U.S. patent number 3,802,626 [Application Number 05/378,906] was granted by the patent office on 1974-04-09 for device for actuating an electromagnetically controlled injector.
This patent grant is currently assigned to Automobiles Peugeot. Invention is credited to Jean Perez, Marcel Regneault.
United States Patent |
3,802,626 |
Regneault , et al. |
April 9, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
DEVICE FOR ACTUATING AN ELECTROMAGNETICALLY CONTROLLED INJECTOR
Abstract
Actuating device for an injector having a chamber the opening of
which for injection is caused by the pressure of the fuel supplied
to the chamber. The actuating device comprises a slidable closure
member of fuel valve means which is shifted by electromagnetic
means. Two opposed faces are provided on opposed ends of the
closure member which respectively co-operate with two opposed seats
on a body surrounding the closure member. The two faces and two
seats define in the body a first end chamber, a second end chamber
and a third chamber. Passage means put the first chamber in
communication with a source of fuel under pressure, the second
chamber in communication with a source of pressure lower than the
pressure of the fuel and the third chamber in communication with
the chamber of the valve.
Inventors: |
Regneault; Marcel (Colombes,
FR), Perez; Jean (Lev Allois-Perret, FR) |
Assignee: |
Automobiles Peugeot (Paris,
FR)
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Family
ID: |
27431718 |
Appl.
No.: |
05/378,906 |
Filed: |
July 13, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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266235 |
Jun 26, 1972 |
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Foreign Application Priority Data
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Jul 8, 1971 [FR] |
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71.266235 |
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Current U.S.
Class: |
239/96;
239/533.5; 239/533.8; 239/585.1 |
Current CPC
Class: |
F02M
51/06 (20130101); F02M 59/366 (20130101); F02M
63/0007 (20130101) |
Current International
Class: |
F02M
51/06 (20060101); F02M 59/20 (20060101); F02M
63/00 (20060101); F02M 59/36 (20060101); F02m
041/16 () |
Field of
Search: |
;239/96,533,585,584
;123/32,139 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wood, Jr.; M. Henson
Assistant Examiner: Mar; Michael Y.
Attorney, Agent or Firm: Burns, Doane, Swecker &
Mathis
Parent Case Text
This application is a Continuation-In-Part of application Ser. No.
266,235, filed June 26, 1972.
Claims
Having now described our invention what we claim as new and desire
to secure by Letters Patent is:
1. An actuating device for an injector having means defining a
first chamber, a movable valve member co-operative with an injector
outlet orifice and partly defining the chamber so as to be
responsive to change in pressure in the chamber; the actuating
device comprising distributor valve means having means defining a
body, means defining a bore in the body, closure means slidable in
the bore, means for subjecting opposite ends of the closure means
to identical pressure forces, two opposite sealing faces on the
closure means, two opposed seats on the body for co-operation with
the sealing faces, electromagnetic means combined with the closure
means for shifting the closure means in the bore between a position
in which a first of said faces sealingly engages a first of said
seats and a position in which a second of said faces sealingly
engages a second of said seats, the closure means defining with the
body a second chamber when said first face and first seat are in
engagement, the closure means defining with the body a third
chamber when said second face and second seat are in engagement, a
fourth chamber in the body capable of communicating with the second
chamber when the first face and first seat are separated from each
other, and capable of communicating with the third chamber when the
second face and second seat are separated from each other, passage
means for putting the second chamber in communication with a source
of fuel under pressure, passage means for putting the third chamber
in communication with a source pressure lower than the pressure of
said fuel and passage means for putting the fourth chamber in
communication with the first chamber.
