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EP 2 425 104 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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09.04.2014 Bulletin 2014/15 |
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Date of filing: 09.04.2010 |
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International Patent Classification (IPC):
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International application number: |
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PCT/FI2010/050285 |
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International publication number: |
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WO 2010/125235 (04.11.2010 Gazette 2010/44) |
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A CONTROL ARRANGEMENT FOR AN INLET VALVE IN A PISTON ENGINE
BETÄTIGUNSVORRICHTUNG FÜR EIN EINLASSVENTIL IN EINER BRENNKRAFTMASCHINE
MÉCANISME DE CONTRÔLE DE DISTRIBUTION POUR UNE SOUPAPE D'ADMISSION DANS UN MOTEUR
À COMBUSTION INTERNE
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Designated Contracting States: |
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AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO
PL PT RO SE SI SK SM TR |
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Priority: |
27.04.2009 FI 20095462
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Date of publication of application: |
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07.03.2012 Bulletin 2012/10 |
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Proprietor: Wärtsilä Finland Oy |
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65380 Vaasa (FI) |
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Inventors: |
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- SUNDSTEN, Magnus
FI-65610 Korsholm (FI)
- KNIPSTRÖM, Leif
FI-66530 Kvevlax (FI)
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Representative: Berggren Oy Ab |
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P.O. Box 16
Antinkatu 3 C 00101 Helsinki 00101 Helsinki (FI) |
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References cited: :
WO-A1-2004/033863 DE-A1- 3 611 476 US-A- 3 817 228
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WO-A1-2008/000899 DE-A1- 3 807 699 US-A- 5 002 022
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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Technical field
[0001] The invention relates to a control arrangement for an inlet valve in a piston engine
according to preamble of claim 1.
Background art
[0002] There are situations in the operation of a four stroke internal combustion engine
in which the cylinders are not provided with enough air for self-ignition to happen
during the compression stroke. This is specifically true as regards engines charged
by high pressure such as two-stage turbo charged engines during engine start and during
load variations. In engines of this kind higher pressures in combination with sharper
or shorter cam nose forms are utilised resulting in charging action taking place in
shorter time respectively. Hence, the opening times of the inlet valves under normal
load of the engine are not long enough for such special situations.
[0003] On the other hand in order to minimise emissions from a diesel engine the timing
of the inlet valves needs to be such that the inlet valve is closed early before the
bottom dead centre of the piston, while the boost pressure is raised accordingly so
as to get a sufficient amount of air to the cylinder. This kind of arrangement is,
however, problematic with low engine loads, when the boost pressure of the turbocharger
is still relatively low.
[0004] One solution could be intensified supply of inlet air during the opening phase of
the inlet valve under such special situations. Another solution is to provide for
a delay in the closing of the inlet valve for prolonging the opening time of the inlet
valve when needed. One solution for such a variable inlet valve closure (VIC) is disclosed
in patent publication
WO 2008/000899 providing a certain delay for the closing of the inlet valve.
[0005] An object of the invention is to provide a further improved control arrangement for
delaying the closing of the inlet valve in a piston engine. A particular aim is to
enable selection of different delaying times to comply with different situations,
especially when combustion engines are operated under low engine loads and during
start of the engines.
Disclosure of the invention
[0006] The objects of the invention can be met substantially as is disclosed in claim 1
and in the other claims presenting more details of different embodiments of the invention.
According to the invention the body part is provided with two or more flow ducts for
arranging different routes for the flow of hydraulic medium from the first chamber
to the second chamber. In addition control means are provided for selecting the route
of flow to be utilised in each case to provide different closing delay. A route may
here include one or more flow ducts depending on the application in each case. Hereby
it is possible to obtain a solution which is easy to put into practice, reliable and
can be utilised according to need.
[0007] The two or more flow ducts are with advantage arranged to open in a common chamber
or the like connection duct arranged in communication with the first chamber. Then
the control means are arranged to operate in said common chamber or the like connection
duct.
[0008] In practice it is of advantage that the second chamber is provided within a guide
member arranged between the cam device and the piston device to be movably responsive
with the movements of cam device. Thereby the two or more flow ducts are arranged
to open into the second chamber at different positions along the track of movement
of the guide member. This provides for a reliable construction. In addition the guide
member is arranged to directly act on the piston device only in the direction for
opening the inlet valve, when the delaying function is utilised.
