ZA200102878B

ZA200102878B - Filter cartridge.

Info

Publication number: ZA200102878B
Application number: ZA200102878A
Authority: ZA
Inventors: Marcus Eyssel; Matthaeus Huber; Jochen Sanguinette; Manfred Tumbrink; Manfred Wagner
Original assignee: Mann & Hummel Filter
Priority date: 1998-10-17
Filing date: 2001-04-06
Publication date: 2002-07-08
Also published as: WO2000023166A1; DE19847998A1; EP1133341B1; KR20010100904A; EP1133341A1; DE59908911D1; ATE261752T1

Abstract

The invention relates to a method which is provided for producing filter cartridges (10) comprising at least one film end disc (11) and which makes it possible to introduce inserts with a high level of positional accuracy. To this end, receptacles (17, 23) are provided in a mold (12), in which the inserts (13, 15) are inserted and can be fixed in the positions thereof. Afterwards, the film blanks (14) are heated in a conventional manner, expand, and as a result, fix the introduced filter medium (16) of the filter cartridge and the inserts (13, 15). In doing this, complicated functional parts can be introduced into the film end discs (11) of filter cartridges (10) without requiring a large amount of effort with regard to manufacturing techniques.

Description

®.-.

Filter cartridge

Description

State of the art

The invention relates to a filter cartridge comprising a foil end disk on at least one side, in which an insert is embedded. The invention furthermore relates to a process for manufacturing filter cartridges comprising inserts put into the foil end disk.

Filter cartridges closed off by foil end disks are known, for example, from DE 44 28 139. The end disks at the ends of the filter cartridge are elastic and consist of foils which are heated in order to bond them to the filter medium. The heating causes the foils tc expand towards the filter medium, as a resuit of which the foiis partly penetrate through same, thus ensuring a sealing off of the filter pleats at the —end-surfaces-of-the filter. The-heating-at-the same time-causes-the foil-material-to harden, resulting in a solid bonding due to the gluing to the filter material. After the hardening process, the foil has a residual elasticity which can be used, for . example, to ensure that the end disks rest in a sealing manner on corresponding sealing surfaces in the associated housing.

To strengthen the sealing surfaces provided on the foil end disks, it is proposed according to DE 44 28 139 to embed a flexible support ring in the elastic end disk.

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This ring can be placed in the mould which is intended to hold the foil end disks that must be hardened. Co oC

During the manufacture of such a filter cartridge, tolerances occur between the support ring and the foil end disk, which must be put up with seeing that the support ring does not co-operate with the operating surfaces for the sealing in the housing. For this corresponding surfaces are provided on the foil end disk, the exact positions of which are determined by the edges of the mould in which the foil disk is placed to harden. The support ring can fulfill its supporting effect irrespective of its exact position in the foil end disk.

If now components such as, for example, seals are to be integrated in the filter cartridge, which correspond with operating surfaces of the housing and therefore must have a high dimensional accuracy, it is possible, for example, to use a solution as indicated in DE 42 25 144. The ring-shaped sealing element used here, for example, is placed on the foil end disk after manufacture of a round filter cartridge. This can be done, for example, by a fusing on of the sealing ring.

However, this requires a further operating step, which follows the hardening process cf the foil end disk, which makes the finished articiec more expensive.

Another possibiiity is proposed in US 5 211 846. The seaiing ring is piaced in an -end-cap-which-is_put. onto. the. elasticend- disks-which-are-made; in-particular-of polyurethane foam. This can take place, for example, during the installation of the filter cartridge. However, in this case an additional component is required to . produce a sealing, so that this solution entails additional costs.

It is, therefore, the object of the invention to create a filter cartridge with foil end disks, which includes at least one further component to influence the functioning, wherein the costs for manufacturing the filter cartridge do not increase significantly.

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WO 00/23116 3 PCT/EP99/07829

According to one aspect of the invention there is provided a process for manufacturing filter cartridges, in particular round filter cartridges comprising at least one foil end disk, with which oo - a filter medium is bonded to a foil blank placed in a mould in such a way that an end surface of the filter medium rests directly on the surface of the foil end disk, - the filter medium is fixed in this position, so that no relative movement is possible between the filter medium and the foil blank, - the foil blank is heated, so that it expands mainly in the direction of the end surface and encloses this surface completely and in this way forms the foil end disk, - the heating is ended as soon as the foil end disk has hardened sufficiently, wherein, prior to heating the foil blank, an insert is fixed in a holder provided for same in the mould, when by the formation of the foil end disk the insert is fixedly bonded to the filter cartridge.

According to another aspect of the invention there is provided a filter cartridge comprising at least one foil end disk, wherein a substantially flat additional filter is embedded in the foil end disk.

