Technical Field
[0001] The disclosure relates to a control valve used in a fuel injector as well as a fuel
injector, in particular a diesel common rail injector, comprising such a control valve.
Background Art
[0002] A fuel injector generally comprises a control valve and an injection valve, the fuel
injection actions of the injection valve being controlled by switching the control
valve between its opened and closed states. Figure 1 schematically shows a partial
structure of such a control valve, the control valve comprising a valve seat 1 which
is formed with a fuel passage 2 and a valve seating surface 3, a spherical valve element
4 which cooperates with the valve seating surface 3 to achieve the opening and closing
of the fuel passage 2, and a holding block 5 which accommodates a portion of the valve
element 4. When the valve element 4 is pushed by the holding block 5 to be biased
against the valve seating surface 3, pressure accumulation of the fuel in the injection
valve is effected. Once the pushing force from the holding block 5 disappears, the
valve element 4 leaves the valve seating surface 3, and a portion of the fuel in the
injection valve flows into the control valve via the fuel passage 2 so that a pressure
difference is established in the injection valve and thus a fuel injection action
of the injection valve is initiated. The fuel passage 2 comprises a first passage
2a, a second passage 2b and a third passage 2c arranged in sequence in a longitudinal
direction, as can be seen in Figure 2. The first passage 2a has a diameter smaller
than that of the third passage 2c, and the second passage 2b has a diameter smaller
than that of the first passage 2a.
[0003] When the fuel passage 2 is opened, the valve element 4 is impacted by the fuel introduced
from the injection valve via the fuel passage 2. As a result, after a long term service,
a portion of the valve element 4 that faces towards the fuel passage 2 may be eroded
under the impaction of a high pressure jet of fuel, especially fuel in gas state generated
in the jet, so an erosion portion 6 will be formed, as shown in Figure 2. For the
reason that the valve element 4 is spherical, the valve element 4 may rotate slowly
and randomly. When the erosion portion 6 is turned to a location facing towards the
valve seating surface 3, the valve element 4 cannot close the fuel passage 2 effectively,
which impedes the pressure accumulation in the fuel in the injection valve and thus
causes malfunction of the fuel injector.
[0004] DE 195 16 565 A1 discloses a nozzle needle (4) that is axially slidable between a stop and open position
in the valve housing (9). In the stop position it is pressed against a nozzle needle
seat (6) with injection ports (5) by a piston (5). A control chamber (2) is coupled
to the valve (1) fuel inlet (7) via one or more closable ducts (14), with the control
chamber pressure actuating the piston. Into a valve seat (15) in the control chamber
opens an intermediate chamber (12), coupled to the fuel inlet and to the control chamber,
which has an outflow port (10) closable by a servo-member (8). In the connecting line
between the control and intermediate chambers is located a stop valve for the fuel
flow to the control chamber.
Summary of the Invention
[0005] An object of the disclosure is to make improvements to the fuel injector to alleviate
or prevent the above problems caused by the erosive impacting of the valve element
in the prior art.
[0006] For this end a control valve according to claim 1 of the present application is provided.
[0007] According to a possible embodiment of the disclosure, the first passage faces towards
the valve element, and the second passage has a flow area smaller than that of the
first passage.
[0008] According to a possible embodiment of the disclosure, the valve seat comprises a
first portion and a second portion which are assembled together, one of the first
and second portions being formed with a projection, the other one of the first and
second portions being formed with a recess, the projection being inserted and fitted
in the recess, the first passage and the turn-back passage being formed in the projection,
and the second passage being formed in the second portion.
[0009] According to a possible embodiment of the disclosure, the first transverse segment
is formed by a transverse through hole in the projection, the second transverse segment
is formed by a transverse groove on an end surface of the projection, and the longitudinal
segment is formed by a longitudinal groove on a side surface of the projection.
[0010] According to a possible embodiment of the disclosure, the turn-back passage comprises
a pair of turn-back passages opposite to each other in a transverse direction, the
pair of turn-back passages comprising two first transverse segments formed by a common
transverse through hole in the projection, two second transverse segments formed by
a common transverse groove on the end surface of the projection, and two longitudinal
segments formed respectively by two longitudinal grooves on opposite side surfaces
of the projection.
