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EP 0 404 342 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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20.01.1993 Bulletin 1993/03 |
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Date of filing: 18.05.1990 |
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Injector for fuel-injection system
Einspritzventil für Kraftstoffeinspritzsystem
Injecteur pour système d'injection de combustible
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Designated Contracting States: |
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DE FR GB |
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Priority: |
21.06.1989 US 369505
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Date of publication of application: |
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27.12.1990 Bulletin 1990/52 |
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Proprietor: GENERAL MOTORS CORPORATION |
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Detroit
Michigan 48202 (US) |
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Inventors: |
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- Stettner, Ernest Richmond
Spencerport,
New York 14559 (US)
- Taylor, Roland Stuart
Fairport,
New York 14450 (US)
- Stoltman, Donald Dibble
Henrietta,
New York 14467 (US)
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Representative: Denton, Michael John et al |
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Delphi Automotive Systems
Centre Technique Paris
117 avenue des Nations
B.P. 60059 95972 Roissy Charles de Gaulle Cedex 95972 Roissy Charles de Gaulle Cedex (FR) |
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References cited: :
US-A- 4 572 436
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US-A- 4 787 418
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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Technical field
[0001] This invention relates to a fuel-injection system for a multi-cylinder internal combustion
engine in which a plurality of injection nozzles discharge fuel adjacent the engine
inlet ports and a single injector meters the fuel to all of the injection nozzles
as specified in the preamble of claim 1, for example as disclosed in US-A-4,572,436.
[0002] An injector according to the present invention is characterised by the features specified
in the characterising portion of claim 1.
Summary of the drawings
[0003] Figure 1 is a sectional view of a single injector that meters fuel to six injection
nozzles in accordance with this invention.
[0004] Figure 2 is an enlarged sectional view of the lower portion of the Figure 1 injector,
taken along the line 2-2 of Figure 1, showing an injector valve engaging its seat.
[0005] Figure 3 is a view similar to Figure 2, showing the injector valve lifted from its
seat.
[0006] Figure 4 is an enlarged sectional view of the Figure 1 injector, taken along line
4-4 of Figure 1 and with various portions broken away, showing the relationship of
the injector valve and the orifices through which the injector meters the fuel to
the injection nozzles.
Detailed description
[0007] Referring to the drawings, an injector 10 has a body 12 that receives fuel through
a plurality of radial inlet passages 14 surrounded by a filter 16. A distributor 18
threaded into the lower end of body 12 delivers fuel through six outlet passages 20,
each of which directs fuel to an associated injection nozzle.
[0008] A valve 22 controls the delivery of fuel through passages 20. As shown in Figure
2, valve 22 is biased by a spring 24 to engage a planar surface 26 formed by raised
valve seat lands 28, each one surrounding a respective one of the passages 20, and
thereby to interrupt fuel delivery through passages 20.
[0009] Injector 10 includes a solenoid having a coil 30, a centre pole 32 surrounding spring
24, a spacer ring 34 surrounding valve 22 and sandwiched with a shim 36 between body
12 and distributor 18, and an armature formed by valve 22. Valve 22 is tapered from
its thickest portion on the left as viewed in Figures 2-3 to its thinnest portion
on the right. When coil 30 is energized as shown in Figure 3 to actuate valve 22,
the thickest portion of valve 22 engages shim 36 and causes the valve to pivot about
its left edge, thereby lifting the valve 22 from lands 28 to allow fuel delivery through
passages 20.
[0010] Each land 28 is separated from the other lands by a recessed space 38 between the
lands. The recessed space 38 assures that each land 28 is isolated from the other
lands to minimize the effect or interaction of fuel delivery through any one passage
20 on fuel delivery through the other passages.
[0011] Because valve 22 pivots as it lifts from lands 28, the clearance between valve 22
and lands 28a and 28b is less than the clearance between valve 22 and lands 28c and
28d which in turn is less than the clearance between valve 22 and lands 28e and 28f.
Unless otherwise compensated, the differences in clearance would create undesirable
inequalities in fuel delivery through passages 20.
[0012] To minimize the differences in clearance, passages 20 are clustered beneath the right,
free end of armature valve 22, and pins 40 hold valve 22 in alignment with passages
20. Pins 40 are imbedded in distributor 18 and constrain the movement of valve 22
to the pivotal motion described above, preventing valve 22 from rotating on distributor
18.