According-to-yet-another-aspect.of the.invention.there is-provided.a filter. cartridge- comprising at least one foil end disk, wherein means to simplify the handling is embedded in the foil end disk.

According to still another aspect of the invention there is provided a filter cartridge comprising at least one foil end disk, wherein the foil end disk is formed by two superposed foil blanks, between which an insert is embedded.

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Advantages of the invention

The process according to the invention provides that the mould which holds the foil blanks for producing the foil end plates of a filter cartridge, comprises additional holder for fixing inserts. With the aid of this mould, filter cartridges for gas filtration or fluid filtration are manufactured. To this end a foil blank, which forms the blank for the to be manufactured foil end disk of the filter cartridge, is placed in the known manner in the mould. In addition to the end surface of the, for example, cylindrical filter medium, also the insert is fixed in the holder prior to heating the foil blank. This step can easily be integrated into the manufacturing process of the filter cartridge. Providing a holder in the mould makes it possible to automate this process, wherein the filter cartridge can be produced in one process step by heating and hardening the foil blanks. The fixing of the insert in the holder takes place in such a way that the finished filter cartridge can be removed from the mould without using excessive force. The forming of the bond between foil end disk and insert takes place in the same way as for the filter medium by embedding in the expanding material of the foil blank. The insert must be embedded in an area of the foil end disk which is not used for embedding the filter medium. This can be done in axial as wall as radial surface sections of the foil end disks. Only by proceeding in tinis imaniner is it possibie 10 ensure that the end surtace of the fiiter -medium.is_completely.enclosed by the-foil end disk, which.is. absolutely. essential for the tightness of the filter cartridge. ~ According to an advantageous embodiment of the invention, only that portion of the insert extends into the mould, which must be bonded to the to be formed foil end disk. The portion of the insert that projects from the mould is intended in particular to achieve the intended function of the component. The foil end disc only expands inside the mould walls or in the direction of the filter medium,

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WO 00/23116 5 PCT/EP99/07829 respectively, so that the portions of the insert that lie outside the mould are not glued by the material of the foil end disc. oo

According to a modification of the invention, the putting of the filter medium into the mould in order to produce a bond between filter medium and foil blank is facilitated by an inserting aid. This can be formed by a conical area which co- operates with the inside of the end surface of the cylindrical filter medium. The conical inserting aid ends at the inside edge of the foil blank, so that the filter medium can be positioned accurately on the foil blank. This measure offers advantages especially with regard to an automated mass production. However, also putting the filter medium in by hand is facilitated in this way.

When the insert is an additional filter it may consist, in particular, of wire grating, but also any other, substantially flat filter medium, e.g. paper, can be used. The edges of the additional filter are embedded in the foil end disk, which ensures a sealing. Depending on the direction of flow of the fluid through the cartridge, the additional filter can serve as a safety element on the clean side of the filter, in the event of a breakdown of the filter medium.

An aiternative solution consists of embedding, in the foil end disk of the filter -cartridge;-means-to-facilitate-its handling: -This-may, for-example; be a centring-aid- to facilitate the installation of the filter cartridge in the associated housing. Other possible components are handles which facilitate a changing of the filter cartridge . or also reducing adapters.

Another alternative for the design of the filter cartridge is obtained when the foil end disk is made of two superposed foil blanks. The insert can in that case be embedded between these two foil blanks. In this way a filter cartridge with increased stability is obtained. It is furthermore ensured that the insert is embedded

® = 4 in an area which is not required for the sealing between filter medium and foil end disk. As possible inserts, sealing rings can be mentioned, which form a sealing area in the radial direction on a pipe connection, onto which the filter cartridge can be pushed for its installation in the filter housing.

These and further characteristics of preferred further developments of the invention can be noted from the claims as well as from the description and drawings, in which connection, in the embodiment of the invention and in other fields, the individual characteristics are realised each one individually or several together in the form of sub-combinations, and can represent advantageous embodiments as well as embodiments capable of being protected, for which protection is claimed here.

Drawing

Further details of the invention are described in the drawings which refer, by way of example, to diagrammatic exemplified embodiments, and wherein:

Figure 1 shows the ond surface of a filter cartridge placed in a mould, with two annuiar discs as biank for the foil end disk, before and after the --manufacturing- process- for the-foil end disk, in-cross-section; -

Figure 2 shows the section through a filter cartridge with foil end disks, : wherein on the one side wire grating as additional filter and on the other side a cover with centre bore for holding a bayonet closure have been put into the foil end disks, and

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Figure 3 shows the end surface of the filter element according to Figure 2 with cover, how same as been put into the mould, wherein only a cut-out corresponding to the detail X in Figure 1 is shown.

