JPH01247712A - Exhaust muffler for automobile - Google Patents

Abstract

PURPOSE:To increase the degree of freedom on setting the car height as well as utilizing the space effectively by arranging the muffler main body inside the space of the bumper of an automobile. CONSTITUTION:The exhaust system of an automobile provides an exhaust pipe 3 so as to release the muffler main body 2 to the outside by connecting it to the flow-in pipe 1 extended from the manifold of an engine E. In this case, the muffler main body 2 is arranged inside the space part 7 of the rear bumper 4 composed of the outer 5 and inner 6. This muffler main body 2 is stored along the car width direction inside the space part 7 by forming in a rectangular sectional shape, formed by working by using the mixture 9 of a heat resistant resin and inorg. substance as well and made by arranging in order the core material 10 consisting of a glass cloth, etc. and the heat resistant lamellar structure 11 therein.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an exhaust system muffler for automobiles, and particularly to a muffler which aims to effectively utilize the space of the automobile.

[Prior Art] Generally, when exhaust gas from an internal combustion engine is released into the atmosphere as it is, it expands rapidly and makes a lot of noise.
The air is introduced into the muffler body through an inflow pipe, where the pulsating airflow generated by the explosion is relaxed, and the air is released into the atmosphere through an ejection pipe as a smooth airflow.

The interior of this muffler body is divided into multiple small chambers using partition plates, and by passing the exhaust gas sequentially through the small chambers, the gas pressure is lowered and the gas is dissipated into the atmosphere.
It suppresses the explosion noise of internal combustion engines, etc.

[Problem M to be solved by the invention] However, in such a conventional automobile exhaust system muffler, a muffler main body having a predetermined volume is disposed on the underside of the floor of the vehicle body. Therefore, in order to avoid interference with the stabilizer, gasoline tank, trunk room, etc., which are parts installed on the underside of the floor, the muffler itself is subject to space constraints due to its design. There was a problem in that the height of the vehicle was restricted by this.

[Means for Solving the Problems] In order to solve the conventional problems, the present invention introduces exhaust gas from an internal combustion engine to a muffler main body via an inflow pipe, and from the muffler main body via an exhaust pipe to the outside. In the automobile exhaust system muffler, the muffler main body is disposed within the space of the bumper, and the exhaust pipe is extended from the bumper to the outside. It is a feature.

The muffler body can be made of metal such as iron, copper or aluminum.

Further, the muffler main body may be made of a heat-resistant resin or a mixture of a heat-resistant resin and an inorganic substance, and a layered structure of a heat-resistant material may be attached to the inner surface of the muffler main body.

Furthermore, the main body of the muffler can be separately disposed within the space of the breadboard made up of the inner and outer parts.

Furthermore, the muffler main body can also be constructed using at least one of the inner and outer parts of the bumper.

[Function] According to this method, since the muffler main body having a predetermined volume is provided by effectively utilizing the conventional bumper space, the muffler body is provided on the lower surface side of the floor panel as in the conventional case. Unlike a vehicle equipped with a muffler body, there is no space restriction, and the degree of freedom in setting the vehicle height is increased.

Further, if the main body of the muffler is made of a heat-resistant resin or a mixture of a heat-resistant resin and an inorganic substance, and a layered structure of a heat-resistant material is attached to the inner surface of the muffler main body, the shape can be improved. Since the bumper can be set more freely than a metal bumper, the space inside the bumper can be used more effectively.

Furthermore, if the silencer body is installed separately within the space of the pump, the silencer body can be protected by the outer and inner parts of the pump, so stones etc. thrown up from the road surface can protect the silencer body. can be prevented from being damaged.

Furthermore, if the muffler main body is constructed using at least one of the inner and outer parts of the bumper, material costs can be reduced when constructing the muffler main body.

[Example] Hereinafter, this invention will be explained based on each example.

1 and 2 are diagrams showing a first embodiment of the present invention.

First, to explain the structure, reference numeral 1 in FIG. 1 is an inflow pipe extended from a manifold of an engine E as an internal combustion engine, and this inflow pipe 1 is connected to a muffler body 2, so that exhaust gas is At the same time, an exhaust pipe 3 is extended from the muffler main body 2 to the outside, so that the exhaust gas from the muffler main body 2 is dissipated into the atmosphere.

As shown in FIG. 2, this muffler main body 2 is separately disposed within a space 7 formed by an outer 5 and an inner 6 of the rear bumper 4, and the structure of this muffler main body 2 is similar to that of the first It is as shown in the figure.