[0009] According to one embodiment the flow of hydraulic medium is arranged via one of said
flow ducts at a time and that the control means include a control valve with a movable
valve member provided with a releasing means to be arranged at the position of one
of said flow ducts. The releasing means can be a narrowing portion dimensioned to
allow flow only through one duct at a time.
[0010] According to another embodiment the control arrangement includes a separate control
valve for each of the flow ducts providing for a shortened delaying time.
[0011] The control means are with advantage arranged to be operated pneumatically by making
use of the control systems included in the engine. Specifically charge air from a
turbocharger of said piston engine can be utilised for controlling the control means.
The operating pressure is with advantage arranged to occur against the force of a
spring providing uncomplicated construction and control.
Brief Description of Drawings
[0012] In the following the invention will be described, by way of example only, with reference
to the accompanying schematic drawing, in which
- Figure 1 shows a piston engine and a skeleton diagram of its valve mechanism,
- Figures 2 - 4 show a general view of a control arrangement according to the invention
in separate consecutive stages of operation,
- Figure 5 shows an enlarged view of a first embodiment of control means according to
the invention,
- Figures 6a and 6b show an enlarged view of a second embodiment of control means according
to the invention in two operation positions,
- Figure 7 shows a relative opening curve of the inlet valve relating to the embodiment
of figure 6a, and
- Figure 8 shows an enlarged view of a third embodiment of control means according to
the invention.
Detailed Description of Drawings
[0013] Figure 1 shows a schematic view of a piston engine 1 as far as it is relevant to
the understanding of the invention. The gas exchange of the cylinders (not shown)
in the piston engine 1 is carried out under the control of gas exchange valves, i.e.
inlet valves and exhaust valves, located on a cylinder head 2. Only inlet valves 3
are shown and they are operated by means of valve mechanisms 6 which are typically
guided by cam profiles 5' of cam devices 5 arranged on a camshaft 4 of the engine.
The force transmission connection between each valve mechanism 6 and the corresponding
cam device 5 is realised by a control arrangement 7.
[0014] The control arrangement 7 is shown in more detail in Figures 2 - 4, of which Figure
2 shows it in a non-operating state, whereby the inlet valve 3 in connection therewith
is closed. The control arrangement 7 comprises a body part 8, which is typically attached
to the engine body. A piston device 9 is movably arranged within the body part 8.
The upper end of the piston device 9 is arranged in force transmission connection
with the valve mechanism 6. This connection is in this case mechanical, but it could
be hydraulic as well. The movements of the piston device 9 are controlled by a guide
member 10 arranged at the lower end of the piston device within the body part 8. The
guide member 10 is in engagement with and urged by a spring 11 towards a roller 12,
which receives its guidance from the cam profile 5' of the cam device 5. Thus, when
the cam shaft 4 rotates, in figures 2 - 4 in clockwise direction, the roller 12 follows
the cam profile 5' of the cam device 5, and the changes in the cam profile 5' are
transmitted so as to affect the opening and closing of the inlet valve 3.
[0015] The body part 8 and the piston device 9 together define a first chamber 13, into
which hydraulic medium can be selectively fed via a feed duct 14, as indicated by
arrow, for providing a delay in the closing of the inlet valve 3. In practice the
feed duct is with advantage provided with a shut-off valve and a non-return valve,
not shown. By means of the shut-off valve the feed line to the first chamber 13 may
be connected or disconnected, depending on whether or not the aim is to use the delay
function for the delayed closing of the inlet valve 3. Due to the non-return valve
the control arrangement cannot cause any pulsations in the source of hydraulic medium.
This is of importance when lubricating oil is used as a hydraulic medium.
[0016] The body part 8 is additionally provided with ducts 15 and 18 by means of which the
first chamber 13 can be connected with a second chamber 19, which is located in the
guide member 10. For this purpose the guide member 10 is provided with an aperture
10a. When the aperture 10a is at the position of the downward end opening of the duct
18 the flow connection between the chambers 13 and 19 is established. In addition,
between the ducts 15 and 18 there is a chamber 16 or the like duct which includes
control means 17 in accordance with the invention, the construction and operation
of which is described more in detail below.
[0017] So in figure 2 the control arrangement 7 is in a non-operating state and the roller
12 is located on the base circle of the cam profile 5'. In figure 3 the cam device
5 has rotated clockwise so that the nose in the cam profile 5' has lifted the roller
12 upwards in the figure. Thus, also the guide member 10 and the piston device 9 have
moved upwards and as a consequence the corresponding inlet valve 3 (not shown) has
opened. Simultaneously the first chamber 13 is filled with hydraulic medium fed through
the feed duct 14.
