Filter element with guide shaft

A Filter element for insertion into a housing of a ventilation unit or air conditioner, comprising a bellows with folds and a front side, which can face a wall of the housing, wherein the folds on the front side define fold cross-sectional surfaces, wherein to the front side at least one guiding slot is assigned and wherein a fold cross-sectional surface has a geometry in the area of a guiding slot that is different from the fold cross-sectional surface of a multiplicity of folds, is, in view of the task of providing an efficient filter element which, after problem-free manufacture is equipped with guiding slots into which guide pins can be inserted, characterized in that a multiplicity of regular fold walls is provided, wherein each two flanking walls flank the guiding slot.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Patent Application No. 10 2011 118 680.1 filed on Jun. 21, 2011 and German Patent Application No. 10 2012 005 188.3 filed on Mar. 16, 2012, the disclosures of which are incorporated by reference herein in their entirety.

FIELD OF THE INVENTION

The invention relates to a filter element for insertion into a housing of a ventilation unit or air conditioner, comprising a bellows with folds and a front side, which can face a wall of the housing, wherein the folds on the front side define fold cross-sectional surfaces, wherein to the front side at least one guiding slot is assigned and wherein a fold cross-sectional surface has a geometry in the area of a guiding slot that is different from the fold cross-sectional surface of a multiplicity of folds, wherein a multiplicity of regular fold walls is provided, wherein each two flanking walls flank the guiding slot.

BACKGROUND

From DE 10 2005 048 841 B3 a filter element is known that is placed in the housing of a ventilation unit of a motor vehicle. Specifically, with this filter arrangement, guide pins of the housing correspond to guiding slots in the filter element.

By this means a mechanical coding is to be implemented that ensures that only a filter element suited for the housing is placed into this housing.

The guiding slots are oriented parallel to the fold backs or to the pleating direction of the folds of a folded bellows. In addition, the guiding slots are oriented parallel to the fold walls.

The bellows is hemmed by an edge strip into which passages have been inserted. The guide pins are run through the passages and then extend parallel to the fold walls or the fold backs.

A passage must be chosen to be somewhat larger than the maximum diameter of a guide pin, so that it can be guided with no problems through the passage.

Therefore, when passages are manufactured by stamping, for example, relatively large tools are needed, which are guided between the fold walls. These tools can damage the bellows.

SUMMARY

Therefore the task of the invention is to provide an efficient filter element which is equipped, after manufacture without problems, with guiding slots into which guide pins can be inserted.

According to the invention, it is recognized that a bellows with regularly configured folds must have an irregular configuration in certain locations, to be able to insert guide pins without problems into the filter element. Specifically recognized is that some folds can be deformed and/or provided with larger dimensions or intervals, so that stamping tools can be inserted without problems between the fold walls.

The stamping tools can be used to stamp in sufficiently large passages for the guide pins in an edge strip. Since according to the invention, some fold cross-sectional surfaces have a geometry differing from the regular fold cross-sectional surfaces, the stamping tools can be placed between the fold walls so that they are not damaged. To that extent the invention-specific configuration of the filter element leads to considerable advantages in production of the filter element.

It has further been recognized that the modification advantageously impairs only a few folds in the area of a guide slot, and outside this area, it comes close to not impairing the fold geometry. The fold geometry outside the area of a guide slot can thus be adapted to the particular technical filter requirements. It is conceivable to adapt to pressure losses, to the degree of fraction deposition for certain particles, or to adsorption performances.

The modification described previously of some folds by deformation, alterations in dimensions or intervals, is determined by the geometry of the guide pins. Lastly, it has been recognized that selective modification of fold cross-sectional surfaces permits a technical filter optimization as well as problem-free manufacture of guiding slots.

A multiplicity of regular fold walls is provided, with each two flanking fold walls flanking the guiding slot. This specific configuration ensures that a bellows can be regularly pleated over large areas and only needs to be modified at selected locations. At the selected locations every two flanking fold walls are modified so that they differ from the remaining fold walls. The flanking fold walls are stamped out or shaped so that a stamping tool can be inserted with no problems between the fold walls.

Therefore an efficient filter element results, which after problem-free manufacture is provided with guide slots into which guide pins can be inserted.

Consequently, the problem mentioned initially is solved.

The guiding slot can lie predominantly or completely within the fold cross-sectional surface with another geometry. By this means, a guide pin can be admitted so that the designed height of a filter element can be kept relatively low.

With this as a background, the flanking fold walls could be deformed. Through a deformation, a fold cross-sectional surface in the area of a guide slot can be adjusted so that a tool can be inserted without problems between the fold walls. The deformation can be effected for example by deep-drawing or by thermal treatment.

In the area of a guiding slot, at least one support element could be assigned to the bellows cross-sectional area in the vicinity of a guiding slot. Deformation can also be induced by insertion of support elements. Support elements can especially be used which stabilize a certain fold geometry. One support element can be assigned to a flanking fold wall, or a support element can be assigned to two flanking fold walls. A support element can be configured to be clamp-shaped.

The flanking fold walls could each have two sections angled toward each other. With this specific embodiment, at least one bending location is assigned to a fold wall. Through the bending locations, fold walls are provided with bulges which create room for a stamping tool.

