DE102005034603A1 - Filter device, in particular particulate filter for an exhaust system of an internal combustion engine - Google Patents

Abstract

A filter device (16), in particular a particle filter for an exhaust system of an internal combustion engine, filters particles out of a gas flow (26). It comprises a housing (17) and a filter structure (22) with a plurality of filter pockets (24). It is proposed that at least one resilient damping element (46, 48) rests on the filter structure (22) under prestress.

Description

The The invention relates to a filter device, in particular a particle filter for a Exhaust system of an internal combustion engine, after the Obergebriff of the claim 1.

A filter device of the type mentioned is from the DE 102 23 452 A1 known. The filter device shown there is a particle filter for an exhaust system of a diesel internal combustion engine. The filter walls in the known filter device are made of sintered metal and arranged so that wedge-shaped filter bags are formed. The tapered wedge edges of the filter pockets show against the flow direction of the exhaust gas, seen in the flow direction rear narrow side of a filter side is open.

The Filter bags are arranged side by side so that a total of annular Filter structure is formed. The individual filter bags are kept at their respective axial ends. During operation, the exhaust gas passes through the side walls the filter bags through, which contained in the exhaust soot particles retained become.

task The present invention is a filter device of the above so-called type so that they have a long life having.

These Task is performed by a filter device with the characteristics of Claim 1 solved. Advantageous developments are specified in subclaims.

Advantages of invention

By doing at least one resilient damping element on the filter structure is applied to the housing transmitted to the filter structure vibrations only attenuated. The filter structure is thus exposed only to reduced vibration loads, which is cheap affects their life.

By a jamming of the damping element can complex additional Haltestrukturen be avoided, which simplifies the production.

Especially suitable is a damping element, which comprises a wire mesh or made of such a knitted fabric is because such a high temperature resistant metal wire manufactured and by selecting the wire thickness and the density of the Metal knit the spring characteristics very well to the individual Requirements can be adjusted. A manufacturing process for a ring-shaped damping element For example, it consists first of a wire hose through Knitting produce, and this then in the axial direction on a Press mold core in shape.

there is within a single damping element also the combination of wire knits of different stiffness possible. For example, a "core" of the damping element be made of a wire mesh of high rigidity, whereas the outboard Contact area made of a wire mesh with less rigidity is made. In this way we realized a "softer" storage of the filter bags.

by virtue of the most cylindrical configuration of the filter structure and the housing the filter device is an annular ausgestaltetes damping element especially effective. Especially in such a ring can recording sections be introduced, in which the corresponding edge regions of individual Filter bags form-fitting are included. Vibrations of the filter bags are on this Way particularly well muted, without high surface forces occur at the contact points.

For the assembly it is helpful if a ring-shaped damping element is formed with a slot, since it is in this case for mounting, for example can be expanded. By obliquely designed wall surfaces in Area of the slot will be an interruption of contact with the casing and the filter structure prevents or at least reduces. Nevertheless a rich fitting damping element To ensure the filter structure and / or the housing, the inherent elasticity of the damping element supported by a spring element become.

By the arrangement of a damping element in the axial center of the filter structure, or by the arrangement several damping elements in axial direction can Natural frequency and associated Vibration amplitudes favorable to be influenced. This is especially true with a support in about about the entire axial length the filter structure. To the desired Position of the damping element over the can ensure the entire life of the filter device this, for example, by beads on the housing or on the filter structure be held axially. Such beads may be used in the formation of the filter structure or of the housing on simple and inexpensive Way be introduced.

drawings

following become particularly preferred embodiments the present invention with reference to the accompanying Drawing closer explained.

In show the drawing:

1 a schematic representation of an internal combustion engine with a filter device;

2 a partial longitudinal section through a portion of the filter device of 1 ;

3 a perspective view of some elements of 2 ;

4 a plan view in the axial direction of the in 2 shown portion of the filter device;

5 a plan view of a damping element of the filter device of 1 ;

6 a plan view of another damping element of the filter device of 1 ;

7 a plan view of an alternative embodiment of a damping element;

8th a plan view of yet another alternative embodiment of a damping element;

9 a side view of yet another alternative embodiment of a damping element; and

10 a side view of yet another alternative embodiment of a damping element.

description the embodiments

An internal combustion engine carries in 1 Overall, the reference number 10 , It includes an engine block 12 and an exhaust pipe 14 in which a filter device 16 is arranged. This serves in particular to filter out soot particles from the exhaust gas flow. The filter device 16 includes a housing 17 with an outer housing 18 , and one in 1 only dash-dotted inner tube 20 , which is an area of the housing 17 is.

