BACKGROUND
Technical Field
[0001] The present invention relates generally to the field of high pressure fuel pumps.
More particularly, but not exclusively, the present invention concerns a pressure
regulation arrangement for high pressure diesel fuel pumps.
Description of the Related Art
[0002] As shown in Figure 1, a typical high pressure diesel fuel pump 1 comprises a plunger
2 extending from a hydraulic head 5 along a pumping axis A-A'. A plunger return spring
3 is seated around the head 5 and extends to the top of a spring seat 4 fixed near
a lower end 2a of the plunger 2. The lower end 2a of the plunger 2 contacts a plunger-driving
configuration, which may comprise a roller-shoe assembly 6. The roller-shoe assembly
6 is driven in a reciprocating path along the pumping axis A-A' by the rotation of
a cam 8 on a driveshaft 9. The reciprocation of the roller-shoe assembly 6, in turn
drives the plunger 2 along the pumping axis A-A'.
[0003] DE102011006092 A1 discloses a high pressure diesel fuel pump with a pressure regulating member comprising
a hollow elastomer.
[0004] During rotation of the cam 8 and as the roller-shoe assembly 6 and plunger 2 reciprocate,
pressure fluctuations are observed in the cambox 10. In particular, pressure spikes
(short periods of high pressure) can have detrimental effects on pump 1 and upstream
engine components.
[0005] It is an object of the present invention to address one or more of the problems of
known designs, particularly, but not exclusively high pressure pumps.
[0006] Therefore, it is now desired to provide an improved arrangement for a high pressure
diesel fuel pump to minimise the effects of such pressure spikes. More particularly,
it is desired to provide an improved drivetrain assembly and a pressure regulating
arrangement for high pressure diesel fuel pumps.
SUMMARY OF THE INVENTION
[0007] In a first aspect of the present invention there is provided a high pressure diesel
fuel pump comprising a pumping assembly and a drivetrain assembly, the pumping assembly
comprising a plunger extending from a pump head along a pumping axis, the drivetrain
assembly comprising a drive shaft and a cam mounted thereon within a cambox of a housing,
a plunger-driving assembly for contact with a lower end of the plunger and mounted
substantially between said plunger and the cam, wherein the plunger is arranged for
reciprocating linear movement along the pumping axis within a pumping chamber of the
housing upon rotation of the cam, characterised in that the pumping chamber comprises
a pressure regulating member adapted to adjust its volume in response to changes in
pressure in the cambox.
[0008] With this arrangement, pressure fluctuations in the cambox can be lessened by the
pressure regulating member, which is adapted to reduce its volume as the pressure
in the cambox rises, which has the effect of increasing cambox volume and causing
the cambox pressure to fall. The pressure regulating member is also adapted to increase
its volume as the pressure in the cambox falls, which has the opposite effect of decreasing
cambox volume and causing the cambox pressure to rise. Accordingly, pressure spikes,
as well as pressure depressions, are balanced out.
[0009] The pressure regulating member comprises a volume adjustment means. The volume adjustment
means comprises a flexible component. The flexible component comprises a flexible
membrane. The flexible component comprises a hollow formed shape having a maximum
internal volume.
[0010] Preferably, the flexible component comprises a maximum internal volume adapted to
decrease by at least 0.2 cc
3 (when subjected to 4 Bar pressure), more preferably, by at least approximately 0.22
cc
3, most preferably, by at least approximately 0.677 cc
3.
[0011] Preferably, the hollow formed shape of the flexible component is adapted to at least
partially deform as pressure rises in the cambox, thereby decreasing an internal volume
of the pressure regulating member. Preferably, the flexible component is adapted to
adopt a concave configuration.
[0012] Preferably, the hollow formed shape of the flexible component is configured to at
least partially reform as pressure falls in the cambox, thereby increasing an internal
volume of the pressure regulating member. Preferably, the flexible component is adapted
to reform to adopt a convex configuration.
[0013] The flexible membrane comprises a shear modulus of between approximately 9 MPa and
approximately 46 MPa (when using the Yeoh hyperelastic model), more preferably between
approximately 12 MPa and approximately 40 MPa, most preferably approximately 13 MPa.
[0014] The pressure regulating member comprises an anchor component. The anchor component
comprises a dovetail-shaped annulus. Preferably, the anchor component comprises an
outwardly-disposed curved wall. Preferably, the outwardly-disposed curved wall is
substantially uncontoured, e.g. flat.
