TECHNICAL FIELD
[0001] The present invention relates to fluid valve, for example a fuel valve for use in
a pump assembly of a diesel engine.
BACKGROUND OF THE INVENTION
[0002] High pressure diesel fuel pumps inherently create complex flows, often shuttling
and with pulsating pressure.
[0003] In many situations it is advantageous to control these flows, in order to protect
other system components from the damage of reverse flow or the increase in pressure
that reverse flow will create in
US2014/151062 A1 and in
US3543781 A.
[0004] Examples of currently known valves, used to eliminate reverse flow, are poppet valves
and ball valve. However these prior art valves have moving parts, and this incurs
durability and cost penalties, and also often requires a method of actuation and/or
timing.
[0005] A further known valve, as described in US patent application
US1329559A (Tesla), comprises a single-piece valve having a maze of switch-backs, allowing almost
free flow in one direction, whilst encouraging the formation of eddies in the opposite
direction. By creating eddies, the flow is disrupted, accordingly causing a slowing
of subsequent flow. This results in a partial fluid-lock effect, which hinders flow
considerably.
[0006] The Tesla valve has limited flexibility due to the single-piece design.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide an improved valve system which
at least mitigates the problems of the prior art valves discussed above.
[0008] Accordingly the present invention provides, in a first aspect, a valve section according
to claim 1.
[0009] The protruding part of the valve may have an outer profile which comprises curved
surfaces. Additionally or alternatively, the bore of the or each second valve portion
may comprise a curved profile.
[0010] Furthermore, the bore of the or each second valve portion may further comprise a
curved recess.
[0011] In one embodiment which is not part of the invention, the valve comprises a single
valve section, comprising one second valve portion, wherein an underside face of the
first valve portion abuts an upper end face of the second valve portion.
[0012] In a further aspect, the embodiment which is not part of the invention comprises
a valve assembly comprising a plurality of second valve portions stacked on top of
one another; wherein an underside face of the first valve portion abuts an upper end
face of an uppermost second valve portion; and wherein an underside end face of the
uppermost second valve portion abuts an upper end face of a further second valve portion.
[0013] In the valve assembly, the protruding part of the first valve portion may extend
through the bores of all second valve portions.
[0014] Preferably, the valve has a cylindrical outer profile.
[0015] The embodiment which is not part of the invention also comprises a method of assembling
a valve assembly, the method comprising:
stacking the second valve portions on top of one another; and
subsequently, locating the first valve portion on top of the uppermost second valve
portion.
[0016] The present invention comprises a valve comprising a valve section body and a central
section; the valve body section comprising a first portion, a second portion, and
a mid-portion provided between the first portion and the second portion; wherein a
fluid flow path is enabled around the central section and between the central section
and the valve section body; wherein the flow path comprises a first flow path section
of substantially uniform cross-sectional area, provided in the first portion, a second
flow path section of substantially uniform cross-sectional area, provided in the second
portion, and a flow path of varying cross-sectional area, provided in the mid-portion;
and wherein the flow path in the mid-portion is split between a venturi provided by
a drilling, and a main mid-portion flow path, and wherein the flow path in the mid-portion
is also split by a fork.
[0017] The valve may comprise a valve section, or may comprises a valve assembly comprising
a plurality of valve sections.
[0018] The present invention provides a valve section and a valve assembly which require
no moving parts. Accordingly, the present invention avoids the durability and cost
penalties encountered with moving-part prior art valves, and also avoid the necessity
for a method of actuation and/or timing required for such prior art valve embodiments.
