JPH11117725A - Noise eliminating material for muffler and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dispersion of glass wool, and also improve noise eliminating effect of the whole muffler by manufacturing a noise eliminating material for the muffler formed in such a way that triaxially knitted sheet is stuck and fixed to at least one surface of a glass fiber layer formed in a mat shape while completing glass fibers of long fiber together with each other in one direction. SOLUTION: Thousands of glass fibers 1a of long fiber are bundled together so as to form a yarn 1, a large number of the yarns 1 are arranged in parallel without spacing, and a mat shaped glass fiber layer 2 is manufactured so as to form a small cross section of each yarn 1 in a nearly rectangular shape. Triaxially knitted sheets 3 are arranged on both surfaces of the glass fiber layer 2, the glass fiber layer 2 is sandwiched by the triaxially knitted sheet 3, and the triaxially knitted sheet 3 and the glass fiber layer 2 are fixed by appropriate fixing means so as to manufacture a mat shaped noise eliminating material A. A linear direction of the glass fiber 1a in the noise eliminating material A is arranged in a circumferential direction of an exhaust pipe 4, the noise eliminating material A is wound around an exhaust pipe 4 on which small holes 4a for a muffler are formed, and thereby, the muffler is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silencer for a silencer and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in an exhaust system of an internal combustion engine of an automobile or the like, a prim muffler or a sub muffler is disposed at an upstream side thereof. Since the prima muffler or the sub muffler is disposed immediately after the purification device, that is, on the upstream side of the main muffler, the temperature of the exhaust gas in the exhaust pipe of the prima muffler or the sub muffler is high and the exhaust flow rate is high.

For this reason, as shown in FIG. 7, a stainless wool or a stainless wool rope 103 is conventionally wound around the outer circumference of an exhaust pipe (inner pipe) 101 having a large number of small holes 102 as a prima muffler or a sub muffler. A glass wool 104 is wound around the outer periphery thereof, and the outer periphery thereof is covered with an outer pipe 105 so that the glass wool 104 has a sound deadening function. Some of the exhaust pipes 101 have a scattering prevention function such that they are not sucked into the exhaust pipe 101.

[0004] Further, there has been known one using a glass cloth instead of the stainless steel wool or the stainless steel rope 103.

[0005]

In the structure shown in FIG. 7, the stainless wool or the rope 103 used is expensive in terms of material, and requires a special processing method. In order to complete the countermeasures, it is necessary to increase the amount of the countermeasures, so that there is a problem that the production cost of the muffler increases.

In the case of a structure using a glass cloth, the weave of the glass cloth is a plain weave or a twill weave, so that the breathable weave becomes finer and the weave contained in the exhaust gas contains soot. For example, there is a problem that clogging is caused due to the above, and the noise reduction performance is reduced.

[0007] In addition, since a cloth having a large gap in the weave is also commercially available among plain weaves, it is conceivable to prevent the clogging by using the cloth for the above-mentioned muffler. Such a cloth is not suitable for use because it has extremely low productivity and high cost.

Accordingly, an object of the present invention is to provide a silencer for a silencer which solves the above problems and a method for manufacturing the same.

[0009]

According to a first aspect of the present invention, there is provided a glass fiber layer in which glass fibers of long fibers are aligned in one direction to form a mat. A muffler for a silencer, characterized in that a triaxial fabric is adhered and fixed to the muffler.

In the present invention, the sound absorbing material is interposed between the exhaust pipe having the small holes and the glass wool layer to prevent the glass wool from being scattered by suction into the exhaust pipe. Furthermore, the arrangement state of the glass fiber layer can be fixed by the triaxial fabric, and the lattice of the triaxial fabric is rough, so that the lattice is not clogged with soot or the like. Further, the glass fiber layer constituting the sound deadening material exhibits a high sound deadening function.

A second aspect of the present invention relates to a method for producing the sound deadening material according to the first aspect of the present invention, wherein a yarn is formed by bundling long fiber glass fibers, and a large number of yarns are aligned to form a mat. Then, a triaxial fabric is bonded and fixed to at least one surface of the mat-shaped glass fiber layer.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described based on an embodiment shown in FIGS. FIG. 1 shows a manufacturing process of the sound deadening material A of the present invention, and FIGS. 2 and 3 are views in which this sound deadening material A is mounted on a pipe-shaped prima muffler or sub muffler.