[0015] Preferably, the anchor component comprises a pair of short side walls connected to
the flexible component to form a ring-shaped member. Preferably, at least one of said
short side walls is inwardly-tapered. Preferably, both side walls are inwardly-tapered.
Preferably, the inwardly-tapered side walls are integrally-formed with the flexible
component. Preferably, the inwardly-tapered side walls are integrally-formed with
the outwardly-disposed curved wall.
[0016] Preferably, the anchor component is resiliently flexible. Preferably, the anchor
component is substantially hollow.
[0017] Preferably, the hollow formed shape of the flexible component comprises a substantially
dome-shaped annulus. Preferably, the dome-shaped annulus is inwardly-disposed.
[0018] Preferably, the flexible component comprises a plurality of reinforcement ribs. Preferably,
the reinforcement ribs are curved to adopt the hollow formed shape of the flexible
component. Preferably, the reinforcement ribs are resiliently flexible. Preferably,
the reinforcement ribs are disposed inside the hollow formed shape of the flexible
component.
[0019] Preferably, at least the flexible membrane comprises a fluorocarbon rubber. Preferably,
the flexible membrane comprises a thickness of up to approximately 0.5 mm, most preferably
approximately 0.3 mm. Preferably, the flexible component comprises a fluorocarbon
rubber.
[0020] Preferably, the anchor component comprises a fluorocarbon rubber.
[0021] Preferably, therefore, the hollow formed shape of the flexible component comprises
an internal height of approximately 4 mm and an internal depth of approximately 2
mm.
[0022] Preferably, the pressure regulating member is disposed in a top half of the pumping
chamber, more preferably in a top quarter of the pumping chamber. Most preferably,
the pressure regulating member is disposed proximal to a top end of the pumping chamber.
[0023] Preferably, the pressure regulating member is arranged around a spring in the pumping
chamber. The pressure regulating member may be arranged around the pump head in the
pumping chamber. The pressure regulating member may be disposed proximal to a top
end of the pumping chamber.
[0024] Preferably, the pressure regulating member is mounted within an internal wall of
the pumping chamber. Preferably, the anchor component is mounted in an internal wall
of the pumping chamber.
[0025] Preferably, therefore, the internal chamber wall comprises a retention means for
the anchor component. Preferably, the retention means comprises an annular slot in
said internal wall. Preferably, the slot comprises an interlocking arrangement with
the anchor component. Most preferably, the slot comprises a dovetail-shape, e.g. having
a narrow opening and tapering towards a wider back slot wall.
[0026] Preferably, the pump is a diesel pump.
[0027] In a second aspect of the present invention there is provided a drivetrain assembly
for a high pressure fuel pump comprising a drive shaft and a cam mounted thereon within
a cambox of a housing, a plunger-driving assembly for contact with a lower end of
the plunger and mounted substantially between said plunger and the cam, characterised
in that the drivetrain assembly further comprises a pressure regulating member adapted
to adjust its volume in response to changes in pressure in the cambox.
[0028] It will be appreciated that the preferred features described in relation to the first
aspect of the invention also apply to the second aspect of the invention.
[0029] In a third aspect of the present invention there is provided a pressure regulating
member for a drivetrain assembly of a high pressure fuel pump comprising a volume
adjustment means adapted to respond to changes in pressure.
[0030] It will be appreciated that the preferred features described in relation to the first
aspect of the invention also apply to the third aspect of the invention.
[0031] In a fourth aspect of the present invention there is provided a high pressure diesel
fuel pump comprising a pumping assembly and a drivetrain assembly, the pumping assembly
comprising a plunger extending from a pump head along a pumping axis, the drivetrain
assembly comprising a drive shaft and a cam mounted thereon within a cambox of a housing,
a plunger-driving assembly for contact with a lower end of the plunger and mounted
substantially between said plunger and the cam, wherein the plunger is arranged for
reciprocating linear movement along the pumping axis within a pumping chamber of the
housing upon rotation of the cam, characterised in that the pumping chamber comprises
a retention means for a pressure regulating member.