2. An actuating device for an injector having means defining a
first chamber, a movable valve member co-operative with an injector
outlet orifice and partly defining the chamber so as to be
responsive to change in pressure in the chamber; the actuating
device comprising distributor valve means having means defining a
body, means defining a first end bore and a second end bore and a
third bore in the body, the third bore being intermediate the first
bore and second bore and having a diameter larger than the diameter
of the first bore and second bore, the three bores being coaxial,
closure means slidable in the first bore and second bore, means for
subjecting opposite ends of the closure means to identical pressure
forces, means defining an enlargement on the closure means, the
enlargement defining two opposite frustoconical sealing faces, a
first guide stem portion extending in one direction from the
enlargement and slidable in the first bore a second guide stem
portion extending from the enlargement and slidable in the second
bore, two opposed frustoconical seats on the body for co-operation
with the sealing faces, one of the seats being interposed between
the first bore and third bore and the other of the seats being
interposed between the second bore and the third bore,
electromagnetic means combined with the closure means for shifting
the closure means in the bores between a position in which a first
of said faces sealingly engages a first of said seats and a
position in which a second of said faces sealingly engages a second
of said seats, the closure means defining with the first bore a
second chamber with said first face and first seat are in
engagement, the closure means defining with the second bore a third
chamber within said second face and second seat are in engagement,
the third bore defining a fourth chamber in the body which is
capable of communicating with the second chamber when the first
face and first seat are separated from each other and capable of
communicating with the third chamber when the second face and
second seat are separated from each other, passage means for
putting the second chamber in communication with a source of fuel
under pressure, passage means for putting the third chamber in
communication with a source of pressure lower than the pressure of
said fuel, and passage means for putting the fourth chamber in
communication with said first chamber.
3. The device of claim 2, wherein said identical pressures
correspond to the pressure of said fuel of said source.
4. The device of claim 2, comprising groove means on said first
guide stem portion which constitute part of said passage means for
putting the second chamber in communication with said source of
fuel, and a by-pass passageway for permitting the passage of said
fuel under pressure to the second bore at the end of the second
guide stem portion.
5. The device of claim 4, wherein the second guide stem portion
includes a smooth bearing portion which is in engagement with the
second bore and defines with the second face of the closure means
and the second bore the third chamber.
6. The device of claim 1, comprising resiliently yieldable means
combined with the closure means for biasing the closure means to a
position in which the fourth chamber communicates with the third
chamber.
7. The device of claim 1, comprising a jet inserted in the passage
means for connecting the fourth chamber to the first chamber.
8. The device of claim 2, wherein the sealing faces and the seats
have different tapers.
9. An actuating device for an injector having means defining a
first chamber, a movable valve member co-operative with an injector
outlet surface and partly defining the chamber so as to be
responsive to change in pressure in the chamber; the actuating
device comprising distributor valve means having means defining a
body, said body comprising a first body member and a second body
member, means defining a first bore in the first body member and a
second bore in the second body member, the first and second bores
being coaxial, closure means comprising a first closure member
slidable in the first bore and a second closure member slidable in
the second bore, the two closure members being in engagement with
each other at first ends of the closure members, means for
subjecting second ends of the closure members opposed to said first
ends to identical pressure forces axially of the bores, a first
sealing face on the first closure member, a second sealing face on
the second closure member, a first seat on the first body member
and a second seat on the second body member for co-operation with
the first sealing face and second sealing face respectively,
electromagnetic means combined with the closure means for shifting
the closure means in the bores between a position in which the
first sealing face sealingly engages the first seat and a position
in which the second sealing face sealingly engages the second seat,
the first closure member defining with the first body a second
chamber when said first face and first seat are in engagement, the
second closure member defining with the second body member a third
chamber when said second face and second seat are in engagement, a
fourth chamber in the body capable of communicating with the second
chamber when the first face and first seats are separated from each
other and capable of communicating with the third chamber when the
second face and second seat are separated from each other, passage
means for putting the second chamber in communication with a source
of fuel under pressure, passage means for putting the third chamber
in communication with a source of pressure lower than the pressure
of said fuel, and passage means for putting the fourth chamber in
communication with the first chamber.
10. The device of claim 9, wherein the electromagnetic means
comprise a thrust member adapted and arranged to exert an axial
thrust on the first closure member upon energization of the
electromagnetic means and spring means are interposed axially
between the second closure member and the second body for biasing
the two closure members into engagement with each other and the
first closure member into engagement with the thrust member of the
electromagnetic means.
