FILTER ARRANGEMENT

AGENCEMENT DE FILTRAGE

English Abstract

A filter arrangement has a two-piece filter housing that contains a filter
element (5) through which flows the medium to be filtered. In the plane of a
joining surface (9), the filter element (5) has approximately the same contour
as the filter housing. A clamping device for the filter element is arranged in
the area of the joining surface (9). The clamping device has studs (11)
distributed at predetermined distances from each other around the whole
joining surface (9). The studs (11) firmly retain a disk made of non-woven
fabric panel that acts as a filter element when the two parts (2, 3) of the
housing are assembled. Central ribs (6) provided with such studs, for example
conical or pyramid-shaped studs, may also be arranged inside the filter
housing. In another embodiment, the filter element (5) is a fabric screen
which may be secured for example by ultrasonic welding between the two parts
(2, 3) of the housing, and which may also be fixed in the housing by a
supporting body (25).

French Abstract

Cet agencement de filtrage comprend un boîtier de filtre en deux parties qui contient un élément de filtrage (5) à travers lequel s'écoule le milieu à filtrer. Dans le plan d'une surface de jonction (9), l'élément de filtrage (5) a un contour qui correspond à peu près au contour du boîtier du filtre. Un dispositif de serrage de l'élément de filtrage est monté dans la zone de la surface de jonction (9). Le dispositif de serrage comprend des pointes (11) distribuées à des intervalles prédéterminés tout autour de la surface de jonction (9) qui serrent fermement un disque en non-tissé qui sert d'élément de filtrage (5) lorsque les deux parties (2, 3) du boîtier sont assemblées. Des nervures médianes (6) pourvues elles aussi de telles pointes, par exemple coniques ou pyramidales, peuvent être en outre façonnées à l'intérieur du boîtier du filtre. Dans un autre mode de réalisation, l'élément de filtrage (5) est un crible en tissu assujetti par exemple par soudage aux ultrasons entre les deux parties (2, 3) du boîtier et susceptible d'être fixé dans le boîtier (1) par un corps de support supplémentaire (25).

Claims

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Claims
1) Filter arrangement with
- a two part filter housing, wherein in a first part (3) an
opening is present for the inlet (8), and in another part an
opening is present for the outlet (7) of the medium to be
filtered, and with
- a filter element (5) through which the medium to be
filtered flows in the filter housing and which has
approximately the contour of the filter housing in the plane
of a seam surface (9), and wherein in the vicinity of the
seam area (9) a clamping means for the filter element is
provided, characterized in that
- the clamping means consists of studs (11) distributed at
predetermined intervals over the entire seam area (9) of at
least one housing part (2, 3), which securely clamp the
filter element (5) when the housing parts (2, 3) are
assembled.

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2) Filter arrangement according to claim 1, characterized
in that
- the studs (11) extend so far into the interior of the
housing parts (2, 3) that, after the contact surfaces (10)
are brought together, the filter element (5) is compressed
by a given amount in the area of the studs (11).
3) Filter arrangement according to one of claims 1 or 2,
characterized in that
- both housing parts (2, 3) have intermediate ribs (6) in
prescribed areas, which extend so far into the interior
that, after the two housing parts (2, 3) have been brought
together, the filter element (5) is additionally gripped
there.
4) Filter arrangement according to claim 3, characterized
in that
- the studs (11) are also disposed on the intermediate ribs
(6).
5) Filter arrangement according to one of claims 1 to 4,
characterized in that
- the studs (11) are rounded off on the side facing the
filter element (5).
6) Filter arrangement according to one of claims 1 to 5,
characterized in that
- the studs (11) on the side facing the filter element (5)
are of conical or pyramidal in shape.