[0011] According to a possible embodiment of the disclosure, the first passage is connected
to a joining portion between the two first transverse segments, and the second passage
is connected to a joining portion between the two second transverse segments.
[0012] According to a possible embodiment of the disclosure, the fuel passage further comprises
a third passage connected between the second passage and the injection valve, the
third passage has a flow area larger than that of the first passage.
[0013] According to a possible embodiment of the disclosure, the valve element comprises
a solid sphere.
[0014] The disclosure in another aspect provides a fuel injector which comprises a control
valve described above and an injection valve assembled to the control valve; wherein
the fuel injection action of the injection valve is controlled in responsive to the
opened/closed state of the control valve.
[0015] According to a possible embodiment of the disclosure, the fuel injector comprises
a diesel common rail injector.
[0016] According to a possible embodiment of the disclosure, the injection valve comprises
an injection valve cavity and a valve needle disposed in the injection valve cavity,
the valve needle being configured to have a structure for operation in responsive
to a pressure difference generated in the injection valve cavity when the control
valve is being opened.
[0017] According to the disclosure, by forming an elongated segment for the fuel passage
in the valve seat of the control valve, the fuel jet in the fuel passage may impact
the valve element at a reduced pressure, and no gas-state fuel will be generated in
the fuel jet, so the erosion of the valve element will be avoided or suppressed effectively.
In this way, the fuel passage of the control valve, which is in a closed state, can
be tightly closed effectively, and the function of the control valve can be reliably
maintained in a long term.
Brief Description of the Drawings
[0018]
Figure 1 is a partial schematic sectional view of a control valve used in a fuel injector
according to prior art.
Figure 2 is a schematic view for explaining the corrosion of the valve element of
the control valve shown in Figure 1.
Figure 3 is a schematic sectional view of a fuel injector according to a possible
embodiment of the disclosure.
Figure 4 is a partial schematic sectional view of a valve seat of a control valve
of the fuel injector shown in Figure 3.
Figures 5 and 6 are schematic sectional views of two portions of the valve seat.
Figure 7 is a schematic view for explaining the fuel flowing state in the control
valve of the disclosure.
Detailed Description of Preferred Embodiments
[0019] Some possible embodiments of the disclosure will be described with reference to the
drawings.
[0020] Figure 3 shows in partial a fuel injector for injecting fuel into an engine according
to a possible embodiment of the disclosure, in particular a fuel injector used in
a common rail type diesel injection system. The fuel injector comprises a control
valve and an injection valve which is assembled together, for example, assembled in
a common fuel injector casing 8 (not illustrated in detail). The improvements made
in the disclosure relate to the control valve, and so Figure 3 shows only corresponding
portions relevant to the control valve. The injection valve is assembled to a front
side (lower side in Figure 3) of the control valve, facing towards the engine. The
control valve is switchable between an opened state and a closed state. The fuel injection
actions of the injection valve are controlled by the opened and closed states of the
control valve.
[0021] The control valve has a central axis extending in a longitudinal direction, and comprises
a valve seat 1 in which a fuel passage 2 is formed, and a valve seat cavity defined
by a valve seating surface 3 and an inner peripheral surface 7. The fuel passage 2
has a front end (lower end in Figure 3) opened into an injection valve cavity of the
injection valve and a back end (upper end in Figure 3) opened into the valve seat
cavity. High pressure fuel that is supplied into the injection valve cavity can flow
into the valve seat cavity via the fuel passage 2 to achieve partial pressure relief
in the injection valve cavity. The valve seating surface 3 is formed between the fuel
passage 2 and inner peripheral surface 7. Both the valve seating surface 3 and inner
peripheral surface 7 are conical surfaces, with the valve seating surface 3 having
a bigger cone angle than the inner peripheral surface 7.
