Note: Descriptions are shown in the official language in which they were submitted.
21574~1
,
FLUID FILTER WITH INTEGRATED PRESSURE REGULATOR
Backqround of the Invention
This invention relates to a filter comprising an inlet
and an outlet.
Filters of this type are known, for example, as fuel
filters in internal-combustion-engine-driven vehicles of any
type. Pressure regulators in a special-steel construction
which limit the pressure in the fuel pipe and are mounted
between the filter and the engine are also known. On the
one hand, this known arrangement of the filter and the
pressure regulating valve requires many parts and, on the
other hand, the costs for several parts have a
disadvantageous effect on the overall cost situation.
It is possible to examine the individual elements as
well as the manufacturing processes with respect to saving
cost. However, this requires a lot of time, which will not
necessarily improve the cost situation, and different
structural units would also still exist.
Summary of the Invention
It is therefore one ~pect f the present invention to
improve a filter of the aforementioned type in such a manner
that an inexpensive multi-purpose module is created which is
easy to install and use.
2s This and other ~pec~ of the invention are achieved by
providing a filter comprising a housing, a filter member
disposed in said housing defining an unfiltered fluid space
and a filtered fluid space, an inlet into the housing
- - 2157d~1
communicating with the unfiltered fluid space, an outlet in
the housing communicating with the filtered fluid space, and
a pressure regulator integrated into the filter housing.
In accordance with the invention, a pressure regulator
is integrated in the filter housing. This reduces the
number of total parts and therefore also the cost. By
creating only one part, the handling will also be
significantly improved during installation and removal.
An advantageous further embodiment of the invention
provides that a return flow passage is arranged behind the
pressure regulator. If the fuel line pressure becomes
excessively high, this return flow passage conducts excess
quantities of fuel from the pressure regulator back to a
supply tank.
Furthermore, the pressure regulator may advantageously
be arranged on the clean side (i.e. the filtered fluid side)
of the filter member or on the unclean side (i.e. the
unfiltered fluid side).
In accordance with an advantageous further embodiment
the pressure regulator comprises a restoring mechanism made
of plastic and/or of metal. Furthermore, the filter housing
may advantageously be made of plastic and/or of metal. The
use of more plastic has advantages with respect to weight
and cost. Also, the demands on the recycling systems are
lower the more that the proportions of material components
are the same.
In accordance with an advantageous further embodiment,
the filter insert has end caps made of metal and/or paper
and/or cardboard. The more the material components of the
overall filter are the same, the more advantageous the
material-related reprocessing after the operating life of
the filter.
Brief Description of the Drawings
The invention will be described in further detail with
reference to representative preferred embodiments
~157~2~
.
illustrated in the accompanying drawings in which:
Figure 1 is a longitudinal sectional view of a fuel
filter with a plastic housing and a pressure regulator
arranged on the clean side of the filter member;
5Figure 2 is a longitudinal sectional view of a fuel
filter with a metal housing and a filter member having a
self-supporting construction;
Figure 3 is a longitudinal sectional view of a fuel
filter with a metal housing and a filter member supported by
a support tube; and
Figure 4 is a longitudinal sectional view of a fuel
filter with a pressure regulator arrangement on the unclean
side of the filter member.
Detailed Description of Preferred Embodiments
The invention will be described hereinafter with
respect to examples of fuel filters for an internal
combustion engine. It should be understood, however, that
the invention is not limited to fuel filters, but is
applicable as well to other types of filters.
In each of the illustrated embodiments, the fuel filter
comprises a housing 1 with an inlet 2 and an outlet 3. A
pressure regulator 4 is integrated in the filter housing.
The pressure regulator comprises a resilient restoring
mechanism, such as a coil spring made of metal or plastic.
Alternatively, the restoring mechanism may comprise a plate
spring or a compressible rubber block. At excessively high
pressures, the pressure regulator 4 acts as a bypass and
conducts excess quantities of fuel back into the supply tank
by way of a return flow passage 5.
Figure 1 illustra'tes a filter with a housing 1 made of
plastic. In the interior of the housing, a filter insert 6
is situated which consists of paper folded in a star shape.
Alternatively, the filter insert may be constructed as a web
comprising a plurality of mechanically, adhesively or
cohesively reinforced textile fiber layers. The filter
~1~i7421
insert divides the interior of the housing into an
unfiltered fluid space and a filtered fluid space. In this
embodiment, the pressure regulator 4 is arranged on the
clean side of the filter member 6 (i.e. in communication
with the filtered fluid space inside the filter housing).
The end caps 7 of the filter insert may consist of metal or,
if the filter housing 1 is constructed of plastic (i.e.
synthetic resin), may be formed of paper and/or cardboard
and contain no metal. In Figure 1, a support tube 8 is
disposed inside the filter insert 6 for increasing its
stability.
Figure 2 depicts a variant with a metal housing in
which the pressure regulator 4 again is mounted on the clean
side. The filter insert is constructed in a self-supporting
manner, and no support tube is required.
Figure 3 shows an embodiment with a metal housing in
which the pressure regulator 4 is again mounted on the
filtered fluid side of the filter member 6. This embodiment
differs from the embodiment of Figure 2 in that a support
tube 8 is provided inside filter insert 6 to assist in
preventing the filter insert from shifting or collapsing
under pressure.
Figure 4 illustrates a variant in which the pressure
regulator 4 is mounted on the unclean side; or in other
words, in communication with the unfiltered fluid space of
the filter housing 1. This arrangement is particularly
advantageous to prevent rupture of the filter housing 1 if
the filter member 6 becomes fouled or clogged.
The foregoing description and examples have been set
forth merely to illustrate the invention and are not
intended to be limiting. Since modifications of the
described embodiments incorporating the spirit and substance
of the invention may occur to persons skilled in the art,
the invention should be construed broadly to include all
variations falling within the scope of the appended claims
and equivalents thereof.
