Fuel filter module with integral regulator

The fuel filter/regulator assembly comprises a cylindrical body open at one end and closed at its opposite end by an annular wall having a pocket for receiving the regulator. The annular fuel filter is received in the body and has an inner end cap configured to bear against and receive an upper portion of the regulator. A further end cap closes the open end of the body and bears against the fuel filter element. A fuel inlet is provided and all components of the housing are formed of stainless steel. In another form, a wave spring is employed to accommodate stack-up tolerances of the fuel filter.

TECHNICAL FIELD 
The present invention relates to a fuel filter and regulator combined into 
a single assembly mounted to a vehicle for fuel pressure filtration and 
regulation and particularly to a fuel filter module having an integral 
regulator pocket for receiving the regulator within the fuel filter 
housing to afford regulated flow of filtered fuel to a vehicle engine. 
BACKGROUND 
With the advent of port fuel injection, fuel systems have required greater 
pressure control and filtration as fuel is delivered to the fuel 
injectors. In certain prior fuel supply systems, the pressure regulator is 
mounted integrally to the fuel rail and the filter is located remotely on 
the underside of the vehicle. Consequently, the fuel filter and regulator 
act independently, with the further disadvantages that two discrete 
components as well as a return line from the fuel rail to the fuel tank to 
deliver regulator bypass flow are required. 
In recent years, a pressure regulator and fuel filter have been combined 
into a single component mounted directly in the fuel pump module housing. 
The fuel pump module housing resides in the fuel tank. Consequently, a 
disadvantage of that system is that should the filter or regulator need 
replacement, the fuel tank must be drained and removed at substantial 
expense to replace the fuel filter/regulator assembly. 
Additionally, prior designs have utilized plastics as the assembly 
material. Plastics are not as durable or resistant to different fuel types 
and temperature fluctuations. Further, in past designs, the integral 
flow-through regulator design required change as the fuel filter area and 
capacity varied by engine type. Moreover, other designs had substantial 
complexity, significant piece part counts and high assembly costs. 
DISCLOSURE OF THE INVENTION 
In accordance with the present invention, there is provided an integral 
fuel filter and regulator module or assembly which minimizes or eliminates 
the foregoing problems associated with prior fuel filters and regulators, 
including those in which the functions of pressure regulation and fuel 
filtration have been combined into a single module or assembly. The 
present invention addresses those problems by employing a unique design 
housing both the fuel pressure regulator and the fuel filter in a single 
assembly in a unique combination and which assembly can be mounted to the 
vehicle for ready access and service. Moreover, the regulator is an 
integral component of the assembly. Hence, fuel system complexity is 
reduced and line routing is minimized and simplified. The assembly of the 
present invention is also formed from stainless steel components which 
afford protection against the combination of stress, corrosive fuels and 
harsh temperatures. Also, the fuel filter area and capacity which vary by 
engine type may be varied without changing the integral flow through 
regulator design. That is, in the present design, only the length of the 
overall design is modified to accommodate greater or less fuel filter 
areas. The regulator may be manufactured as an integral part separate from 
the fuel filter assembly, affording capability for mass production to 
accommodate a wide range of engine applications. Further, the regulator 
spring is readily modified in the regulator assembly apart from the filter 
to enable separate fuel pressures in the same fuel filter arrangement. 
Complexity, piece part counts and assembly costs are also reduced in the 
filter module with integral regulator according to the present invention. 
More particularly, the assembly of the present invention includes a 
cylindrical body having an open end for receiving a fuel filter and a 
closed end having an integral pocket or cup projecting therefrom for 
receiving a regulator. When the fuel filter is disposed in the cylindrical 
body, a first end cap closes the open end of the cylindrical body 
overlying the fuel filter, thereby capturing the filter within the body. A 
second end cap within the cylindrical body spaced slightly inwardly from 
the closed end of the body provides a seat for the filter, as well as for 
the regulator. In this fashion, the regulator is captured between the 
filter and the outer end cap, simplifying assembly. A fuel inlet is 
integrally formed on the closed end of the cylindrical body for receiving 
fuel and passing that fuel through the filter to an outlet. The closed end 
pocket also includes a fuel bypass outlet. Consequently, it will be seen 
that the combined fuel filter and regulator assembly comprises essentially 
a four-part construction (excluding the filter and regulator per se) which 
simplifies manufacture and reduces costs. Further, the regulator may be 
readily sealed to the internal or second end cap and the pocket of the 
cylindrical body by the use of conventional O-ring seals. 
