EP2898196A1 - Bag for insertion into a cavity of a silencer, which cavity is intended for sound damping - Google Patents

Description

 Bag for insertion into one for soundproofing

 certain cavity of a muffler

The invention relates to a bag for insertion into a

Soundproofing certain cavity of a silencer, a set of such bags, a silencer with such bags as well

corresponding method for producing the aforementioned.

A silencer is a device for reducing

Sound emissions. There are different types of silencers that produced due to different mechanisms of action

 Reduce sound power. An absorption silencer contains porous material, usually rockwool, glass wool or fiberglass, which the

Sound energy partially absorbed, that is, converted into heat. The effect of sound absorption is enhanced by the multiple reflection. The invention particularly relates to such mufflers. such

 Silencers for internal combustion engines, in particular of vehicles or trucks, have a perforated inner tube for passing the exhaust gases. This is in an outer air, dirt and moisture-proof

Guided jacket, so that forms a cavity between the inner tube and sheath. This is filled with a sound-absorbing or -absorbierenden filling. This must be heat resistant. The filling of the cavity is complex and it is therefore on prefabricated flexible or more or less dimensionally stable elements with

Sound-absorbing filling used.

For example, are dimensionally stable glass fiber basalt wool and

Multi-component moldings are known, which contain flammable components to retain the mold, which burn off during the first use of the muffler.

Pouches are known for insertion into a cavity of a silencer with an all-round side for soundproofing or absorption closed envelope, with a sound-absorbing or -absorbierenden filling, wherein the envelope consists of plastic films or nets. After filling these are welded. WO 2005/049982 discloses a bag for insertion into a cavity intended for sound absorption or absorption

Silencer with a knitted tubular casing and with a sound-absorbing or absorbing filling, the casing being made of glass fibers. The filling is introduced into the shell and the shell is then closed at its ends. It is not disclosed to make certain 3D shapes.

DE 203 05 409 U discloses a bag for insertion into a cavity intended for sound absorption or absorption

Silencer with a hose-like non-heat-resistant casing and with a sound-absorbing or absorbing filling. The filling is introduced into the shell and the shell is then closed at its ends. It is not disclosed to make certain 3D shapes. The shell burns during operation of the muffler.

US 6,068,082 discloses a grid-like element for insertion into a cavity intended for sound absorption or absorption

Silencer with a heat-resistant casing and with a

sound-absorbing or absorbing filling. The filling is introduced into the shell and the shell is then closed.

GB 2 267 731 discloses a flexible bag for insertion into a cavity of a soundproofing or absorption cavity

Silencer with a fusible shell and with a

sound-absorbing or absorbing filling. It is u.a. disclosed to place the bag around the inner tube of the muffler.

It is an object of the invention to provide an improved bag for insertion in a cavity of a muffler or a muffler provided therewith. This object is achieved by a bag having the features of the main claim. A set of such bags, a muffler with such bags and corresponding methods for producing the above are the subject of the independent claims.

Advantageous developments are the subject of the dependent claims.

As already known from the prior art, includes

proposed pouches for insertion into a cavity of a silencer intended for soundproofing or absorption, first a shell closed on all sides with a shell enclosed therein

sound-absorbing or absorbing filling. Under one

closed envelope according to the invention is not a dense, for example, water, dirt or pressure-tight understood, such as a film. The term "closed" simply means that the envelope during transport, during normal handling and when inserted into the cavity of the muffler in the manufacture of the same

impermeable to the filling placed therein. The

inventive feature now consists in that the shell consists of glass fibers and the filling is blown through the envelope of the bag into the interior of the bag. Thus, it is possible for the first time to provide a compact filling for labor-saving insertion into the cavity of a muffler, which releases no toxic combustion gases when first using the muffler. For the production of the bag while fewer steps are needed because the bag does not need to be closed after filling.

Another aspect of the invention, which can be implemented independently of or in conjunction with the invention described above, is that in the generic bag, the all-sided closed envelope has bushings. This allows adaptation to the geometry in the interior of the cavity, for example at indentations. The above-mentioned implementation in the shell can therefore absorb the indentation. It is therefore not manual customization

Pressing / inserting individual bags needed. Preferably, however, the implementation of the outer cross section of the inner tube of the Muffler adapted †. The bags can then simply be pushed over the inner tube. In the prior art, however, it was necessary to wrap individual bags around the inner tube or to lay several bags around the inner tube. This aspect of the invention, irrespective of the material used, the shell, that is also known from the prior art, the above-mentioned bags z. B. plastic, can be realized.

