JPH0524913U - High durability silencer - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a silencer having high durability without pulverization and crushing of the sound absorbing material in the silencer. [Structure] A mineral fiber mat 2 impregnated with 25 to 35% by weight of an inorganic adhesive is fixed to the bottom of a muffler case 1, while a large number of exhaust pipes 3 penetrate the case 1. A small hole portion 4 is formed, and the outer circumference of the small hole portion 4 is covered with a metal ribbon layer 5.
Furthermore, a highly durable silencer in which the sound absorbing material 6 is filled in the space inside the silencer case 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a highly durable silencer, which has high durability and is used in an exhaust system of an automobile or the like.

[0002]

[Prior Art]

 BACKGROUND ART Conventionally, a muffler used for an exhaust system of an automobile or the like has a structure that penetrates a muffler case as disclosed in, for example, Japanese Utility Model Publication No. 59-71912 or Japanese Utility Model Publication No. 62-47714. A large number of ventilation holes are formed in the exhaust pipe, and a sound absorbing layer in which long glass fibers are intertwined is provided on the outer circumference, the sound absorbing layer is covered with punching metal, or both sides of the sound absorbing layer are supported by support metal fittings. There are also those in which the sound absorbing layer is covered with a glass fiber cloth, and the outer circumference thereof is wrapped with a heat resistant string.

[0003]

[Problems to be solved by the device]

 However, as the performance of automobiles has become higher in recent years, the temperature of exhaust gas exceeds 500 ° C, and the silencer is exposed to pulsating waves of exhaust gas exceeding 500 ° C for a long time. There is a problem that the sound absorbing material such as glass wool is deteriorated, and it is pulverized and scattered by the vibration of the vehicle body, and the sound absorbing characteristics of the silencer deteriorate.

The present invention aims to provide a muffler that improves the above-mentioned drawbacks and has high durability that can be used for a long time.

[0005]

[Means for Solving the Problems]

 According to the present invention, a cushioning material made of a mineral fiber mat impregnated with 25 to 35% by weight of an inorganic adhesive is fixed to the bottom of the muffler case, and the exhaust pipe passing through the muffler is fixed to the other. A small hole portion is formed in which a large number of small holes are formed, the outer periphery of the small hole portion is covered with a metal ribbon layer, and the space inside the silencer case is filled with rock wool granular cotton. It is configured to be.

The mineral fiber mat, which is a cushioning material in the present invention, is formed by, for example, defibrating long glass fibers into a glass wool shape, and forming it into a felt shape with a needle punching machine using a needle punching machine. An inorganic adhesive such as lithium silicate or monobasic aluminum phosphate was added to water in an amount of 25 to 35% by weight to form a sol, which was then impregnated and dried to obtain a bulk specific gravity of 0.30 to 0.35. It has been done.

The cushioning material can be attached to the bottom of the muffler case with a fixing hook or can be attached with an inorganic adhesive. The cushioning material protects the rock wool granular cotton from breakage and pulverization due to microvibration at the bottom of the muffler case. Especially, when the automobile is started, the water contained in the exhaust gas is condensed to form rock wool granular cotton. It is possible to prevent the layers from becoming heavy and breaking and powdering in combination with vibration.

On the other hand, the metallic ribbon layer covering the outer periphery of the small hole formed in the exhaust pipe penetrating the inside of the silencer case of the present invention is formed by spirally twisting a ribbon of stainless steel or the like. A plurality of pieces are pressed against each other and bundled to be wound around the outer periphery of the small hole to form a coating.

Since the metal ribbon layers have a spiral twist in each of the metal ribbons, they can be bundled without being in surface contact simply by pressing each other, and between the metal ribbon layers. Innumerable vent holes are formed. Therefore, the pressure loss of exhaust gas is not significantly impaired. High-temperature, high-velocity exhaust gas exhausted through the small holes in the exhaust pipe reduces the energy of the exhaust gas as it passes through the numerous vent holes in the metal ribbon layer, thus reducing its temperature. To do.

Further, the rock wool granular cotton layer, which is a sound absorbing material and is filled in the space inside the silencer case, is made by filling rock wool granular cotton in a bulk specific gravity of 0.23 to 0.33. If the specific gravity is less than 0.23, the packing balance in the muffler case is poor, and if it is greater than 0.33, the sound absorption characteristics deteriorate. The exhaust gas discharged into the silencer case is silenced when it comes into contact with the metal ribbon layer and the rock wool granular cotton layer.

[0011]

[Action]

 The present invention is constructed as described above, and the pulsating wave of high-temperature, high-velocity exhaust gas discharged from the small hole portion of the exhaust pipe penetrating the inside of the muffler is generated by the small hole portion of the exhaust pipe. The metal ribbon layer coated on the outer periphery is dispersed and attenuated in the numerous air holes.

Since the metal ribbon forming the metal ribbon layer is made of metal such as stainless steel, there is no possibility of deterioration or damage even if it is exposed to exhaust gas having a high temperature exceeding 500 ° C. and a high flow rate. Further, the pulsating wave of exhaust gas attenuated by the metal ribbon layer is exhausted after being attenuated and absorbed by the sound absorbing material layer made of rock wool granular cotton filling the inside of the silencer case.

Further, since the cushioning material made of glass fiber fixed to the bottom of the muffler absorbs the vibration of the case at the bottom of the muffler, there is no risk of degrading or crushing the sound absorbing material of rock wool granular cotton. .. Since the cushioning material is reinforced by impregnating the glass fiber mat with an inorganic adhesive in an amount of 25 to 35% by weight, the cushioning material is deteriorated even when moisture contained in the exhaust gas is condensed when the automobile is started. There are few things.