[0022] The control valve further comprises a valve element 4, preferably having a spherical
shape, the valve element 4 being disposed in the valve seat cavity, facing the valve
seating surface 3, and fitting with the valve seating surface 3 to achieve the opening
and closing of the fuel passage 2. The cone angle of the valve seating surface 3 facilitates
the centering of the valve element 4.
[0023] The control valve further comprises a holding block 5, which is located axially behind
the valve element 4 and is formed with an accommodating recess, the accommodating
recess having a shape corresponding to the outer shape of a first or substantially
back half portion of the valve element 4 for accommodating the first portion of the
valve element 4, and a substantially front half portion of the valve element 4 being
exposed and facing the valve seating surface 3 and the fuel passage 2. The two portions
of the valve element 4 may be formed to be integral with each other, or be formed
separately and then assembled to each other.
[0024] The control valve further comprises an intermediate ring 9 disposed behind the valve
seat 1 and a guiding tube 10 disposed behind the intermediate ring 9. The guiding
tube 10 comprises a tubular portion 10a extending in the axial direction and a flange
member 10b extended radially outwards from a front end of the tubular portion 10a,
the flange member 10b being formed with a plurality of through holes 10c extending
therethrough axially.
[0025] The control valve further comprises an assembling sleeve 11 disposed behind the flange
member 10b, the assembling sleeve 11 being fixed in the fuel injector casing 8 by
screw threads or other means. A circular space is formed between the assembling sleeve
11 and the tubular portion 10a. In additional, a front end of the valve seat 1 is
biased against a corresponding step in the fuel injector casing 8. In this way, the
valve seat 1, the intermediate ring 9 and the guiding tube 10 are clamped together
in the axial direction by means of the assembling sleeve 11.
[0026] The control valve further comprises an armature core 12 having a main body in the
form of a cylinder extending in the axial direction and a circular flange 12a formed
adjacent to a front end of the main body or assembled thereto and extending radially.
The main body of the armature core 12 inserts through an inner hole in the tubular
portion 10a in an axially slidable manner, with the circular flange 12a being in front
of the flange member 10b and mainly within an internal space of the intermediate ring
9. The internal space of the intermediate ring 9 is in fluid communication with the
circular space between the assembling sleeve 11 and the tubular portion 10a via the
through holes 10c, and the internal space of the intermediate ring 9 is also in fluid
communication with the valve seat cavity.
[0027] The front end of the main body of the armature core 12 is adhered to a back end of
the holding block 5. A back end (not shown) of the main body of the armature core
12 extends out of a back end of the tubular portion 10a. A compressive spring 13 is
disposed in the circular space between the assembling sleeve 11 and the tubular portion
10a, the compressive spring 13 having a front end biased against a back end surface
of the flange member 10b and a back end applying an axially backward pushing force
to the back end of the main body of the armature core 12 via an element or structure
not shown.
[0028] The control valve further comprises a magnetic coil which generates an axially forward
pushing force in the armature core 12 by electric-magnetic induction in an energized
state. The forward pushing force generated in the magnetic coil overcomes a backward
pushing force provided by the compressive spring 13 and the fuel pressure in the fuel
passage 2 so that the armature core 12 is in an advanced position as shown in Figure
3 and thus pushes the valve element 4 against the valve seating surface 3 via the
holding block 5 to close the fuel passage 2 and achieve the closed state. In this
position, the back end surface of the circular flange 12a is separated from a front
end surface of the flange member 10b by a small axial distance. For the sake of clarity,
this axial distance is shown in a larger scale in Figure 3, but it is very small in
actual. Once the magnetic coil is de-energized, the forward pushing force generated
by the magnetic coil disappears, and the armature core 12 is moved axially backwards
under the backward pushing force of the compressive spring 13 and the fuel pressure
in the fuel passage 2 until the back end surface of the circular flange 12a comes
into contact with the front end surface of the flange member 10b. Meanwhile, the valve
element 4 moves axially backwards together with the armature core 12 under the action
of the fuel pressure in the fuel passage 2 to leave the valve seating surface 3 and
open the fuel passage 2, so the control valve is switched to the opened state.