The following advantageous embodiments apply to both

inventions:

If the envelope is essentially made of meshed glass fibers,

especially a glass fiber knit, there is an expandable and malleable shell. One of the advantages of this construction is that closed casings, which do not need to be welded, sewn or closed separately, can be manufactured in a single operation. It is therefore a feature that the sheath is free of sutures. As a knitted fabric are textile fabrics

in which a loop formed by means of thread is looped into another loop. The resulting stitches may be formed using one or more threads.

The mesh size or size of the meshed glass fibers is therefore to be chosen so that the components of the filling are initially well inflated by a mesh of the shell and usually after the

Blowing an increased volume filling after blowing can not fall out through the mesh.

The mesh size is therefore preferably 2-9 mm, in particular 2.5-5 mm and in particular preferably 3 mm.

Preferably, the sheath closed on all sides by a single working method, in particular knitting, preferably on one

Flat knitting machine, made. Flat knitting machines make it possible to produce complex structures, for example pullovers or closed pouches. Also, when knitting at desired locations other, even higher temperature resistant threads are used. Known from the prior art glass fiber sheaths are on

Circular knitting machines manufactured and therefore on hose forms

limited and must be manually or in a further step

be closed.

If the shell has a shape adapted to the cavity, the cavity is particularly densely filled with the filling, without laborious stuffing, fitting, impressions is necessary. Therefore, the sheath may preferably have over its length, width and / or height variable cross-sections, in particular steps, curves, bulges, constrictions and / or indentations. From the prior art, only comparatively simple, tubular or pillow-like forms have hitherto been known.

Preferably, the filling consists wholly or partly

heat-resistant rovings, fibers or yarns. These allow the inventively preferred blowing into the closed envelope of the bag. Roving is a bundle, strand or multifilament yarn made from parallel filaments used predominantly in the manufacture of fiber reinforced plastics (FRP) or fiber reinforced plastics, a sub-group of composites. The cross-section of a roving is usually elliptical or rectangular. However, there are also rovings with a slight

Protective rotation (e.g., 10 turns / m), thereby making the cross section more round. Most commonly filaments of glass, aramid or carbon are grouped into rovings. These are easy to inflate, z. B. by a mesh of the shell and increase its volume after blowing, so that they can not fall out through the mesh.

Because of its high heat resistance, the filling is preferably made of glass or basalt materials. Preferably, the shell and / or the filling are heat resistant in the range of 400-1300 ° C, preferably 450-1100 ° C. The materials used are preferably E glass, silica, glass fibers with Si0 ₂ content greater than 75%, ECR glass, S glass, C glass. Preferably, the shape of the bag is to the cavity of a

Muffler adapted so that the cavity can be filled well, without manual plugging or fitting is necessary. It is further proposed to provide a set of the bags described above, the shapes of which are such that together they can fill the cavity of a muffler. Similar to a puzzle so each bag has its predetermined place and is adapted to this and the adjacent bags. Therefore, in cramped conditions, for example with undercuts,

labor-saving the fillings are used. For this purpose, each bag is preferably designed such that it has a shape adapted to a specific area of the cavity. Furthermore, a complete muffler is claimed using the bags made according to the teachings described above. This muffler, especially for internal combustion engines, preferably for vehicles or trucks, has a perforated inner tube for passing

Exhaust gases, an outer air, dirt and moisture density

Sheath, a cavity formed between the inner tube and sheath on. In this case, one or more bags are preferably arranged in the cavity, wherein in particular the cavity is completely filled. Furthermore, one or more bags can be arranged with passages in the cavity, wherein the inner tube through the

Passage in the shell runs.

The inventive method for producing the above

described bag has the following steps in the order given:

- Producing the all-sided closed envelope of glass fibers by a single method, in particular knitting, preferably on a flat knitting machine, preferably no stitching takes place;

- Blowing a sound-absorbing or -absorbierenden filling through the envelope of the bag into the interior of the bag. So it is not a separate step for sewing the bag

Introducing the filling necessary.

The method according to the invention for producing a silencer comprises the following steps:

- Carrying out the above-described method for producing a bag

 - Inserting the bag in the cavity formed between the inner tube and the jacket of the muffler, in particular to the predetermined position for each bag, to which the shape of the bag is adapted.

