FILTER ELEMENT

Abstract

A filter element, at least consisting of a filter mat web (10), the free, mutually adjacent web ends (12) of which are joined along a joint (16), forming a hollow body, is characterized in that the joint (16) is made of at least one connecting part (18), which is provided with groove-shaped receiving channels (20, 22), each of which is used to receive one web end (12) of the filter mat (10).

Claims

1. A filter element, at least consisting of a filter mat web (10), the free, mutually adjacent web ends (12) of which are joined along a joint (16), forming a hollow body, characterized in that the joint (16) is made of at least one connecting part (18), which is provided with groove-shaped receiving channels (20, 22), each of which are used to receive one web end (12) of the filter mat (10).

2. The filter element according to claim 1, characterized in that the connecting part (18) extends along the entire axial length of the hollow body-like filter mat web (10).

3. The filter element according to claim 1, characterized in that the depth of the respective receiving channel (20, 22) is selected to accommodate the assignable web end (12), formed from the last filter pleat of the filter mat web (10), which opens out into the interior of the hollow body.

4. The filter element according to claim 1, characterized in that the respective web end (12) consist of a strip-shaped end piece (26, 28), which is adjoined at each end by a longitudinal edge of the filter material of the filter mat web (10).

5. The filter element according to claim 1, characterized in that a receiving channel (20, 22) is provided in the connecting part (18) for the two web ends (12) each, which receiving channels (20, 22) extend in parallel to each other away from the interior of the filter element outwards toward the environment.

6. The filter element according to claim 1, characterized in that the connecting part (18) is preferably an integral component of an at least partially fluid-permeable support tube (32), against which the preferably pleated filter mat web (10) rests towards the interior.

7. The filter element according to claim 1, characterized in that the receiving channels (20, 22) have a step-shaped offset relative to each other in the direction of the formed hollow body such that, viewed along the circumference, the web ends (12) open into the respective receiving channel (20, 22) at different level positions relative to each other.

8. The filter element according to claim 1, characterized in that there is a preferably elastically yielding, fluid-permeable jacket film (56) on the outer circumference of the pleated filter mat web (10), wherein said jacket film (56) allows the mat web (10) to be stretched on the support tube (32) as soon as the web ends (12) are secured in the receiving channels (20, 22) of the connecting part (18).

9. The filter element according to claim 1, characterized in that the two opposite, front ends of the filter mat web (10) are provided with an end cap (60).

10. The filter element according to claim 1, characterized in that a strip-shaped sealing web (70) is folded into at least one free end face end area of the filter mat web (10), which sealing web (70) seals the interior of the element with respect to the environment when the end cap (60) is fitted.

Description

[0014] Below, a filter element according to the invention will be explained in more detail with reference to the drawing. In the figures, in general view, not to scale,

[0015] FIG. 1 shows a schematically simplified cross-section of essential parts of the filter element according to the invention;

[0016] FIG. 2 shows, magnified in relation to FIG. 1, a partial cross-section of the area designated by A in FIG. 1; and

[0017] FIG. 3 shows a schematically simplified partial longitudinal section of the filter element according to the invention of FIG. 1.

[0018] FIGS. 1 and 2 show a cross-section through a filter element according to the invention, having a filter mat web 10. The free, adjacent web ends 12 of the filter mat web 10 are joined to form a hollow body at a joint 16. The joint 16 is formed by a connecting part 18, which is provided with groove-shaped receiving channels 20, 22. Every receiving channel 20, 22 is used to receive one web end 12 of the filter mat web 10.

[0019] Laid out flat, the filter mat web 10 is rectangular in shape with two parallel longitudinal sides and two parallel transverse sides that are shorter than the longitudinal sides. Fashioned into a hollow body, the longitudinal sides match the end faces 24 of the filter mat web 10. Viewed in the longitudinal direction, the respective web ends 12 of the filter mat web 10, i.e. their respective transverse ends, are formed as a first 26 and a second 28 strip-shaped end piece. The two end pieces 26, 28 may be molded onto the respective end 12 of the filter mat web 10 or prefabricated from thermoplastic material and each welded to the respective end 12 of the filter mat web 10. An edge of the filter material 30 of the filter mat web 10 adjoins the respective end pieces 26, 28 of the filter mat web 10, wherein the filter material 30 interconnects the two end pieces 26, 28. The filter mat web 10 is pleated.

[0020] The connecting part 18 is an integral part of an at least partially fluid-permeable support tube 32 for supporting the filter mat web 10. The support tube 32 is made from an almost completely circular tubular body 34, from the circumferential side of which a first 38, a second 40 and a third 42 rib extend outwards, which are of basically equal length in that direction. The three ribs 38, 40 42 extend in parallel to each other and in the axial direction across at least the perforated area of the tubular body 34 and the entire axial height of the filter mat web 10. A first receiving channel 20 for engaging the first strip-shaped end piece 26 is formed between the first 38 and the second 40 rib, and a second receiving channel 22 for engaging the second strip-shaped end piece 28 is formed between the second rib 40 and the third rib 42. The respective receiving channel 20, 22 are basically U-shaped when viewed in cross-section. The three ribs 38, 40 42 and at least the part connecting the three ribs 38, 40, 42, of the tubular body 34 in conjunction form the connecting part 18. The respective receiving channels 20, 22 are designed in such a way that at least the respective strip-shaped end piece 26, 28 can be completely accommodated therein in a latching manner.

