Information
-
Patent Grant
-
6364220
-
Patent Number
6,364,220
-
Date Filed
Thursday, February 12, 199826 years ago
-
Date Issued
Tuesday, April 2, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Morris; Lesley D.
- Kim; Christopher S.
Agents
-
CPC
-
US Classifications
Field of Search
US
- 239 5851
- 239 5852
- 239 5853
- 239 5854
- 239 5855
- 239 900
- 251 12921
- 251 12915
- 251 12901
-
International Classifications
-
Abstract
A fuel injector for fuel-injection systems of internal combustion engines which includes an elongated, axially running, thin-walled, non-magnetic sleeve. At its downstream end, the sleeve has a bottom section, which runs substantially normal to the otherwise axial extent of the sleeve along a longitudinal valve axis. A valve needle, which is securely joined to an armature and a valve-closure member, can move axially within a feed-through opening of the sleeve. The valve-closure member cooperates with a valve-seat surface provided on a valve-seat body, the valve-seat body being pressed into the sleeve and likewise abutting, for example, on the bottom section of the sleeve. The sleeve constituted as a drawn sheet-metal part extends axially over more than half of the axial length of the fuel injector. The fuel injector is suited for applications in fuel-injection systems of mixture-compressing internal combustion engines having externally supplied ignition.
Description
FIELD OF THE INVENTION
The present invention relates to a fuel injector.
BACKGROUND INFORMATION
U.S. Pat. No. 4,946,107 describes an electromagnetically operable fuel injection valve, which has a non-magnetic sleeve as a connecting part between a core and a valve-seat body. The sleeve is securely fixed with its two axial ends to the core and to the valve-seat body. The sleeve has a constant external diameter and a constant internal diameter over its entire axial length and, accordingly, has same-size inlet orifices at both of its ends. The core and the valve-seat body are so formed with respect to their outer diameter that they extend into the sleeve at both ends, so that the sleeve fully surrounds the two component parts, core and valve-seat body, in these inwardly projecting areas. A valve needle moves axially within the sleeve and has an armature which is guided through the sleeve. The sleeve is permanently joined to the core and to the valve-seat body by welding, for example, as described in German Patent Application No. 43 10 819, which also describes using a thin-walled, non-magnetic sleeve as a connecting part between the core and valve-seat body of a fuel injector. In terms of its structural design, this sleeve corresponds substantially to the sleeve described in U.S. Pat. No. 4,946,107. The tubular sleeves make it possible to reduce the volume and the weight of the fuel injectors.
ADVANTAGES OF THE INVENTION
One of the advantages of the fuel injector of the present invention is that it makes it possible, in a simple and cost-effective manner, to further diminish the volume and weight of the fuel injector and to fulfill a greater number of functions using only one sleeve-shaped component part. In addition to the benefit of lower manufacturing costs, it is also simpler to assemble the fuel injector because it entails comparatively few production steps. The present invention achieves these advantages by employing a thin-walled, non-magnetic sleeve as a connecting part between a core and a valve-seat body in the fuel injector, said non-magnetic sleeve also fulfilling the retaining, supporting or holding (seating) functions. Thus at its one axial end, the sleeve has a bottom section which runs normal to the axial extent of the sleeve and which assures an optimal and secure attachment of the valve-seat body and increases sleeve stability. A major factor in reducing the volume and weight is that the sleeve extends over more than half of the axial length of the fuel injector and can, therefore, even assume the function of a fuel intake fitting.
It is also advantageous to press a valve-seat body having a valve-seat surface into the sleeve, the bottom section of the sleeve providing a contact surface to prevent the valve-seat body from slipping.
It is further advantageous to produce the sleeve by deep drawing the sheet metal, as this method is simple and economical and, nevertheless, meets the required precision.
For “side-feed” injectors, which are partially traversed by a transverse flow, it is advantageous to provide bores or orifices in the inner sleeve wall to assure a direct fuel supply to the spray orifices of the fuel injector.
One particular benefit is attained by providing the bottom section of the sleeve with the spray orifices for metering fuel arranged therein. This is especially cost-effective, since one can then eliminate one component part (spray-orifice plate) and its associated joint.