Further advantages will become apparent from the following description and the accompanying figure. Likewise, according to the invention, the features mentioned above and even further can be used individually or in any desired combinations with one another. The mentioned embodiments are not exhaustive and have exemplary character.

FIG. 1 shows the pouch 1 according to the invention for insertion into a cavity of a soundproofing or absorption cavity

Silencer. Its all-sided closed glass fiber sheath 2 is made by means of a working method on a flat knitting machine and was not sewn. Inside the shell 2 is a

Sound absorbing or absorbing filling 3. This was blown through the shell, that is through a mesh of the fabric forming the shell into the interior of the bag. The closed on all sides sheath 2 has inside a passage 21 for pushing through the inner tube of the muffler. their

Diameter is therefore adapted to the outer cross section of the inner tube of the muffler.

Claims

 Cuylits Holding GmbH claims Bag (1) for insertion into a cavity of a muffler intended for sound damping or absorption, with a cover (2) closed on all sides, with a sound-absorbing or absorbing filling (3),  wherein the sheath (2) consists essentially of intermeshed glass fibers, in particular a glass fiber knit. characterized in that the filling (3) is blown through a mesh in the envelope of the bag into the interior of the bag. Bag (1) according to claim 1, characterized in that the cover (2) closed on all sides has feedthroughs (21) which are preferably connected to the outer cross section of the inner tube of the  Muffler are adapted and preferably the sheath (2) consists of glass fibers. Bag according to claim 1 or 2, characterized in that the mesh size of the meshed glass fibers is 2 - 9 mm,  in particular 2.5 to 5 mm and in particular preferably 3 mm. Bag according to one of the preceding claims, characterized  characterized in that the sheath is free of seams. Bag according to one of the preceding claims, characterized in that the cover closed on all sides is produced by a single working method, in particular knitting, preferably on a flat knitting machine. , Bag according to one of the preceding claims, characterized  characterized in that the shell has a shape adapted to the cavity and in particular over its length, width and / or height variable cross sections, in particular steps, curves, bulges, constrictions and / or indentations. , Bag according to one of the preceding claims, characterized  in that the filling comprises or consists of heat-resistant rovings, fibers or yarns, in particular of glass or basalt, wherein preferably the casing and / or filling are heat-resistant in the range of 400-1300 ° C, preferably 450-1100 ° C. , Bag according to one of the preceding claims, characterized characterized in that the filling comprises as materials E glass, silica, glass fibers with Si0 ₂ content greater than 75%, ECR glass, S glass, C glass. , Bag according to one of the preceding claims, characterized  characterized in that the shape of the bag is adapted to the cavity of a muffler. 0. Set of bags according to one of the preceding claims, whose shapes are such that together they form the cavity of a  Fill each muffler, preferably each bag is formed so that it has a shape adapted to a specific area of the cavity. 1. Silencer, in particular for internal combustion engines, preferably for vehicles or trucks, with a perforated inner tube for passing exhaust gases, an outer air, dirt and moisture-tight sheath, a formed between inner tube and sheath cavity, characterized in that in the cavity or a a plurality of bags are arranged according to one of the preceding claims 1-9, wherein preferably the cavity. 12. Silencer, in particular for internal combustion engines, preferably for vehicles or trucks, with a perforated inner tube for passing exhaust gases, an outer air, dirt and moisture-tight sheath, a between inner tube and Sheath formed cavity, characterized in that in the cavity a set is arranged according to claim 10, wherein preferably the cavity is completely filled. 13. Silencer, in particular for internal combustion engines,  preferably for a motor vehicle or truck, with a perforated inner tube for passing off exhaust gases, an outer air, dirt and moisture-proof sheath, a cavity formed between inner tube and sheath, characterized in that in the cavity one or more bags are arranged according to claim 2, wherein the inner tube passes through the passage in the shell. 14. A method for producing a bag according to one of  previous claims 1-9, with the following steps:  - Producing the closed-sided envelope of glass fibers in particular by a single working method, in particular knitting, preferably on a flat knitting machine, preferably no stitching takes place;  - blowing a sound-absorbing or -absorbierenden Filling through a loop in the bag's pouch into the interior of the bag. 15. A method for manufacturing a silencer according to any one of claims 11 to 13, comprising the following steps:  - Carrying out the method according to claim 14 for the production of a bag  - Inserting the bag in between the inner tube and  Sheath of the muffler formed cavity,  in particular to the predetermined for the respective bag body to which the shape of the bag is adapted.