[0019] The present invention also provides a modular cartridge system, which is more package-friendly
than the prior valve embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The present invention is now described by way of example with reference to the accompanying
Figures in which:
Figure 1 is an expanded isometric view of a valve section in accordance with a first
embodiment which is not part of the invention in cross-section;
Figure 2 is an isometric view of the valve section of Figure 1 in an assembled state
which is not part of the invention;
Figure 3 is an isometric view of the valve section of Figure 1 in the assembled state
which is not part of the invention;
Figure 4 is an isometric view of a stacked valve assembly which is not part of the
invention;
Figure 5 is a longitudinal cross-sectional view of a valve section in accordance with
an embodiment of the present invention;
Figures 6 and 7 are axial cross-sectional views of the valve section of Figure 5;
Figure 8 is a cross-sectional view of a flow path provided by the valve section of
Figure 5;
and
Figure 9 is cross-sectional view of a valve assembly in accordance with the embodiment
of Figures 5 to 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Referring to the Figures, the present invention comprises a valve, comprising either
a valve portion, or a valve assembly.
[0022] Referring to Figures 1 to 3, a first embodiment which is not part of the invention
comprises a valve comprising a valve section 2, comprising a first valve portion 4
and a second valve portion 6.
[0023] The first valve portion 4 comprises an annular end portion 10, and a protruding part
12. The end portion 10 has a central section which comprises cut-outs 14, and a bridge
section 18, which connects the protruding part 12 to the end portion 10.
[0024] The second valve portion 6 comprises an elongated cylindrical member 40, which is
provided with a bore 42.
[0025] To assemble the valve section 2, the protruding part 12 of the first valve portion
4 is inserted into the bore 42 of the second valve section 4, until an underside face
64 of the end portion 10 of the first valve portion 4 abuts an upper end face 66 of
the cylindrical member 40 of the second valve portion 6.
[0026] The outer diameter of the end portion 10 of the first valve portion 4 is equal to
that of the cylindrical member 40, such that the assembled valve section 2 comprises
an elongate cylindrical component. A fluid pathway is enabled through the valve section
2 via the cut-outs 14 provided in the end portion 10 of the first valve section 4,
and the bore 42 of the second valve section 6. The fluid pathway is therefore provide
between the protruding part 12 and the bore 42.
[0027] The behaviour of fluid passing through the fluid pathway is affected by the varying
cross-sectional form of the fluid pathway, which is determined by the external form
of the protruding part 12, and by the form of the bore 42, and in particular by curved
surfaces of the protruding part 12 and the bore 42, as explained in greater detail
below.
[0028] Moving from top to bottom in the orientation of Figures 1 to 3 which is not part
of the invention, the protruding part 12 comprises a first, cylindrical portion 20
which extends away from the bridge section 18. A second portion 22, extending from
the first portion 20, has a curved outer profile, which increases non-linearly in
diameter moving away from the first portion 20, such that an outer surface 24 of the
second portion 22 is curved. A third portion 26 extending from the second portion
22 has a maximum diameter, at a junction 28 with the second portion 22, which is equal
to a maximum diameter of the second portion 22 at the junction 28. Moving away from
the second portion 22, the third portion 26 decreases non-linearly in diameter such
that an outer surface 28 of the third portion 26 is also curved. A fourth portion
30 extending from the third portion 26 is cylindrical, having a diameter which is
equal to a minimum of the third portion 26.
[0029] The bore 42 comprises a first section 44, a second section 46, and a third section
48. The first section 44 and the third section 48 are provided towards a first end
50 and second end 52 of the second valve portion 6 respectively, wherein the first
end 50 is proximate to, and the second end 52 remote from, the first valve portion
4.
[0030] The second section 46 of the bore 42 is located between the first section 44 and
the third section 48. At a junction 54 with the first section 44, the second section
46 has a diameter which is equal to that of the first section 44. At a junction with
the third section 48, the second section 46 has a diameter which is equal to that
of the third section 48.
[0031] Moving from the junction 54 with the first section 44, to a junction 56 with the
third section 48, the second section 48 initially increases non-linearly in diameter,
and subsequently forms a curved recess 58, adjacent the third section 48. The profile
of the second section 46 is therefore curved.