[0029] The injection valve comprises a valve needle (not shown) disposed in its injection
valve cavity, and the opening and closing of the injection valve is controlled by
the axial movement of the valve needle to perform fuel injection. When the magnetic
coil in the control valve is energized so that the control valve comes into the closed
state shown in Figure 3, the fuel (for example, comes from a common rail) supplied
into the injection valve cavity is under a pressure accumulation state, so that ultimately
every portion of the injection valve cavity becomes under high pressure, and then
the valve needle in the injection valve closes the injection valve. After that, the
magnetic coil in the control valve is de-energized so that the control valve comes
into the opened state, so a portion of the fuel in the injection valve cavity flows
into the control valve via the fuel passage 2. This results in lowering down of the
pressure of the fuel behind the valve needle, so that a pressure difference appears
between front and back sides of the valve needle. Under this pressure difference,
the valve needle moves backwards to open the injection valve, so a fuel injection
action is performed. The fuel that flows into the control valve via the fuel passage
2 will then flow through the valve seat cavity, the internal space of the intermediate
ring 9, the through holes 10c, and the circular space between the assembling sleeve
11 and the tubular portion 10a in sequence, and finally flows back to a fuel tank.
Then, the magnetic coil in the control valve is energized again so that the control
valve comes to the closed state again, and thus the injection valve is switched to
the pressure accumulation state until the fuel pressures at the front and back sides
of the valve needle become the same level. Now the valve needle closes the injection
valve under the action of a returning element for the valve needle. Then, the next
fuel injection action will be performed.
[0030] It is noted that, since there is a fuel film between the armature core 12 and the
holding block 5, and the holding block 5 is always subjected to a fuel pressure from
the fuel passage 2 (directly, or transmitted from the valve element 4 to the holding
block 5), the holding block 5 always keeps to be adhered to the armature core 12 when
the armature core 12 moves.
[0031] When the control valve is switched from closed state to the opened state, as the
valve element 4 leaves the valve seating surface 3 axially backwards, the high pressure
fuel comes from the injection valve via the fuel passage 2 will impact the valve element
4 in the form of a jet flow. In the control valve according to prior art, the jet
carries a very high impact force, and gas-state fuel is contained in the jet, which
result in the portion of the valve element 4 which faces towards the fuel passage
2 is eroded under the impaction. As shown in Figure 4, according to a possible embodiment
of the disclosure, the fuel passage 2 comprises a first passage 2a, a pair of turn-back
passages, a second passage 2b and a third passage 2c arranged in sequence in the back
to front direction. The first passage 2a, the second passage 2b and the third passage
2c extend in the longitudinal direction along the central axis. The first passage
2a has a back end facing towards the valve element 4, forming a valve hole of the
control valve. The front end of the third passage 2c extends to the injection valve
cavity of the injection valve. The front end of the second passage 2b is connected
to the back end of the third passage 2c, and the second passage 2b has a diameter
smaller than that of each of the first passage 2a and the third passage 2c to form
a throttle portion in the fuel passage 2. The pair of turn-back passages are continuous
between the front end of the first passage 2a and the back end of the second passage
2b, and the two turn-back passage are disposed to be opposite to each other in a transverse
direction perpendicular to the central axis, and are preferably substantially symmetric
with each other. Each turn-back passage comprises a first transverse segment 2d extending
transversely from the front end of the first passage 2a, a second transverse segment
2e extending transversely from the back end of the second passage 2b, and a longitudinal
segment 2f continuous between the transversely outer ends of the first transverse
segment 2d and the second transverse segment 2e. The first transverse segment 2d and
the second transverse segment 2e are parallel with each other and are much longer
than the longitudinal segment 2f.
[0032] For facilitating forming the turn-back passages in the valve seat 1, according to
the disclosure, the valve seat 1 is divided into two portions, a first back portion
1a and a second front portion 1b. With reference to Figures 5 and 6, the first portion
1a has a front end surface formed with a projection 14 protruded forwardly, and the
second portion 1b has back end surface formed with a recess 15 recessed forwardly.