The flanking fold walls could be configured to be arch-shaped. One arch shape can be formed in especially problem-free fashion with a tubelike instrument into the bellows. With this as the background it is conceivable that the tubelike instrument is heated so that the bellows is thermally deep-drawn.

The flanking fold walls could form a rectangular fold cross-sectional surface. A rectangular fold cross-sectional surface can be inserted with especial ease into the bellows by means of a cuboid-shaped instrument.

The flanking fold walls could be inclined at a larger angle to each other than the regular fold walls. By this specific embodiment, between the flanking fold walls, areas are created in which they are placed at a farther interval from each other than the regularly spaced fold walls are.

With this as the background, the flanking fold walls could manifest greater fold-wall height than the regular fold walls. Due to this specific embodiment, a bellows can be created with a unitary field height, but with individual areas in which two flanking fold walls are at a more obtuse angle to each other than the regular fold walls.

The geometry of the fold cross-sectional surface in the area of a guiding slot could also be adjusted by a fanning-out of the bellows. Due to an at least partial bending or distortion of the bellows, the flanking fold walls can suitably be spaced from each other. Thus a bellows can be adapted in cost-effective fashion to the geometric conditions that are preset by the guide pins. The fanned state of the bellows can be secured by the edge strips and/or the side strips.

A filter element with a fan-shaped progression in the area of the passages or stampings can have only a front-side edge strip with a passage or a stamping.

By stampings or passages made in asymmetric fashion, the structure can be made to be secure against torsion. The filter element can be situated in only one position in the housing. A Poka-Yoke system can be created.

DETAILED DESCRIPTION

FIG. 1shows a cuboid-shaped filter element1for insertion in a housing of a ventilation unit or air conditioner, in a perspective view.

Filter element1comprises a bellows2with folds and a front side3which can be turned toward one wall of a housing. The front side3is hemmed by an edge strip4, in which passages5for guide pins are inserted.

In addition, filter element1has side strips6, from which V-shaped securing brackets project. Bellows2is manufactured from a fleece material. The edge strip4is also manufactured from a fleece material. The side strips6along with the V-shaped projecting securing brackets are likewise manufactured from a fleece material.

FIG. 2shows a filter element1for insertion into a housing of a ventilating system or air conditioner, comprising a bellows2with folds and a front side3which can face a wall of the housing, wherein the folds on front side3define fold cross-sectional surfaces and wherein at least one guiding slot8is assigned to front side3. A fold cross-sectional surface9in the area of a guiding slot8has a geometry different from the fold cross-sectional surface7of a multiplicity of folds. This is depicted in an enlarged view inFIG. 3.

FIG. 3shows that in the area of guiding slot8, the fold cross-sectional surface9has a geometry different from the adjoining fold cross-sectional surfaces7of a multiplicity of folds.

A multiplicity of regular fold walls7ais provided, wherein every two flanking fold walls9aflank the guiding slot8.FIG. 3shows that the flanking fold walls9ahave two sections that are angled toward each other. Therefore each of the fold walls9ahas a bending location. The irregular fold cross-sectional surface9in the area of the guiding slot8therefore has a considerably larger surface than the regular fold cross-sectional surfaces7of the multiplicity of folds.

FIG. 4shows a sectional view of an additional filter element1, in which the flanking fold walls9aare deformed. The flanking fold walls9aare configured as arches. They flank guiding slot8.

FIG. 5shows an additional embodiment example of a filter element1. In this filter element1, the flanking fold walls9aform a rectangular fold cross-sectional surface9.

FIG. 6shows an additional embodiment example of a filter element1. With this filter element1, the flanking fold walls9aform a kind of gatelike arch, within which the guiding slot8is placed.

FIG. 7shows another embodiment example of a filter element1, in which the flanking fold walls9aare inclined toward each other at a larger angle than the regular fold walls7a. In this embodiment, fold tip9b, at which the flanking fold walls9aconverge, is placed lower than fold tips7bof the regular fold walls7a.

FIG. 8shows an additional embodiment example of a filter element1with geometric relationships similar to those depicted inFIG. 7. InFIG. 8, the flanking fold walls9aare inclined to each other at a considerably larger angle than the regular fold walls7a.

FIG. 9shows an additional embodiment example of a filter element1in which flanking fold walls9aare inclined to each other at a larger angle than the regular fold walls7a.

Moreover, the flanking fold walls9ahave a greater fold wall height than the regular fold walls7a. It is due to this that the fold tips7bof the regular fold walls7aand the fold tips9bof the flanking fold walls9aare at the same height.

All of the filter elements1described previously have one or more edge strips4, in which or into which passages5are formed for guide pins.

FIGS. 2 to 9show that the guiding slot8lies completely within the fold cross-sectional surface9having a different geometry. However, it is also conceivable to place the guiding slot8into the fold cross-sectional surface9with a different geometry, especially predominantly, so that the design heights of filter elements1remain small.

FIGS. 10 to 12show further embodiment examples of filter elements1, in which the geometry of the fold cross-sectional surface9in the area of a guiding slot8is set by a fanning of bellows2.FIG. 12depicts that a front side3is hemmed by an edge strip4, into which a passage5is made for guide pins.

Filter elements1comprise bellows made of fleece materials. Preferably, filter elements1are configured as combination filters with a particle filter layer and an adsorbent layer.