[0021] If the filter mat web 10 is connected to the support tube 32, in which the first end piece 26 is secured in a latching manner in the first receiving channel 20 and the second end piece 28 is secured in a latching manner in the second receiving channel 22, the end facing the tube body 34, of the pleated filter mat web 10 is supported indirectly or directly strip-shaped in the area of the pleat valleys 46 of its filter material each on the outer circumference 44 of the tube body 34. To this end, the respective end area having the end pieces 26, 28, of the filter mat web 10, as viewed in the direction of the respective end of the respective end area, starting from its last pleat valley 48, first extends in the direction away from the interior of the support tube along the side facing away from the second rib 40, of the first 38 and third 42 rib and then opens into the respective receiving channel 20, 22, forming its last pleat crest 50 in the direction of the interior of the support tube.

[0022] The tubular body 34, as viewed in cross-section, has a spiral or helical shape while forming a step 52, which connects a strip-shaped area of the smallest radius of the tubular body 34 to a strip-shaped area of the largest radius of the tubular body 34. The second rib 40 extends radially outwards away from the tubular body 34 in a strip-shaped area of the outer circumference 44 of the tubular body 34, in which area the tubular body 34 has its largest radius, such that the second rib 40 is aligned with the step 52 of the tubular body 34 on both sides. The first rib 38 extends outwards away from the tubular body 34 in a strip-shaped area of the outer circumference 44 of the tubular body 34, in which area the tubular body 34 has a radius slightly smaller than the largest radius, such that the free ends of the first rib 38 and second rib 40 are substantially flush with each other. The third rib 42 extends outwards away from the tubular body 34 in a strip-shaped area of the outer periphery 44 of the tubular body 34, in which area the tubular body 34 has a radius slightly larger than its smallest radius. Therefore, the base 54 extending in parallel to the inner circumference of the tube body 34, of the second receiving channel 22 and the free end of the third rib 42 in the direction of the support tube interior each have an offset from the base 54 extending in parallel to the inner circumference of the tube body 34, of the first receiving channel 20 and the free ends of the first 38 and second 40 ribs, respectively. These offsets essentially correspond to each other and to the height of the step 52 of the tubular body 34.

[0023] As a result, viewed in the radial direction, the two web ends 12 of the filter mat web 10 open into the respective receiving channel 20, 22 at different levels relative to each other.

[0024] On the side facing away from the support tube 32, of the filter mat web 10 an elastically yielding and fluid-permeable jacket film 56 extends between the two end pieces 26, 28 across the pleated filter mat web 10 in such a way that the jacket film 56, resting against all pleat peaks 58 of the pleated filter mat web 10, radially pre-loads the filter mat web 10 in the direction of the tubular body 34 of the support tube 32. For this purpose, the rectangular jacket film 56, laid out flat, at least in the longitudinal direction is shorter than the rectangular filter mat web 10 laid out flat. The pretensioning effect results as soon as the end pieces 26, 28 are secured in the receiving channels 20, 22 of the connecting part 18. The two end pieces 26, 28 may be molded onto the end 12 of the jacket film 56, just as they are molded onto the filter mat web 10, or they may be prefabricated from thermoplastic material and each welded onto the end 12 of the filter mat web 10. The jacket film 56 may be provided with information and/or have a punched hole.

[0025] As FIG. 3 shows, the filter mat web 10 is provided with a commonly formed end cap 60 at each of its two opposite, front ends. The axial thickness of the respective end cap 60 increases radially outwards from its longitudinal axis while forming two steps 62, 64, wherein the outer step 64 is formed by a wall 64 extending axially away from a respective disk-shaped end cap base body 66. The wall 64 delimits an annular holder 68 for the respective axial end of the filter mat web 10 radially outwards, which is radially inwards delimited by the respective end cap 60.

[0026] If the support tube 32 and the pleated filter mat web 10 are arranged in combination with the jacket film 56 between the two end caps 60, the support tube 32, which is free of perforations in this area, on the outside in the two end areas of its outer circumference comes into contact with the inner step 62 of the respective end cap 60, and the filter mat web 10 comes on its inside into contact on the outside of the support tube 32 and on its outside on the outer step 64, i.e. the wall. The jacket film 56 is formed such that it is spaced apart from the outer wall 64 of the respective end cap 60 in the axial direction.

[0027] On the end facing the support tube 32, of the filter mat web 10, an elastic and strip-shaped sealing web 70 is folded into each of the free end edge areas of the lateral surface of the filter mat web 10, which sealing web 70 seals the pleats of the filter mat web 10 from each other and from the first and third ribs, respectively, as well as sealing the filter mat web 10 inwards in the radial direction from the support tube 32, which is free of perforations in this area. The sealing web 70 may be attached to the face edge areas of the side surface of the filter mat web 10 prior to a sealing operation of the filter mat web 10 or after a sealing operation. The sealing web 70 seals the interior of the filter element from the environment when the end caps 70 are in place. It is also conceivable that, alternatively, a sealant is provided which is applied for this purpose to the free end face areas of the filter mat web 10 by means of a proportioning system.