JPH09133014A - Silencer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate necessity for an outer cylinder as it was conventionally, reduce a cost and a number of part items, also eliminate limitation by the outer cylinder, so that the length of glass wool can be freely set, in case of mounting the glass wool in a silencer. SOLUTION: In a silencer of vehicle exhaust system mounting glass wool 55 in the periphery of a muffler pipe drilling many small holes 53 in a peripheral wall, a scatter preventing hard layer 57 consisting of non-metal inorganic material is provided in an outer surface of the glass wool 55. In the silencer, the hard layer 57 is a foaming glass layer fusing the outer surface of the glass wool 55 under a high temperature condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silencer mounted on a vehicle exhaust system.

[0002]

2. Description of the Related Art In order to reduce exhaust noise when a vehicle is running,
Conventionally, a vehicle exhaust system is equipped with a silencer as disclosed in Japanese Utility Model Publication No. 5-36979, and the exhaust is exhausted by the expansion damping action in the expansion chamber and the resonance damping action in the resonance chamber of the silencer. It reduces noise. By the way, recently, a burr sound of a high frequency component generated from the exhaust gas discharge port during cold weather has tended to occur frequently as a user complaint. And, such burr noise is generally generated at the time of rapid acceleration / deceleration of the engine or when the engine is not warmed up completely, but the silencer having the above structure cannot muffle the high frequency burr noise. It was a reality.

Therefore, as a sound deadening countermeasure against such exhaust noise of high frequency components, as disclosed in Japanese Utility Model Laid-Open No. 6-53710, a muffler in which glass wool is attached to the outer periphery of a muffler pipe such as an inlet pipe or an outlet pipe has been recently used. Is widely known. Fig. 3 shows the actual Kaihei 6-53
The muffler disclosed in Japanese Patent No. 710 is shown, and conventionally, the glass wool 1 is filled in the outer cylinder 7 surrounding the outlet pipe 5 in the muffler 3, and the peripheral wall of the outlet pipe 5 surrounded by the outer cylinder 7 is shown. A large number of small holes 9 are bored in this.

Then, welding margins 7c and 7d are formed on both ends of the outer cylinder 7 via tapered diameter-reduced portions 7a and 7b, and the welding margin 7c on the upstream side is welded to the outer circumference of the outlet pipe 5. In addition, the outer cylinder 7 is press-fitted into the outer cylinder insertion hole 17 of the baffle plate 15 that divides the expansion chamber 11 and the resonance chamber 13, and the outer cylinder 7 is held by the baffle plate 15.

According to the muffler 3 as described above, the exhaust noise of high frequency components such as the burr sound emitted from the engine is absorbed by the glass wool 1. In the figure, 1
Reference numerals 9 and 21 denote end plates for closing the openings at both ends of the shell 23, and 25 denotes an inlet pipe.

[0006]

As described above, in order to reduce the exhaust noise of high frequency components, the glass wool 1 is conventionally mounted in the silencer 3, but the glass wool 1 is used for the purpose of preventing scattering by exhaust gas. It is filled in the outer cylinder 7.

However, as described above, the conventional outer cylinder 7
Welds allowances 7c and 7d through the reduced diameter portions 7a and 7b at both ends.
When the glass wool 1 is mounted in the limited space of the silencer 3, the reduced diameter portions 7a and 7b and the welding allowance 7c, with respect to the total length L of the outer cylinder 7, are formed.
There was a constraint that the glass wool 1 could not be filled by the length dimension of 7d.

Further, it is pointed out that mounting the outer cylinder 7 on the muffler pipe and filling the glass wool 1 into the outer cylinder 7 are not only troublesome, but the use of the outer cylinder 7 causes a high cost. Was there. The present invention has been devised in view of such circumstances, and when mounting the glass wool in the muffler, it is possible to reduce the cost and the number of parts by eliminating the conventional outer cylinder, and to eliminate the restriction by the outer cylinder. It is an object to provide a silencer capable of freely setting the length of glass wool.

[0009]

In order to achieve such an object, the invention according to claim 1 is a muffler for a vehicle exhaust system, in which glass wool is attached to the outer periphery of a muffler pipe having a large number of small holes formed in its peripheral wall. At the outer surface of the glass wool,
A scattering preventing hard layer made of a non-metallic inorganic material is provided.

The invention according to claim 2 is the invention according to claim 1.
In the silencer described above, the hard layer is a foamed glass layer obtained by melting the outer surface of glass wool under high temperature conditions.

(Operation) According to the inventions according to the respective claims, the exhaust noise of high frequency components such as the burr sound discharged from the engine is absorbed by the glass wool.