The projection 14 and the recess 15 have shapes complementary with each other and
dimensions fitting with each other, so that the projection 14 can be inserted and
fitted in the recess 15 to achieve the assembled state of the first portion 1a and
the second portion 1b as shown in Figure 4, in which the front end surface of the
first portion 1a abuts tightly against the back end surface of the second portion
1b, and the side surfaces and the front end surface of the projection 14 closely contact
the side walls and the bottom wall that define the recess 15.
[0033] The first passage 2a and the pair of turn-back passages are formed in the first portion
1a, and the second passage 2b and the third passage 2c are formed in the second portion
1b.
[0034] Specifically, in the first portion 1a, the two first transverse segments 2d of the
pair of turn-back passages are formed by a transverse through hole in the projection
14, the two second transverse segments 2e are formed by a the transverse groove on
the front end surface of the projection 14, and the two the longitudinal segments
2f are formed by longitudinal grooves on transversely opposite side surfaces of the
projection 14. The first passage 2a extends to the joining portion between the two
first transverse segments 2d from the valve seat cavity.
[0035] In the second portion 1b, the second passage 2b is formed to extend to the third
passage 2c from the recess 15. In the assembled state of the first portion 1a and
the second portion 1b, the back end of the second passage 2b is in fluid communication
with the joining portion between the two second transverse segments 2e.
[0036] It is appreciated that, as an alternative solution, the projection 14 with the pair
of turn-back passages may be formed on the second portion 1b, while the recess 15
is formed in the first portion 1a.
[0037] By adding the pair of turn-back passages in the fuel passage 2, the length of the
fuel passage 2 is significantly increased. In addition, since the first transverse
segment 2d and the second transverse segment 2e extend transversely, the flow direction
of the fuel changes several times. Thus, the flow field of the fuel in the fuel passage
2 is changed remarkably.
[0038] The flow state of the fuel in the control valve has been studied by analysis and
simulation experiments. As shown in Figure 7, during the valve opening operation,
high pressure fuel from the injection valve enters the third passage 2c and the second
passage 2b, is divided into the pair of turn-back passages and then converged in the
first passage 2a, and finally flows into the valve seat cavity via the gap between
the valve element and the valve seating surface.
[0039] The fuel is in a high pressure state in the third passage 2c and the second passage
2b, so the fuel in the joining portion (marked by "A" in Figure 7) between two second
transverse segment 2e is still at a high pressure. However, the high pressure fuel
here impacts on the projection 14, and has no effect on the valve element 4. Then,
the fuel changes direction several times in the pair of turn-back passages and the
first passage 2a so the pressure of the fuel reduces gradually. When the fuel reaches
the back end of the first passage 2a, the pressure and speed of it are both reduced,
thus the fuel applies a smaller impact force on the valve element 4. After that, the
fuel comes into the valve seat cavity and becomes gas state at a low pressure. The
flow path of the fuel is schematically marked by arrows in Figure 7.
[0040] An additional effect resulted from the above pressure reducing and direction changing
solution is that no gas-state fuel is existed in the first passage 2a.
[0041] For the reason that the valve element 4 is subjected to reduced fuel impaction force
and there is no impaction of gas-state fuel during the valve opening operation of
the control valve, the portion of the valve element 4 that faces the fuel passage
2 is not likely to be eroded. The valve element 4 always effectively guarantee that
the fuel passage of the control valve is closed when the control valve is in the closed
state, so the function of the control valve can be maintained in a long time. As a
result, the service time of the control valve, or even of the whole fuel injector,
can be prolonged.
[0042] It is appreciated that those skilled in the art can make various modifications to
the described structure according to the theory of the disclosure. For example, the
number of the turn-back passages is not limited to a pair, and one, three or more
can be adopted. Further, the shape of the turn-back passage is not limited to the
illustrated one. In addition, depending on the machining technique, the two-part form
of the valve seat 1 may not be used; rather, the portions of the fuel passage 2 may
be formed directly in the valve seat 1 which is in the form of a single part. Other
changes to the structural details of the control valve can also be conceived.
1. A control valve used in a fuel injector, comprising:
a valve seat (1) defining a valve seating surface (3) and a fuel passage (2) extending
through the valve seating surface (3), the fuel passage (2) being in communication
with an injection valve of the fuel injector and forming a pressure releasing path
which is provided for controlling the operation of the injection valve; and
a valve element (4) moveable in a longitudinal direction and configured to cooperate
with the valve seat (1) to open and close the fuel passage (2);
wherein the fuel passage (2) comprises a first passage (2a) and a second passage (2b),
both extending in the longitudinal direction, and a turn-back passage continuously
joined between the first and second passages, and
wherein the turn-back passage comprises a first transverse segment (2d) continuous
with the first passage (2a), a second transverse segment (2e) continuous with the
second passage (2b), and a longitudinal segment (2f) connecting the first transverse
segment with the second transverse segment.
2. The control valve of claim 1, wherein the first passage (2a) faces towards the valve
element (4), and the second passage (2b) has a flow area smaller than that of the
first passage (2a).
3. The control valve of claim 2, wherein the valve seat (1) comprises a first portion
(1a) and a second portion (1b) which are assembled together, one of the first and
second portions being formed with a projection (14), the other one of the first and
second portions being formed with a recess (15), the projection (14) being inserted
and fitted in the recess (15), the first passage (2a) and the turn-back passage being
formed in the projection (14), and the second passage (2b) being formed in the second
portion (1b).
4. The control valve of claim 1, wherein the first transverse segment (2d) is formed
by a transverse through hole in the projection (14), the second transverse segment
(2e) is formed by a transverse groove on an end surface of the projection (14), and
the longitudinal segment (2f) is formed by a longitudinal groove on a side surface
of the projection (14).
5. The control valve of claim 1, wherein the turn-back passage comprises a pair of turn-back
passages opposite to each other in a transverse direction, the pair of turn-back passages
comprising two first transverse segments (2d) formed by a common transverse through
hole in the projection (14), two second transverse segments (2e) formed by a common
transverse groove on the end surface of the projection (14), and two longitudinal
segments (2f) formed respectively by two longitudinal grooves on opposite side surfaces
of the projection (14).
6. The control valve of claim 5, wherein the first passage (2a) is connected to a joining
portion between the two first transverse segments (2d), and the second passage (2b)
is connected to a joining portion between the two second transverse segments (2e).
7. The control valve of claim 1 or 2, wherein the valve element (4) is a solid sphere.
8. A fuel injector comprising a control valve and an injection valve assembled to the
control valve, the injection valve performing a fuel injection action in responsive
to the open/close state of the control valve;
wherein the control valve comprises a control valve of any one of claims 1-7.
9. The fuel injector of claim 8, wherein the fuel injector is a diesel common rail injector;
and
wherein the injection valve comprises an injection valve cavity and a valve needle
disposed in the injection valve cavity, the valve needle being configured to have
a structure for operation in responsive to a pressure difference generated in the
injection valve cavity when the control valve is opened.
1. Steuerventil zur Verwendung in einer Kraftstoffeinspritzdüse, umfassend:
einen Ventilsitz (1), der eine Ventilauflagefläche (3) und einen Kraftstoffkanal (2),
der sich durch die Ventilauflagefläche (3) erstreckt, definiert, wobei der Kraftstoffkanal
(2) mit einem Einspritzventil der Kraftstoffeinspritzdüse in Verbindung steht und
einen Druckentlastungspfad bildet, der zum Steuern der Funktion des Einspritzventils
bereitgestellt ist; und
ein Ventilelement (4), das in einer Längsrichtung beweglich und derart gestaltet ist,
dass es mit dem Ventilsitz (1) zusammenwirkt, um den Kraftstoffkanal (2) zu öffnen
und zu schließen;
wobei der Kraftstoffkanal (2) einen ersten Kanal (2a) und einen zweiten Kanal (2b),
die sich beide in der Längsrichtung erstrecken, und einen Rücklaufkanal, der fortlaufend
zwischen dem ersten und dem zweiten Kanal verbunden ist, umfasst, und
wobei der Rücklaufkanal einen ersten Querabschnitt (2d) fortlaufend mit dem ersten
Kanal (2a), einen zweiten Querabschnitt (2e) fortlaufend mit dem zweiten Kanal (2b)
und einen Längsabschnitt (2f), welcher den ersten Querabschnitt mit dem zweiten Querabschnitt
verbindet, umfasst.
