Gas separation valve assembly for a diesel motor system equipped for measuring fuel consumption

A gas separation valve assembly for a diesel motor system having a tank with a float therein controlling a valve mechanism through which fuel is dispensed from the tank. A dual sleeve assembly is arranged within the tank having an inner sleeve with a lower end in fluid-tight connection with the tank and an outer sleeve arranged to define an annular space between itself and the outer wall of the tank and an intermediate space between itself and the inner sleeve. Fuel is introduced into the tank through an aperture so as to flow into the annular space between the tank wall and the outer sleeve and then to pass through the intermediate space so as to overflow the inner wall and to flow into an interior space of the tank within which the float is located.

The present invention is directed to diesel motor control equipment and 
more particularly to a gas separation valve assembly adapted for use in 
the operational system of such a diesel motor which is equipped for 
measurement of fuel consumption. 
The arrangement of the type to which the present invention relates consists 
of a tank which is equipped with an aperture for gas exchange and which 
comprises a float and a valve in a base support plate of the tank with the 
valve being controlled by the float. The valve operates to control 
admission of excess fuel quantity flowing back from an injection pump of 
the diesel motor system through an additional aperture back into the tank 
in the operating system of the diesel motor. 
In an operating system of a diesel motor, excess fuel is normally placed 
into the circulation cycle of the fuel pump and this excess is greater 
than the injection pump of the system can utilize, as is well known. 
Relatively large excess fuel quantity returning to the fuel reservoir of 
the system serves for cooling and, at the same time, it fulfills a purging 
function as far as gas bubble accumulation in the injection pump is 
concerned. 
If fuel consumption is to be measured in such an operational system, this 
then can be accomplished either by differential measurement, by placing a 
flow meter into the circuit upstream and downstream of the injection pump 
or it can be accomplished in that a fuel circulation cycle designated as 
the injection circuit is constituted by return of the excess fuel quantity 
into the suction line between the fuel pump and the fuel reservoir, with a 
flow meter being provided only between the feed point of the excess fuel 
quantity and the fuel reservoir. 
Both of the aforementioned approaches result in adulteration of the 
measured results when the returning excess fuel contains a high percentage 
of gaseous content which, depending on the injection process, is 
particularly noticeable, for example, in a Cummins motor or when using 
distributor injection pumps. Since degassing of the returning fuel in such 
an operational system of a diesel engine can no longer occur in the fuel 
reservoir, it is imperative to provide an additional tank for gas 
separation. Here it is proposed, in the case of feeding excess fuel 
quantity into the suction line, to provide in this tank and preferably in 
its base area, a valve connecting, for example, the tank space and the 
suction line. The valve and thus the feed of the excess fuel quantity into 
the injection circuit or the ensuing aspiration of the fuel from the fuel 
reservoir may be controlled by means of a float located within the tank. 
Of course, it is desirable to minimize the expense for such an auxiliary 
device required for fuel consumption measurement and it is also above all 
desirable to reduce the structural volume of this additional tank as much 
as possible in view of the expected installation problems. On the other 
hand, a contrary requirement arises particularly in view of the direct 
correlation of the suction line and gas separating tank, whereby gas 
separation must occur with a relatively high efficiency and wherein the 
additional complication arises that the returning excess fuel quantity 
contain a gaseous proportion of up to 15% which is present partially in a 
foaming phase. Apart from that, in the existing operational conditions, 
the return flow often has a surge-like nature so that calming and rapid 
degassing of the fuel flowing into the tank is delayed. 
A gas separation tank known in the prior art from DE-PS No. 29 32 014 has 
an inside space which is subdivided by a partially conical, partially 
cylindrical sleeve into an outer space into which the return float 
discharges and an inner space in which are located the float and the valve 
assigned thereto. This sleeve consists of a tissue with the task of 
filtering out gas bubbles. Actual practice has shown, however, that the 
incoming fuel does not distribute itself within the required manner over a 
large surface and that the gas finely distributed or dissolved in the fuel 
penetrates through the tissue and thus will be present in the float space 
in the vicinity of the valve. Since it is additionally necessary in actual 
practice to support the tissue sleeve in a suitable manner, for which 
purpose, the screen-like metal sheet is provided, additional turbulence 
arises when the fuel flows passed the hole edges and this turbulence 
results in bubble formation. The same applies to the considerably varying 
tank level during operation of the motor vehicle so that a relatively high 
tank must be selected. 