[0018] In figure 4 the roller 12 has returned on the base circle of the cam profile 5'.
Due to the hydraulic medium in the first chamber 13 the piston device 9 remains first
in its top position thereby keeping the inlet valve also open. As can be seen in figure
4 the engagement between the piston device 9 and the guide member 10 is hereby disconnected.
Thereafter, when the aperture 10a of the guide member 10 is moved at the position
of the opening of duct 18 the pressure in the first chamber 13 is released and the
piston device 9 starts to move downwards in the figure thereby allowing also the inlet
valve to close. Then also the contact between the piston device 9 and the guide member
10 is re-established. The hydraulic medium flows further from the chamber 19 to an
oil sump providing lubrication for the camshaft and the parts connected therewith.
[0019] In case the variable inlet valve closure (VIC) function related to the chamber 13
is not utilised the piston device 9 is in continuous connection with the guiding member
10 and the communication between the chamber 13 and the chamber 19 is established
in a normal way.
[0020] Figure 5 shows a first embodiment of control means 17 according to the invention.
The chamber 16 is provided with three ducts 18a, 18b and 18c which each can be arranged
in communication with the chamber 19 via the aperture 10a by means of the control
means 17, which include a control valve 17a movable in a chamber 20 located in the
body part 8. The control valve 17a is provided with a valve member 17b and releasing
means 17c, which in this case is a groove circumventing the valve member 17b. In figure
5 the releasing means 17c is at the position of the duct 18b, whereby communication
between the chambers 13 and 19 is established through this duct 18b. As obvious from
the figure the end openings of the ducts 18a, 18b and 18c are at different height.
This means that during the movement of the guide member 10 the end openings of these
ducts will be at the position of the aperture 10as at different time, whereby the
releasing of pressure in chamber 13 will occur at different time respectively. This
entails different delay of the closing of the inlet valve depending, thus, on the
duct selected in each case.
[0021] The operation of the valve means 17 can with advantage be accomplished pneumatically
by feeding pressure air into the chamber 20, as indicated by the arrow, which will
result in urging the control valve 17a with the valve member 17b to the left in the
figure against the force of a spring 21. Thus, the movement of the control valve 17a
and the selection of the respective duct 18a, 18b and 18c is dependent on the pressure
of the air to be fed into the chamber 20. Preferably the control systems of the engine
should be availed of so that for instance the charge air from a turbocharger of the
engine is utilised. Hereby variation in inlet valve closing can be accomplished more
or less automatically as a function of the charge air pressure being dependent on
the load of the engine in each case.
[0022] Figures 6a and 6b disclose another embodiment of the control means 17'. In this case
the chamber 16' which is formed as a connection duct is operationally connected with
a control valve 17'a, a control member 17'b of which controlling the communication
between the chamber 16' and a second duct 18'b. The control valve 17'a is located
in a chamber 20' into which pressure air is fed to urge it against the force of a
spring 21'. When the connection between the chamber 16' and the duct 18'b is closed,
as shown in figure 6b, the communication between the chambers 13 and 19 is established
via the duct 18'a. On the other hand when the connection between the chamber 16' and
the duct 18'b is open, as shown in figure 6a, the communication between the chambers
13 and 19 is established earlier via the duct 18'b the end opening of which being
above the end opening of the duct 18'a. However, also in this case the duct 18'a remains
open, and there is no need to have a separate control valve for closing it.
[0023] The operation of the embodiment of figures 6a and 6b and its effect on the delay
of the closing of the inlet valve of the engine is illustrated in figure 7 showing
the relative opening curve of the inlet valve as a function of the cam angle of the
engine. Curve C shows a situation, in which hydraulic medium is not led at all to
the chamber 13, whereby the inlet valve control is carried out merely determined by
the cam profile 5'. Curves A and B relate to the situation, in which hydraulic medium
is led to the chamber 13, while the piston device 9 moves in the opening direction
of the inlet valve. It is thus possible to provide a delay in the closing of the inlet
valve in relation to its normal operation e.g. in different load situations of the
engine. The curve A relates to a situation when the delay is affected by selecting
the communication between the chambers 13 and 19 via the duct 18'a, the control valve
17'a thus being in a position closing the duct 18'b as shown in figure 6b. The curve
B then represents a situation corresponding to figure 6a, according to which the control
valve 17'a is open and allows communication via the duct 18'b. Hereby the releasing
of pressure in the chamber 13 occurs earlier and the inlet valve, thus, is closed
earlier as well, but the closing is still delayed in comparison with the normal situation
depicted by the curve A.