[0032] It will be appreciated that the preferred features described in relation to the first
aspect of the invention also apply to the fourth aspect of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] For a better understanding of the invention, and to show how exemplary embodiments
may be carried into effect, reference will now be made to the accompanying drawings
in which:
Figure 1 is a cross-sectional partial view of a prior art pumping assembly and drivetrain assembly of a high pressure diesel fuel pump;
Figure 2 is a cross-sectional partial view of a high pressure diesel fuel pump according
to the invention;
Figure 3 is an exploded cross-sectional partial view of the high pressure fuel pump
of Figure 2;
Figure 4 is a schematic perspective view of a first embodiment of a pressure regulating
member for a drivetrain assembly of the high pressure fuel pump of Figure 2; and
Figure 5 is an exploded cross-sectional partial view of the pressure regulating member
of Figure 3 within a pumping chamber;
Figure 6 is a schematic perspective view of a second embodiment of a pressure regulating
member for a drivetrain assembly of the high pressure fuel pump of Figure 2.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0034] The invention is shown in Figures 2 to 5. A high pressure diesel fuel pump 20 comprises
a pumping assembly 30 and a drivetrain assembly 40. The pumping assembly 30 comprises
a plunger 32 extending from a pump head 34 along a pumping axis A-A'. The drivetrain
assembly 40 comprises a drive shaft 42 and a cam 44 mounted thereon within a cambox
46 of a housing 48, a plunger-driving assembly 50 for contact with a lower end 32a
of the plunger 32 and mounted substantially between said plunger 32 and the cam 44.
The plunger 32 is arranged for reciprocating linear movement along the pumping axis
A-A' within a pumping chamber 36 of the cambox 46 upon rotation of the cam 44, characterised
in that the pumping chamber 36 comprises a pressure regulating member 60, 80 adapted
to adjust its volume in response to changes in pressure in the cambox 46.
[0035] As shown more clearly in Figures 4 and 5, a first embodiment of the pressure regulating
member 60 is substantially ring-shaped comprising an outer wall 62 and an inner dome
64. The outer wall 62 is substantially circular and planar and is outwardy-facing.
The dome 64 comprises a relatively shallow convex curve and is inwardly-facing. It
will be appreciated that the shape of the pressure regulating member 60 is primarily
chosen for ease of machining, but may take on another suitable shape.
[0036] Connecting the outer wall 62 with the inner dome 64 is a tapered section 66. The
tapered section 66 comprises a pair of short walls 66a, 66b protruding inwardly of
the outer wall 62 to join ends 64a, 64b of the dome 64. The outer wall 62 and the
tapered section 66 form a dovetail shape, which serves as an anchor component for
mounting of the pressure regulating member 60 in an internal wall 36a of the pumping
chamber 36 (as later described).
[0037] The outer wall 62, short walls 66a, 66b of the tapered section 66 and dome 64 form
a substantially hollow body 61 with a maximum possible volume V1.
[0038] The outer wall 62, short walls 66a, 66b of the tapered section 66 and dome 64 each
comprise a resiliently deflectable material, which in the described embodiment comprise
thin walls of fluorocarbon rubber. However, it is to be appreciated that other suitable
resiliently flexible materials demonstrating resilience in a diesel fuel environment
may be utilised.
[0039] Under normal or low pressure conditions, the dome 64 is able to retain a convexly
curved shape and a maximum volume V1. Under rising or high pressure conditions, at
least the dome 64 is configured to allow deflection inwardly to adopt a flattened,
or concavely curved shape as can be seen in Figures 7a - c, with a reduced volume
V2, V3, V4.
[0040] The exact shape and minimum possible volume of the pressure regulating member 60
following the inward deflection, depends upon (a) the shear modulus of the material,
namely the material composition, (b) wall thickness of the material used and (c) the
presence of any additional resilient components (e.g. see Figure 6). However, it will
be appreciated that the actual pressure in the pumping chamber 36 will impact on whether
the pressure regulating member 60 reaches its minimum possible volume V2, V3, V4 at
any one time.