It is also advantageous to design the sleeve to be long enough to extend over the entire axial extension length of the fuel injector. This enables the sleeve to assume the function of a fuel intake fitting as well. Furthermore, the core can be easily pressed into the sleeve, making it simple to adjust the valve needle lift Moreover, the problem of seal tightness toward the interior valve space is eliminated in this long sleeve arrangement. A top sealing ring provides a direct sealing action on the sleeve.
Another advantage achieved by the sleeve configuration is that valve needles or armatures of the same design can be installed for completely different types of valves.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
shows a first embodiment of a fuel injector according to the present invention.
FIG. 2
shows an embodiment of a sleeve according to the present invention.
FIG. 3
shows a first embodiment of a downstream end of the sleeve with the valve-seat body installed.
FIG. 4
shows a first embodiment of a valve needle that can be installed in the fuel injector.
FIG. 5
shows a second embodiment of the fuel injector according to the present invention.
FIG. 6
shows a second embodiment of the downstream end of the sleeve with the valve-seat body installed.
FIG. 7
shows a third embodiment of the fuel injector according to the present invention.
FIG. 8
shows a fourth embodiment of the fuel injector in the form of a seed-feed injector.
FIG. 9
shows a second embodiment of the valve needle that can be installed in the fuel injector.
DETAILED DESCRIPTION OF THE INVENTION
The electromagnetically actuated valve illustrated in
FIG. 1
, for example as a first embodiment in the form of an injector for fuel-injection systems of mixture-compressing internal combustion engines having externally supplied ignition, has a tubular core
2
surrounded by a solenoid coil
1
, and is used as a fuel intake fitting. A bobbin core
3
holds a winding of solenoid coil
1
and, in conjunction with core
2
having a constant outer diameter, makes it possible to design the injector to be especially compact and short in the area of solenoid coil
1
. Solenoid coil
1
is embedded with its bobbin core
3
, e.g. in a pot-shaped magnetic housing
5
, i.e., it is completely surrounded by magnetic housing
5
in the circumferential direction and toward the bottom. A cover element
6
that is insertable into extruded magnetic housing
5
assures that solenoid coil
1
is covered to the top and, thus, that solenoid coil
1
is completely enclosed, and is used for closing the magnetic circuit. In general, this type of pot-shaped construction keeps magnetic housing
5
, together with solenoid coil
1
, dry. There is no need to provide for additional sealing.
Joined imperviously, e.g. by means of welding, to a lower core end
9
of core
2
and concentrically to a longitudinal valve axis
10
, is a tubular and thin-walled sleeve
12
used as a connecting part, which in this context with an upper sleeve section
14
partially axially surrounds core end
9
. Bobbin core
3
overlaps sleeve section
14
of sleeve
12
at least partially axially. Over its entire axial extent, bobbin core
3
has, namely, a larger inner diameter than the diameter of sleeve
12
in its upper sleeve section
14
. Tubular sleeve
12
, e.g., of non-magnetic steel, extends downstream with a bottom sleeve section
18
to a bottom section
20
that forms downstream closure of sleeve
12
and extends normal to the axial extent of sleeve
12
.
Sleeve
12
thus has a tubular form over its entire axial length, but in its entirety, together with bottom section
20
, is cup-shaped. In this context, over its entire axial extent to bottom section
20
, sleeve
12
forms a feed-through opening
21
having a substantially constant diameter, which runs concentrically to longitudinal valve axis
10
. With its bottom sleeve section
18
, sleeve
12
surrounds an armature
24
and, further downstream, a valve-seat body
25
. A spray-orifice plate
26
that is, e.g., permanently fixed to valve-seat body
25
, is surrounded by sleeve
12
, in the circumferential direction by sleeve section
18
and, in the radial direction, by bottom section
20
. Sleeve
12
is thus not only a connecting part, but also fulfills retaining, supporting or holding functions, in particular for valve-seat body
25
, so that sleeve
12
effectively also constitutes the valve-seat support. Disposed in passage
21
is, e.g., a tubular valve needle
28
, which is joined, e.g. by welding, at its downstream end
29
facing spray-orifice plate
26
to, e.g., a spherical valve-closure member
30
, on whose periphery are provided, for example, five flattened areas
31
allowing the fuel to be spray-discharged to flow past.