[0024] Figure 8 discloses a third embodiment of the control means according to the invention.
This is a variation of the embodiment of figures 6a and 6b, which includes a third
duct 18"c in addition to the ducts 18"a and 18"b. As can be seen the end openings
of each of these ducts is located at different height, that is at different position
along the return movement of the guide member 10, thereby providing a possibility
for changing the delay of the closing of the inlet valve. In principle a number of
further ducts 18" could be provided as well depending on the need for closer variation
of the delay available in each case for the closing of the inlet valve in question,
and the space available in the body part 8 in the engine respectively. In case of
the embodiments of figures 6a, 6b and 8 the control valves 17, 17' and 17" can be
operated by means of any pressure medium preferably available in the engine, i.e.
pneumatic, hydraulic, or also electrically. The control of the control valves and
the selection of the flow duct in each case can be arranged by making use of pressure
sensors for each control valve and due control logic so as to determine the needed
delay in each case and to ensure correct operation of the control valves accordingly.
[0025] The invention is not limited to the examples mentioned above but can be implemented
in many other different embodiments within the scope of the inventive idea and the
attached claims.
1. A control arrangement for an inlet valve in a piston engine adapted between a cam
device (5) of a camshaft (4) of the engine (1) and an inlet valve mechanism (6) arranged
to open and close the inlet valve (3) in association with a cylinder of the engine,
which control arrangement (7) comprises a body part (8), in which a piston device
(9) is movably arranged to be in force transmission connection with the camshaft (4)
and the valve mechanism (6), said body part (8) and the piston device (9) together
defining a first chamber (13), into which hydraulic medium can be selectively fed,
and a second chamber (19) connected to the first chamber via duct means (18,18',18"),
the flow of hydraulic medium from the first chamber (13) to the second chamber (19)
being controlled for providing a delay in the closing of the inlet valve (3), the
body part (8) being provided with two or more flow ducts (18a,18b,18c;18'a,18'b;18"a,18"b,18"c)
for arranging different routes for the flow of hydraulic medium from the first chamber
(13) to the second chamber (19), and control means (17,17',17") being provided for
selecting the route of flow to be utilised in each case to provide different closing
delay, characterised in that the second chamber (19) is provided within a guide member (10) arranged between the
cam device (5) and the piston device (9) to be movably responsive with the movements
of cam device (5), and that the two or more flow ducts (18a,18b,18c;18'a,18'b;18"a,18"b,18"c)
are arranged to open into the second chamber (19) at different positions along the
track of movement of the guide member (10).
2. A control arrangement according to claim 1, characterised in that the two or more flow ducts (18a,18b,18c;18'a,18'b;18"a,18"b,18"c) are arranged to
open in a common chamber (16,16',16") or the like connection duct arranged in communication
with the first chamber (13), and that the control means (17,17',17") are arranged
to operate in said common chamber (16,16',16") or the like connection duct.
3. A control arrangement according to claim 1 or 2, characterised in that the guide member (10) is arranged to directly act on the piston device (9) only in
the direction for opening the inlet valve (3).
4. A control arrangement according to any one of the preceding claims, characterised in that the flow of hydraulic medium is arranged via one of said flow ducts (18a,18b,18c)
at a time and that the control means (17) include a control valve (17a) with a movable
valve member (17b) provided with a releasing means (17c) to be arranged at the position
of one of said flow ducts (18a,18b,18c).
5. A control arrangement according to claim 4, characterised in that the releasing means (17c) is a narrowing portion dimensioned to allow flow only through
one duct (18a,18b,18c) at a time.
6. A control arrangement according to any one of the claims 1-3, characterised in that it includes a separate control valve (17'a,17"a) for each of the flow ducts (18'b;18"b,18"c)
providing for a shortened delaying time.
7. A control arrangement according to any one of the preceding claims, characterised in that the control means (17,17',17") are arranged to be operated pneumatically, preferably
against the force of a spring, by making use of the control systems included in the
engine.
8. A control arrangement according to claim 7, characterised in that charge air from a turbocharger of said piston engine is arranged to be utilised for
controlling the control means (17,17',17").