Description of the exemplified embodiments

From Figure 1 the manufacturing process for filter cartridges 10 with foil end discs 11 in a mould 12 can be noted. Placed into the mould the one after the other are an insert in the form of a handle 13, a foil blank 14, a sealing ring 15 and another foil blank 14a. Next a filter medium 16 made of star-shape folded filter paper is placed on the top foil blank 14a. The mould is made in such a way that the putting in of the individual parts can take place in an accurate position. For the handle 13 an elongated slot 17 is provided in the mould. The handle falls into this slot, wherein the ends 18 of the handle 13 are placed on a mould bottom 19 of the mould. (The elongated slot at the same time permits a lifting of the finished filter cartridge 10 out of the mould). Next a first foil blank 14 is putin, which is centred by an outer ring wall 20 and an inner ring wall 21 of the mould 12. The inner ring wall 21 has a shoulder 22 with an annular groove 23, which can hold the sealing ring 15, which in this way can be positioned accurately. After the seaiing ring 15, a further foil blank 14a is put into the mould, and is centred by the outer ring wall -20:--After-the-filter medium 1-6 has-been-put-on, the resultant-component-structure- is heated. When doing so, the foil material expands and fills up cavities 25 that have occurred in the component structure or it expands in the direction of an end surface 26 of the filter medium, wherein the latter is enclosed in the foil material.

When the foil material hardens, the foil end disk 11 is obtained.

A filter cartridge 10 manufactured in this manner is illustrated in Figure 2. Wire grating is provided in the one foil end disk as additional filter 27. The outer edges of the wire grating are embedded in the foil end disk 11. On the opposite side of the filter cartridge, the edges of a cartridge cover 28 are embedded in the foil end disk 11. This cartridge cover furthermore has a centring aid 29. This centring aid can also be combined with a not illustrated bayonet closure. With this exemplified embodiment the filter medium 16 consists of star-folded filter paper.

From Figure 3 it can be noted how the cartridge cover 28 is put into the mould 12.

The centring takes place by an inner ring wall 21, the inserting of the cartridge cover 28 being facilitated by a chamfer 30 at the upper end of the inner ring wall 21. The centring of the filter medium 16 does not take place by the mould, but by the cartridge cover 28. The latter is made partly conical so as to form an inserting aid 31. As a result of this shape, when the filter medium 16 is put onto the foil blank 14a, it slips automatically into the inside centring 31 created by the cartridge cover 28.

Claims

@® - Claims

1. Process for manufacturing filter cartridges, in particular round filter cartridges comprising at least one foil end disk, with which - a filter medium is bonded to a foil blank placed in a mould in such a way that an end surface of the filter medium rests directly on the surface of the foil end disk, - the filter medium is fixed in this position, so that no relative movement is possible between the filter medium and the foil blank, - the foil blank is heated, so that it expands mainly in the direction of the end surface and encloses this surface completely and in this way forms the foil end disk, - the heating is ended as soon as the foil end disk has hardened sufficiently, wherein, prior to heating the foil blank, an insert is fixed in a holder provided for same in the mould, when by the formation of the foil end disk the inset is fixedly bonded to the filter cartridge.

2. Process according to claim 1, in which the filter medium is ring-shaped formed froin star foided niter paper and a ring-shaped end surface of the } filter medium_rests.on. the-surface-of-the. foil-end- disk.

3. Process according to claim 1 or claim 2, in which the insert, after it has been fixed in the mould, projects partly out of the mould.

4. Process according to any one of the preceding claims, in which the putting in of the filter medium is facilitated by an inserting aid integrated in the insert.

PCT/EP99/07829 insert, which inserting aid is formed by a conical area which co-operates with the inside edge of the end surface of the cylindical filter medium.

5. Filter cartridge comprising at least one foil end disk, wherein a substantially flat additional filter is embedded in the foil end disk.

6. Filter cartridge as claimed in claim 5, in which the additional filter is in the form of wire grating.

7. Filter cartridge comprising at least one foil end disk, wherein a centering aid is embedded in the foil end disk in order to simplify the installation in the associated housing of the filter cartridge.

8. Filter cartridge comprising at least one foil end disk, wherein the foil end disk is formed by two superposed foil blanks, between which an insert is embedded.

9. Filter cartridge as claimed in claim 8, in which the insert is a seal.

10. A process according to ciaim 1, substantially as herein described and - --illustrated-

11. A cartridge according to claim 5 or claim 7 or claim 8, substantially as herein described and illustrated.

12. Anew process for manufacturing a cartridge, or a new cartridge, substantially as herein described. : AMENDED SHEET