[0013] To compensate for the remaining differences in clearance, an orifice formed at the
entrance to each passage 20 is sized to assure equal fuel delivery through passages
20. Orifices 42a and 42b associated with lands 28a and 28b are larger than orifices
42c and 42d associated with lands 28c and 28d, and orifices 42c and 42d in turn are
larger than orifices 42e and 42f associated with lands 28e and 28f. In one embodiment,
the clearance between valve 22 and lands 28a and 28b is about 0.0056 and the diameter
of orifices 42a and 42b is about 0.041, the clearance between valve 22 and lands 28c
and 28d is about 0.0060 and the diameter of orifices 42c and 42d is about 0.0395,
and the clearance between valve 22 and lands 28e and 28f is about 0.0065 and the diameter
of orifices 42e and 42f is about 0.038.
[0014] Specific dimensional units are not quoted for the above figures for the various clearances
and diameters, since it is only the proportions of these figures, one to the other,
which are significant.
[0015] Stated another way, the dimensional relationships between the respective clearances
and the diameters of the orifices in this embodiment are such that the clearance between
valve 22 and lands 28a and 28b is 86.15% of the clearance between valve 22 and lands
28e and 28f, and the clearance between valve 22 and lands 28c and 28d is 92.30% of
the clearance between valve 22 and lands 28e and 28f; whilst the diameter of the orifices
42a and 42b is 108% of the diameter of orifices 42e and 42f, and the diameter of the
orifices 42c and 42d is 104% of the diameter of orifices 42e and 42f.
[0016] Injector 10 also includes an invention as set forth in European patent application
No. 90305385.8 (0 404 343) filed concurrently herewith.
1. An injector (10) comprising a distributor (18) having a plurality of outlet passages
(20) and an orifice at the entrance of each of said passages (20) and a valve seat
(28a,28b,28c,28d,28e, 28f) surrounding each orifice (42a,42b,42c,42d,42e, 42f), a
tapered valve (22) biased to engage said valve seats (28a,28b,28c,28d,28e,28f) to
interrupt fuel delivery through said outlet passages, and a valve actuator (30) adapted
to pivotally displace said valve (22) from said valve seat (28) to allow fuel delivery
through said passages (20), said valve (22) pivoting about one end thereof as it is
displaced, and the lift of said valve (22) from the valve seats (28e,28f) furthest
from said end of said valve (22) being greater than the lift of said valve (22) from
the valve seats (28a,28b) closest to said end of said valve (22), characterised in that said orifices (42a,42b,42c,42d, 42e,42f) are sized to compensate for the differences
in lift of the valve (22) from the associated valve seats (28a,28b,28c,28d,28e,28f),
the orifices (42a,42b) associated with the valve seats (28a,28b) closest to said end
of said valve (22) being larger than the orifices (42e,42f) associated with the valve
seats (28e,28f) furthest from said end of said valve (22).
2. An injector (10) according to claim 1, characterised in that, on lift of the valve (22), the clearance between said valve (22) and the valve seats
(28a,28b) closest to said end of said valve (22) is 86.15% of the clearance between
said valve (22) from the valve seats (28e,28f) furthest from said end of said valve
(22); and the diameter of the orifices (42a,42b) associated with the valve seats (28a,28b)
closest to said end of said valve (22) is 108% of the diameter of the orifices (42e,42f)
associated with the valve seats (28e,28f) furthest from said end of said valve (22).
1. Injecteur (10) comprenant un distributeur (18) pourvu de plusieurs passages de sortie
(20) et d'un orifice à l'entrée de chacun des dits passages (20) et d'un siège de
clapet (28a, 28b, 28c, 28d, 28e, 28f) entourant chacun des orifices (42a, 42b, 42c,
42d, 42e, 42f), un clapet biaisé (22) destiné à s'engager sur lesdits sièges de clapet
(28a, 28b, 28c, 28d, 28e, 28f) de manière à interrompre la distribution de carburant
à travers lesdits passages de sortie, et un actionneur (30) de clapet adapté pour
déplacer ledit clapet (22) de façon basculante depuis ledit siège (28) de clapet,
de manière à permettre la distribution de carburant à travers lesdits passages (20),
ledit clapet (22) basculant sur l'une de ses extrémités lorsqu'il est déplacé, et
la levée du clapet (22) par rapport aux sièges de clapet (28e, 28f) les plus éloignés
de ladite extrémité du dit clapet (22) étant supérieure à la levée du clapet (22)
par rapport aux sièges de clapet (28a, 28f) les plus proches de ladite extrémité du
dit clapet (22), caractérisé en ce que lesdits orifices (42a, 42b, 42c, 42d, 42e,
42f) sont calculés de façon à compenser les différences de levée du clapet (22) par
rapport aux sièges de clapet associés (28a, 28b, 28c, 28d, 28e, 28f), les orifices
(42a, 42b) associés aux sièges de clapet (28a, 28b) les plus proches de ladite extrémité
du dit clapet (22) étant plus larges que les orifices (42e, 42f) associés aux sièges
de clapet (28e, 28f) les plus éloignés de ladite extrémité du dit clapet (22).