One of the features of the present invention resides in the ability to use 
a fuel filter comprising a folded paper filter cartridge between two metal 
end caps using a temperature-activated adhesive (Plastisol). While this 
decreases costs, there is a length variation in the paper cartridge which 
can exceed tolerances. Because the length of the fuel filter cartridge 
varies widely, there is a stack-up of tolerances which must be 
accommodated and which must also account for the need to seal the 
regulator against the fuel filter cartridge to eliminate contaminated fuel 
from bypassing the filter. To accomplish this, a wave spring is disposed 
between the closed end of the cylindrical body and a radial flange on the 
regulator for biasing the regulator toward the open end of the cylindrical 
body. With the regulator sealed to the second internal end cap as well as 
within the pocket, the compression of the spring accommodates the 
variations in the end of the internal filter end cap. Thus, the spring 
affords the assembly an allowance for stacked-up tolerances in the fuel 
filter cartridge in a most inexpensive manner. 
In a preferred embodiment according to the present invention, there is 
provided a fuel filter module with integral regulator, comprising an 
outer, generally cylindrical body open at a first end and closed at a 
second end, the second end having a reduced diameter cup projecting 
therefrom with an outlet at an end of the cup remote from the second end, 
a regulator disposed in the cup and projecting from the second end toward 
the first end, a fuel filter within the cylindrical body, an end cap for 
closing the open end of the cylindrical body and overlying the fuel filter 
and a second end cap within the cylindrical body between the regulator and 
the filter for engaging the filter whereby the filter is supported in the 
body between the first and second end caps and a fuel inlet through the 
body for flowing fuel to the filter. 
In a further preferred embodiment according to the present invention, there 
is provided a fuel filter module with integral regulator, comprising an 
outer body open at a first end and closed at a second opposite end, the 
second end having a seat and an outlet at an end of the seat remote from 
the second end, a regulator disposed in the seat, a fuel filter within the 
body, an end cap for closing the open end of the body and overlying the 
fuel filter, a second end cap within the body between the regulator and 
the filter for engaging the filter and the regulator whereby the filter is 
supported in the body between the first and second end caps and the 
regulator is retained between the seat and the second end cap, a fuel 
inlet through the body for flowing fuel to the filter and a fuel outlet 
for flowing filtered fuel from the module. 
Accordingly, it is a primary object of the present invention to provide a 
low-cost, minimum piece part count combined filter and regulator module 
for regulating flow of filtered fuel to the engine of a vehicle.

BEST MODE FOR CARRYING OUT THE INVENTION 
Referring now to the drawings, particularly to FIG. 1, there is illustrated 
a fuel filter and regulator assembly according to the present invention 
and generally designated 10. Assembly 10 includes a housing 12 essentially 
formed of four component parts: a cylindrical body 14, a first end cap 16, 
a second end cap 18 and a fuel inlet 20. Within housing 12, there is 
provided a conventional fuel filter 22. Filter 22 is in the form of an 
annulus formed of corrugations of paper, per se forms no part of the 
present invention and therefore further description of the filter itself 
is not necessary. Additionally, a conventional pressure regulator 24 is 
disposed within the housing 12 in a unique manner, as will become clear 
from the ensuing description. 
The first component part, i.e., the cylindrical body 14, similarly as the 
other four component parts, is formed of stainless steel. Particularly, 
the cylindrical body 14 includes a cylindrical outer side wall terminating 
in an open end, i.e., the upper end as illustrated in FIG. 1. Body 14 is 
closed at its opposite end by a wall 26. The wall includes a seat for 
receiving and mounting the regulator 24. Preferably, the seat comprises a 
pocket or a cup 28 formed on the axis of the cylindrical body 14 and which 
pocket or cup 28 projects from the end wall 26. The pocket or cup 28 has a 
step 30 whereby the initial cylindrical portion 32 of the pocket 28 is 
larger in diameter than the integrally formed extension 34 of the pocket 
28. The pocket 28 terminates at its lower end in a fitting 36 for coupling 
to a return fuel line. From a review of FIG. 1 and also FIG. 2, it will be 
appreciated that the first part, i.e., the cylindrical body 14, comprises 
a single part and which not only forms end and side walls for the filter 
22 but also a receptacle for regulator 24. 
In FIG. 1, the upper end of the housing 12 includes a second component, 
i.e., a first end cap 38. End cap 38 is formed of an integral stamping 
which retains the pressure regulator and filter together, as discussed 
below. End cap 38 has a quick connect male fitting formed axially of the 
assembly, affording an outlet port 40 for fuel flow to a fuel rail, not 
shown. The end cap 38 also serves as one end for the fuel filter 22. To 
secure the end cap 38 to the cylindrical body 14, a crimp or laser weld 
may be formed at the juncture of the end cap 38 and body 14, a crimp being 
illustrated. 