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7) Filter arrangement according to one of claims 1 to 6,
characterized in that
- the filter element (5) consists of a nonwoven sheet, and
that
- the housing parts (2, 3) are of plastic and are welded at
their contact surfaces (10) by vibration or ultrasound
welding.
8) Filter arrangement according to claim 7, characterized
in that
- the nonwoven sheet (5) is likewise welded with the housing
parts at the studs (11).
9) Filter arrangement with
- a two part filter housing, wherein in a first part (3) an
opening is present for the inlet (8), and in another part an
opening is present for the outlet (7) of the medium to be
filtered, and with
- a filter element (5) through which the medium to be
filtered flows in the filter housing and which has
approximately the contour of the filter housing in the plane
of a seam surface (9), and wherein in the vicinity of the
seam area (9) a clamping means for the filter element is
provided, characterized in that
- the seam area (9) of both housing parts (2, 3) consists in
each case of a contact surface (10) at which the two housing
parts can be joined together, and of laterally inwardly
arranged clamping means for the filter element (5), and that
- the filter element (5) consists of a screen material which
can be severed from a larger sheet of screen material during
the assembly of the two housing parts (2, 3).

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10) Filter arrangement according to claim 9, characterized
in that
- the clamping means projects with a blunt surface on one of
the housing parts (2, 3) beyond the line of separation of
the two housing parts (2, 3) at the seam area (9) to such an
extent that the screen material surface is gripped with a
predetermined pressure inside of the filter arrangement
after assembly.
11) Filter arrangement according to claim 9 or 10,
characterized in that
- the screen material (5) is also gripped between
intermediate ribs (6) in the interior of the filter
arrangement.
12) Filter arrangement according to one of claims 9 to 11,
characterized in that
- the housing parts (2, 3) can be welded ultrasonically
through the screen material at the contact surfaces (10),
whereby the necessary seal between the chambers of the two
housing parts (2, 3) being produced primarily by the
uninterrupted weld seam.
13) Filter arrangement according to one of claims 9 to 12,
characterized in that
- the screen material (5) can be severed from a band form
web running between the unassembled housing parts (2, 3),
whereby
- during the assembly of the housing parts (2, 3) at the
weldable contact surfaces (10), the portion of the screen
material (5) which remains as the filter element is stamped
out.

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14) Method of manufacturing a filter arrangement according
to one of claims 9 to 13,
characterized in that
- in a first manufacturing step a band form web consisting
of a screen material is drawn over the lower housing part
(3), that
- in a second manufacturing step the upper housing part (2)
is pressed in the seam position onto the web surface,
whereby the web while being pressed together is initially
held at the contour of the contact surface and stretched in
the interior by means of the welding apparatus and that
- in a third manufacturing step the housing parts (2, 3) are
welded at the contact surfaces (10) and the screen material
is cut out at the weld by the effect of the heat.
15) Filter arrangement with
- a two part filter housing, wherein in a first part (3) an
opening is present for the inlet (8), and in another part an
opening is present for the outlet (7) of the medium to be
filtered, and with
- a filter element (5) through which the medium to be
filtered flows in the filter housing and which has
approximately the contour of the filter housing in the plane
of a seam surface (9), and wherein in the vicinity of the
seam area (9) a clamping means for the filter element is
provided, characterized in that
- the seam area (9) of both housing parts (2, 3) comprises
in each case a contact surface (10) at which the two housing
parts can be joined together and from which clamping means
offset laterally inward for the filter element (5) exist,
and that
- the filter element consists of a screen material (5) which
is provided with a support body (25) which has at least one
projection (26) which extends inwardly to at least one part

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(2, 3) of the filter housing and thus fixes the position of
the filter element in the assembled filter housing.
16) Method for manufacturing a filter arrangement according
to claim 15,
characterized in that
- in a first manufacturing step band form web of screen
material is drawn into an injection molding tool, that
- in a second manufacturing step the support body is
injection molded from one side onto the screen material (5)
with projections (26), and that
- in a third manufacturing step the housing parts (2, 3) are
welded at the contact surfaces (10) with the inclusion of
the screen material (5).
17) Filter arrangement according to one of claims 1 to 13
or 15, characterized in that
- the two housing parts (2, 3) and/or the support body (25)
are comprised of glass fiber reinforced polyamide and the
screen material preferably is comprised of polyester or
polyamide.