The injector is actuated electromagnetically, e.g., in a conventional manner. The electromagnetic circuit includes solenoid coil
1
, core
2
, magnetic housing
5
, and armature
24
for axially moving valve needle
28
and, thus, for opening the injector against the spring force of a return spring
33
, or for closing it. Armature
24
is joined to the end of valve needle
28
facing away from valve-closure member
30
, e.g. by a weld, and is aligned to core
2
. A guide opening
34
of valve-seat body
25
is used for guiding valve-closure member
30
during the axial movement of valve needle
28
, together with armature
24
, along longitudinal valve axis
10
. Moreover, armature
24
is guided during the axial movement in sleeve
12
. For cost reasons, it is beneficial for magnetic housing
5
and armature
24
to be manufactured from an extruded part in a lathe fixture. Cover element
6
is, e.g., a stamped part that is fastened to magnetic housing
5
by a jointed-flange connection
36
, following installation of solenoid coil
1
in magnetic housing
5
.
Spherical valve-closure member
30
cooperates with a valve-seat surface
35
of valve-seat body
25
, said valve-seat surface
35
tapering frustoconically in the direction of flow and being formed in the axial direction downstream from guide opening
34
. At its front end facing away from valve-closure member
30
, valve-seat body
25
is concentrically and securely joined to, e.g. saucer-shaped spray-orifice plate
26
, e.g., by a weld, as shown in FIG.
3
.
Inserted into a graduated flow-through bore
43
of core
2
that runs concentrically to longitudinal valve axis
10
and is used for supplying fuel in the direction of the valve seat, in particular of valve-seat surface
35
, is an adjusting sleeve
45
. Adjusting sleeve
45
is used for adjusting the resilience of return spring
33
that adjoins it, said return spring
33
, in turn, being braced with its opposite side against valve needle
28
.
The depth of insertion of valve-seat body
25
having saucer-shaped spray-orifice plate
26
is decisive, among other things, for the lift of valve needle
28
. It is essentially already set by the spatial position of bottom section
20
of sleeve
12
. In this context, the one end position of valve needle
28
is defined, given a de-energized solenoid coil
1
, by the valve-closure member's
30
contact making on valve-seat surface
35
of valve-seat body
25
, while the other end position of valve needle
28
, given an energized solenoid coil
1
, results from armature's
24
contact making on core end
9
. To prevent magnetic sticking, provision can be made between armature
24
and core end
9
for a limit-stop washer
47
made, e.g. of a non-magnetic, wear-resistant, hard-rolled material. Thus, one can then prevent the surfaces of core
2
and armature
24
from being coated (e.g., chromized) in their limit-stop areas. The limit-stop areas on core
2
and armature
24
are cold work-hardened and compressed in a smoothing-rolling operation. Moreover, the lift is adjusted by axially shifting core
2
in upper sleeve section
14
of sleeve
12
, said core
2
being pressed in with little (not substantially tight) interference. Core
2
is then securely joined in the appropriate, desired position to sleeve
12
, a laser weld being useful on the periphery of sleeve
12
. The jointing excess (interference) of the press fit can also be selected to be large enough to absorb any occurring forces and to guarantee complete seal tightness, thus making it possible to eliminate a welding operation.
A fuel filter
52
projects into the inflow end of flow-through bore
43
of core
2
and assures that those fuel components are filtered out, which, because of their size, could block or damage the injector. The ready adjusted injector is substantially enclosed by a plastic extrusion coat
55
, which starts out from core
2
, extending axially over solenoid coil
1
up to sleeve
12
, and even extends downstream past bottom section
20
of sleeve
12
, an electrical plug connector
56
also being extruded on along with said plastic extrusion coat
55
. Solenoid coil
1
is electrically contacted and, thus, energized via electrical plug connector
56
.