Another component of the assembly comprises a quick connect male fitting 20 
which may be attached at one end to the annular wall 26 of the cylindrical 
body 14, for example, by welding or brazing. Component 20 is formed from 
either tubing or as a progressively stamped component. This simplifies the 
complexity of the cylindrical body which requires two outlet ports, the 
component 20 acting as the inlet to the fuel filter regulator assembly 
from the fuel pump. 
The final component 18 of the assembly comprises the second end cap. It 
will be appreciated that the fuel filter element may be captured between 
the end elements 16 and 18 by using an adhesive (Plastisol). The second 
end cap 18 has an annular flange 44 about its outer diameter for enclosing 
the lower end of the fuel filter element 22. Second end cap 18 also 
includes an inward projection 46 forming a cylindrical recess for 
receiving the upper end of the pressure regulator 24. In FIG. 1, the 
pressure regulator has a radially outwardly projecting flange 48 located 
between the annular wall 26 of body 14 and the second end cap 18. 
Additionally, O-ring seals 50 and 52 are disposed between the regulator 
and the central recess 46 of the end cap 18 and the pocket 28, 
respectively. Thus, the second end cap 18 and pocket 28 seal the regulator 
to ensure leak-free regulation of only filtered fuel. When the assembly is 
fabricated, the regulator 24 is placed into the cylindrical pocket 28 
using the O-ring 52 to seal the interface. The filter 22 between the end 
caps 16 and 18 is then installed over the regulator. The regulator mates 
into the inwardly extending recess 46 of the second end cap component 18 
and the end cap 16 mates with the open end of the cylindrical body 14. The 
end cap 16 is then laser welded or crimped to the body 14, capturing the 
regulator 24 on axis between the second end cap and the annular wall 26 of 
body 14. Thus, it will be seen that by employing essentially four 
component parts which may be readily fabricated and coupled one to the 
other, a very simple, robust fuel filter/regulator assembly is provided. 
Referring now to the embodiment of FIGS. 8-10, like reference numerals 
apply to like parts, followed by the letter suffix "a." The fuel 
filter/regulator assembly of FIGS. 8-10 is similar to the assembly of FIG. 
1, except that it is of a somewhat smaller filter size and has a different 
end cap. The component parts 14a, 16a and 20a remain essentially the same 
as previously described. However, the second end cap 18a accommodates the 
reduced length of the fuel filter. In this form, the end 18a has an outer 
flange 44a for encapsulating the lower end of the filter 22a. Instead of 
an inwardly directed recess 46 as in the first embodiment, the component 
18a has an axially projecting, integrally formed sleeve 54 which is 
received about the upper end portion of the regulator 24a. The fitting 54 
is stepped radially outwardly to receive an O-ring seal 50a sealing the 
regulator to the component 18a. The outer end of the fitting 54 bears 
against the flange 48a of the regulator 24a. 
Referring now to the third and final embodiment of the present invention, 
wherein like reference numerals apply to like parts followed by the suffix 
"b," there is illustrated a fuel filter/regulator assembly 10b which 
greatly simplifies packaging and assembly. There is a wide tolerance due 
to the assembly of the folded paper element of the filter which is adhered 
between the two metal end caps using a temperature-activated adhesive. The 
variations in the length of the paper fuel filter can exceed plus or minus 
1 millimeter. Because the length of the fuel filter cartridge varies 
widely, it poses a problem when trying to capture the regulator between 
the cartridge and the filter housing. The problem is exacerbated by the 
need to seal the regulator against the fuel filter cartridge to eliminate 
contaminated fuel from bypassing the filter and to seal the regulator 
against the filter housing to seal high pressure and low pressure. 
To accommodate the stack-up of tolerances between the fuel filter cartridge 
and the wall 26b of the assembly 10b, there is provided a wave spring 70 
disposed between a grommet 72 in the pocket 28b of the body and the 
underside of the radial flange 48b of regulator 24b. The wave spring 70 is 
annular in plan form and includes peaks and valleys in the form of 
corrugations about the circumference of the spring. The wave spring 
therefore has a play in excess of the variations in length of the fuel 
filter and hence can take up the differences in tolerances. Additionally, 
the grommet or spacer 72 provides a secondary function of acting as a 
positive stop for any travel of the O-ring 52b in the pocket 28b. The step 
in the pocket 28b provides the stop in the opposite direction. Thus, the 
wave spring 70 provides the assembly with substantial allowance for 
stack-up tolerances in the fuel filter cartridge, employing an inexpensive 
and durable component to accomplish that purpose. 
While the invention has been described in connection with what is presently 
considered to be the most practical and preferred embodiment, it is to be 
understood that the invention is not to be limited to the disclosed 
embodiment, but on the contrary, is intended to cover various 
modifications and equivalent arrangements included within the spirit and 
scope of the appended claims.