11. The device of claim 9, wherein said sealing faces and seats are
annular and frustoconical.
12. Combination comprising an injector holder having a lateral
extension portion; an injector held in the injector holder and
comprising means defining a first chamber, a seat defined by a
portion of the first chamber, a movable valve member of the
injector disposed in the first chamber and co-operative with the
seat; and an actuating device for the injector, the actuating
device being disposed in the extension portion and comprising
distributor valve means having means defining a body, means
defining a bore in the body, closure means slidable in the bore,
means for subjecting opposite ends of the closure means to
identical pressure forces, two opposite sealing faces on the
closure means, two opposed seats on the body for co-operation with
the sealing faces, electromagnetic means combined with the closure
means for shifting the closure means in the bore between a position
in which a first of said faces sealingly engages a first of said
seats and a position in which a second of said faces sealingly
engages a second of said seats, the closure means defining with the
body a second chamber when said first face and first seat are in
engagement, the closure means defining with the body a third
chamber when said second face and second seat are in engagement, a
fourth chamber in the body capable of communicating with the second
chamber when the first face and first seat are separated from each
other and capable of communicating with the third chamber when the
second face and second seat are separated from each other, passage
means for putting the second chamber in communication with a source
of fuel under pressure, passage means for putting the third chamber
in communication with a source of pressure lower than the pressure
of said fuel, and passage means for putting the fourth chamber in
communication with the first chamber.
13. The combination of claim 12, wherein the means defining the
body comprise a first body member defining a first portion of said
bore and a second body member defining a second portion of said
bore and the closure means comprise a first closure member slidable
in the first bore portion and a second closure member slidable in
the second bore portion, the closure members being relatively
movable, the first sealing face and second sealing face being on
the first closure member and second closure member respectively and
the first seat and second seat being on the first body member and
second body member respectively.
Description
The present invention relates to internal combustion engines of the
fuel injection type and more particularly concerns injecting
devices in which the injectors are actuated partly by electrical or
electronic means.
The latter expression is intended to mean that the device
controlling the injection comprises a calculator which, as a
function of a number of parameters, furnishes control or command
signals to electromagnets which directly or indirectly actuate the
injector. Usually, these injectors comprise a needle received in an
injector holder in which are also incorporated the actuating means
which raise the needle from its seat and consequently control the
injection.
Generally, these means may be put into two categories: in the first
category the needle of the injector is raised directly by the
action of a magnetic device the moving part of which is constituted
by the needle. This arrangement has the drawback of requiring large
magnetic forces since it is necessary to overcome the force of the
return spring returning the needle and possibly the hydraulic
pressure exerted by the fuel on the rear part of the needle.
In a second category, the needle of the injector is raised by the
action of the pressure of the fuel prevailing in an annular chamber
located in the vicinity of the point of the needle and partly
defined by the seat for the latter, this chamber being put in
communication with or cut off from the pressure by a valve which is
actuated by an electromagnetic device. This valve can be
constituted by a ball valve or a cylindrical slide valve having
bearing portions which stop or allow the communication between
conduits which communicate laterally with the interior of the body
of this valve. This mode of actuating also has drawbacks. Indeed,
the ball valve requires an electromagnetic device of some power in
order to overcome the pressure of the liquid and moreover it has an
operating time which is a function of the pressure, which does not
permit varying this pressure in the desired manner for reducing the
duration of injection when the engine running speed increases so as
to avoid spreading the injection over an excessively large
angle.
The slide valve can be balanced but this requires a relatively long
stroke which results in excessively slow opening and closing of the
needle valve, a drawback which can be overcome only partly by
providing an electromagnetic device which is powerful enough to
overcome the forces of inertia.
Thus the known devices all have serious drawbacks and an object of
the invention is to provide an actuating device for an injector
which overcomes these drawbacks.
The invention provides an actuating device for an injector
comprising a chamber which is defined partly by a seat co-operating
with the moving element of the injector and which surrounds this
moving element and may be selectively put under pressure by way of
a valve having a sliding or closure member, the valve being
controlled by an electromagnet, wherein the closure member is
subjected on both ends to the same force of pressure, the closure
member and the body in which it is received having respectively two
opposite active faces and two opposite seats defining a centre
chamber and two lateral chambers which chambers are respectively
connected to the injector, to a source of fuel under pressure, such
as an injection pump, and to an enclosure in which prevails a
pressure lower than the pressure of said source, for example
atmospheric pressure.
With such an arrangement, the closure member is perfectly balanced
and requires a very short travel which results in a number of
advantages.
According to a modification of the actuating device, the closure
member is made in two parts which bear axially against each other,
each of these parts having its own guide stem and an active face
which cooperates with the corresponding seat.
In this way each closure member part is independent of the other
and any possible lack of alignment of the bores receiving these
parts will have no adverse effect on the operation of the closure
member.
Further features and advantages of the invention will be apparent
from the ensuing description with reference to the accompanying
drawings in which:
FIG. 1 is a sectional view of an injector and an injector holder in
which is incorporated the device according to the invention;
FIG. 2 is a detail sectional view, to an enlarged scale, of the
distributor valve employed in accordance with the invention;
FIG. 3 is a detail view to an enlarged scale of the distributor
valve in which the closure member is in two parts, the bores
receiving the two parts being shown radially offset from each
other, and
FIG. 4 is a detail view similar to FIG. 3 in which the two bores
receiving the two parts of the closure member are angularly out of
alignment.
FIG. 1 shows an injector holder 1 in which is mounted an injector
comprising an injector head 2 and a needle 3. The injector is fixed
to the injector holder by a screwthreaded collar 4 and the needle 3
is biased by a spring 5 which bears against a plug 6 to which a
connector 7 is connected. The latter is connected to an enclosure
in which prevails a pressure in the neighbourhood of atmospheric
pressure.
The injector head 2 has at its end an injection orifice 8 and
defines a seat 9 at the end of the needle 3. An annular chamber 10
is formed in the head of the injector around the needle and in the
vicinity of the seat 9 and a conduit 11 connected to a source of
fuel under pressure, in the present case the fuel injection pump,
opens into this annular chamber 10.
The injector holder 1 has a lateral extension portion 1a in which
are received a distributing valve 12 and an electromagnet 13 which
is adapted to actuate this valve and will be described in more
detail hereinafter. This lateral projecting portion is connected by
a connector 1b to the delivery side of the injection pump (not
shown).
The distributor valve 12 (FIG. 2) comprises a composite body 14,
15, 16, 17 defining two bores 18, 19 of the same diameter and a
centre chamber 20 of larger diameter. The centre chamber is
connected by way of a passageway 21, 22, 23 to the conduit 11
leading to the annular chamber 10. The chamber 18, on the left as
viewed in the drawing, is connected to the delivery side of the
injection pump, the chamber 19, on the right as viewed in the
drawing, being put under pressure by way of a lateral passage 24
and a conduit 25. Slidably mounted in the body of the distributing
valve is a slide member 26 having in the following order, starting
from the left as viewed in the drawing: a grooved guide stem 27
slidable in the bore 18, an enlarged centre portion 28 defining two
active faces 29 and 30 constituting valve closure members adapted
to co-operate with two seats 31, 32 defined by the body, and then a
solid guide stem 33 slidably mounted in the bore 19. In the chosen
embodiment, the faces 29, 30 and the seats 31, 32 have
frustoconical shapes with slightly different included angles.
A conduit 34 extends from the chamber 35 defined between the valve
closure member 30 and the solid guide stem 33, this conduit being
connected to the upper part of the injector holder. Provided
between the wall of the injector holder which constitutes the end
of the bore 19 and the guide stem 33 of the slide member is a
spring 36 which biases the slide member to its position shown in
FIG. 2.
The electromagnet 13 comprises a coil 37 and a moving part 38
constituted by a needle which bears by its right end, as viewed in
the drawing, against the adjacent end face of the slide member
26.
The actuating device operates in the following manner:
The fuel delivered under pressure by the injection pump enters the
assembly by way of the connector 1b. This fuel under pressure flows
through the electromagnet and reaches the chamber 18 by way of the
grooves or flutes of the slide member 26 and also reaches the
chamber 19 by way of the passage 24 and the conduit 25. Thus it can
be seen that the member 26 is subjected to balanced hydraulic
pressures and that only the spring 36 is operative for shifting the
valve closure member 30 from its seat 32 and apply the valve
closure member 29 against its seat 31. In this position of the
slide member, the annular chamber 10 communicates with the
atmosphere by way of the conduits 11, 23, 22, 21, the chambers 20,
35 and the conduit 34.
When the electromagnet 13 is energized by a signal from an
electronic calculator (not shown), the moving part 38 urges the
slide member 26 to the right as viewed in the drawing and
compresses the spring 36. The communication between the chamber 20
and the exhaust is then cut off whereas the pressure of injection
prevails in the chamber 20 and is communicated to the annular
chamber 10 by way of the conduits 21, 22, 23 and 11. The needle 3
of the injector is then urged upwardly in opposition to the action
of its return spring 5 and the injection occurs through the orifice
8 until the coil 37 of the electromagnet is no longer supplied with
current.
When the slide member 26 is shifted by the electromagnet, the
section of the passage thus provided for the fuel is large even if
the travel of the slide member is small since this area is disposed
around the whole of the periphery of the closure member. Further,
in view of the fact that the slide member is subjected on both end
faces to balanced hydraulic forces and its mass is very small, the
power that the electromagmet must develop is also very small while
it still ensures the required characteristics of a rapid opening
and closure. This electromagnet can consequently be of small size
and consume a small amount of current so that it is also possible
to reduce the characteristics of the electronic components
constituting the power stage of the calculator.
According to another feature of the invention, there is inserted in
the conduit 11 a jet 39 which acts on the flow of the fuel during
the injection time. Consequently, as a result of this jet, the
amount of fuel injected is unaffected by a possible soiling of the
nose of the injector whose passage section may be chosen much
greater than that of the jet 39.
Further, although it has been proposed to apply on the two end
faces of the slide member 26 the pressure of the fuel supplied by
the injection pump, an equivalent result may be obtained by
subjecting these two end faces to a different pressure which may
be, for example, the discharge pressure which is in the
neighbourhood of atmosphere pressure. The necessary transformation
of the circuit will be obvious to one skilled in the art and
therefore has not been illustrated or described. Likewise, the
configuration of the injector proper is not criticle and the
invention is applicable to both teat injectors and orifice
injectors.
In the modification of the actuating device shown in FIGS. 3 and 4,
the distributor valve D.sub.1 mounted in the injector holder
extension portion 1a comprises a composite body 101, 102, 103, 104.
Each of the parts 101 and 102 defines a bore 105 and 106. This body
thus defines three chambers:
a centre chamber 107 having a diameter exceeding that of the bores
105, 106;
a chamber 108 located on the left side, as viewed in the
drawing;
a chamber 109 located on the right side, as viewed in the
drawing.
Chamber 107 is connected, in the presently-described embodiment, to
the chamber 10 of the injector by a conduit 140, chamber 108 is
connected to the source of fuel under pressure as in the embodiment
shown in FIGS. 1 and 2 and chamber 109 is connected, in the
presently described embodiment, to the enclosure in which prevails
a pressure at about atmospheric pressure, by a conduit 141.
In the composite body just described there are mounted two closure
or slide members, constituting a composite closure or slide member,
namely closure member 110 and closure member 120, the member 110
having a grooved or fluted guide stem 111 slidable in the bore 105
and a head 112 of larger diameter defining a frustoconical active
face 113 acting as a valve member and adapted to co-operate with a
seal 114 which is also frustoconical and formed in the part 102 of
the composite body.
The closure member 120 has a guide stem 121 slidable in the bore
106 and an enlarged head 122 which defines an active face 123
co-operating with a seat 124 formed in the part 104 of the body.
The face 123 and seat 124 are also frustoconical.
The frustoconical faces 113, 123 and seats 114, 124 may have
slightly different included angles.
At its left end (as viewed in the drawing), the closure member 110
bears against the point of the moving part 38 of the electromagnet
13 and this member 110 is shifted by the electromagnet in the same
way as in the embodiment shown in FIGS. 1 and 2. The right end of
closure member 110 is in axial abutting relation to the left end of
the closure member 121 which has its right end engaged with a
return spring 131 which biases the member 121 to the left and
thereby maintains the adjacent faces 115, 125 of the closure
members 110 and 121 in contact and biases the composite closure
member 110, 121 against the point of the moving part 38 of the
electromagnet.
As can be seen in FIG. 3, in view of the fact that the two bores
105, 106 are formed in different parts of the composite body, their
axes X--X, Y--Y, while being parallel, could be slightly out of
alignment (shown in an exaggerated manner in FIG. 3) and this would
be a disadvantage if the closure member were in one piece and
defined both the active face 113 and the active face 123. Indeed,
the seal between these faces and their seats would not be achieved
correctly in both directions of movement of the closure member and
the distributor valve would not perform its function perfectly
well.
Now, according to the presently-described modification of the
closure member, the closure members 110 and 120 are independent
from each other and have their own guide means and their own active
face. Thus the radial offset between the axes X--X and Y--Y can be
accommodate by the fact that the end faces 115 and 125 are radially
relatively slidable and the axes X--and and Y--Y are free to take
up their respective positions.
In FIG. 4, the same distributor valve is shown in the case where
the axes X--X and Y--Y of the bores 105 and 106 formed in the parts
102 and 104 of the composite body are angularly out of alignment
and not radially offset (the angular lack of alignment has been
exaggerated). Here again, it can be seen that the fact of making
the closure member in two parts 110, 120 enables this lack of
alignment to be accommodated with no inconvenience, the end faces
115 and 125 being in contact with each other on their edges and not
throughout their area. This type of contact has no adverse effect
on the correct operation of the distributor valve since it is
merely sufficient to ensure contact in a given zone. Note,
moreover, that this lack of angular alignment would be infinitely
small in practice.
The advantages of this modification to the closure or slide member
of the distributor valve will be clear from the foregoing
description. They concern, on one hand, the very construction of
the distributor valve the machining and assembly of which no longer
need to be so precise, which considerably reduces production costs,
and on the other hand, the operation of the distributor valve which
becomes more precise and more reliable. The latter advantage in
particular enables the distributor valve to be used for actuating
fuel injectors in which pressures of several hundred bars are set
up and in which the response time must be very short.
A modification may be made in the shape of the faces 115 and 125.
Instead of being both planar as shown in FIGS. 3 and 4, one of them
could be so shaped as to result in a point contact with the face of
the other closure member. For example, the closure member 110 could
have a conical end face instead of the planar end face 115, the
point of the cone contacting the face 125. This arrangement is
above all of interest in the event that the axes X--X and Y--Y are
angularly out of alignment as shown in FIG. 4.
It will be understood that the distributor valve shown in FIGS. 3
and 4 may be modified but still incorporate the advantages of the
composite closure member 110,120. For example, the closure members
110 and 120 may be reversed in position in the body 101,102,103,
104 so that the point of member 38 acts on the end of closure
member 120 instead of closure member 100, the chamber 109 being
defined by the part 102 instead of the part 104 and the chamber 108
being defined by the part 104. In this case the conduit 141 would
traverse the part 103 and part 102 to communicate with the chamber
109 in its new location on the left side of chamber 107 (as viewed
in the drawing). Further, the conduit 140 need not lead to a
chamber of an injector such as chamber 10 between the seat 9 and
the enlarged part of the needle 3. For example, it could lead to a
chamber of a fuel injector at the end of the injector needle
opposed to the end co-operating with the seat.
* * * * *