The hard layer provided on the outer surface of the glass wool prevents the glass wool from scattering due to the exhaust gas flowing into the silencer.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a silencer according to claims 1 and 2, wherein 27 is a shell whose both end openings are closed by end plates 29 and 31, and the inside of the shell 27 is 2 By the baffle plates 33, 35, the first chamber 37, the second chamber 39,
Three chambers, the third chamber 41, are defined and formed. And
An inlet pipe 43 is inserted into the end plate 29 so as to pass through the baffle plate 33, and the end portion on the insertion side is open to the second chamber 39. An outlet pipe 45 is inserted into the downstream end plate 31 so as to pass through the baffle plates 33 and 35, and the outlet pipe 45 has an insertion side end opening to the first chamber 37.

Further, a resonance pipe 47 which connects the second chamber 39 and the third chamber 41 to the baffle plate 35 is coaxially inserted to the inlet pipe 43, and the baffle plate 33 has a first chamber 37. One communication pipe 49 that connects the second chamber 39 with the second chamber 39 is inserted. With this configuration, the first chamber 37 and the second chamber 39 function as expansion chambers, and the third chamber
The chamber 41 functions as a resonance chamber.

The muffler 51 according to this embodiment has the following features in addition to the above-mentioned conventional structure. That is, in the figure, 53 is a plurality of small holes formed in the peripheral wall of the outlet pipe 45, and each small hole 53 is formed in the peripheral wall in the second chamber 39 partitioned by the baffle plates 33, 35.

Glass wool 55 is sandwiched between the baffle plates 33 and 35 with a certain thickness on the outer circumference of the outlet pipe 45 so as to cover the small holes 53, and the burr sound emitted from the engine, etc. The exhaust noise of the high frequency component is absorbed by the glass wool 55 through the small holes 53. Then, as shown in FIG. 2, a hard layer 57 is formed on the outer surface of the glass wool 55 to prevent the glass wool 55 from scattering due to the exhaust gas flowing into the silencer 51 with a certain thickness.

The hard layer 57 is made of a foamed glass layer,
In manufacturing the muffler 51, after the glass wool 55 is wound around the outer circumference of the outlet pipe 45 having the small holes 53 with a certain thickness, the outer surface of the glass wool 55 is heated at a temperature of 800 ° C. or higher. By melting with, the hard layer 57 made of such a foamed glass layer is formed.
And the outlet pipe 45 and the inlet pipe 4
Before inserting 3 and the like into the baffle plates 33 and 35 and incorporating them into the shell 27, the outlet pipe 45 is inserted into the outlet pipe insertion hole 59 provided in the baffle plate 33, and the hard layer 57 of glass wool 55 is inserted. After making one end side 57a of the baffle plate 33 contact the baffle plate 33, the outlet pipe 45 is inserted into the outlet pipe insertion hole 61 of the baffle plate 35, and the hard layer 57
By bringing the other end side 57b of the baffle plate 35 into contact with the baffle plate 35, the glass wool 55 becomes
It is sandwiched by 5 and is prevented from moving in the front-back direction. By incorporating the baffle plates 33 and 35 in the shell 27, the glass wool 55 having the hard layer 57 formed on the outer surface is sandwiched between the baffle plates 33 and 35 and mounted in the silencer 51. It will be.

Since the muffler 51 according to the present embodiment is constructed in this way, the exhaust noise discharged from the engine causes the expansion damping effect in the first chamber 37 and the second chamber 39 and the third chamber 41. The exhaust noise of high-frequency components such as burr noise is absorbed by the glass wool 55 while being reduced by the resonance damping action of. The hard layer 57 provided on the outer surface of the glass wool 55 prevents the glass wool 55 from scattering due to the exhaust gas flowing into the silencer 51.

As described above, in the present embodiment, instead of the conventional outer cylinder 7 shown in FIG. 3, glass wool 55 is melted under a high temperature condition of 800 ° C. or higher to form a hard foam glass layer. Since the hard layer 57 made of such a foamed glass layer is formed on the outer surface of the glass wool 55 to prevent the glass wool 55 from scattering due to the exhaust gas, the conventional outer cylinder is no longer necessary.

Therefore, according to this embodiment, since the outer cylinder for preventing the scattering of the glass wool 55 becomes unnecessary, the troublesome work of mounting the outer cylinder on the muffler pipe such as the outlet pipe 45 and the inlet pipe 43 and the outer cylinder. Since the work of filling the glass wool into the inside is unnecessary and the outer cylinder 7 is not used, the cost and the number of parts can be reduced as compared with the conventional silencer.

