GB2281940A - I.c. engine fuel injector - Google Patents

I.c. engine fuel injector Download PDF

Info

Publication number
GB2281940A
GB2281940A GB9319256A GB9319256A GB2281940A GB 2281940 A GB2281940 A GB 2281940A GB 9319256 A GB9319256 A GB 9319256A GB 9319256 A GB9319256 A GB 9319256A GB 2281940 A GB2281940 A GB 2281940A
Authority
GB
United Kingdom
Prior art keywords
fuel
valve member
control element
seating
piston
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Withdrawn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
GB9319256A
Other versions
GB9319256D0 (en
Inventor
Christopher Stringfellow
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 GB9319256A priority Critical patent/GB2281940A/en
Publication of GB9319256D0 publication Critical patent/GB9319256D0/en
Publication of GB2281940A publication Critical patent/GB2281940A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • 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
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • F02M45/02—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts
    • F02M45/04—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts with a small initial part, e.g. initial part for partial load and initial and main part for full load
    • F02M45/08—Injectors peculiar thereto
    • F02M45/086—Having more than one injection-valve controlling discharge orifices
    • 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
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
    • F02M61/06—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series the valves being furnished at seated ends with pintle or plug shaped extensions
    • 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
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for

Abstract

A valve member 20 is lifted from a seating 16 by fuel under pressure to provide fuel flow through an outlet 17. The effective size of the outlet can be modified by a shaped control element 24 which extends through the outlet and is slidable within an axial drilling 23 in the valve member. The element is coupled to a fluid pressure actuated piston 26 for the purpose of adjusting the position of the control element within the outlet. The end of the element 24 within the outlet 17 may have different forms (Figs. 2 and 3). A restrictor 31 may damp movements of the piston 26 due to fluctuating pressures applied to the element 24. Electrically operated valves may control fuel pressure applied to the piston and a non-return valve may replace the restrictor 31. <IMAGE>

Description

INJECTOR This invention relates to a fuel injection nozzle for supplying fuel to an internal combustion engine, the nozzle including a nozzle body in which is defined a blind bore, a seating defined at the blind end of the bore, a fuel pressure actuated valve member slidable in the bore, the valve member being shaped for cooperation with the seating and being lifted from the seating by fuel under pressure which is applied to a surface of the valve member to allow fuel flow through an outlet orifice disposed downstream of the seating.
It is known in nozzles of the aforesaid type to provide a shaped projection on the valve member, the projection extending with clearance through the outlet orifice. Such a nozzle is known in the art as a "Pintle" nozzle and the purpose of the projection is to vary the effective flow area of the outlet orifice as the valve member moves relative to the seating. Varying the flow area of the outlet orifice varies the fuel flow rate through the orifice and in the known form of nozzle the flow area is in part determined by the pressure of fuel which is supplied to the nozzle. The fuel pressure is dependent upon the speed of the associated engine since this determines the period of injection, and the load on the associated engine since this determines the amount of fuel which is supplied through the nozzle during each injection period.
In order to meet engine exhaust emission regulations it is desirable to be able to control the rate at which fuel is supplied to the engine independently of the engine speed and load and the object of the present invention is to provide a nozzle of the kind specified in a form in which this desideratum is achieved.
According to the invention in a fuel injection nozzle of the kind specified the valve member is provided with an axial drilling and there is located within the drilling a slidable control element which extends through the outlet orifice, the nozzle further including means for varying the axial position of the valve element within the outlet orifice and the portion of the control element which lies within the outlet orifice being shaped so that variation of the axial position of the control element effects variation of the effective flow area of the outlet orifice.
An example of a fuel injection nozzle in accordance with the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a sectional side elevation of the nozzle, and Figures 2 and 3 show alternative profiles for a part of the nozzle seen in Figure 1.
Referring to Figure 1 of the drawings the nozzle comprises a nozzle body 10 of cylindrical form and having a flange 11 at one end. A hollow cap nut 12 engages with the flange to secure the nozzle body to a holder 13. A distance piece 14 is sandwiched between the nozzle body and the holder.
Formed in the nozzle body is a blind bore 15 which extends inwardly from the flanged end of the body and at the blind end of the bore there is formed a tapered seating which extends inwardly to an outlet orifice 17. Adjacent the seating the bore is enlarged to form a fuel inlet chamber 18 which communicates by way of passages in the nozzle body, the distance piece and the holder with a fuel inlet 19 which in use is connected to the outlet of a fuel injection pump.
Slidable within the bore is a valve member 20 which has a reduced diameter portion which is shaped for cooperation with the seating to prevent flow of fuel from the inlet chamber through the outlet orifice.
The valve member is biased into engagement with the seating by means of a coiled compression spring 21 which is located within a chamber 22 defined in the holder and distance piece. The diameter of the chamber 22 is slightly less than that of the bore 15 and the axial length of the valve member is such that in the closed position of the valve member a small gap exists between the end of the valve member and the distance piece, this gap representing the maximum lift of the valve member in use.
The portion of the nozzle so far described is conventional and when fuel under pressure is supplied to the inlet 19 the pressure of fuel in the inlet chamber 18 acts upon the valve member in opposition to the force exerted by the spring. When the force due to the fuel under pressure is sufficient, the valve member is lifted from its seating to allow fuel flow through the outlet orifice 17. It will be appreciated that when the valve member is lifted from the seating there is an increased area against which fuel under pressure can act.
The valve member is provided with an axially disposed drilling 23 and slidably mounted within the drilling is a control element 24. The control element extends through the chamber 22 into a cylinder 25 which is formed in the holder and which accommodates a piston 26.
Conveniently the connection between the control element and the piston is by means of a screw thread and interposed between the piston and the end of the cylinder adjacent the spring 21 is a further coiled compression spring 27. The portion of the cylinder which contains the spring 27 together with the spring chamber 22 are vented to a low pressure through an outlet 28. The open end of the cylinder 25 is closed by a cap 29 which is in screw thread engagement with the holder and the cap defines an inlet 30 which can be connected to a source of fluid under pressure for example a low pressure fuel pump associated with the injection pump.
The end of the control element which lies within the outlet orifice is contoured as will be seen, so that the axial position of the control element will determine the effective flow area of the outlet orifice.
Alternative profiles for the end of the control element are shown in Figures 2 and 3. The axial position of the control element can be varied by varying the fuel pressure which is applied to the piston 26 by way of the inlet 30. Since in use, the control element will be subject to fuel pressure and also the pressure attained within the combustion chamber of the engine, a damping orifice 31 is provided to damp the movement of the piston and the control element due to fluctuating pressures applied to the control element.
Instead of a restrictor 31 a non-return valve can be provided which will allow fuel to flow into the-cylinder but will prevent fuel escaping by the same route. In this case leakage of fuel between the piston and cylinder is relied upon to permit the piston to move under the action of its spring.
The pressure which is applied to the piston may be controlled by an electrically operated valve or valves.
As described the valve member of the nozzle has a single stage of lift.
The control element as described may be applied to nozzles in which the valve member has two stages of lift.