1. Steueranordnung für ein Einlassventil in einem Kolbenmotor, die zwischen einer Nockenvorrichtung
(5) einer Nockenwelle (4) des Motors (1) und einem Einlassventilmechanismus (6), der
eingerichtet ist, um das einem Zylinder des Motors zugehörige Einlassventil (3) zu
öffnen und zu schließen, eingerichtet ist, wobei die Steueranordnung (7) einen Körperteil
(8) umfasst, in dem eine Kolbenvorrichtung (9) so beweglich angeordnet ist, dass sie
in einer Kraftübertragungsverbindung mit der Nockenwelle (4) und dem Ventilmechanismus
(6) steht, wobei der Körperteil (8) und die Kolbenvorrichtung (9) zusammen eine erste
Kammer (13), in die ein Hydraulikmedium selektiv geführt werden kann, und eine zweite
Kammer (19), die über ein Kanalmittel (18, 18', 18") mit der ersten Kammer verbunden
ist, definieren, wobei der Fluss des Hydraulikmediums von der ersten Kammer (13) zu
der zweiten Kammer (19) gesteuert wird, um eine Verzögerung beim Schließen des Einlassventils
(3) bereitzustellen, wobei der Körperteil (8) mit zwei oder mehr Durchflusskanälen
(18a, 18b, 18c; 18'a, 18'b; 18"a, 18"b, 18"c) versehen ist, um verschiedene Wege für
den Fluss des Hydraulikmediums von der ersten Kammer (13) zu der zweiten Kammer (19)
einzurichten, und ein Steuermittel (17, 17', 17") bereitgestellt ist, um den Weg des
Flusses, der jeweils benutzt werden soll, zu wählen, um eine unterschiedliche Schließverzögerung
bereitzustellen, dadurch gekennzeichnet, dass die zweite Kammer (19) in einem Führungselement (10) bereitgestellt ist, das so zwischen
der Nockenvorrichtung (5) und der Kolbenvorrichtung (9) angeordnet ist, dass es als
Reaktion auf die Bewegungen der Nockenvorrichtung (5) beweglich ist, und dass die
zwei oder mehr Durchflusskanäle (18a, 18b, 18c; 18'a, 18'b; 18"a, 18"b, 18"c) so angeordnet
sind, dass sie sich an unterschiedlichen Positionen entlang der Bewegungsstrecke des
Führungselements (10) in die zweite Kammer (19) öffnen.
2. Steueranordnung nach Anspruch 1, dadurch gekennzeichnet, dass die zwei oder mehr Durchflusskanäle (18a, 18b, 18c; 18'a, 18'b; 18"a, 18"b, 18"c)
so angeordnet sind, dass sie sich in eine gemeinsame Kammer (16, 16', 16") oder einen
ähnlichen Verbindungskanal öffnen, die bzw. der in Verbindung mit der ersten Kammer
(13) angeordnet ist, und dass das Steuermittel (17, 17', 17") so angeordnet ist, dass
es in der gemeinsamen Kammer (16, 16', 16") oder in dem ähnlichen Verbindungskanal
wirkt.
3. Steueranordnung nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass das Führungselement (10) so angeordnet ist, dass es nur in der Richtung zum Öffnen
des Einlassventils (3) direkt auf die Kolbenvorrichtung (9) wirkt.
4. Steueranordnung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der Fluss des Hydraulikmediums immer über einen der Durchflusskanäle (18a, 18b, 18c)
eingerichtet ist, und dass das Steuermittel (17) ein Steuerventil (17a) mit einem
beweglichen Ventilelement (17b), das mit einem Entlastungsmittel (17c) zur Anordnung
an der Position eines der Durchflusskanäle (18a, 18b, 18c) versehen ist, umfasst.
5. Steueranordnung nach Anspruch 4, dadurch gekennzeichnet, dass das Entlastungsmittel (17c) ein sich verengender Abschnitt ist, der so in der Größe
bemessen ist, dass er immer nur einen Fluss durch einen Kanal (18a, 18b, 18c) gestattet.
6. Steueranordnung nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass sie für jeden der Durchflusskanäle (18'b, 18"b, 18"c) ein gesondertes Steuerventil
(17'a, 17"a) umfasst, das für eine verkürzte Verzögerungszeit sorgt.
7. Steueranordnung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass das Steuermittel (17, 17' 17") so eingerichtet ist, dass es unter Gebrauch der in
dem Motor enthaltenen Steuersysteme pneumatisch, vorzugsweise gegen die Kraft einer
Feder, betrieben wird.
8. Steueranordnung nach Anspruch 7, dadurch gekennzeichnet, dass Ladeluft von einem Turbolader des Kolbenmotors zur Verwendung für die Steuerung des
Steuermittels (17, 17', 17") eingerichtet ist.