SUMMARY OF THE INVENTION 
The present invention is therefore directed toward providing an arrangement 
for gas separation adapted to the rough operating conditions existing in 
the fuel circulation cycle of a diesel motor, and particularly an 
arrangement which can be manufactured with low manufacturing and 
installation expenses and which will permit the provision of a relatively 
small tank with a reliable functional process. 
Briefly, the present invention may be defined as a gas separation valve 
assembly in the operational system of a diesel motor equipped for fuel 
consumption measurement which includes an injection pump, said assembly 
comprising a tank having an outer wall and including an aperture for 
receiving excess fuel flowing back to the tank from the injection pump, 
float means located within the interior space defined within the tank and 
valve means responsive to the float means for controlling the flow from 
the interior space out of the tank. 
The invention is particularly characterized by the dual valve assembly 
which is arranged within the tank essentially concentrically with the 
central axis thereof and which surrounds the interior space of the tank. 
The dual sleeve assembly includes an inner sleeve having a lower end in 
fluid-tight connection with the tank and an outer sleeve arranged to 
define an annular space between itself and the outer wall of the tank and 
an intermediate space between itself and the inner sleeve. The excess fuel 
receiving aperture of the tank is arranged to deliver the fuel flowing 
therethrough into the annular space and means are provided for effecting a 
lower fluid flow connection between the annular space and the intermediate 
space and a higher or upper fluid flow connection between the intermediate 
space and the interior space, the upper fluid flow connection being at an 
elevation higher than the lower fluid flow connection. 
Accordingly, in accordance with the present invention, there is basically 
provided a sleeve assembly within the tank which is formed with at least 
two sleeves, with the inner sleeve being connected with a base support 
plate of the tank in an essentially liquid impermeable manner and with the 
aperture for the excess fuel quantity returning into the tank being 
directed so that incoming fuel flows into the space constituted by the 
outer sleeve and the outer wall of the tank with the space constituted by 
the outer sleeve and the outer wall of the tank being in fluid connection 
at the base support plate of the tank. The space enclosed by the inner 
sleeve has the float located therein and is in fluid connection at a 
higher level with the intermediate space defined between the two sleeves. 
In a preferred embodiment of the invention, the outer sleeve and a baffle 
cupola are designed as an integral member and the inner sleeve is adapted 
to be connected with the outer sleeve by means of a plug-in connection 
with at least one pressure spring acting in the axial direction and 
arranged between the cover of the tank and the baffle cupola being 
provided. 
As a result of the present invention, an optimal degassing process is 
achieved as well as a lessening of the turbulence of the fuel flowing 
back, particularly by distribution over as large a surface as possible. In 
other words, this occurs by a capturing process over as large a surface of 
the walls as possible. Apart from that, the arrangement of the invention 
provides a relatively long flow path by the redirection of the fuel in a 
cascading fashion, but also an extensive "thinning out" of the fuel flow. 
The various features of novelty which characterize the invention are 
pointed out with particularity in the claims annexed to and forming a part 
of this disclosure. For a better understanding of the invention, its 
operating advantages and specific objectives attained by its use, 
reference should be had to the drawings and descriptive matter in which 
there are illustrated and described the preferred embodiments of the 
invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings and particularly to FIG. 1, there is shown an 
operational system for a diesel motor which includes a fuel reservoir 1, a 
suction line 2 leading from the reservoir 1 with a filter 3 being provided 
in the suction line 2 together with a float meter 4 and a check valve 5. 
The system includes an injection circuit 6 within which a specific 
quantity of excess fuel is maintained in circulation. The quantity of 
excess fuel is usually relatively large as compared with the quantity of 
injection fuel which is consumed, and the flow occurs from a fuel pump 7 
through an injection pump 8 including injection nozzles 9 and a tank 10 
which operates as a gas separation mechanism. A gas line 11 connects the 
fuel reservoir 1 with the gas separation tank 10. 
The present invention is particularly directed to the structure and 
arrangement of the gas separation tank 10 and a first embodiment of the 
invention is shown in greater detail in FIGS. 2 and 3. The gas separation 
tank 10 is formed with an essentially cylindrical configuration which 
includes a cover member 12 at which hose connection means 13 and 14 are 
provided. The hose connection means are arranged for providing a 
connection for the return flow branch of the injection circuit 6 emanating 
from the injection pump 8 and for connecting the gas line 11. Thus, it may 
be assumed that the hose connection 14 provides inflow into the tank 10 
from the injection pump 8 and that the hose connection 13 provides a 
connection with the gas line 11. The hose connection 14 may be considered 
as providing an aperture for gas exchange. 