[0041] In a specific embodiment, the outer diameter of the pressure regulating member 60
is approximately 32 mm. To achieve a maximum volume V1 of 0.677 cc
3, the approximate geometry of a cross-section of the pressure-regulating member 60
is as follows: a maximum internal height H1 of the pressure regulating member 60 is
measured as an internal length of the outer wall 62 and comprises approximately 4
mm; a maximum internal depth D1 of the pressure regulating member 60 is measured at
approximately 2 mm; the short tapered walls 66a, 66b are measured at approximately
1.25 mm long and are disposed at an approximate angle of 8° from the horizontal; and
the dome 64 comprises a radius of curvature of approximately 3.5 mm. The body 61 of
the pressure regulating member 60 is formed of thin walls of fluorocarbon rubber at
approximately 0.3 mm thick. However, it will be appreciated that the outer diameter,
geometry and maximum volume of the pressure regulating member may be increased or
decreased depending upon the diameter of the pumping chamber into which it is being
disposed.
[0042] In an alternative embodiment as shown in Figure 6, the pressure regulating member
80 is substantially ring-shaped comprising an outer wall 82 and an inner dome 84.
The outer wall 82 is substantially circular and planar and is outwardy-facing. The
dome 84 comprises a relatively shallow convex curve and is inwardly-facing. Connecting
the outer wall 82 with the inner dome 84 is a tapered section 86. The tapered section
86 comprises a pair of short walls 86a, 86b protruding inwardly of the outer wall
82 to join ends 84a, 84b of the dome 84. The outer wall 82 and the tapered section
86 form a dovetail shape, which serves as an anchor component for mounting of the
pressure regulating member 80 in an internal wall 36a of the pumping chamber 36 (as
later described). The body 81 of the pressure regulating member 60 is hollow as described
in relation to the first embodiment. In this embodiment, inside the body 81 of the
pressure regulating member 80, there are a plurality of additional resilient components
in the form of reinforcing ribs 88 disposed at regular intervals. The reinforcing
ribs 88 comprises a curved section 88a mirroring the shape of the dome 64 and a pair
of outwardly-deflected legs 88b that mirror the angle of the tapered section 66. The
reinforcing ribs 88 comprise a resiliently deflectable material that, under normal
or low pressure conditions, retain their convexly curved shape and under high pressure
conditions, are configured to allow at least the curved section 88a to deflect inwardly
to adopt a concavely curved shape. The reinforcing ribs 88 help to prevent permanent
deformation of the dome 64.
[0043] As is shown in Figure 3, the pressure regulating member 60, 80 is mounted within
the internal wall 36a of the pumping chamber 36. The internal wall 36a is provided
with an annular slot 38, which comprises a dovetail shape and is configured to receive
and retain the anchor component (outer wall 62, 82 and the tapered section 66, 86)
of the pressure regulating member 60, 80. Better seen in Figure 8, the slot 38 comprises
a narrow annular aperture 38a and an annular wedge- or dovetail-shaped cavity 38c
with a rear wall 38b, and is sized to be a clearance fit with the outer wall 62, 82
and the tapered section 66, 86.
[0044] As shown in Figure 3, the slot 38 can be located proximal to an upper end 36b of
the pumping chamber 36 so as to generally surround the pump head 34, the plunger 32
and a plunger spring 39. In this embodiment, the slot 38 is disposed in the wall between
a first turn 39a and a second turn 39b of the spring 39 in a resting condition, primarily
for ease of machining. However, other positions within the pumping chamber are possible.
[0045] During installation, the resiliently deflectable nature of the anchor component (outer
wall 62, 82 and the tapered section 66, 86) of the pressure regulating member 60,
80 allows it to be deflected/ reduced in height to clear the narrow aperture 38a and
pass into the cavity 38b, where it opens back out to substantially fill the cavity
38b with the outer wall 62, 82 resting against the back wall 38c of the slot 38. The
dome 64, 84 protrudes from the slot 38, beyond the internal wall 36 into the pumping
chamber 36. Due to the cooperating dovetail shaped anchor component (outer wall 62,
82 and the tapered section 66, 86) and slot cavity 38b, the pressure regulating member
60, 80 is not easily dislodged from the slot 38 without force or intention.
[0046] In use, in normal or low pressure conditions, the dome 64, 84 of the pressure regulating
member 60, 80 adopts a normal convex configuration (as seen in Figure 7 as C1) comprising
the maximum possible internal volume V1. As the pressure conditions in the pumping
chamber 36 of the cambox 46 rise, the dome 64, 84 of the pressure regulating member
60, 80 is encouraged to deform inwardly, to reduce the internal volume of from the
maximum internal volume V1 to a reduced internal volume V2, V3, V4 and reduced depth
D2, D3, D4 respectively.