Using the relatively inexpensive sleeve
12
makes it possible for one to do without the lathed parts customarily found in injectors, such as valve-seat supports or nozzle holders, which, because of their larger outer diameter, are more voluminous and more expensive to manufacture than sleeve
12
. In
FIG. 2
, sleeve
12
of the first embodiment shown in
FIG. 1
is depicted as a single component part on a different scale. Thin-walled sleeve
12
is formed, e.g., by deep-drawing, a non-magnetic material, such as rust-resistant CrNi steel being used as a material. Sleeve
12
constituted as a drawn sheet-metal part is used, as described above, because of its large extent, for accommodating valve-seat body
25
, spray-orifice plate
26
, valve needle
28
with armature
24
, return spring
33
, as well as at least partially core
2
and, consequently, also the lift-limiting limit-stop area of armature
24
and core
2
. In its bottom section
20
, the sleeve
12
has a centrally disposed outlet orifice
58
with a diameter large enough to allow the fuel that is spray-discharged through spray orifices
39
of spray-orifice plate
26
to leave the injector unimpeded. If the intention is to use sleeve
12
in a “seed-feed” injector, as shown in
FIG. 8
, then provision can easily be made in sleeve
12
for inlet orifices
59
, which permit fuel to enter into the interior of sleeve
12
. The top-feed injector shown in
FIG. 1
has a sleeve
12
that does not have any inlet orifices
59
, since the fuel enters along longitudinal valve axis
10
, axially via flow-through bore
43
, into sleeve
12
. At its axial end opposing bottom section
20
, sleeve
12
has, for example, a peripheral rim
60
that is bent slightly radially to the outside. Peripheral rim
60
is formed by dissociating spillover (excess) material during the deep-drawing process. The preassembled subassembly includes solenoid coil
1
, bobbin core
3
, magnetic housing
5
and cover element
6
is slid axially onto the periphery of sleeve
12
, a delimiting effect by peripheral rim
60
and a clamping of cover element
6
in the assembled state being possible. Bobbin core
3
, magnetic housing
5
, and cover element
6
all have centrally disposed feed-through openings, through which sleeve
12
then extends.
FIGS. 2 and 3
show bottom sleeve section
18
and bottom section
20
, together with an installed valve-seat body
25
, as well as with a spray-orifice plate
26
attached thereto. Besides a bottom part
38
, to which valve-seat body
25
is secured and in which run at least one, (e.g. four), spray-discharge orifice
39
formed through erosion or stamping, saucer-shaped spray-orifice plate
26
also has an upstream, circumferential retention rim
40
. Retention rim
40
is bent upstream conically outwardly, so that it abuts on the inner wall of sleeve
12
defined by feed-through opening
21
, a radial pressing (squeezing) being given. Valve-seat body
25
is pressed in cold into sleeve
12
and is not welded. The pressing, e.g. into feed-through opening
21
of sleeve
12
, is carried out until spray-orifice plate
26
, which is secured, e.g., by welding to valve-seat body
25
, abuts with its bottom part
38
on bottom section
20
of sleeve
12
. At its end, retention rim
40
of spray-orifice plate
26
has a slightly larger diameter than the diameter of feed-through opening
21
of sleeve
12
, so that retention rim
40
presses at its end against sleeve
12
, thus in addition to pressing in valve-seat body
25
, safeguards against a slipping of valve-seat body
25
.
As an alternative to sleeve-shaped valve needle
28
shown in
FIG. 1
, another embodiment of a valve needle
28
in the injector is shown by FIG.
4
. In this embodiment, valve needle
28
is designed as an oblong, solid component. Thus, it is no longer possible for the fuel to be supplied within valve needle
28
in the direction of valve-seat surface
35
. Therefore, provision is already made in armature
24
for outlet orifices
62
′, through which the fuel arriving from an inner orifice
63
of armature
24
can flow, to then arrive outside of valve needle
28
, further downstream, in feed-through opening
21
of sleeve
12
. Armature
24
has, e.g., a stepped design, a top, upstream armature section
64
having a larger diameter than a bottom downstream armature section
65
. Opening
63
running inside of armature
24
has a smaller cross-section in bottom armature section
65
than in top armature section
64
. Outlet bores
62
′ are provided, e.g., as radially running transverse bores in the wall of bottom armature section
65
. A permanent connection of armature
24
and valve needle
28
is achieved, e.g., in that armature
24
is pressed onto upstream end
66
of valve needle
28
, since there is an interference fit between valve needle
28
, at least at its end
66
to be pressed in, and orifice
63
. Provision is made at end
66
of valve needle
28
, for example, for a few circumferential, e.g., crimped grooves
67
, which are used for latching armature
24
after it has been pressed on valve needle
28
.
After the press-in operation, valve needle
28
extends with its end
66
only so far into orifice
63
that outlet orifices
62
′ still remain completely free. An alternative jointing method, however, is the laser welding operation (shown in FIG.
