U.S. patent application number 11/819836 was filed with the patent office on 2008-01-10 for transfer pump with several pistons.
This patent application is currently assigned to SIEMENS AUTOMOTIVE HYDRAULICS SA. Invention is credited to Philippe Bauer, David Humblot, Eric Meunier.
Application Number | 20080008605 11/819836 |
Document ID | / |
Family ID | 37311874 |
Filed Date | 2008-01-10 |
United States Patent
Application |
20080008605 |
Kind Code |
A1 |
Bauer; Philippe ; et
al. |
January 10, 2008 |
Transfer pump with several pistons
Abstract
Transfer pump of the type in which the moving part for pumping
is a bellows (4) that is alternately filled with and emptied of
hydraulic liquid at high pressure by a piston (1) that is driven by
a cam (2), whereby the amount of fuel allowed into the chamber (5)
into which the bellows (4) moves is determined, upstream, by a
solenoid valve (8) that is driven by the computer for monitoring
the engine, characterized by the fact that it comprises at least
two pumping units (piston 1/bellows 4) that are supplied by a
single intake system (6) that is common to the units on which the
flow-monitoring solenoid valve (8) is placed and that have a
conveyor circuit (10) that may be unique and common, or specific to
each pumping unit.
Inventors: |
Bauer; Philippe; (Marly Le
Roi, FR) ; Humblot; David; (Meudon La Foret, FR)
; Meunier; Eric; (Poigny La Foret, FR) |
Correspondence
Address: |
YOUNG & THOMPSON
745 SOUTH 23RD STREET, 2ND FLOOR
ARLINGTON
VA
22202
US
|
Assignee: |
SIEMENS AUTOMOTIVE HYDRAULICS
SA
ASNIERES SUR SEINE
FR
|
Family ID: |
37311874 |
Appl. No.: |
11/819836 |
Filed: |
June 29, 2007 |
Current U.S.
Class: |
417/375 |
Current CPC
Class: |
F04B 43/107 20130101;
F02M 59/102 20130101; F02M 59/442 20130101; F02M 2200/16 20130101;
F04B 43/084 20130101 |
Class at
Publication: |
417/375 |
International
Class: |
F04B 17/00 20060101
F04B017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 7, 2006 |
FR |
06/06240 |
Claims
1. Transfer pump of the type in which the moving part for pumping
is a bellows (4) that is alternately filled with and emptied of
hydraulic liquid at high pressure by a piston (1) that is driven by
a cam (2), whereby the amount of fuel allowed into the chamber (5)
into which the bellows (4) moves is determined, upstream, by a
solenoid valve (8) that is driven by the computer for monitoring
the engine, characterized by the fact that it comprises at least
two pumping units (piston 1/bellows 4) that are supplied by a
single intake system (6) that is common to the units on which the
flow-monitoring solenoid valve (8) is placed and that has a
conveyor circuit (10) that may be unique and common, or specific to
each pumping unit.
2. Pump according to claim 1, wherein the pistons (1) are actuated
by at least one single-lobe or multi-lobe cam (2).
3. Pump according to claim 2, comprising several pistons (1a, 1b .
. . 1n) that drive bellows (4a, 4b . . . 4n) that are arranged in
chambers (5a, 5b . . . 5n) that are connected to a common supply
circuit (6).
4. Pump according to claim 3, wherein the chambers (5a, 5b . . .
5n) are connected to a common conveyor circuit (10).
5. Pump according to claim 1, wherein the pistons (1a, 1b . . . 1n)
are actuated by single-lobe or multi-lobe cams (2a, 2b . . . 2n)
that are arranged in parallel on a camshaft (3).
6. Pump according to claim 3, wherein the chambers (5a, 5b . . .
5n) are each connected to a conveyor circuit that is specific
thereto.
7. Pump according to claim 1, wherein the pistons (1a, 1b . . . 1n)
are actuated by a single cam (2), whereby said pistons are arranged
radially around the cam (2).