Like from the 2 and 3 shows is in the inner tube 20 a filter structure 22 held. This includes a plurality of wedge-shaped filter bags 24 of which in 3 for purposes of illustration only one is shown. The filter bags 24 have one opposite to the flow direction (arrow 26 ) tapered closed end 28 , and one in the flow direction 26 seen back narrow side 30 that is open. Radial inside are filter walls 31a and 31b to each other (reference numeral 32 ), whereas on the radially outer side they are initially spaced apart before they reach the narrow side 30 in a rounding 36 merge. The filter bag 24 are made of a porous sintered metal.

That in the direction of flow 26 seen the rear end 30 the filter bags 24 is through an outer ring 38 and an inner ring 40 held. The outer ring 38 is in turn with the inner tube 20 welded. Also the connection of the outer ring 38 with the filter bags 24 as well as the inner ring 40 with the filter bags 24 done by welding. With the inner ring 40 is a lid-like end flange 42 connected.

That in the direction of flow 26 seen front end 28 the filter bags 24 is with a only in 2 shown retaining ring 42 welded, which is about half the radial height of the filter bags 24 attacks. The retaining ring 42 is about a holding structure of no interest here 44 also with the inner tube 20 rigidly connected.

In operation, the filter structure 22 flows through the exhaust gas in the flow direction 26. The exhaust gas flow passes through the filter walls 31a and 31b passing through, being on the outside of the filter bags 24 deposit soot particles contained in the exhaust stream. The purified gas stream occurs at the open narrow sides 30 the filter bags 24 from the filter structure 22 out.

To vibrations of the individual filter bags 24 to reduce, includes the filter structure 22 a radially inner damping element 46 , and a radially outer damping element 48 , The inner damping element 46 is designed as a closed ring, which is made of a knitted wire. At the in 2 illustrated variant of a filter structure 22 is the inner damping element 46 simply in through the radially inner edges 32 the filter bags 24 formed opening 50 inserted, and it is biased with its radially outer boundary surface 52 on the inner edges 32 the filter bags 24 at. In the axial direction of the filter structure 22 seen is the inner damping element 46 , in flow direction 26 seen, about one third of the length of the filter structure 22 , In this position, the inner damping element 46 by radially extending tabs 54a and 54b held on some or all filter bags 24 available.

At the in 3 shown variant of a filter structure 22 is the inner damping element 46 on a pipe 56 deferred, which is from the inner ring 40 extends out. In this case, the inner damping element 46 also under pretension between the inner tube 56 , which ultimately as the housing 17 belonging to, and the filter structure 22 jammed.

The outer damping element 48 is also made of knitted wire and in the form of a ring between the curves 36 the filter bags 24 and the inner tube 20 jammed. Here are the curves 36 the filter bags 24 positively in corresponding receiving sections 58 the outer damping element 48 added. For axial retention of the outer damping element 48 are in the inner tube 20 two beads 60a and 60b available.

The basic principle of the vibration-damping support of the filter bags 24 (For illustrative reasons, only one is provided with a reference numeral) by the damping elements 46 and 48 is in again 4 which provides a simplified axial view of particularly essential components. One recognizes from this representation as well as from the representation in 5 in which the outer damping element 48 shown enlarged again that the existing in this receiving sections 58 represent even more pronounced recesses than in the 3 illustrated damping element 48 , As a result, vibrations of the filter bags 24 as well as their filter walls 31a and 31b particularly effective steamed.

Alternative embodiments of damping elements are in the 6 . 7 and 8th the example of an inner damping element 46 shown: In all three variants is the annular damping element 46 with a slot 62 provided in the manner of a clamping ring. The facing boundary surfaces of the slot 62 carry in the 6 to 8th the reference numerals 64a and 64b , Between a radius line 66 and the boundary surfaces 64 An angle A is present.

By the presence of the slot 62 can the damping element 46 when mounting in the in 2 For example, shown use case are elastically compressed so that it easily in its axial position between the two tabs 54a and 54b can be brought. Due to its spring elasticity, the damping element relaxes 46 again, when it is positioned, leaving it under tension on the inner edges 32 the filter bags 24 is applied and can effectively dampen vibrations there. To support these elastic spring properties can, as out 7 shows, in the damping element 46 a spring element 68 be incorporated, for example in the form of a spring plate.