1
). Valve needle
28
and spherical valve-closure member
30
are permanently joined, e.g., by the laser welding operation, valve needle
28
, at its downstream end facing away from armature
24
, having an upset, collar-shaped attachment flange
68
. Attachment flange
68
is formed to conform to the radius of spherical valve-closure member
30
.
The fuel injector shown in
FIG. 5
substantially corresponds in its basic design to the injector shown in FIG.
1
. Therefore, the following will only describe those components or subassemblies having a different design. Parts that have remained the same or that have equivalent functions as those in
FIG. 1
are characterized by the same reference symbols in all further exemplary embodiments. In place of magnetic housing
5
, solenoid coil
1
is surrounded by at least one conductive element
70
designed, e.g., as a bracket and being used as a ferromagnetic element. Conductive element
70
circumferentially surrounds solenoid coil
1
, at least partially, and fits with its one end on core
2
and with its other end on sleeve
12
, e.g., in the area of top sleeve section
14
, and is able to be joined to sleeve section
14
, e.g., by means of welding, soldering, or cementing. Another distinguishing feature lies in the embodiment of armature
24
. In contrast to armature
24
shown in
FIG. 4
whose outlet bores
62
′ run radially, outlet bores
62
″ are now designed to run axially and, to be specific, in a transition region
72
, which represents a step between top armature section
64
and bottom armature section
65
.
The important distinction pertains, however, to the design of sleeve
12
. The stepped, thin-walled, non-magnetic sleeve
12
, e.g., is so designed that top sleeve section
14
guiding armature
24
has a slightly larger diameter than bottom sleeve section
18
, feed-through opening
21
of sleeve
12
being reduced to the same extent in the downstream direction. Moreover, bottom section
20
of sleeve
12
assumes the functions of a spray-orifice plate, so that spray-orifice plate
26
can be omitted. Similarly to the known spray-orifice plates, base section
20
has at least one, e.g., four spray orifices
39
, which are introduced, e.g., by means of stamping or erosion.
As shown in
FIG. 6
, which conforms to
FIG. 3
, valve-seat body
25
and sleeve
12
are again shown on an enlarged scale in the area of bottom section
20
. Bottom section
20
is designed as a conventional spray-orifice plate and, thus, does not have any outlet orifice
58
, but rather only spray orifices
39
for metering the fuel. In addition to the connecting, holding and supporting functions already described, sleeve
12
now also fulfills a metering and spray-discharge function. Valve-seat body
25
can either be imperviously welded to sleeve
12
in the area of bottom section
20
and/or in the area of bottom sleeve section
18
, or be pressed imperviously into sleeve
12
. The benefit of this arrangement is that it eliminates the need for one component (spray-orifice plate
26
), as well as for at least one joint. Moreover, sleeve
12
, together with said bottom section
20
, is rendered more rigid, lessening the risk of damage to the valve components during handling.
While in the preceding embodiments, sleeve
12
always extended over approximately ⅔ of the injector's length, the injector shown in
FIG. 7
uses, as a valve base, a sleeve
12
which itself predefines the length of the injector and, thus, also runs nearly over the entire length of the injector. The advantage of sleeve
12
that traverses the injector is that there is no longer a need for joints that adversely affect seal tightness. Therefore, a laser welding on sleeve
12
is not necessary, because a top sealing ring
74
provides a direct sealing action on sleeve
12
. Moreover, the lift adjustment can be carried out very easily. For this, core
2
is pressed so far into sleeve
12
from the inflow end of the fuel injector until the lift of valve needle
28
reaches the desired magnitude. After that, the adjusted lift is no longer negatively influenced by other assembly steps. As an alternative to the version shown in
FIG. 7
, bottom section
20
can also directly have spray orifices
39
(compare FIGS.
5
and
6
).
The injector is easily assembled, e.g., in that first solenoid coil
1
, magnetic housing
5
, and cover element
6
(or optionally at least one conductive element
70
) are mounted on sleeve
12
, plastic coat
55
is then extrusion-coated on, valve-seat body
25
is subsequently pressed into sleeve
12
, and valve needle
28
, together with armature
24
, are introduced, and core
2
is then pressed in so far until the nominal lift is reached. All of the subsequent assembly steps are already sufficiently known. Sleeve
12
is designed, e.g., so as to be stepped twice over its axial length, the cross-section of feed-through opening
21
being reduced slightly in each case in the downstream direction. The steps provided, e.g., in the limit-stop area of armature
24
and core
2
, as well as above core
2
facilitate assembly.