8. Pump according to claim 2, wherein the pistons (1a, 1b . . . 1n)
are actuated by single-lobe or multi-lobe cams (2a, 2b . . . 2n)
that are arranged in parallel on a camshaft (3).
9. Pump according to claim 3, wherein the pistons (1a, 1b . . . 1n)
are actuated by single-lobe or multi-lobe cams (2a, 2b . . . 2n)
that are arranged in parallel on a camshaft (3).
10. Pump according to claim 4, wherein the pistons (1a, 1b . . .
1n) are actuated by single-lobe or multi-lobe cams (2a, 2b . . .
2n) that are arranged in parallel on a camshaft (3).
11. Pump according to claim 2, wherein the pistons (1a, 1b . . .
1n) are actuated by a single cam (2), whereby said pistons are
arranged radially around the cam (2).
12. Pump according to claim 3, wherein the pistons (1a, 1b . . .
1n) are actuated by a single cam (2), whereby said pistons are
arranged radially around the cam (2).
13. Pump according to claim 4, wherein the pistons (1a, 1b . . .
1n) are actuated by a single cam (2), whereby said pistons are
arranged radially around the cam (2).
Description
[0001] This invention has as its object a pump of the type called a
transfer pump, i.e., of the type that comprises a moving part that
pumps an aggressive liquid such as automotive fuel, whereby this
moving part is driven by an alternating movement by the oil that is
pumped by a hydraulic pump.
[0002] It is known to use a hydraulic pump with a single piston, a
so-called single-piston pump, to supply the injectors of an engine
with fuel at high pressure.
[0003] A pump of this type is described in the patent U.S. Pat. No.
1,696,825 of Dec. 25, 1928, as well as in the patent application
Ser. No. 06/02,594 of Mar. 24, 2006, in the name of the
applicant.
[0004] The flow rate provided by a single-piston pump, however, has
proven inadequate for high capacities.
[0005] Actually, in practice, it turns out that there is a maximum
limit of the capacity of the single-piston pumps, a limit that is
approximately a bit more than 1 cc per turn.
[0006] To increase this capacity, the travel of the piston should
be increased or the diameter should be increased. If the travel is
increased, the accelerations are high; if the diameter is
increased, the force upon contact with the cam that drives the
piston becomes too significant.
[0007] The use of two single-piston pumps is therefore proposed,
but it then is necessary to double the electronic control means,
which is suitable for a prototype but is not economically suitable
for the very large-scale production (2,000 single-piston pumps with
2,000 electronic control means are necessary for 1,000 engines per
day).
[0008] These electronic control means are in general solenoid
valves that are controlled by the engine monitoring computer.
[0009] The transfer pump according to the invention is of the type
in which the moving part for pumping is a metal bellows that is
alternately filled with and emptied of hydraulic liquid at high
pressure, whereby the amount of fuel allowed into the chamber in
which said bellows moves is determined, upstream, by a solenoid
valve that is driven by the computer for monitoring the engine,
characterized by the fact that it comprises at least two pumping
units (bellows/piston) that are supplied by a single intake system,
common to the two units.
[0010] This invention can also comprise all or part of the
following arrangements: [0011] a. The conveyor circuit is common to
pumping units; [0012] b. The pump comprises two pistons, whereby
each piston is actuated by a cam, whereby the two cams are carried
in parallel by a camshaft and are angularly offset by 60.degree.;
[0013] c. The pump comprises "n" pistons, whereby each piston is
actuated by a cam, whereby the "n" cams are carried parallel to one
another by a camshaft and are angularly offset; [0014] d. The pump
comprises a single cam and at least two pistons placed radially
around the cam; [0015] e. The pump comprises two pistons that are
placed in a V at 60.degree. C. from one another.
[0016] By way of nonlimiting examples and to facilitate the
understanding of the invention, there have been shown in the
accompanying drawings:
[0017] FIG. 1, a diagrammatic view of a first embodiment of the
invention.
[0018] FIG. 2, a variant of FIG. 1.