2. Injecteur (10) selon la revendication 1, caractérisé en ce que, lorsque ledit clapet
(22) est soulevé, le jeu entre ledit clapet (22) et les sièges de clapet (28a, 28b)
les plus proches de ladite extrémité du dit clapet (22) représente 86,15 % du jeu
existant entre ledit clapet (22) et lesdits sièges de clapet (28e, 28f) les plus éloignés
de ladite extrémité du dit clapet (22); et en ce que le diamètre des orifices (42a,
42b) associés aux sièges de clapet (28a, 28b) les plus proches de ladite extrémité
du dit clapet (22) représente 108 % du diamètre des orifices (42e, 42f) associés aux
sièges de clapet (28e, 28f) les plus éloignés de ladite extrémité du dit clapet (22).
1. Einspritzventil (10) das umfaßt einen Verteiler (18) mit einer Vielzahl von Auslaßkanälen
(20) und einer Düse am Eingang eines jeden der Kanäle (20) und einem Ventilsitz (28a,
28b, 28c, 28d, 28e, 28f), der jede Düse (42a, 42b, 42c, 42d, 42e, 42f) umrandet, ein
sich verjüngendes Ventil (22), das geführt ist, um in die Ventilsitze (28a, 28b, 28c,
28d, 28e, 28f) einzugreifen, um die Kraftstoffabgabe durch die Auslaßkanäle zu unterbrechen,
und ein Ventilantrieb (30), der ausgebildet ist, schwenkbar das Ventil (22) von dem
Ventilsitz (28) zu verstellen um Kraftstoffabgabe durch die Kanäle (20) zu ermöglichen,
wobei das Ventil (22) sich bei seiner Versetzung um eines seiner Enden verschwenkt,
und die Hubhöhe des Ventils (22) von den Ventilsitzen (28e, 28f), die am weitesten
von dem Ende des Ventils (22) entfernt sind, größer ist als die Hubhöhe des Ventils
(22) von den Ventilsitzen (28a, 28b), die am nächsten zu dem Ende des Ventils (22)
liegen,
dadurch gekennzeichnet,
daß die Düsen (42a, 42b, 42c, 42d, 42e, 42f) eine Größe aufweisen, um die Hubhöhenunterschiede
der Ventile (22) von den zugehörigen Ventilsitzen (28a, 28b, 28c, 28d, 28e, 28f) zu
kompensieren, wobei die Düsen (42a, 42b), die den Ventilsitzen (28a, 28b) zugeordnet
sind, welche dem Ende des Ventils (22) am nächsten liegen, größer sind als die Düsen
(42e, 42f), die den Ventilsitzen (28e, 28f) zugeordnet sind, welche am weitesten von
dem Ende des Ventils (22) entfernt liegen.
2. Einspritzventil (10) nach Anspruch 1,
dadurch gekennzeichnet,
daß beim Heben des Ventils (22) der Spielraum zwischen dem Ventil (22) und den dem
Ende des Ventils (22) nächstliegendsten Ventilsitzen (28a, 28b) 86,15 % des Spielraums
zwischen dem Ventil (22) und den Ventilsitzen (28e, 28f) beträgt, welche von dem Ende
des Ventils (22) am weitesten entfernt sind; und daß der Durchmesser der Düsen (42a,
42b), die den dem Ende des Ventils (22) nächstliegendsten Ventilsitzen (28a, 28b)
zugeordnet sind, 108 % des Durchmessers der Düsen (42e, 42f) beträgt, welche den Ventilsitzen
(28e, 28f) zugeordnet sind, die am weitesten von dem Ende des Ventils (22) entfernt
liegen.