A fixture 16 is provided on the tank 10 which is attached by means of 
screws 15, the fixture operating to allow the tank 10 to be installed at a 
suitable location in the motor compartment of a vehicle. Nuts 17 and 18 
are provided in the cover 12 for fastening the cover 12 to supports 20 and 
21 fastened in a base support plate 19 of the tank 10. 
The sectional view depicted in FIG. 3 shows that the tank 10 apart from the 
cover 12 and the base support plate 19 consists of an outer sleeve or wall 
22 which is retained between the cover 12 and the base support plate 19 by 
the interposition of seals 23 and 24. A channel 25 extends transversely to 
a vertical axis of the tank 10 and is provided in the base support plate 
19. The channel 25 is positionable by means of hose connections, one of 
which is the illustrated hose connection 26, between the suction line 2 
and the injection circuit 6. The channel 25 is in flow communication with 
two apertures 27 and 28 spaced apart in the direction of the vertical axis 
of the tank 10 which connect the channel 25 in a fluid flow connection 
with an interior space 29 of the tank 10. 
The aperture 28 is defined by a member which defines a first valve seat 30 
and the aperture 27 is defined by a second valve seat member 31. 
The valve seat member 31 is formed as an integral part of a hollow threaded 
member 33 which is insertable into the base plate 19 together with an 
interposed seal member 32. For the sake of completeness, it should be 
noted that the hollow threaded member 33 is provided with a knurled collar 
(not shown) serving for receiving a support member 34 provided with 
apertures (not shown) with the support member 34 being retained in the 
hollow threaded member 33 by means of a spring washer 35, with the support 
member 34 providing one support point for a valve rod or stem 36. 
A second support point for the valve rod 36 is provided by a support plate 
37, also having apertures extending therethrough, which is inserted in a 
relief area 38 located on the rear side of the aperture 28 or of the valve 
seat 30 defining the aperture 28. 
The relief area 38 constitutes a chamber together with a cover fastened in 
a liquid sealing manner by a seal 39 at the base support plate 19, this 
chamber being connected with the interior space 29 by means of several 
channels, one of such channels 41 being shown in FIG. 3. 
FIG. 3 furthermore shows that a pair of valve disk members 42 and 43 are 
arranged on the valve rod 36 and that the valve rod 36 is under the 
influence of a pressure spring 44 arranged in the hollow threaded member 
33, with the valve rod being connected in an articulated manner by a 
cotter pin 45 with a float 46 which, as shown in FIG. 3, is formed to 
extensively occupy interior space 29 of the tank 10. A pair of seals 
including a seal 47 are assigned to the supports 20 and 21. The pressure 
spring 44 which is dimensioned so as to be relatively soft serves 
essentially to provide the float controlled double valve which, in the 
application of a motor vehicle, is exposed to considerable shock with a 
certain basic load. The float controlled double valve serves in the 
embodiment described for unpressurized supply of excess fuel into the 
channel 25 and thus into the suction line 2. The actual arrangement for 
gas separation is constituted by two relatively thin-walled and deformable 
sleeves 48 and 49 which, as shown in FIG. 2, are connected with each other 
at connection points 50 and 51 at outer contour lines lying opposite each 
other so that, during their installation, only one sleeve, in this case, 
double walled, needs to be handled. 
Thus, it will be seen particularly with reference to FIGS. 2 and 3 that one 
of the principal elements of the invention is a dual sleeve assembly which 
is constituted by the two sleeves 48 and 49 which, with particular 
reference to FIG. 2, define therebetween two intermediate spaces - one of 
which is identified by reference numeral 61 - with the outer sleeve 48 
defining an annular space 60 between an outer sleeve 22 of the tank 
assembly and the outer sleeve 48 of the dual sleeve assembly 48 / 49. 
Located within the tank 10 is a baffle cupola 52 which is arranged in 
cooperative relationship with the dual sleeve assembly 48 / 49. The dual 
sleeve assembly 48 / 49 is fixed in position by means of a pair of 
supports 20, 21 which extend between the base support plate 19 and the 
cover 12 with the supports 20, 21 also supporting the dual sleeve assembly 
48 / 49. 
The baffle cupola 52 has an overlapping edge 53 engaging about the dual 
sleeve assembly 48 / 49 for centering or retention of the assembly within 
the tank 10. It will be noted from the drawings that the dual sleeve 
assembly 48 / 49 is generally centrally located to extend concentrically 
about the longitudinal central axis of the tank 10. 