Description

CA 02221300 1997-11-17
WO 96/36414 PCT/EP96/01945
Filter Arrangement
The invention relates to a filter arrangement with a two
part filter housing in accordance with the preamble of
the main claim.
State of the Art
In E-0 396 385 A2 a filter arrangement of the above-
described kind is disclosed, in which two housing parts
of plastic material are bonded together by means of a
friction or vibration welding method, and thereby enclose
a filter element. This filter element is gripped between
the two housing parts by a circumferential mounting edge.
It can occur that, due to varying thickness of the filter
element at some points, the housing parts fail to become
securely fastened together or the filter element is not
securely mounted. If the filter element is too thick at
some points, the welded seam between the housing parts
may also break apart.

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Also, a filter arrangement is disclosed in U.S. Patent
No. 4,828,694 in which a two part filter housing likewise
has in its interior a filter element through whose walls
a fluid to be filtered flows in such a way that the
undesired residues remain in the filter element. The
inlet for the fluid is situated in the bottom part and
leads directly into the interior of the hollow filter
element.
The filter element in this case is gripped only partially
between the housing parts; in the outlet area the filter
element disclosed in this last-named publication is not
situated near the seams. To assure the hollow shape and
a stable location inside of the filter system, a
relatively complicated grid-like mounting is disposed
within the hollow filter element and is fastened to the
bottom part of the housing.
Object
It is the object of the invention to improve a filter
arrangement of the kind referred to above such that a
filter element can be securely integrated into the filter
housing in a simple manner.
Advantages of the Invention
Setting out from this general type (of filter), the
filter arrangement according to the invention is
advantageously suited to achieve the stated object with
the characterizing features of the main claim. It is
especially advantageous that, due to the forming of studs
at the contact surfaces of the two housing parts in

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accordance with the invention, a simple manufacturing
process is assured, and a secure installation of a filter
element of relatively simple form is made possible. For
this purpose the filter element, prior to its attachment to
one of the housing parts, is provided with the necessary
contours by a simple stamping apparatus, and upon assembly
it is held by the studs according to the invention. In the
assembled state, the medium to be filtered flows through the
filter element in the entire area of the filter housing.
The contact surfaces at which the two housing parts are
securely joined together, are situated preferably outside at
the seam area, so that a good seal of the filter housing can
also be achieved. By appropriately dimensioning the contact
surfaces, making allowance for the possibility that a defect
might be caused by the assembly process, it can be brought
about that, after assembly, a sufficient contact pressure
will hold the nonwoven sheet over the studs. The studs are
advantageously arranged at an appropriate spacing, which is
not too close, so that no excessive surface pressure will
occur.
The mounting of the nonwoven sheet is especially
advantageous if according to dependent claim 3, intermediate
ribs are formed on both housing parts, which on the one hand
will promote the flow and distribution of the medium in the
housing, and on the other hand will improve the grip on the
filter element.
Advantageously, the prefabricated housing parts comprised of
plastic material are joined together by a vibratory or
ultrasound welding method, in which case precise positioning
and in some cases an additional welding of the nonwoven
sheet to the housing parts and/or the intermediate ribs can
be performed. Known nonwoven webs used in the motor vehicle

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--4--
industry, are preferably used as the material for the filter
element.
In another embodiment of the filter arrangement according to
the invention, having the features of claim 9, a web of
screen material is advantageously clamped between the
housing parts, the screen material being able to be cut out
of a larger area of screen material and surface clamped by
the assembly of the housing parts. In accordance with a
manufacturing method of the invention, recited in claim 14,
the manufacture of the filter arrangement can be simply
integrated into a conveyor belt assembly in which the screen
material is punched out of a band, for example during
ultrasound welding of the two housing parts at the contact
surfaces.
Drawing
Illustrative embodiments of the filter arrangement of the
invention will be explained with reference to the drawing,
in which:
Figure 1 shows a longitudinal section through a filter
arrangement for the transmission oil of a motor
vehicle;
Figure 2 shows a plan view of the bottom housing part
with intermediate ribs and inlet;
Figure 3 shows a first detail view of a section of the
seam area between the two housing parts, as well as the
intermediate ribs with studs for mounting the filter
element;
Figure 4 shows another illustrative embodiment with a
modified seam area;
Figure 5 shows a section through a further illustrative
embodiment with a screen material as the filter

CA 02221300 1997-11-17
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-5-
element;
Figure 6 shows a view of the bottom housing part
according to Figure 5;
Figure 7 shows a detail illustration of a section of
the seam area between the two housing parts of Figure
6, and
Figure 8 shows a section through an illustrative
embodiment with a support body for the filter element.
Description of the Illustrative Embodiments
In Figure 1 there is shown a section through a filter
arrangement 1 with a top housing part 2 and a bottom housing
part 3. Between the two housing parts 2 and 3 a nonwoven
sheet 5 is held as a filter element which is clamped between
the two housing parts, as will be explained below with
reference to Figures 3 to 6. In Figure 1, intermediate ribs
6 are indicated and an outlet 7, as well as an inlet 8
(suction port), for the medium to be filtered are shown.
An explanation of the manner of operation will be given with
reference to Figures 1 and 2. In Figure 2 as viewed from
the bottom, an inlet 8 for the medium to be filtered is
seen, through which, for example, a transmission oil for the
transmission of a motor vehicle flows to be filtered into
the bottom housing part 3 and along the intermediate ribs 6.
In the inlet 8 an additional supplemental coarse filter,
e.g., a metal or plastic strainer, not shown here, can be
arranged. Since the nonwoven sheet 5 is held securely and
sealingly at the seam areas 9 between the two housing parts
2 and 3 and optionally also at the intermediate ribs 6, the
transmission oil which is to be filtered must pass through
the nonwoven sheet 5 in order to reach the outlet 7 on the
upper housing part 2. The transmission oil is, as a rule,

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--6--
forced with a certain pressure through the filter
arrangement 1.
On the seam area 9 there is a contact surface 10 (see upper
cutaway in Figure 2) at which the housing parts are
joined/welded together, and studs 11 are arranged so that
the filter element is tightly clamped by them. Figure 3
shows a first embodiment of the configuration of the seam
area 9 in which prefabricated plastic parts which serve as
housing parts 2 and 3, are provided with a contact surface
10 for securely joining the two parts together and conical
studs 11 for gripping the nonwoven sheet 5. The studs 11
penetrate through the nonwoven sheet 5 both at the seam 9 at
the margin, and at the intermediate ribs 6 and compress the
nonwoven disk 5 by an amount a. The conical studs 11 can be
disposed either on the upper part 2 (as shown) or on the
bottom part 3.
Another configuration of the contact surface 10 is to be
seen in Figure 4, in which the positioning of the housing
parts 2 and 3 is accomplished by an additional cone-shaped
stud 13. This manner of configuring the contact surface 10
is especially suited for joining the housing parts 2 and 3
and the nonwoven sheet 5 by means of an ultrasound welding
process. The remaining features of this illustrative
embodiment correspond to those of the previously described
example.
A further illustrative embodiment of the filter element 5
is, according to Figure 5, a screen material which here can
be seen as a considerably thinner layer between the chambers
of housing parts 2 and 3. Figure 6 serves to show the seam
area 9, which here is smooth and which is suitable for
fastening the housing parts 2 and 3 and the screen material
5.

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Figure 7 shows an illustrative embodiment of the
configuration of the seam area 9, in which prefabricated
plastic parts which serve as the housing parts 2 and 3 are
provided with a contact surface 10 and optionally
supplemental welding studs 20. A clamping means 21 with a
blunt edge projects past the contact surface 10 such that,
when the housing parts 2 and 3 are assembled, the screen
material 5 is tightly stretched. The screen cloth 5 is
thereby held both at the contact area 10 at the periphery
and at the intermediate ribs 6. In the subsequent welding
of the housing parts 2 and 3 at the contact area 10, the
screen material 5 is by the effect of the heat more or less
stamped out from web of material inserted there during
production.
The sectional view in Figure 8 shows a filter element in
which a screen material 5 is provided with a support body
25. The clamping of this screen material at the seam areas
9 takes place as described in the preceding examples. For
optimum support of the filter element, the support body 25
has projections 26 which thus fix the location of the screen
material 5 in the housing 1 of the filter arrangement. In
order to manufacture this embodiment of the filter element,
the screen material 5 is pulled into an injection molding
tool and thereafter the supports 25 with the projections 26
are molded onto one side of the screen material 5.

Representative Drawing