First, the manufacturing process of the sound deadening material A will be described with reference to FIG. FIG. 1A shows a state in which glass fibers to be used are bundled in a yarn shape. This single yarn 1 is a bundle of thousands of long fiber glass fibers, for example, large diameter glass fibers having a fiber diameter of 15 μm or more. By making the glass fiber have a large diameter of 15 μm or more, the cross-sectional area becomes large and the toughness to heat increases.

Next, as shown in FIG. 1 (b), a large number of the yarns 1 thus bundled are aligned without gaps as shown in FIG.
A mat-like glass fiber layer 2 is made. As shown in FIG. 1, each of the arranged yarns 1 has a small cross-section that is substantially rectangular.

Next, a triaxial fabric 3 as shown in FIG.
Are arranged on the front and back surfaces of the glass fiber layer 2, and FIG.
As shown in the figure, the glass fiber layer 2 is sandwiched between the triaxial fabrics 3, and the triaxial fabric 3 and the glass fiber layer 2 are fixed by an appropriate fixing means to produce a mat-shaped sound-absorbing material A.

As the fixing means, for example, an adhesive, for example, an adhesive such as acrylic resin, is previously adhered to the triaxial fabric 3, and the triaxial fabric 3 is laminated on the glass fiber layer 2. To fix them together. By fixing the glass fiber layer 2 with the triaxial fabric 3 in this manner, the yarns 1 and 1 arranged without gaps are fixed, and the generation of gaps between them is prevented.

Next, as shown in FIG. 1 (e), the above-mentioned silencer A is inserted into an exhaust pipe (inner pipe) 4 having a small hole 4a of the silencer, in a line direction of the glass fiber 1a in the silencer A. Are wound around the exhaust pipe 4 so as to be arranged in the circumferential direction.
By winding in this manner, it is possible to prevent a gap from being generated between the yarns 1 and 1.

The sound deadening material A wound as described above
The glass wool (glass needle mat) 5 shown in FIGS. 3 and 4 is wound around the outer periphery of the outer pipe 6 in this state.
And the front and rear ends of the outer pipe 6 are caulked and welded to the exhaust pipe 4 to form a muffler.

The triaxial fabric 3 used above will be described. The triaxial braided fabric is a fabric-like nonwoven fabric obtained by braiding three threads vertically, horizontally or diagonally and fixing them with an adhesive (binder), and is manufactured by Nitto Boseki Co., Ltd.

For example, as shown in FIG. 4, three yarns 3a, 3b, 3c made of glass fiber are arranged at an angle of 60 degrees in three directions, that is, form a triangular regular triangular lattice. Are fixed with an adhesive, for example, an acrylate resin as appropriate at the intersection of. The length of one side of the grid is determined by the yarn count and denier, and 5.2 mm, 10.4 mm, and 15.6 mm for fine yarn.
20.8 mm, 31.0 mm, 43.
Some are 3 mm.

The present invention selects and uses a desired yarn diameter and lattice mesh among these. The characteristics of the triaxial fabric 3 are such that the number of shafts is one more than that of the biaxial plain weave, so that the triaxial braid 3 has higher unidirectionality than the plain weave and the burst resistance,
High tear resistance, shear resistance, impact strength, etc. Furthermore, the production speed is about 100 times compared with the plain weaving method. In addition, the material of the triaxial fabric may be other chemical fiber, cotton yarn, or the like.

Next, FIG. 2 and FIG.
The operation of the silencer shown in FIG. When the exhaust noise flows into the exhaust pipe 4 in a state where the exhaust pipe 4 is connected to the exhaust system, a part of the exhaust noise is reduced through the small holes 4a.
And 5 parts of glass wool. At this time, the silencing effect is mainly performed by the glass wool layer. However, since the silencing material A is formed by the glass fiber layer 2 in which a large number of glass fibers 1a are bundled, the silencing effect is also reduced by the silencing material A. It is higher than the above-mentioned conventional stainless steel wool, stainless steel rope and glass cloth. Therefore, the use of the silencing material A increases the silencing volume of the silencer.

Further, a negative pressure is generated in the small holes 4a by the exhaust gas flowing through the exhaust pipe 4, and the glass wool 5 is sucked toward the small holes 4a by the negative pressure. Is extremely small, so that the glass wool 5 is prevented from being scattered by suction into the exhaust pipe 4 through the small hole 4a.