FIGS. 8 and 9
show that a sleeve
12
according to the present invention can also be installed in completely different valve types, e.g., in “side-feed” injectors. A further description of such injector will not be provided, as it is already known, at least in terms of its basic design, from the German Patent Application No. 39 31 490 and can be gleaned from there. Valve needle
28
shown in
FIG. 9
includes a nozzle pintle
76
that extends into a centrally disposed valve-seat body bore
75
of valve-seat body
25
can have a simplified design as compared to known valve needles of comparable injectors by providing only one guide section
77
. Usually such valve needles have two guide sections
77
. Moreover, valve needle
28
is guided through armature
24
in sleeve
12
. As already shown in
FIG. 2
, for applications in side-feed injectors, sleeve
12
can have at least one inlet orifice
59
, via which fuel is supplied in the direction of valve-seat surface
35
.
Claims
- 1. A fuel injector for a fuel-injection system of an internal combustion engine, comprising:a valve-seat body; a valve seat situated on the valve-seat body; a thin-walled axially-extending non-magnetic sleeve including a bottom section at a downstream end of the sleeve, the bottom section extending substantially normal to the sleeve, the valve-seat body being axially and radially surrounded by the sleeve; and a valve needle including a valve-closure member, the valve needle being axially movable in the sleeve along a longitudinal valve axis of the fuel injector and cooperating with the valve seat.
- 2. The fuel injector according to claim 1, wherein the sleeve has a first axial length that is more than half of a second axial length of the fuel injector.
- 3. The fuel injector according to claim 1, wherein the sleeve includes a drawn sheet-metal part.
- 4. The fuel injector according to claim 1, wherein the valve-seat body is pressed into the sleeve, the valve-seat body including a bottom section and an axially running bottom sleeve section for contacting the sleeve.
- 5. The fuel injector according to claim 1, wherein the sleeve includes an axially extending wall, the wall having at least one inlet orifice.
- 6. The fuel injector according to claim 1, wherein the bottom section has an outlet orifice, and wherein fuel pre-metered upstream from the bottom section flows through the outlet orifice and emerges unimpeded.
- 7. The fuel injector according to claim 1, wherein the bottom section has an outlet orifice, and further comprising:a spray-orifice plate securely joined to the valve-seat body at a body downstream end of the valve-seat body and including at least one spray orifice, the spray-orifice plate at least partially contacting on the bottom section, the at least one spray orifice cooperating with the outlet orifice.
- 8. The fuel injector according to claim 1, wherein the bottom section has at least one spray orifice to generate a fuel-metering effect.
- 9. The fuel injector according to claim 1, wherein the sleeve includes a feed-through opening and at least one step to form a stepped shape extending along an axial length of the sleeve, the feed-through opening having a diameter being reduced with each of the at least one step in a downstream direction.
- 10. The fuel injector according to claim 1, wherein the sleeve extends along an axial length of the fuel injector.
- 11. The fuel injector according to claim 1, further comprising:a coat surrounding the sleeve.
- 12. The fuel injector according to claim 11, wherein the coat is a plastic extrusion coat.
- 13. The fuel injector according to claim 1, further comprising:a magnet core arranged inside the sleeve; an armature arranged inside the sleeve; a magnet coil arranged outside of the sleeve; and a magnetic housing arranged outside of the sleeve, wherein the magnet coil, the armature and the magnetic housing form an electromagnetic circuit for axially moving the valve needle, and the magnetic housing is arranged outside of the magnet coil.
- 14. The fuel injector according to claim 1, wherein:the sleeve has a first axial length that is more than half of a second axial length of the fuel injector; and the sleeve includes a drawn sheet-metal part.
- 15. The fuel injector according to claim 1, wherein:the valve-seat body is pressed into the sleeve, the valve-seat body including a bottom section and an axially running bottom sleeve section for contacting the sleeve; and the sleeve includes an axially extending wall, the wall having at least one inlet orifice.
- 16. The fuel injector according to claim 1, wherein:the sleeve has a first axial length that is more than half of a second axial length of the fuel injector; the sleeve includes a drawn sheet-metal part; the valve-seat body is pressed into the sleeve, the valve-seat body including a bottom section and an axially running bottom sleeve section for contacting the sleeve; and the sleeve includes an axially extending wall, the wall having at least one inlet orifice.
- 17. The fuel injector according to claim 16, wherein a plastic extrusion coat directly surrounds the sleeve.
- 18. The fuel injector according to claim 16, further comprising:a magnet core arranged inside the sleeve; an armature arranged inside the sleeve; a magnet coil arranged outside of the sleeve; and a magnetic housing arranged outside of the sleeve, wherein the magnet coil, the armature and the magnetic housing form an electromagnetic circuit for axially moving the valve needle, and the magnetic housing is arranged outside of the magnet coil.
- 19. The fuel injector according to claim 18, wherein a plastic extrusion coat directly surrounds the sleeve.
- 20. The fuel injector according to claim 1, wherein the bottom section includes an outlet orifice, and fuel pre-metered upstream from the bottom section flows through the outlet orifice and emerges unimpeded, and further comprising:a spray-orifice plate securely joined to the valve-seat body at a body downstream end of the valve-seat body and including at least one spray orifice, the spray-orifice plate at least partially contacting on the bottom section, the at least one spray orifice cooperating with the outlet orifice, the at least one spray orifice providing a fuel-metering effect.
- 21. The fuel injector according to claim 20, wherein a plastic extrusion coat directly surrounds the sleeve.
- 22. The fuel injector according to claim 20, wherein:the sleeve has a first axial length that is more than half of a second axial length of the fuel injector; the sleeve includes a drawn sheet-metal part; the valve-seat body is pressed into the sleeve, the valve-seat body including a bottom section and an axially running bottom sleeve section for contacting the sleeve; and the sleeve includes an axially extending wall, the wall having at least one inlet orifice.
- 23. The fuel injector according to claim 22, wherein a plastic extrusion coat directly surrounds the sleeve.
- 24. The fuel injector according to claim 20, further comprising:a magnet core arranged inside the sleeve; an armature arranged inside the sleeve; a magnet coil arranged outside of the sleeve; and a magnetic housing arranged outside of the sleeve, wherein the magnet coil, the armature and the magnetic housing form an electromagnetic circuit for axially moving the valve needle, and the magnetic housing is arranged outside of the magnet coil.
- 25. The fuel injector according to claim 24, wherein a plastic extrusion coat directly surrounds the sleeve.
- 26. The fuel injector according to claim 22, wherein:the sleeve includes a feed-through opening and at least one step to form a stepped shape extending along an axial length of the sleeve, the feed-through opening having a diameter being reduced with each of the at least one step in a downstream direction; and the sleeve extends along an axial length of the fuel injector.
- 27. The fuel injector according to claim 26, wherein a plastic extrusion coat directly surrounds the sleeve.
- 28. The fuel injector according to claim 22, further comprising:a magnet core arranged inside the sleeve; an armature arranged inside the sleeve; a magnet coil arranged outside of the sleeve; and a magnetic housing arranged outside of the sleeve, wherein the magnet coil, the armature and the magnetic housing form an electromagnetic circuit for axially moving the valve needle, and the magnetic housing is arranged outside of the magnet coil.
- 29. The fuel injector according to claim 28, wherein a plastic extrusion coat directly surrounds the sleeve.
- 30. The fuel injector according to claim 28, wherein:the sleeve includes a feed-through opening and at least one step to form a stepped shape extending along an axial length of the sleeve, the feed-through opening having a diameter being reduced with each of the at least one step in a downstream direction; and the sleeve extends along an axial length of the fuel injector.
- 31. The fuel injector according to claim 30, wherein a plastic extrusion coat directly surrounds the sleeve.
- 32. The fuel injector according to claim 1, wherein a plastic extrusion coat directly surrounds the sleeve.
Priority Claims (1)
Number |
Date |
Country |
Kind |
195 47 406 |
Dec 1995 |
DE |
|
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/DE96/01391 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO97/22798 |
6/26/1997 |
WO |
A |
US Referenced Citations (15)
Foreign Referenced Citations (1)
Number |
Date |
Country |
39 31 490 |
Apr 1991 |
DE |