1. Agencement de commande pour une soupape d'entrée dans un moteur à pistons adapté entre
un dispositif de cames (5) d'un arbre à cames (4) du moteur (1) et un mécanisme de
soupape d'entrée (6) agencé pour ouvrir et fermer la soupape d'entrée (3) en association
avec un cylindre du moteur, lequel agencement de commande (7) comprend une partie
de corps (8) dans laquelle un dispositif à piston (9) est agencé de façon mobile pour
être en liaison de transmission de force avec l'arbre à cames (4) et le mécanisme
de soupape (6), la partie de corps (8) et le dispositif à piston (9) définissant ensemble
une première chambre (13) dans laquelle du fluide hydraulique peut être alimenté de
façon sélective, et une seconde chambre (19) reliée à la première chambre via des
moyens de tuyaux (18, 18', 18''), l'écoulement de fluide hydraulique de la première
chambre (13) à la seconde chambre (19) étant commandé en fournissant un retard dans
la fermeture de la soupape d'entrée (3), la partie de corps (8) étant dotée de deux
ou plusieurs tuyaux d'écoulement (18a, 18b, 18c ; 18'a, 18'b ; 18" a, 18"b, 18" c)
pour agencer différents trajets d'écoulement du fluide hydraulique de la première
chambre (13) à la seconde chambre (19) et des moyens de commande (17, 17', 17") étant
prévus pour sélectionner le trajet d'écoulement à utiliser dans chaque cas pour fournir
un retard de fermeture différent, caractérisé en ce que la seconde chambre (19) est dotée d'un élément de guidage (10) agencé entre le dispositif
de cames (5) et le dispositif à piston (9) pour réagir de façon mobile aux mouvements
du dispositif de cames (5), et en ce que les deux ou plusieurs tuyaux d'écoulement (18a, 18b, 18c ; 18'a, 18'b ; 18" a, 18"b,
18" c) sont agencés pour déboucher dans la seconde chambre (19) à différentes positions
le long de la trajectoire de mouvement de l'élément de guidage (10).
2. Agencement de commande selon la revendication 1, caractérisé en ce que les deux ou plusieurs tuyaux d'écoulement (18a, 18b, 18c ; 18'a, 18'b ; 18"a, 18''b,
18''c) sont agencés pour déboucher dans une chambre commune (16, 16', 16'') ou le
tuyau de connexion similaire agencé en communication avec la première chambre (13),
et en ce que les moyens de commande (17, 17', 17") sont agencés pour fonctionner dans la chambre
commune (16, 16', 16") ou le tuyau de connexion similaire.
3. Agencement de commande selon la revendication 1 ou 2, caractérisé en ce que l'élément de guidage (10) est agencé pour agir directement sur le dispositif à piston
(9) uniquement dans la direction d'ouverture de la soupape d'entrée (3).
4. Agencement de commande selon l'une quelconque des revendications précédentes, caractérisé en ce que l'écoulement de fluide hydraulique est agencé via l'un des tuyaux d'écoulement (18a,
18b, 18c) à la fois et que le moyen de commande (17) comprend une soupape de commande
(17a) avec un élément de soupape mobile (17b) doté d'un moyen de déclenchement (17c)
destiné à être agencé à la position de l'un des tuyaux d'écoulement (18a, 18b, 18c).
5. Agencement de commande selon la revendication 4, caractérisé en ce que le moyen de déclenchement (17c) est une partie qui rétrécit dimensionnée pour permettre
l'écoulement uniquement à travers un tuyau (18a, 18b, 18c) à la fois.
6. Agencement de commande selon l'une quelconque des revendications 1 - 3, caractérisé en ce qu'il comprend une soupape de commande séparée (17'a, 17''a) pour chacun des tuyaux d'écoulement
(18'b, 18''b, 18''c) fournissant un temps de retard réduit.
7. Agencement de commande selon l'une quelconque des revendications précédentes, caractérisé en ce que les moyens de commande (17, 17', 17') sont agencés pour fonctionner de façon pneumatique,
de préférence contre la force d'un ressort, par l'utilisation des systèmes de commande
inclus dans le moteur.
8. Agencement de commande selon la revendication 7, caractérisé en ce que de l'air de suralimentation d'un turbocompresseur du moteur à pistons est agencé
pour être utilisé pour commander les moyens de commande (17, 17', 17'').
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only.
It does not form part of the European patent document. Even though great care has
been taken in compiling the references, errors or omissions cannot be excluded and
the EPO disclaims all liability in this regard.
Patent documents cited in the description