By using a glass fiber 1a having a thickness of 15 μm or more, its toughness is increased, which is effective in preventing glass wool 5 from scattering. Further, since the arrangement of the yarn 1 in which the glass fibers 1a are bundled is fixed by the triaxial cloth 3, the yarn 1
Of the yarn at the time of attachment to the exhaust pipe 4 and after the attachment,
That is, it is possible to prevent the aligned arrangement state of the glass fibers 1a from being broken and the gap from being enlarged, and to more surely prevent the glass wool 5 from being sucked and scattered.

Further, since the grids of the triaxial fabric 3 are larger than the plain and twill weaves, the grids are not clogged by soot or the like. In the above embodiment, the triaxial fabric 3 is provided on the front and back surfaces of the glass fiber layer 2 in a state where one end of the glass fiber layer 2 is folded.
May be provided on only one of the front surface and the back surface of the glass fiber layer 2.

FIG. 5 shows an example in which the above-mentioned sound deadening material A is mounted on an elliptical prim muffler or sub muffler. That is,
The above-described sound deadening material A is wound around the outer periphery of the exhaust pipe 4 having the small hole 4a formed thereon, and the glass wool 5 is wound around the outer periphery thereof, which is covered with the outer pipe 7 and the end plates 8,8.

Also in this embodiment, the silencing material A exhibits the same function and effect as described above. FIG. 6 shows an example in which the silencing material A is used for a main muffler. That is, a small hole 12 a is formed in a part of the outlet pipe 12 of the main muffler 10, a silencer is wound around the small hole 12 a part, and the outside is covered with an outer tube 13. The above uses the sound deadening material A of the present invention. In the figure, reference numeral 11 denotes an inlet pipe.

In the embodiment shown in FIG. 6, only the silencing material A of the present invention is wound without using the glass wool 5 as described above, and the silencing material A alone is used for silencing. .

In the embodiment shown in FIGS. 2 and 3, the silencing material of the present invention is single-wound. However, in this embodiment and the embodiments shown in FIGS. The sound-absorbing effect may be enhanced by wrapping the sound.

[0030]

As described above, according to the first aspect of the present invention, in a silencer in which glass wool is wound around an exhaust pipe having a small hole, the silencer of the present invention is combined with the exhaust pipe. By wrapping the glass wool between the glass wools, the glass wool can be prevented from scattering, and in particular, since the glass fiber layer of the sound deadening material has a high sound deadening function, the conventional stainless steel wool, stainless steel rope or glass cloth is used. It is possible to improve the silencing effect of the entire silencer as compared to the case.

Further, since the arrangement state of the glass fibers in the glass fiber layer can be fixed by the triaxial fabric, it is possible to prevent the arrangement state from being broken and the function from being lowered. Furthermore, since the triaxial fabric can form the lattices roughly, the lattices are not clogged by soot or the like.

Furthermore, the triaxial fabric is manufactured at a higher production speed and cheaper than plain weaves and the like, and since the glass fiber is cheaper than the stainless steel fiber, the sound deadening material of the present invention can prevent the conventional scattering. It is cheaper than wood. Therefore,
A silencer exhibiting a high scattering prevention function and a high silencing function can be provided at low cost.

According to the second aspect of the present invention, the muffler according to the first aspect can be easily manufactured at low cost.

[Brief description of the drawings]

1 (a) to 1 (e) are views showing a sound deadening material of the present invention and a manufacturing process thereof.

FIG. 2 is a longitudinal sectional view of a muffler using the muffler of the present invention.

FIG. 3 is a sectional view taken along line XX in FIG. 2;

FIG. 4 is a partially enlarged view of a triaxial fabric used in the present invention.

FIG. 5 is a cross-sectional view in which the silencing material of the present invention is used for an elliptical silencer.

FIG. 6 is a cross-sectional view in which the silencing material of the present invention is used for a part of a main muffler.

FIG. 7 is a longitudinal sectional view showing a conventional silencer.

[Explanation of symbols]

1a: Glass fiber 2: Glass fiber layer 3: Triaxial fabric

Claims (2)

[Claims] 1. A silencer for a silencer, wherein a triaxial fabric is adhesively fixed to at least one surface of a mat-shaped glass fiber layer in which glass fibers of long fibers are aligned in one direction. 2. A yarn formed by bundling glass fibers of long fibers, a large number of yarns are drawn and aligned to form a mat, and then a triaxial fabric is bonded and fixed to at least one surface of the glass fiber layer having the mat shape. A method for producing a silencer for a silencer, comprising: