Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
2Q~77~
Material for filters, especially oil, petrol or diesel
filters of motor vehicles
Technical Field
The present invention relates to a materlal for
filters, especially oil, petrol or diesel filters of
motor vehicles, a method for its manufacture and
filters manufactured thereafter.
Background of the Invention
In particular oil filters that are used in the field
of motor vehicles are exchanged with all their oil
drawn up by suction and their filtrate. The filtrate
consists of abraded metal particles and additives
which are simply thrown away with them, resulting in
a corresponding pollution of the environment unless
measures are taken for sophisticated, and hence
expensive, waste disposal. A repeated use of such oil
filters is not planned for several reasons, in
particular for reasons of lack of shelf life and the
lack of the possibility of cleaning the filter.
In general, according to the prior art, such filters
consist of a paper fleece or mat, which, because of
its low strength and solubility in oil, has only a
limited service life. The paper fleece or mat is
arranged in a filter cartridge and the oil flows
through it.
summary o~ the Invention
An ob~ect of the present invention is therefore to
create a material for a filter, especially an oil
filter of motor vehicles, which possesses a higher
strength and which is thereby reusable when needed.
2~8777~
According to this invention, the object of the
invention is achieved by a material consisting of a
sintered metal fleece or mat with a fabric as
supporting or carrying matrix, onto which metallic
fibres are sintered at least on one side.
In addition to or instead of metallic fibres,
especially short fibres, metal chips or metal powder
can also be sintered onto the supporting or carrying
matrix. Likewise, mixtures of the said substances are
also possible.
In an advantageous way, metallic short fibres, metal
chips or metal powder or a mixture thereof are
sintered onto both sides of the matrix.
Through this embodiment, even greater stability and
improved efficiency are obtained.
One of the main advantages of this filter material
consists in that it has a far higher strength than
known paper fleeces or mats. For this reason, it has
a distinctly greater service life and can, if
required, be used many times. In particular, because
of its greater strength, the filter is not destroyed
or damaged if it is cleaned for multiple use, e.g.
after an oil change. The filter can be back-flushed
for this purpose. This can, for example, be done when
the filter is not installed or else, if need be, also
when it is installed, if appropriate back-flushing
means are provided.
A further advantage of the material according to the
-3- ~o877~3
invention lies in the fact that it possesses a very
high porosity with a high degree of separation of
impurities.
Despite the greater strength of the sintered metal
fleece or mat, this is, however, sufficiently elastic
and/or flexible so that it can be brought into any
desired shape or form of filter.
A tangle of endless isotropic metallic fibres are used
as the material for the supporting or carrying matrix.
A commercially available product is also suitable for
this, which consists, for example, of a fabric with
warp and weft threads woven in a well-known linen
bond.
Values between 0.05 to 0.2 mm, preferably 0.1 mm have
proven to be suitable thicknesses for the supporting
or carrying matrix. The total thickness of the
material, together with the sintered-on parts lies
preferably between O.2 to 1 mm.
Rustfree or stainless or ferritic steel can be used as
the material for the matrix and the sintered-on parts.
In case of need, however, other materials are also
suitable. When used as a petrol filter, for example,
in which event the creation of sparks should be
avoided, copper, aluminium or a nonferrous metal is
suitable. Aluminium or nonferrous metal have a lower
weight as an additional advantage.
The material according to the invention can be
manufactured in any way desired. In a simple way a
;2~7773
band or strip material is used as a matrix. This
material is brought in a simple manner into the
desired filter form or shape, which is generally a
cylindrical shape. With the material according to the
invention, the joints can be made in a simple way and
thus very cheaply, preferably soldered or welded. It
goes without saying, however, that a connection can
also be made by bonding or gluing.
The manufacture of the sintered metal fleece or mat
out of the supporting or carrying matrix and the
sintered-on parts can be done in a simple manner by
coating the matrix with a bonding agent and
subsequently sprinkling on the fibres and/or metal
chips or metal powder or a mixture thereof. Because of
the bonding agent, these parts then cling to the
matrix, after which sintering takes place in the
well-known manner, which is effected at appropriate
temperatures depending on the metals used.
In the following, an embodiment of the invention is
described showing the underlying principle.
Brief Description of the Drawing
ig. 1 a section through the material according to
the invention;
ig. 2 a view of a filter made out of the material
according to the invention.
Detailed Description of the Invention
A supporting or carrying matrix is used as the basic
material for a filter, which consists of a fabric with
2~8~73
--5--
endless isotropic metal fibres.
Metallic short fibres with lengths between 1 mm and
5 mm are applied to both sides of matrix 1, which are
sintered together with the matrix.
As can be seen in Fig. 2, the sintered metal fleece or
mat is formed from a band or strip of appropriate
length, which is wound into a cylindrical form or
shape. The two ends of the band or strip are connected
to each other by a soldered or welded seam 3.
Sin~e the sintered metal fleece or mat is very
variable with regard to its profiling, it can be used
in a very advantageous way as a purely exchangeable
part for the well-known paper fleece or mat filter.
This means that, for example, oil filters in motor
vehicles can be retrofitted or re-equipped in a simple
way and without any problems with the sintered metal
fleece or mat according to the invention. The sintered
metal fleece or mat according to the invention can be
inserted in conventional oil-filter tanks or
receptacles or oil-filter cartridges. Because of its
great stability it can, if need be, remain therein
during the entire period of use and must solely be
removed and cleaned or subjected to back-flushing at
well-defined intervals.