[0032] In use of the valve section 2, fluid flowing through the valve section 2, initially
through the first valve portion 4 and subsequently through the second valve portion
6, i.e. in either a free direction (indicated by arrow A in Figures 2 and 3), or a
restrictive direction (indicated by arrow B in Figures 2 and 3), is guided by the
curved outer surfaces of the protruding part 12 of the first valve portion 4, and
by the curved profile of the second section 46 of the bore 42 of the second valve
portion 6. The recess 58 provides a hair-pin turn in the fluid pathway, which provides
a switch-back effect. As a result of following the hair-pin turn provided by the curved
recess 58, fluid flow around this point is disrupted. Specifically, the flow is either
hindered, or reversed.
[0033] The disruption of the fluid flow in the region of the recess 58 causes a slowing
of approaching fluid flow, and a valve effect is thereby achieved.
[0034] Referring to Figure 4 which is not part of the invention, a valve comprising a valve
assembly 100 can be formed by stacking a plurality of second valve portions 6 on top
of each other, i.e. such that an upper end face 66 of one second valve portion 6 abuts
an underside end face 62 of a further second valve portion 6. After the plurality
of second valve portions 6 have been stacked on top of one another, a single first
valve portion 4 is provided on the top of the stacked second valve portions 6, such
that the underside face 64 of the first valve portion 4 abuts the upper end face 66
of the uppermost second valve portion 6 of the stack.
[0035] In the stacked valve assembly, the protruding part 12 of the first valve portion
4 may be elongated (with respect to that illustrated in Figures 1 to 3), and may be
of sufficient length to protrude through the bores 42 of all second valve portions
6 in the stack. The elongated protruding part 12 may comprises a repeated series of
the profile of the protruding part 12 illustrated in Figures 1 to 3, such that the
profile of the fluid pathway of the valve portion 2 of Figure 1 is repeated throughout
the stacked valve assembly.
[0036] In the stacked valve assembly 100, the effect slowing effect which each valve portion
2 has on fluid flow is cumulative, i.e. a chain of switch-backs created by the stack
increases the valve effect.
[0037] The embodiment which is not part of the invention provides a valve and a valve assembly
which has no moving parts. Furthermore, as the outer profiles of the valve section
2, and the stacked valve assembly 100, are cylindrical, the valve section 2 or assembly
100 can be inserted into a simple drilling.
[0038] The present invention can be used to prevent reverse flow from a digital inlet valve
from reaching an inlet of a diesel fuel pump. This allows greater control of fuel
flow, and therefore a more stabilised inlet pressure / pressure at fuel filter.
[0039] The profiles of the curved sections of the fluid pathway which is not part of the
invention, i.e. the radii and angles of the protruding part 12 and the bore 42, can
be selected for optimum performance of the valve portion 2 or assembly 100.
[0040] Figure 5 is a longitudinal cross-sectional view of a valve in accordance with an
embodiment of the present invention.
[0041] Figure 6 is an axial cross-sectional view of the embodiment taken at section 6-6
as indicated on Figure 5, i.e. through a restricted section 204 of the valve section
302.
[0042] Figure 7 is an axial cross-sectional view of the embodiment taken at section 7-7
as indicated on Figure 5, i.e. taken at an end 214 of a narrow drilling 202 of the
valve section 302.
[0043] The alternative valve comprises a valve section 302, formed of a valve section body
304 and a central section 312, wherein a fluid flow path 200 is enabled around the
central section 312, i.e. between the valve section body 304 and the central section
312.
[0044] The valve section body comprises a first portion 306, a second portion 308, and a
mid-portion 310 provided between the first and second portions 306, 308.
[0045] Figure 6 is an axial cross-sectional view of the embodiment taken at section 6-6
as indicated on Figure 5, i.e. through a restricted flow path section 204 provided
in the mid-portion 310 of the valve section 302.