[0047] The extent of deformation and therefore, the extent to which the volume is reduced
depends upon how high the pressure rises in addition to (a) the shear modulus (elasticity)
of the material forming the dome 64, 84, (b) wall thickness of the material used and
(c) the presence of any additional resilient components (e.g. see Figure 6).
[0048] A material with a high shear modulus (when using the Yeoh hyperelastic model), e.g.
86.81 MPa as in Figure 7a, may only achieve a small degree of deformation by flattening
the dome 64, 84 and therefore a volume V2 reduced by approximately 0.04 cc
3 (when subjected to pressures of 4 Bar). On the other hand, a material with a medium
shear modulus, e.g. 45.58 MPa as in Figure 7b, may achieve a greater degree of deformation
by creating a concave dome and therefore a volume V3 reduced by approximately 0.25
cc
3 (when subjected to pressures of 4 Bar). Other examples of Shear modulus and volume
reduction are shown in the table below:
Shear Modulus of flexible material at 4 Bar pressure |
Volume Reduction [cc] |
8.68 |
0.000 |
13.02 |
0.534 |
30.39 |
0.463 |
43.41 |
0.300 |
45.58 |
0.249 |
47.75 |
0.188 |
52.09 |
0.116 |
86.81 |
0.035 |
[0049] By using fluorocarbon rubber with a relatively low shear modulus of approximately
13 MPa (when using the Yeoh hyperelastic model), a minimum reduced volume V4 is expected
to be achievable, namely a reduction of 0.534 cc
3 (when subjected to pressures of 4 Bar) in the internal volume of the pressure regulating
member 60, 80. In this case, the dome 64, 84 is able to reach an inverse configuration
where a peak of the dome 64, 84 contacts the outer wall 62, 82 of the anchor member
and the tapered section 66 retaining a relatively normal configuration.
[0050] With the described embodiments, the pressure in the cambox 46 can be effectively
regulated by providing a change in volume of the cambox 46 using one of the described
pressure regulating members 60, 80. The possible changes in volume of the pressure
regulating members 60, 80 in response to fluctuating pressures, helps to minimise
pressure spikes and equalise the pressure in the cambox 46 during a pumping cycle.
In other words, a decrease in pressure regulating member 60, 80 volume, provides an
equivalent increase in the cambox 46 volume, thereby reducing pressure, and
vice versa.
[0051] Although a few preferred embodiments have been shown and described, it will be appreciated
by those skilled in the art that various changes and modifications might be made without
departing from the scope of the invention, as defined in the appended claims.
1. A high pressure diesel fuel pump (20) comprising a pumping assembly (30) and a drivetrain
assembly (40), the pumping assembly (30) comprising a plunger (32) extending from
a pump head (34) along a pumping axis (A-A'), the drivetrain assembly (40) comprising
a drive shaft (42) and a cam (44) mounted thereon within a cambox (46) of a housing
(48), a plunger-driving assembly (50) for contact with a lower end (32a) of the plunger
(32) and mounted substantially between said plunger (32) and the cam (44), wherein
the plunger (32) is arranged for reciprocating linear movement along the pumping axis
(A-A') within a pumping chamber (36) of the housing (48) upon rotation of the cam
(44),
wherein the pumping chamber (36) comprises a pressure regulating member (60, 80) adapted
to adjust its volume in response to changes in pressure in the cambox (46),
wherein the pressure regulating member (60, 80) comprises a volume adjustment means,
wherein the volume adjustment means comprises a flexible component (64, 84) comprising
a flexible membrane, wherein the flexible component (64, 84) comprises a hollow formed
shape having a maximum internal volume (V1), characterized in that the flexible membrane comprises a shear modulus of between approximately 9 MPa and
approximately 46 MPa (when using the Yeoh hyperelastic model),
wherein the pressure regulating member (60, 80) comprises an anchor component (62,
82),
wherein the anchor component (62, 82) comprises a dovetail-shaped annulus.
2. The pump according to any one of claim 1, wherein the flexible component (64, 84)
comprises a maximum internal volume (V1) adapted to decrease by at least approximately
0.2 cc3.
3. The pump according to any one of claims 1 to 2, wherein the hollow formed shape of
the flexible component (64, 84) is adapted to at least partially deform as pressure
rises in the cambox (46), thereby decreasing an internal volume of the pressure regulating
member (64, 84).