Further, according to the present embodiment, since the outer cylinder is not used, when the glass wool 55 is mounted in the limited space in the muffler 51, the length of the glass wool 55 formed by the outer cylinder is adjusted as in the conventional case. There is no restriction, and as a result, the length of the glass wool 55 is reduced by the silencer 5.
If the value is within 1, it can be freely set, and there is an advantage that the sound absorbing effect can be expanded as compared with the conventional case.

In the above-mentioned embodiment, the outer surface of the glass wool 55 wound around the outlet pipe 45 is melted under a high temperature condition of 800 ° C. or higher to form the hard layer 57 for preventing the glass wool 55 from scattering due to exhaust gas. However, the hard layer 57 is not limited to such a material,
A non-metallic inorganic material having properties required for a silencer member is widely used.

That is, in recent years, for example, Toagosei Kagaku Kogyo Co., Ltd. has developed a one-component heat-curable heat-resistant inorganic adhesive / coating agent called Aron ceramic. This Aron ceramic withstands high temperatures of 1200 to 1300 ° C by being heat-cured at 150 ° C, has strong adhesive strength to glass, metal, ceramics, etc. even at high temperatures, and has resistance to cold and heat cycles, oil resistance, Excellent water resistance.

Therefore, in manufacturing the silencer, the outlet pipe 4 having the small holes 53 formed therein as described above.
After the glass wool 55 is wound around the outer periphery of the glass wool 5 with a certain thickness, the above adhesive is applied to the outer surface of the glass wool 55, and the glass wool 55 is heated and cured at 150 ° C.
A hard layer may be formed on the outer surface of the. Then, before inserting the outlet pipe 45, the inlet pipe 43 and the like into the baffle plates 33 and 35 and incorporating them into the shell 27, the glass wool 55 is sandwiched between the baffle plates 33 and 35 as in the above embodiment. The shell 27
It should be built in.

Thus, even with such a muffler, the hard layer provided on the outer surface of the glass wool 55 is the glass wool 55.
Since it prevents the scattering of the
As a result, also in this embodiment, similar to the above embodiment,
It is possible to achieve the intended purpose.

Since the hard layer made of this non-metallic inorganic material is used for a silencer, at least 50.
Of course, it is a substance that can be used for a silencer, such as having a heat resistance of 0 ° C. Further, in the muffler 51 of the above-mentioned embodiment, the glass wool 55 is mounted on the outer circumference of the outlet pipe 45, but the present invention can be applied to a muffler in which the glass wool is mounted on the inlet pipe as shown in FIG. is there.

Further, in the above embodiment, glass wool 55
The baffle plates 33, 35 are sandwiched between the baffle plates 33, 35 to prevent their movement.
It is not necessary to sandwich the glass wool 55 between the five, and the movement of the glass wool 55 may be prevented by an adhesive or the like.

[0029]

As described above, according to the invention described in each of the claims, the hard layer made of the non-metallic inorganic material provided on the outer surface of the glass wool prevents the scattering of the glass wool due to the exhaust gas. An outer cylinder such as is unnecessary.

Therefore, the troublesome work of attaching the outer cylinder to the muffler pipe and the work of filling the glass wool into the outer cylinder are unnecessary, and since the outer cylinder is not used, the cost and the number of parts are smaller than those of the conventional silencer. Reduction has become possible. Further, according to the present invention, since the outer cylinder is not used, when the glass wool is mounted in the limited space in the silencer, the outer cylinder does not limit the length of the glass wool as in the conventional case. As a result, the length of glass wool can be freely set within the silencer, and the sound absorbing effect can be expanded as compared with the conventional one.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an embodiment of a silencer according to claims 1 and 2.

FIG. 2 is an enlarged cross-sectional view of a main part of the silencer shown in FIG.

FIG. 3 is a sectional view of a conventional silencer.

FIG. 4 is an enlarged sectional view of a main part of the silencer shown in FIG.

[Explanation of symbols]

 27 Shell 43 Inlet Pipe 45 Outlet Pipe 51 Muffler 53 Small Hole 55 Glass Wool 57 Hard Layer

Claims (2)

[Claims] 1. A silencer for a vehicle exhaust system, comprising a muffler pipe having a large number of small holes (53) formed in its peripheral wall, and a glass wool (55) mounted on the outer periphery of said muffler pipe.
A silencer characterized in that a hard layer (57) made of a non-metallic inorganic material for preventing scattering is provided on the outer surface of the silencer. 2. The hard layer (57) is made of glass wool (5).
The silencer according to claim 1, which is a foamed glass layer obtained by melting the outer surface of 5) under high temperature conditions.