[0046] Figure 7 is an axial cross-sectional view of the embodiment taken at section 7-7
as indicated on Figure 5, i.e. taken at an end 214 of a narrow drilling 202 provided
in the mid-portion 310 of the valve section 302.
[0047] Figure 8 is a cross-sectional view of a section of the fluid flow path 200 enabled
by the alternative valve of Figure 5.
[0048] Referring to Figure 5, a first flow path section 206 of substantially uniform cross-section
area is enabled in the first portion 306 of the valve section body 304. A second flow
path section 308 of substantially cross-sectional area is enabled in the second portion
308 of the valve section body 304. A flow path of varying cross-sectional area, including
the restricted flow path section 204, is enabled in the mid-portion 310 of the valve
section body 304.
[0049] In the embodiment of Figures 5 to 8, a switch-back effect is provided by the narrow
drilling 202, which becomes a funnel for a venturi. The flow path in the mid-portion
310 is therefore split between a main mid-portion flow path 216, and a flow path through
the drilling 202, such that fluid may flow through either the main mid-portion flow
path 216, and/or through the drilling 202, as described below.
[0050] In a free direction (i.e. in the direction of arrow F, from right to left in the
orientation of Figures 5 and 8), flow having an initial high pressure in the first
flow path section 206 provided in the first valve body section 306, avoids the drilling
202, and passes through the main mid-portion flow path 216 and the restricted section
204. Fluid pressure is caused to drop within the restricted section 204. Pressure
is quickly regained as the flow path widens from the restricted section 204 to the
second flow path section 208 provided in the second portion 308 of the valve body
304.
[0051] In a restrictive direction (i.e. in the direction of arrow R, from left to right
in the orientation of Figures 5 and 8), the flow increases in velocity (and therefore
decreases in pressure) in the restricted section 204, and as a result, fluid is pulled
through the narrow drilling 202 by a venturi effect.
[0052] Fuel continues from left to right and is split by a fork 210 provided in the mid-portion
310 of the valve section body 304. Some of the fluid flow is thereby stopped, and
creates and area 212 of high pressure which the narrow drilling 202 feeds off. As
flow in the narrow drilling 202 has low pressure at the end 214 remote from the high
pressure area 212 one end and high pressure at the other, the drilling 202 is fed
with fuel, raising the pressure of flow (and the quantity of fluid in the volume of
the drilling 202). Once the flow reaches an area where it can slow down, it requires
more volume and this slows it further.
[0053] In the free direction, fluid pressure changes (from right to left) from high pressure
to mid-high pressure. In the restrictive direction, fluid pressure changes (from left
to right) from high pressure to low pressure, as energy has been taken from the system.
[0054] A plurality of valve sections 302 may be stacked together to form a valve assembly
400 as illustrated in Figure 9. In this stacked embodiment, the effect of pressure
change (in either the free or restrictive direction) is increased.
REFERENCES
First embodiment
[0055] valve section 2
first valve portion 4
second valve portion 6
annular end portion 10
protruding part 12
cut-outs 14
bridge section 18
protruding part first portion 20
protruding part second portion 22
protruding part second potion outer surface 24
protruding part third portion 26
section / third portion junction 28
third portion outer surface 28
protruding part fourth portion 30
second valve portion cylindrical member 40
second valve portion bore 42
bore first section 44
bore second section 46
bore third section 48
second valve potion first end 50
second valve potion second end 52
first / second bore portion junction 54
second / third bore potion junction 56
recess 58
second valve portion underside end face 62
first valve portion underside face 64
cylindrical member upper end face 66
valve assembly 100
restrictive flow direction arrow A
free flow direction arrow B
Second embodiment
[0056] fluid flow path 200
narrow drilling 202
restricted flow path section 204
flow path section 206
flow path section 208
fork 210
high pressure area 212
narrow drilling end 214
main mid-portion flow path 216
valve section 302
valve section body 304
valve section body first portion 306
valve section body second portion 308
valve section body mid-portion 310
central portion 312
valve assembly 400