In the area immediately following the inflow aperture, there is provided a 
fin 54 located on the baffle cupola 52. Furthermore, the baffle cupola 52 
is provided with a stub 56 defining an aperture 55 assigned to the 
interior space 29 of the tank 10 and also with two consoles, one of which 
is identified by reference numeral 57 in FIG. 3. Pressure springs 58 
guided by the supports 20, 21 which abut between the cover 12 and the 
consoles 57 of the cupola 52 operate to provide an effect in that the 
sleeve 49 which is axially offset with respect to the outer sleever 48 
rests upon the support plate 19 with its end face which constitutes, 
therefore, an adequate liquid sealing connection with the base support 
plate 19 of the tank 10. Thus, it will therefore be seen that the inner 
sleeve 49 is thereby placed at its lower end in fluid-tight connection 
with the tank through its liquid sealing engagement with the support plate 
19. 
As will be evident from FIG. 3, at the base of the dual sleeve assembly 48/ 
49, there is provided a fluid flow connection 59 between the annular space 
60 surrounding the sleeve 48 and the intermediate spaces 61 defined 
between the two sleeves 48 and 49. From FIG. 2, it will be seen that the 
annular space 61 is divided into two sickle-shaped parts above and below 
the connections 50, 51. 
The fluid flowing back from the injection pump 8 which may, for example, 
flow into the tank 10 through the hose connection 14, as shown by the 
arrows in FIG. 3, initially impinges upon the baffle cupola 52. The fin 54 
operates to avoid splashing and thus additional gas inclusion and also 
causes extensive distribution of the fuel across the baffle cupola 52. The 
baffle cupola 52 is preferably made of a material which has as high an 
adhesion as possible for diesel fuel. The fuel flowing away from the 
baffle cupola 52 initially flows downwardly externally of the outer sleeve 
48 through the annular space 60. It then flows through the fluid 
connection 59 into the intermediate space 61 and again rises therein until 
it overflows an edge 62 of the inner sleeve 49. After overflowing the 
upper edge 62 of the inner sleeve 49, the fluid then discharges into the 
interior space 29 of the tank 10 within which the float 46 is located. 
A further embodiment of the invention is shown in FIG. 4. In FIG. 4, there 
is shown a different structure for the dual sleeve assembly 48 / 49 which 
forms the basis for the present invention. In the embodiment of FIG. 4, 
the baffle cupola and the outer sleeve of the dual sleeve assembly are 
formed integrally or as a single unitary part 63 which is preferably 
fabricated by injection molding. Ribs 64 are provided for stiffening and 
for centering an inner sleeve 65 of the dual sleeve assembly. The ribs 64 
are provided on the outer sleeve 63 with a sliding seat and which is 
possibly also stiffened with ribs. As will be apparent from FIG. 4, the 
inner sleeve 65 is retained at an extension 66 molded to the base plate 19 
and a single pressure spring 67 is provided about a stub 68 which is 
formed on the part 63 forming the one piece cupola and outer sleeve with 
the stub 68 defining therethrough an aperture similar to the aperture 55. 
A further embodiment of the invention is shown in FIG. 5, wherein the dual 
sleeve assembly is formed of two metallic sleeves 69 and 70 retained 
between the cover 12 and the base support plate 19. Ribs 71 and 72 
respectively formed at the cover 12 and the base support 19 serve for 
centering of the sleeves 69 and 70. A row of holes 73 provided on the 
outer sleeve 70 in the vicinity of the base support plate and a row of 
holes 74 provided at a higher level on the inner sleeve 69 operate to 
guide flow of the fuel, while two tension springs 75 and 76 in cooperation 
with a web 77 operate as an assembly assistance. The web 77 penetrates 
through apertures which simultaneously serve as gas exit means, which 
apertures are provided in the two sleeves 69 and 70. 
Thus, it will be seen that with the present invention, there is provided an 
arrangement for gas separation for the operational system of a diesel 
motor equipped with fuel consumption measurement means, which arrangement 
permits as long a flow travel as possible within a suitable tank 10 and a 
distribution of the gas containing fuel over as large an area as possible. 
Considered in more detail, it will be seen that the arrangement is 
constituted by a dual sleeve assembly including, for example, the sleeves 
48 and 49 of which the inner sleeve 49 is in an essentially liquid sealing 
connection with the tank 10 at the base support plate 19 thereof, with the 
other or external sleeve 48 enabling a fluid connection 59 between the two 
sleeves 48 and 49 and being preferably closed off by a baffle cupola 52 
facing the inflow aperture. 
While specific embodiments of the invention have been shown and described 
in detail to illustrate the application of the inventive principles, it 
will be understood that the invention may be embodied otherwise without 
departing from such principles.