[0019] FIG. 3, a perspective view illustrating a pump according to
FIG. 1.
[0020] FIG. 4, a diagrammatic view of a variant embodiment of FIGS.
1 and 2 with "n" pistons.
[0021] FIG. 5, a diagrammatic view of a second embodiment of the
invention.
[0022] By referring to FIGS. 1 and 2, it is seen that the pump
according to the invention comprises two pistons 1a and 1b that are
driven by two cams 2a and 2b that are parallel and carried by a
shaft 3.
[0023] Each cam 2a and 2b comprises three lobes, placed at
120.degree. C. from one another (as is shown in FIG. 3).
[0024] In a way that is known in the art, each piston 1a and 1b
moves hydraulic liquid inside a bellows 4a, 4b, which extends and
retracts in a chamber 5a, 5b. The inside of the bellows 4a, 4b
receives hydraulic liquid that is put under high pressure when the
piston 1 rises, high pressure that is communicated to the fuel that
is found in the chambers 5a, 5b.
[0025] According to this invention, the fuel is allowed into the
two chambers 5a, 5b by means of a single supply circuit 6 that
comprises two branches 6a, 6b.
[0026] The supply circuit 6 is connected by the orifice 7 to the
tank by way of a solenoid valve 8 that measures the amount of fuel
that can be introduced into the chambers 5a and 5b.
[0027] Two nonreturn valves 7a, 7b allow the fuel that is fed via
the hose 6 to penetrate the chambers 5a, 5b, and two nonreturn
valves 9a, 9b allow the fuel that is fed at high pressure via the
bellows 4a, 4b to flow into the single conveyor duct 10 toward the
conveyor orifice 11.
[0028] Preferably, the cams 2a and 2b are offset angularly by
60.degree..
[0029] This arrangement provides the following advantages: [0030]
As there is a single supply and conveyor circuit, there are fewer
components than with two standard single-piston pumps. [0031] In
particular, there is only a single solenoid valve 8 for monitoring
the amount of fuel sent to the engine. [0032] The force exerted by
the pistons on the camshaft 3 is less than the equivalent capacity
that would be present if there were a single piston. [0033] The
angular offset of the two cams 2 ensures better progressiveness of
the pressurized flow toward the injection rail and makes it
possible to reduce the variations of the torque on the
camshaft.
[0034] In the embodiment shown in FIG. 1, the conveyor circuit is
common to two pistons 1a and 1b, but the invention is not limited
to this particular embodiment: it is possible to use a conveyor
circuit 10a and 10b for each piston as is illustrated in FIG. 2 in
which the same elements bear the same references.
[0035] FIG. 4 illustrates a variant embodiment in which the same
elements bear the same references.
[0036] According to this variant, there are more than two pistons
1a, 1b . . . 1n each driven by a cam 2a, 2b . . . 2n, whereby these
cams are parallel to one another and carried by the same camshaft
3.
[0037] There is a conveyor circuit 10 that is common to all "n"
pistons, as in the case of FIG. 1; but it would be possible to use
a conveyor circuit (10a, 10b . . . 10n) for each piston, as in the
case of FIG. 2.
[0038] The only difference with the pump of FIG. 1 is that there is
only a single cam 1 (whereby the camshaft 3 is drawn symbolically)
to drive the two pistons 1a and 1b, but the latter are placed in a
V, their axes being arranged at 60.degree..
[0039] The same advantages as in the example of FIG. 2 are
obtained, whereby the unit is a bit more compact.
[0040] In this same FIG. 5, an additional piston 1m, . . . is shown
symbolically by the branching 6m of the duct 6 and by being
connected at 10m to the conveyor duct 10.
[0041] The purpose of this representation is to demonstrate that it
is possible to use, in a radial manner, a number "m" of pistons,
around the cam 2.
[0042] In all of the examples that are shown, the cams are cams
with three lobes arranged at 120.degree. from one another, but it
is necessary to note that the invention is not limited to this
particular example: the cam 2 can comprise one or more lobes.
* * * * *