4. The pump according to any one of claims 1 to 3, wherein the hollow formed shape of
the flexible component (64, 84) is configured to at least partially reform as pressure
falls in the cambox (46), thereby increasing an internal volume of the pressure regulating
member (64, 84).
5. The pump according to any one of claims 1 to 4, wherein the anchor component (62,
82) is resiliently flexible and substantially hollow.
6. The pump according to any one of claims 1 to 4, wherein the flexible component (84)
comprises a plurality of resiliently flexible reinforcement ribs (88).
7. The pump according to any one of claims 1 to 5, wherein at least the flexible membrane
comprises a fluorocarbon rubber.
8. The pump according to any one of claims 5 to 7, wherein the pressure regulating member
(60, 80) is mounted within an internal wall (36a) of the pumping chamber (36) via
a retention means (38) for the anchor component (62, 82).
9. The pump according to claim 8, wherein the retention means (38) comprises an annular
dovetail-shaped slot in said internal wall (36a).
1. Hochdruckdieselkraftstoffpumpe (20) mit einer Pumpanordnung (30) und einer Antriebsanordnung
(40), wobei die Pumpanordnung (30) einen Kolben (32) aufweist, der sich von einem
Pumpenkopf (34) entlang einer Pumpachse (A-A') erstreckt, wobei die Antriebsanordnung
(40) eine Antriebswelle (42) und eine Nocke (44) aufweist, die daran in einer Nockenbox
(46) eines Gehäuses (48) angebracht ist, eine Kolbenantriebsanordnung (50) für einen
Kontakt mit einem unteren Ende (32a) des Kolbens (32) und im Wesentlichen zwischen
dem Kolben (32) und dem Nocken (44) angebracht, wobei der Kolben (32) ausgebildet
ist zur linearen Hin- und Herbewegung entlang der Pumpachse (A-A') innerhalb einer
Pumpkammer (36) des Gehäuses (48) bei Rotation des Nockens (44),
wobei die Pumpkammer (36) ein Druckregelungselement (60, 80) aufweist, das ausgebildet
ist zum Anpassen seines Volumens in Reaktion auf Änderungen des Drucks in der Nockenbox
(46),
wobei das Druckregelungselement (60, 80) ein Volumenanpassungsmittel aufweist, wobei
das Volumenanpassungsmittel eine flexible Komponente (64, 84) mit einer flexiblen
Membran aufweist,
wobei die flexible Komponente (64, 84) eine hohl-geformte Form mit einem maximalen
Innenvolumen (V1) aufweist,
dadurch gekennzeichnet, dass die flexible Membran einen Schermodul zwischen ungefähr 9 MPA und ungefähr 46 MPA
aufweist (bei Verwendung des hyperelastischen Yeoh-Modells),
wobei das Druckregelungselement (60, 80) eine Ankerkomponente (62, 82) aufweist, wobei
die Ankerkomponente (62, 82) eine schwalbenschwanzförmige ringförmige Öffnung aufweist.
2. Die Pumpe gemäß einem von Anspruch 1, wobei die flexible Komponente (64, 84) ein maximales
Innenvolumen (V1) aufweist, das ausgebildet ist, um zumindest um ungefähr 0,2 cc3 verringert zu werden.
3. Die Pumpe gemäß einem der Ansprüche 1 bis 2, wobei die hohl-geformte Form der flexiblen
Komponente (64, 84) ausgebildet ist, um sich zumindest teilweise zu verformen, wenn
der Druck in der Nockenbox (46) ansteigt, wodurch ein Innenvolumen des Druckregelungselements
(64, 84) verringert wird.
4. Die Pumpe gemäß einem der Ansprüche 1 bis 3, wobei die hohl-geformte Form der flexiblen
Komponente (64, 84) konfiguriert ist, sich zumindest teilweise zurückzubilden, wenn
der Druck in der Nockenbox (46) fällt, wodurch ein Innenvolumen des Druckregelungselements
(64, 84) erhöht wird.
5. Die Pumpe gemäß einem der Ansprüche 1 bis 4, wobei die Ankerkomponente (62, 82) elastisch
flexibel und im Wesentlichen hohl ist.
6. Die Pumpe gemäß einem der Ansprüche 1 bis 4, wobei die flexible Komponente (84) eine
Vielzahl von elastisch flexiblen Verstärkungsrippen (88) aufweist.
7. Die Pumpe gemäß einem der Ansprüche 1 bis 5, wobei zumindest die flexible Membran
einen Fluorkohlenstoffgummi aufweist.
8. Die Pumpe gemäß einem der Ansprüche 5 bis 7, wobei das Druckregelungselement (60,
80) innerhalb einer Innenwand (36a) der Pumpkammer (36) über ein Haltemittel (38)
für die Ankerkomponente (62, 82) angebracht ist.
9. Die Pumpe gemäß Anspruch 8, wobei das Haltemittel (38) einen ringförmigen schwalbenschwanzförmigen
Schlitz in der Innenwand (36a) aufweist.
1. Pompe à haute pression pour carburant diesel (20) comprenant un assemblage de pompage
(30) et un assemblage d'entraînement mécanique (40), l'assemblage de pompage (30)
comprenant un plongeur (32) s'étendant depuis une tête de pompe (34) le long d'un
axe de pompage (A-A'), l'assemblage d'entraînement mécanique (40) comprenant un arbre
d'entraînement (42) et une came (44) montée sur celui-ci à l'intérieur d'une boîte
à came (46) d'un boîtier (48), un assemblage d'entraînement de plongeur (50) destiné
à venir en contact avec une extrémité inférieure (32a) du plongeur (32) et monté sensiblement
entre ledit plongeur (32) et la came (44), dans laquelle le plongeur (32) est agencé
pour un mouvement linéaire en va-et-vient le long de l'axe de pompage (A-A') à l'intérieur
d'une chambre de pompage (36) du boîtier (48) lors d'une rotation de la came (44),
dans laquelle la chambre de pompage (36) comprend un élément de régulation de pression
(60, 80) adapté pour ajuster son volume en réponse à des changements de pression dans
la boîte à came (46),
dans laquelle l'élément de régulation de pression (60, 80) comprend un moyen d'ajustement
de volume,
dans laquelle le moyen d'ajustement de volume comprend un composant flexible (64,
84) comprenant une membrane flexible,
dans laquelle le composant flexible (64, 84) comporte une conformation de forme creuse
ayant un volume interne maximum (V1),
caractérisée en ce que
la membrane flexible présente un module de cisaillement entre approximativement 9
MPa et approximativement 46 MPa (lorsqu'on utilise le modèle hyper élastique de Yeoh),
dans laquelle l'élément de régulation de pression (62, 80) comprend un composant d'ancrage
(62, 82),
dans laquelle le composant d'ancrage (62, 82) comprend un anneau en forme de queue
d'aronde.
2. Pompe selon la revendication 1, dans laquelle le composant flexible (64, 84) comprend
un volume interne maximum (V1) adapté à diminuer d'au moins approximativement 0,2
cc3.
3. Pompe selon l'une quelconque des revendications 1 et 2, dans laquelle la conformation
de forme creuse du composant flexible (64, 84) est adaptée pour se déformer au moins
partiellement lorsque la pression augmente dans la boîte à came (46), en diminuant
ainsi un volume interne de l'élément de régulation de pression (64, 84).
4. Pompe selon l'une quelconque des revendications 1 à 3, dans laquelle la conformation
de forme creuse du composant flexible (64, 84) est configurée pour se reformer au
moins partiellement lorsque la pression chute dans la boîte à came (46), en augmentant
ainsi un volume interne de l'élément de régulation de pression (64, 84).
5. Pompe selon l'une quelconque des revendications 1 à 4, dans laquelle le composant
d'ancrage (62, 82) est élastiquement flexible et sensiblement creux.
6. Pompe selon l'une quelconque des revendications 1 à 4, dans laquelle le composant
flexible (84) comprend une pluralité de nervures de renforcement élastiquement flexibles
(88).
7. Pompe selon l'une quelconque des revendications 1 à 5, dans laquelle au moins la membrane
flexible comprend un caoutchouc fluorocarboné.
8. Pompe selon l'une quelconque des revendications 5 à 7, dans laquelle l'élément de
régulation de pression (62, 80) est monté dans une paroi interne (36a) de la chambre
de pompage (36) via un moyen de rétention (38) pour le composant d'ancrage (62, 82).
9. Pompe selon la revendication 8, dans laquelle le moyen de rétention (38) comprend
une fente annulaire en forme de queue d'aronde dans ladite paroi interne (36a).