This in 8th shown damping element 46 has a first section forming a "core" 70 of a wire knit having a first stiffness and a second portion forming a "wrap" 72 from a knitted wire with a second stiffness. The serving 72 forming wire mesh is softer (lower stiffness) than that of the core 70 , This allows the wrapper 72 to the inner edges 32 the filter bags 24 adapt or "cling", resulting in a correspondingly soft or gentle storage of the filter bags 24 leads, at the same time still sufficient bias, from the core 70 provided. The lower stiffness of the envelope 72 can be provided, for example, by using a thinner wire knit and / or a lower density wire knit. The serving 72 can only on the radial outside of the core 70 be provided, as in 8th is drawn, or even the core surrounded on all sides.

In the 9 and 10 is another variant of an inner damping element 46 shown: In this extends the inner damping element 46 over about the entire length of the filter structure 22 and in this respect replaces the one in 3 shown pipe 56 , One recognizes 9 in that in this case the inner damping element is made of a comparatively coarse wire mesh, so that a "porous" tube 56 is formed. An area of such a pipe 56 is in 2 indicated on the right.

By such over the entire axial length of the filter structure 22 extending inner damping element 46 become the inner edges 32 the filter bags 24 particularly evenly supported. An alternative to this are several damping elements 46 with a small axial extent, over the axial length of the filter structure 22 are arranged distributed. As with the in 8th shown damping element 46 can also do that in 9 shown damping element 46 a rather stiff core 70 and a rather soft serving 72 exhibit, as in

10 is indicated.

Claims (12)

Filter device ( 16 ), in particular particulate filter for an exhaust system ( 14 ) an internal combustion engine ( 10 ), which particles from a gas stream ( 26 ) filters out, with a housing ( 17 ), and with a filter structure ( 22 ) with a plurality of filter bags ( 24 ), characterized in that on the filter structure ( 22 ) at least one resilient damping element ( 46 . 48 ) is applied under prestress. Filter device ( 16 ) according to claim 1, characterized in that the damping element ( 46 . 48 ) between the housing ( 17 ) and the filter structure ( 22 ) is jammed. Filter device ( 16 ) according to one of claims 1 or 2, characterized in that the damping element ( 46 . 48 ) comprises a wire mesh. Filter device ( 16 ) according to claim 3, characterized in that the damping element ( 46 ) a first section ( 70 ) with a wire mesh having a first stiffness and a second portion ( 72 ) comprising a wire knit having a second stiffness. Filter device ( 16 ) according to one of the preceding claims, characterized in that the filter structure ( 22 ) an overall cylindrical outer contour and the housing ( 17 ) a corresponding, radially outside of the filter structure ( 22 ) area ( 20 ), and that the damping element ( 48 ) annular and between the filter structure ( 22 ) and the outdoor area ( 20 ) is jammed. Filter device ( 16 ) according to one of the preceding claims, characterized in that the filter structure ( 22 ) a radially inner and axially extending opening ( 50 ) and the housing ( 17 ) a corresponding radially inwardly of the opening area ( 56 ), and that the damping element ( 46 ) annular and between the filter structure ( 22 ) and the interior ( 56 ) is jammed. Filter device ( 16 ) according to one of claims 5 or 6, characterized in that the damping element ( 48 ) on its the filter bags ( 24 ) facing side receiving sections ( 58 ) for preferably positive reception of the damping element ( 48 ) facing edge regions ( 36 ) of the filter bags ( 24 ) having. Filter device ( 16 ) according to one of the preceding claims, characterized in that the damping element ( 46 ) as a clamping ring with a slot ( 62 ) is formed whose boundary surfaces ( 64 ) against a radius line ( 66 ) preferably have an angle (A). Filter device ( 16 ) according to claim 8, characterized in that the damping element ( 46 ) a spring element ( 68 ), in particular a spring plate having. Filter device according to one of the preceding Claims, characterized in that, seen in the axial direction, a Plurality of similar damping elements available. Filter device ( 16 ) according to one of the preceding claims, characterized in that at least one damping element ( 46 ) over approximately the entire axial length of the filter structure ( 22 ). Filter device ( 16 ) according to one of the preceding claims, characterized in that the damping element ( 46 ; 48 ) by at least one holding section ( 54 ; 60 ), in particular a bead, is axially supported, on the housing ( 20 ) and / or the filter structure ( 22 ) is available.