2. Steuerventil nach Anspruch 1, wobei der erste Kanal (2a) zum Ventilelement (4) zeigt
und der zweite Kanal (2b) einen Strömungsquerschnitt aufweist, der geringer ist, als
jener des ersten Kanals (2a).
3. Steuerventil nach Anspruch 2, wobei der Ventilsitz (1) einen ersten Abschnitt (1a)
und einen zweiten Abschnitt (1b) umfasst, die miteinander gekoppelt sind, wobei entweder
der erste oder der zweite Abschnitt mit einem Vorsprung (14) ausgebildet ist, während
der andere der ersten und zweiten Abschnitte mit einer Vertiefung (15) ausgebildet
ist, wobei der Vorsprung (14) in die Vertiefung (15) eingesetzt und dort angebracht
ist, wobei der erste Kanal (2a) und der Rücklaufkanal im Vorsprung (14) ausgebildet
sind, und der zweite Kanal (2b) im zweiten Abschnitt (1b) ausgebildet ist.
4. Steuerventil nach Anspruch 1, wobei der erste Querabschnitt (2d) durch ein Querdurchgangsloch
im Vorsprung (14) ausgebildet ist, der zweite Querabschnitt (2e) durch eine Quernut
an einer Endfläche des Vorsprungs (14) ausgebildet ist, und der Längsabschnitt (2f)
durch eine Längsnut an einer Seitenfläche des Vorsprungs (14) ausgebildet ist.
5. Steuerventil nach Anspruch 1, wobei der Rücklaufkanal ein Paar einander in einer Querrichtung
gegenüberliegend angeordneter Rücklaufkanäle umfasst, das Paar von Rücklaufkanälen
zwei erste Querabschnitte (2d), die durch ein gemeinsames Querdurchgangsloch im Vorsprung
(14) ausgebildet sind, zwei zweite Querabschnitte (2e), die durch eine gemeinsame
Quernut an der Endfläche des Vorsprungs (14) ausgebildet sind, und zwei Längsabschnitte
(2f), die jeweils durch zwei Längsnuten an gegenüberliegenden Seitenflächen des Vorsprungs
(14) ausgebildet sind, umfasst.
6. Steuerventil nach Anspruch 5, wobei der erste Kanal (2a) mit einem Verbindungsabschnitt
zwischen den zwei ersten Querabschnitten (2d) verbunden ist, und der zweite Kanal
(2b) mit einem Verbindungsabschnitt zwischen den zwei zweiten Querabschnitten (2e)
verbunden ist.
7. Steuerventil nach Anspruch 1 oder 2, wobei das Ventilelement (4) eine massive Kugel
ist.
8. Kraftstoffeinspritzdüse umfassend ein Steuerventil und ein Einspritzventil, das am
Steuerventil angebracht ist, wobei das Einspritzventil als Reaktion auf den geöffneten/geschlossenen
Zustand des Steuerventils einen Kraftstoffeinspritzvorgang durchführt;
wobei das Steuerventil ein Steuerventil nach einem der Ansprüche 1 - 7 umfasst.
9. Kraftstoffeinspritzdüse nach Anspruch 8, wobei die Kraftstoffeinspritzdüse eine Common-Rail-Dieseleinspritzdüse
ist; und wobei das Einspritzventil eine Einspritzventilkammer und eine Ventilnadel,
die in der Einspritzventilkammer angeordnet ist, umfasst, wobei die Ventilnadel derart
gestaltet ist, dass sie einen Aufbau zur Funktion in Reaktion auf einen in der Einspritzventilkammer
beim Öffnen des Steuerventils erzeugten Druckunterschied aufweist.
