WO2002066800A1

WO2002066800A1 - Soundproofing material for exhaust silencers that expands at a certain temperature

Info

Publication number: WO2002066800A1
Application number: PCT/IT2002/000077
Authority: WO
Inventors: Gerardo Ciro Esposito
Original assignee: Klevers Italiana S.R.L.
Priority date: 2001-02-13
Filing date: 2002-02-07
Publication date: 2002-08-29
Also published as: ITNA20010011A1; DE60211122D1; DE60211122T2; ITNA20010011A0; EP1360401A1; EP1360401B1; ATE325260T1

Abstract

Soundproofing and lagging material, which has the characteristic to increase its volume with the heat, thanks to fiber glass yarn (1, 2) or other suitable material; the above mentioned yarns (1, 2) are arranged at 90 degree among them, forming a double fiber glass weft. Then are superimposed on the above mentioned weft two other layers of yarn (3, 4) at +45 degree. All these fibers are compacted and hold together by not heat-resistant filament (5).

Description

SOUNDPROOFING MATERIAL FOR EXHAUST SILENCERS THAT EXPANDS AT A CERTAIN TEMPERAT

URE

The present state of art for internal combustion engines' silencer construction in the automotive and motorcycling field, makes a large use of fiber glass because of its excellent soundproofing property. 5 The fiber glass is inserted, during the silencer's working process, in the interspace between the exhaust pipe and the external covering (aluminium, carbon, titanium, steel and similar) simply pressing inside the interspace a predetermined weight of fiber glass or needled mat.

10 This working process doesn't allow an homogeneous and even distribution of the fiber; in other words we may have somewhere an absence of material that could cause an heat escape damaging the silencer' s external covering with the consequent reduction of acoustic efficiency.

15 The present industrial invention purpose is to propose a material that allows a correct disposition and an homogeneous insulation inside the silencer.

The right material for this application has been obtained by the solution idea that is object of the present industrial invention,

20 which consists of a particular weaving process of : fiber glass yarn, treated for high temperature, aramid fiber, synthetic, steel and inconel.

This kind of weaving consists of the disposition of this fiber at 90°, at +45° and at -45°, so that we can obtain a traction and

25 disposition homogeneity and also an even insulation.

The yarns, arranged in this way, are compacted and hold together by synthetic or natural fiber, arranged at variable distance.

The particular yarns and stitching disposition is shown on the enclosed plate.

With reference to it, the fiber glass yarns, arranged horizontally, are indicated with (1); on them are overlapped the yarns (2), made of fiber glass and arranged orthogonally to the precedent yarns .

Then, the yarns (3) and (4) are overlapped on^' the two wefts forming an angle of about +45° and -45° with the horizontal yarn. The yarns so overlapped and compacted are sewed with synthetic or cotton yarns (5), preferably arranged parallel to (1).

The sewing yarn isn't heat - resistant, so, when it is struck by the heat flow, it's burned in a few time, releasing the compacted yarns which increase their volume. These yarns, even if they have increased their volume, will maintain a controlled and homogeneous arrangement, thanks to the special compacting process they have been subjected to.

The described material may simply be winded up around the exhaust pipe, because during the first silencer's use, the synthetic yarns burns, so that the fiber glass increases its volume, filling the whole available cavity.

This product may be supplied precutted and/or preformed so that it can be quickly applied by unskilled personnel.

The homogenized yarns that have increased their volume, arranged inside the silencer, assure a great thermal and acoustic efficiency, together with a sure and even insulating action.

The material may be hybridized with other materials in order to satisfy the specific requirements of the purchaser.

The material may be combined with needled felt of low, medium and high density, so that it can be successfully used at various temperature up to 1200° C.

The above mentioned hybridization gives the possibility to commercialize a product adaptable to the purchasers' requirement.

The product density may be changed according to the specification.

In any case, formal and structural modification of the proposed solution may be made under the same inventive step as it is defined in the appended claims.

Claims

1. Soundproofing and lagging material which has the characteristic to have a double fiber glass weft, on which is orthogonally overlapped a fiber glass yarn; then is overlapped another fiber glass yarn with a "V" arrangement. The yarns so compacted are sewed with synthetic yarns, with the purpose to cause, with a certain temperature, the material volume increase.

2. The material of the preceding claim, characterized in that the fiber glass may be substituted by aramid fiber.

3. The material of the preceding claims, characterized in that the fiber glass may be substituted by syntetic fibers.

4. The material of the preceding claims, characterized in that the fiber glass may be substituted by steel.

5. The material of the preceding claims, characterized in that the fiber glass may be substituted by inconel.

6. The material of the preceding claims, characterized in that the above mentioned fibers may be arranged in different ways from claim 1, so that they can increase their volume by a cotton fiber heating which is the compaction element before burning.

7. The material of the preceding claims, characterized in that the stitching of fiber glass yarn may be made of cotton.

8. The material of the preceding claims, characterized in that it may be hybridized with other materials like needled felt of low, medium and high density so that it can be successfully used at various temperature up to 1200°.