Claims (3)

1. A fuel injection nozzle for supplying fuel to an internal combustion engine, the nozzle including a nozzle body in which is defined a blind bore, a seating defined at the blind end of the bore, a fuel pressure actuated valve member slidable in the bore, the valve member being shaped for cooperation with the seating and being lifted from the seating by fuel under pressure which is applied to a surface of the valve member to allow fuel flow through an outlet orifice disposed downstream of the seating, an axial drilling formed in the valve member, and a slidable control element located in the drilling, the control element extending through the outlet orifice, the portion of the control element which lies within the outlet orifice being shaped so that variation of the axial position of the control element effects variation of the effective flow area of the outlet orifice.
2. A fuel injection nozzle according to Claim 1, in which said control element is coupled to and is positioned by a fluid pressure operable piston.
3. A fuel injection nozzle according to Claim 2, in which said piston is slidable in a cylinder, the fluid under pressure being supplied to one end of the cylinder through a restricted orifice and the piston being moved by the fluid pressure against the action of the spring.
GB9319256A 1993-09-17 1993-09-17 I.c. engine fuel injector Withdrawn GB2281940A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9319256A GB2281940A (en) 1993-09-17 1993-09-17 I.c. engine fuel injector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9319256A GB2281940A (en) 1993-09-17 1993-09-17 I.c. engine fuel injector

Publications (2)

Publication Number Publication Date
GB9319256D0 GB9319256D0 (en) 1993-11-03
GB2281940A true GB2281940A (en) 1995-03-22

Family

ID=10742138

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9319256A Withdrawn GB2281940A (en) 1993-09-17 1993-09-17 I.c. engine fuel injector

Country Status (1)

Country Link
GB (1) GB2281940A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009091685A1 (en) * 2008-01-14 2009-07-23 North Carolina State University Fuel injection device for an internal combustion engine, and associated method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2137280A (en) * 1983-03-26 1984-10-03 Orange Gmbh Fuel-injection system for an internal-combustion engine
US4546739A (en) * 1983-08-10 1985-10-15 Diesel Kiki Co., Ltd. Fuel injection valve with variable discharge area of nozzle holes
US4658824A (en) * 1984-08-10 1987-04-21 L'orange Gmbh Fuel-injection device for an internal-combustion engine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2137280A (en) * 1983-03-26 1984-10-03 Orange Gmbh Fuel-injection system for an internal-combustion engine
US4546739A (en) * 1983-08-10 1985-10-15 Diesel Kiki Co., Ltd. Fuel injection valve with variable discharge area of nozzle holes
US4658824A (en) * 1984-08-10 1987-04-21 L'orange Gmbh Fuel-injection device for an internal-combustion engine

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009091685A1 (en) * 2008-01-14 2009-07-23 North Carolina State University Fuel injection device for an internal combustion engine, and associated method
US9316189B2 (en) 2008-01-14 2016-04-19 North Carolina State University Fuel injection device for an internal combustion engine, and associated method

Also Published As

Publication number Publication date
GB9319256D0 (en) 1993-11-03

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Legal Events

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