1. Soupape de commande utilisée dans un injecteur de carburant, comprenant :
un siège de soupape (1) définissant une surface d'assise de soupape (3) et un passage
de carburant (2) s'étendant à travers la surface d'assise de soupape (3), le passage
de carburant (2) étant en communication avec une soupape d'injection de l'injecteur
de carburant et formant une voie de relâchement de pression permettant de commander
le fonctionnement de la soupape d'injection ; et
un élément de soupape (4) mobile dans une direction longitudinale et conçu pour coopérer
avec le siège de soupape (1) pour ouvrir et fermer le passage de carburant (2) ;
le passage de carburant (2) comprenant un premier passage (2a) et un second passage
(2b) s'étendant l'un et l'autre dans la direction longitudinale, et un passage de
refoulement joint de manière continue entre les premier et second passages, et
le passage de refoulement comprenant un premier segment transversal (2d) continu avec
le premier passage (2a), un second segment transversal (2e) continu avec le second
passage (2b), et un segment longitudinal (2f) connectant le premier segment transversal
au second segment transversal.
2. Soupape de commande selon la revendication 1, dans laquelle le premier passage (2a)
est en regard de l'élément de soupape (4), et le second passage (2b) a une section
d'écoulement inférieure à celle du premier passage (2a).
3. Soupape de commande selon la revendication 2, dans laquelle le siège de soupape (1)
comprend une première partie (1a) et une seconde partie (1b) assemblées ensemble,
une des première et seconde parties étant formée avec une protubérance (14), l'autre
des première et seconde parties étant formée avec un évidement (15), la protubérance
(14) étant insérée et ajustée dans l'évidement (15), le premier passage (2a) et le
passage de refoulement étant formés dans la protubérance (14), et le second passage
(2b) étant formé dans la seconde partie (1b).
4. Soupape de commande selon la revendication 1, dans laquelle le premier segment transversal
(2d) est formé par un orifice débouchant transversal dans la protubérance (14), le
second segment transversal (2e) est formé par une rainure transversale sur une surface
extrême de la protubérance (14), et le segment longitudinal (2f) est formé par une
rainure longitudinale sur une surface latérale de la protubérance (14).
5. Soupape de commande selon la revendication 1, dans laquelle le passage de refoulement
comprend une paire de passages de refoulement opposés l'un à l'autre dans une direction
transversale, la paire de passages de refoulement comprenant deux premiers segments
transversaux (2d) formés par un orifice débouchant transversal commun dans la protubérance
(14), deux seconds segments transversaux (2e) formés par une rainure transversale
commune sur la surface extrême de la protubérance (14), et deux segments longitudinaux
(2f) formés respectivement par deux rainures longitudinales sur des surfaces latérales
opposées de la protubérance (14).
6. Soupape de commande selon la revendication 5, dans laquelle le premier passage (2a)
est connecté à une partie de liaison entre les deux premiers segments transversaux
(2d), et le second passage (2b) est connecté à une partie de liaison entre les deux
seconds segments transversaux (2e).
7. Soupape de commande selon la revendication 1 ou 2, dans laquelle l'élément de soupape
(4) est une sphère solide.
8. Injecteur de carburant comprenant une soupape de commande et une soupape d'injection
assemblée à la soupape de commande, la soupape d'injection réalisant une action d'injection
de carburant en réponse à l'état ouvert/fermé de la soupape de commande ;
la soupape de commande consistant en une soupape de commande selon l'une quelconque
des revendications 1 à 7.
9. Injecteur de carburant selon la revendication 8, l'injecteur de carburant étant un
injecteur diesel à rampe commune ; et
dans lequel la soupape d'injection comprend une cavité de soupape d'injection et un
pointeau de soupape disposé dans la cavité de soupape d'injection, le pointeau de
soupape étant conçu pour avoir une structure fonctionnant en réponse à une différence
de pression générée dans la cavité de soupape d'injection quand la soupape de commande
est ouverte.