[0014]

【Example】

 1 and 2 show one embodiment of the present invention, the structure and operation of the present invention will be specifically described with reference to the drawings, and the effects of the present invention will be described with reference to a comparative example. explain.

At the bottom of the case 1 of the muffler, a mineral fiber mat is impregnated with 25 to 35% by weight of an inorganic adhesive such as silica, alumina sol, lithium silicate, monobasic aluminum phosphate, etc., and dried to obtain a bulk specific gravity of 0.30. The shock-absorbing material 2 of 0.35 is fixed.

On the other hand, the exhaust pipe 3 penetrating the inside of the silencer case 1 is formed with a small hole portion 4 in which a large number of small holes are formed, and the outer periphery thereof is covered with a metal ribbon layer 5. is doing . The metal ribbon layer 5 is made by twisting a stainless steel ribbon having a width of 0.4 to 0.5 mm and a thickness of 0.03 to 0.06 mm twice or more in a spiral shape of 10 mm, and by arranging a plurality of the ribbons together. It is pressed, bundled into a diameter of 15 to 20 mm, and wrapped around the small hole portion 4 of the exhaust pipe 3 so as to be covered.

Since the metal ribbons are twisted in a spiral shape one by one, the metal ribbons are bundled without being in surface contact with each other only by pressing them. Therefore, innumerable vent holes are formed between the metal ribbons. Therefore, the pressure loss of the exhaust gas is not significantly impaired, and the pulsating wave of the high-temperature, high-velocity exhaust gas discharged from the innumerable vent holes can be rapidly attenuated.

In the space inside the silencer case 1, a sound absorbing layer 6 filled with rock wool granular cotton in a bulk specific gravity of 0.23 to 0.33 is formed, and the sound absorbing layer 6 is formed. Can absorb the exhaust gas.

The loose shock impregnated needle-punched glass fiber mat on the bottom [Chubukogyo Co., Ltd., trade name SWM over 8 ^t] 30 wt% SiO ₂ based inorganic adhesive in Example 1 silencer casing A material (bulk specific gravity: 0.34, thickness: 8 mm) was fixed by a metal hook that was previously welded to the inner bottom of the case of the silencer. Further, a stainless steel ribbon (width 0.48 mm, thickness 0.05 mm) was twisted 4 times / 10 mm to form a spiral ribbon. The spiral ribbons were bundled into a bundle having a diameter of 15 to 20 mm and wound around the outer periphery of the small hole of the exhaust pipe to form a metal ribbon layer.

Further, an exhaust pipe covered with the metal ribbon layer is attached to a silencer case to which a cushioning material is fixed, and a rock wool granular cotton (Nitto Boseki Co., Ltd. ), A trade name Rock Fiber # 15) was filled to obtain a muffler of the present invention as a rock wool granular cotton layer (filled bulk specific gravity 0.27).

Comparative Example 1 A muffler was obtained in the same manner as in Example 1 except that the cushioning material was not used.

Comparative Example 2 A needle punched glass fiber mat (manufactured by Chubu Kogyo Co., Ltd., trade name SWM, bulk specific gravity 0.24, thickness 8 mm) not impregnated with an inorganic adhesive was used as a cushioning material. A muffler was obtained in the same manner as in Example 1 except for the above.

Comparative Example 3 As a cushioning material, a cushioning material (thickness 8 mm, bulk specific gravity 0.27) obtained by impregnating a needle punched glass fiber mat (same as in Example 1) with 10% by weight of SiO ₂ inorganic adhesive. A muffler was obtained in the same manner as in Example 1 except that () was used.

Comparative Example 4 As a cushioning material, a needle punching glass fiber mat (same as in Example 1) impregnated with 20 wt% of a SiO ₂ inorganic adhesive (thickness 8 mm, bulk specific gravity 0.30) A muffler was obtained in the same manner as in Example 1 except that () was used.

Comparative Example 5 A commercially available silencer (using glass fiber as a sound absorbing material) which has been conventionally used in a four-wheel drive automobile was used.

Test The silencers obtained in Example 1 and Comparative Examples 1 to 5 were mounted on a Mirage (motor type G11B) manufactured by Mitsubishi Motors, and when the exhaust noise value reached 85 horns or the test run distance was 40,000 km. When the weight loss of the rock wool granular cotton was measured, the results are shown in Table 1. The exhaust noise values at the start of the test run were all within the range of 65 to 68 horns.

[0027]

[Table 1]
Note) Exhaust noise measurement method: According to Article 30 of the safety standards for road vehicles.

[0028]

[Effect of the device]

 As described above, according to the present invention, the cushioning material is fixed to the inner bottom of the muffler case, and the outer circumference of the small hole of the exhaust pipe penetrating the muffler is covered with the metal ribbon layer to reduce the size of the muffler. It is possible to prevent dusting and breakage of the sound absorbing material filled inside due to vibration, and to cover the outer circumference of the small hole of the exhaust pipe that penetrates the muffler with a metal ribbon layer to keep the temperature at 500 ° C. It is possible to prevent pulsating waves due to exhaust gas with a high temperature and a high flow velocity that exceed, and it is possible to make a silencer with extremely high durability by the synergistic effect of these actions.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

[Explanation of symbols]

 1: Muffler case 2: Cushioning material 3: Exhaust pipe 4: Small hole portion 5: Metal ribbon layer 6: Sound absorbing layer

Claims (1)

[Scope of utility model registration request] 1. An inorganic adhesive 2 is attached to the bottom of the muffler case.
A cushioning material made of a mineral fiber mat impregnated with 5 to 35% by weight is fixed, and on the other hand, an exhaust pipe passing through the muffler is provided with a small number of small holes. A high durability silencer, characterized in that the outer periphery of the small hole is covered with a metal ribbon layer, and the space inside the silencer case is filled with rock wool granular cotton.