that it constitutes the armature of the electromagnet of the injector.
It has been recognized by the applicant that it is desirable to provide a break in the magnetic circuit which exists when the electromagnet of the injector is energised, the break being in the form of a non-magnetic spacer against which the armature of the electromagnet abuts. The break in the magnetic circuit minimizes the risk of the armature remaining in its "energised" position when the electromagnet is de-energised, and thus improves the "drop-out" characteristic of the injector. Additionally the use of a non-magnetic spacer enables a simple electrical drive circuit to be used, since the improvement in the electromagnetic characteristics of the injector minimises the need for drive circuitry having accurate pulse shaping as is necessary in certain known injectors in order to achieve accurate control over opening and closing (pull-in and dropout) of the injector.The applicant has used stainless steel to produce the non-magnetic spacer, but has found that this approach is unsatisfactory in that the repeated impact of the armature on the spacer seems to impare the nonmagnetic properties of the stainless steel. It is thought that the repeated impacts convert a proportion of the austenite (non-magnetic) of the stainless steel into martensite (magnetic) with a result some some at least of the benefits of a nonmagnetic spacer are lost.
It will be recognised that engagement of the armature closure member with the spacer controls the position of the armature/closure member in the energised condition of the electromagnet. The energised condition is normally the open condition and the degree of movement of the member from its closed to its open position is critical to the operating characteristics of the injector. It follows therefore that after accurate setting of the gap which exists between the spacer and the member in the de-energised condition the gap should not alter in use of the injector.
In order to overcome the problems encountered with stainless steel a beryllium-copper alloy spacer was utilized. While this spacer does not become magnetic in use, it suffers from the problem that it is deformed by repeated impacts of the armature thus varying the critical gap. It is an object of the present invention to provide an electromagnetically operated fuel injector of the plate-type wherein these problems are minimized.
A plate-type electromagnetic fuel injector according to the present invention includes a spacer against which the armature of the electromagnet abuts, said space being formed from a material which is non-magnetic, electrically insulating, resultant to attack by the fuel, and dimensionally stable when subject to, and able to withstand, repeated impact loading by the armature of the electromagnet.
The use of an electrically insulating material has additional advantages in that it reduces eddy current losses in the valve, thus speeding up both the pull-in and drop-out characteristics of the injector. Such improvement of the drop-out characteristic permits a weaker armature return spring to be utilized thus further speeding-up the pull-in characteristic (opening) of the injector.
Preferably the spacer is formed from a synthetic resin material.
Desirably the synthetic resin material is a filmtype polyester.
Conveniently the synthetic resin material is a film-type polyester having a repeat unit of C10H804 which is resistant to attack by petroleum hydrocarbon fuels and which is non-malleable in use.
Desirably the film-type polyester is polyethylene-terephthalate.
Alternatively the synthetic resin spacer is formed from a so-called "paper" formed of an aromatic polyamide, conveniently that material sold under the Trade Name "NOMEX".
One example of the invention is illustrated in the accompanying drawings, wherein: Figure 1 is a longitudinal sectional view of an electromagnetic fuel injector for an internal combustion engine; Figure 2 is an enlargement of part of Figure 1; and Figure 3 is a plan view of a spacer shown in section in Figures 1 and 2.
Referring to the drawings, the fuel injector is an electromagnetic valve of the plate-type, that is to say having a plate or disc-like member as its closure member, the closure member also being the armature of the electromagnet of the injector.
The injector comprises a hollow, generally cylindrical outer body 11 formed from steel and having a fuel inlet 12 at one end thereof. Within the body 11 is a hollow steel core 13 having extending therethrough a passage 14 which connects the inlet 12 with an outlet 1 5 of the body 11. Encircling the core 1 3 within the body 11 is a moulded synthetic resin coil former 1 6 upon which is wound an electromagnetic winding 17. The winding 17 thus encircles the core 1 3.
Adjacent the outlet 1 5 the body 11 defines an integral, radially inwardly extending circumferentiai shoulder 1 8 against which a steel annulus 19 is trapped by a steel valve seat member 21. The valve seat member 21 is in the form of a disc the diameter of which is equal to the internal diameter of the body 1 the disc 21 having a centrally disposed fuel flow passage or metering orifice 22. The core 1 3 terminates short of the valve seat member 21 and the face of the member 21 presented to the end of the core 1 3 is shaped to provide an annular land 23 encircling the end of the passage 22. Positioned within the annulus 19 between the member 21 and the end of the core 13 is the closure member 24 of the injector.The closure member 24 (which is also the armature of the electromagnet 13, 1 7) is in the form of a steel disc slidably received within the annulus 1 9 and having extending therethrough a plurality of bores 25 arranged in a circular row about the central axis of the disc. The diameter of the circular row of bores 25 is greater than the diameter of the land 23 on the face of the member 21, and a compression spring 26 housed within the core 1 3 urges the closure member 24 into engagement with the land 23 on the face of the valve seat member 21. This is the closed position of the injector since engagement of the member 24 with the land 23 prevents flow of fuel between the inlet 12 and outlet 1 5 of the body 11.
The internal diameter of the shoulder 1 8 is less than the internal diameter of the annulus 1 9, and thus the shoulder 1 8 overlies the outer peripheral region of the closure member 24. The thickness of the closure member 24 is less than the thickness of the annulus 19 by a predetermined amount to permit the closure member 24 to move by said predetermined amount from the closed position to an open position where the closure member is arrested by the shoulder 1 8. In this position, which is achieved by energising the winding 1 7 so that the member 24 is magnetically attracted to the core 13, fuel can flow through the passage of the core 13, across the upper face of the closure member 24, through the bores 25 of the closure member 24, beneath the closure member 24 over the top of the land 23, and through the passage 22 of the valve seat member 21 at the outlet 1 5.
When the electromagnet winding 1 7 is de-energised the spring 26 returns the closure member 24 to its closed position in engagement with the land 23 of the valve seat member 21.
In order to ensure that the closure member 24 returns quickly to its closed position when the electromagnetic winding 1 7 is de-energised a non-magnetic spacer 27 is placed between the shoulder 1 8 and the closure member 24 (see Figure 2). The spacer 27 thus prevents contact between the steel closure member 24 and the steel shoulder 18, and thus improves the "dropout" characteristic of the electromagnet of the valve. Additionally, therefore, a simple drive circuit for the electromagnet can be utilized since accurate drive pulse shaping is not essential. The non-magnetic spacer 27 is in the form of an annulus of a film-type polyester synthetic resin material and is trapped in place against the shoulder 1 8 by being trapped between the shoulder 18 and the annuius 19.The electrical insulation characteristic of the spacer 27 is found to minimise eddy current losses in the iron circuit of the electromagnet, and thus is found to improve the "drop-out" characteristic of the electromagnet. The improved "drop-out" characteristic in turn permits a weaker spring 26 to be utilized than would otherwise have been the case, and the use of a weaker spring of course improves the "pull-in" characteristic.
It will be recognised that the actual material from which the spacer 27 is constructed must fulfil certain requirements. Firstly the material must be resistant to the petroleum hydrocarbon fuels which the injector is to control. The material must also be non-magnetic and electrically insulating. Furthermore, the material must be dimensionally stable when subjected repeatedly to the impact of the closure member 24 in use, that is to say the material must be non-malleable, in use. The distance through which the closure member 24 is permitted to move relative to the core 1 3 is a critical factor in a fuel injector.Clearly therefore if the material of the spacer 27 is not dimensionally stable when subject to repeated impact, and, for example, the spacer is caused to become thinner, then the distance through which the closure member 24 is permitted to move will increase, and correspondingly the gap between the closure member and the core 13 in the energised position will be reduced. Such variations are not acceptable in fuel injectors. As well as being dimensionally stable in relation to repeated impacts, the dimensional stability must be retained over a suitable temperature range bearing in mind the environment of the injector.
Thus in a fuel injector for an internal combustion engine the material of the spacer 27 must be dimensionally stable over the range -4O0C to 1700C.
Since the space member 27 is desirably very thin (conveniently no greater than 0.006 inches), it is convenient to manufacture the spacer 27 from a film-forming synthetic resin material. Amongst those materials which are suitable for use in an injector for petroleum hydrocarbon fuel are the polyester films sold under the Trade Names "MYLAR", "MEL NEX", and "HOSTOPHAN".
There may be other synthetic resin materials from which the spacer 27 could be produced. A suitable material will fulfil the following criteria. It will be magnetically and electrically nonconductive, it will be inert with respect to the relevant fuel, primarily petroleum hydrocarbon fuels, and it will be non-malleable in use. A suitable test for resistance to attack by petroleum fuel is to immerse the spacer in ASTM Reference fuel C (i.e. iso-octane/toluene) at 600C for 240 hours. A satisfactory spacer material will survive this test without evidence of cracking, crazing, softening or embrittlement and with a percentage weight change not exceeding 2.5%, and will also survive a 3 month immersion at 21 0C with a weight change not exceeding 1.0%.
A suitable test for non-malleability in use is to construct an injector using a material to be tested and to subject the injector to 500 million cycles of operation (opening and closing being one cycle).
The spacer material can be said to be sufficiently non-malleable if the calibration of the injector does not change significantly during the test.
The film-type polyester "MYLAR" which is well suited to constitute the spacer 27 is polyethylene terepththalate, a film-type polyester having a repeat unit of C,0H804. The repeat unit molecular weight is 1 92 but a typical commercial polymer having this repeat unit would have a molecular weight average between 20,000 and 30,000.
Other suitable materials exist and, for example, it is believed that other olefin derivatives of an alkyl ester of terephthalic acid may be suitable.
Also it is believed that other materials such as certain aromatic polyamide "papers" for example "NOMEX" may pass the tests set out above.

Claims (7)

1. A plate-type electromagnetc fuel injector including a spacer against which the armature of the electromagnet of the injector abuts, said spacer being formed from a material which is nonmagnetic, electrically insulating, resistant to attack by the fuel and dimensionally stable when subject to, and able to withstand, repeated impact loading by the armature of the electromagnet.
2. An injector as claimed in claim 1, wherein the spacer is formed from a synthetic resin material.
3. An injector as claimed in claim 2 wherein the synthetic resin material is a film-type polyester.
4. An injector as claimed in claim 2, wherein the synthetic resin material is a film-type polyester having a repeat unit of C10H8O4 which is resistant to attck by petroleum hydrocarbon fuels and which is non-malleable in use.
5. An injector as claimed in claim 4, wherein the film-type polyester is polyethyleneterephthalate.
6. An injector as claimed in claim 2, wherein the synthetic resin is a so-called "paper" formed of an aromatic polyamide.
7. A plate-type electromagnetic fuel injector substantially as hereinbefore described with reference to the accompanying drawings.
GB08319322A 1982-07-29 1983-07-18 An electromgnetic fuel injector with a plate-type armature Withdrawn GB2124430A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08319322A GB2124430A (en) 1982-07-29 1983-07-18 An electromgnetic fuel injector with a plate-type armature

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8221972 1982-07-29
GB08319322A GB2124430A (en) 1982-07-29 1983-07-18 An electromgnetic fuel injector with a plate-type armature

Publications (2)

Publication Number Publication Date
GB8319322D0 GB8319322D0 (en) 1983-08-17
GB2124430A true GB2124430A (en) 1984-02-15

Family

ID=26283463

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08319322A Withdrawn GB2124430A (en) 1982-07-29 1983-07-18 An electromgnetic fuel injector with a plate-type armature

Country Status (1)

Country Link
GB (1) GB2124430A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0184125A1 (en) * 1984-12-06 1986-06-11 VDO Adolf Schindling AG Electromagnetically actuated fuel injector
GB2175143A (en) * 1985-03-29 1986-11-19 Bosch Gmbh Robert Electromagnetically actuable valve
DE3811003A1 (en) * 1988-03-31 1989-10-12 Pierburg Gmbh Solenoid injection valve for internal combustion engines
WO2014206872A1 (en) * 2013-06-27 2014-12-31 Robert Bosch Gmbh Magnet assembly for a fuel injector

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB457540A (en) * 1935-05-31 1936-11-30 Standard Telephones Cables Ltd Improvements in or relating to electromagnetic light-current relays
GB1365608A (en) * 1971-05-14 1974-09-04 Sprecher & Schuh Ag Electromagnet more particularly for driving electric switchgear
GB1369187A (en) * 1972-06-22 1974-10-02 Bosch Gmbh Robert
GB2002594A (en) * 1977-08-05 1979-02-21 Europ Commutation Moving-armature electromagnetic device
GB2058466A (en) * 1979-09-08 1981-04-08 Bosch Gmbh Robert Electromagnetic fuel injection valve

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB457540A (en) * 1935-05-31 1936-11-30 Standard Telephones Cables Ltd Improvements in or relating to electromagnetic light-current relays
GB1365608A (en) * 1971-05-14 1974-09-04 Sprecher & Schuh Ag Electromagnet more particularly for driving electric switchgear
GB1369187A (en) * 1972-06-22 1974-10-02 Bosch Gmbh Robert
GB2002594A (en) * 1977-08-05 1979-02-21 Europ Commutation Moving-armature electromagnetic device
GB2058466A (en) * 1979-09-08 1981-04-08 Bosch Gmbh Robert Electromagnetic fuel injection valve

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0184125A1 (en) * 1984-12-06 1986-06-11 VDO Adolf Schindling AG Electromagnetically actuated fuel injector
GB2175143A (en) * 1985-03-29 1986-11-19 Bosch Gmbh Robert Electromagnetically actuable valve
DE3811003A1 (en) * 1988-03-31 1989-10-12 Pierburg Gmbh Solenoid injection valve for internal combustion engines
WO2014206872A1 (en) * 2013-06-27 2014-12-31 Robert Bosch Gmbh Magnet assembly for a fuel injector

Also Published As

Publication number Publication date
GB8319322D0 (en) 1983-08-17

Similar Documents

Publication Publication Date Title
EP0102723A1 (en) Plate type fuel injector
US6808133B1 (en) Fuel injection valve
CN101105165B (en) Electromagnetic fuel injection valve
CN1086585A (en) Improve the device of the opening feature of solenoid operated Fluid valve
EP1936181A1 (en) Electromagnetic fuel injector for a direct injection internal combustion engine
US4233585A (en) Plunger type electromagnet
US4660770A (en) Electromagnetic fuel injector
GB2124430A (en) An electromgnetic fuel injector with a plate-type armature
EP0896724A1 (en) Magnetic core-coil assembly for spark ignition systems
EP2835520A1 (en) Fuel injector and method for operating a fuel injector
JPS6238949B2 (en)
JPH04507125A (en) Electromagnetic actuated fuel injection valve
GB2113301A (en) Electromagnetic fuel injector with a substantially spherical valve
US5271565A (en) Fuel injector with valve bounce inhibiting means
GB2147949A (en) Fuel injector for an I.C. engine
DE3627499A1 (en) LIQUID LEVEL INDICATOR
EP0665374B1 (en) Electromagnet for controlling the metering valve of a fuel injector
DE4329976A1 (en) Method for measuring the travel (lift) of a valve and setting a valve
DE102006055088A1 (en) Injector valve for controlling a fuel quantity injected into an internal combustion engine for motor vehicles, comprises a valve body movable by an electromagnetic coil system against a valve seat
US20050098665A1 (en) Fuel injection valve
GB2201039A (en) A solenoid valve for a fuel injection pump of an internal combustion engine
US20020158155A1 (en) Fuel injection valve
GB2146846A (en) Temperature compensated solenoid device
JPS60153466A (en) Electromagnetic fuel injection valve
JPH081161B2 (en) Electromagnetically operated fuel injection valve

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)