That is, the muffler main body 2 is disposed within the bumper space 7 along the vehicle width direction, and has a rectangular cross section as shown in FIG. This muffler body 2 is processed and molded using a mixture 9 of heat-resistant resin and an inorganic substance, and this mixture 9 is made of glass cloth, asbestos cloth, carbon fiber, etc. to ensure strength. A core material 10 is provided. Further, on the inner surface side of the muffler main body 2, a layered structure 11 made of a heat-resistant material is disposed in front.

The heat-resistant resin of the mixture 9 can be appropriately selected depending on the temperature of exhaust gas discharged from the engine E. For example, as a thermosetting resin, epoxy resin, unsaturated polyester resin, diallyl phthalate resin, melamine resin and thermosetting polycarbodiimide resins, etc., and further, as thermoplastic resins, polyamide resins, polyester resins, polyphenylene sulfide resins, thermoplastic fluororesins, polysulfone resins, polyphenylene ether resins, etc. can be used.

When selecting this heat-resistant resin, when the temperature of the exhaust gas in the inlet pipe 1 of the muffler body 2 reaches a temperature of 300 to 400°C, it is preferable to use the thermosetting resin described above. When the temperature is lower than the above temperature, the above thermoplastic resin can also be used.

In addition, when the heat-resistant resin used is a bisphenol-based epoxy resin, acid anhydrides, aromatic amines, dicyamide, etc. are used as curing agents, and 2.
4. 6-dimethylaminophenol (DMP-30)
, dimethylaminoiminodazole, etc. can be used. In order to further improve the heat resistance of epoxy resins, - epoxy compounds having three or more epoxy groups in the molecule 1 For example, phenol novolak epoxy resins (E
pi ko te 154. (manufactured by Shell Kagaku KK), NIN, N, N-tetraglycidylamine L resin, etc. may be used in combination or alone, and it is also effective to use phenol novolak as a curing agent. The heat resistance of epoxy resin varies depending on the base agent, curing agent, curing accelerator used, and their blending amount, but it depends on the load temperature due to exhaust gas in the silencer body 2 and the glass transition point of the epoxy resin (
It is preferable to select a resin so that the temperature of the exhaust gas in the inflow pipe 1 is low, and a heat-resistant resin 9 suitable for that temperature is used, for example, a thermoplastic resin. You can also do that.

The above heat-resistant resin may be used alone, but in order to reduce the cost of the heat-resistant resin and improve heat dissipation, it is used in a range of 30 to 500 (parts by weight) per 100 (parts by weight) of the heat-resistant resin. It is preferable to use a mixture 9 in which an inorganic substance is added.

If the amount of the inorganic substance added is less than 30 parts by weight, the temperature gradient of the heat-resistant resin will be too large and the heat dissipation performance of the silencer will decrease.On the other hand, if the amount of the inorganic substance added is more than 500 parts by weight, The moldability is poor, and the strength of the molded product decreases, resulting in poor durability.

A typical example of the inorganic substance to be added is alumina (AI
20 m), beryllia (BeO), cesium oxide (CeO7) + magnesia (MgO),
Silica (SiOt), quartz (Sio2), titania (TiO2) + Zir':lnia (ZrO2
), mullite (3A 120 m ・2 Si O2
) + spinel (MgO-Al tos ),
Niagerite (2Mg0 ・2A 120 m・5S
iO□), silicon carbide (Si・C), titanium carbide (TiC), boron carbide (84G), tungsten carbide (WC).

Graphite (C), boron nitride (BN), silicon nitride (S
iYukiNs) + Aluminum titanate (AIT
iOs).

Mica semis (muscovite, sericite, etc.),
Seviolite, pyrophyllite, steatite (Mg
O・5iO2), forsterite (2MgO・S
io 2), Zirco"/ (Z ro 2゜S
x Ot ) + cordierite (2Mg0・
Ceramics such as 2A120-.5S i Ot).

Or glass wool, glass fiber, glass cloth,
Examples include fibrous materials such as asbestos cloth and carbon fiber, cotton-like materials, and cloth-like materials. However, it is needless to say that the material is not limited to the above-mentioned inorganic materials, and two or more kinds of these materials may be used.

Furthermore, a layered structure 1 attached to the inner surface side of the silencer main body 2
1 may be any material as long as it can withstand the temperature of the exhaust gas, such as metals such as stainless steel, aluminum, and copper, ceramics as described above mixed with heat-resistant resin, and glass wool.

Glass fiber, glass cloth, asbestos cloth.

Examples include carbon fiber.

As a method for attaching this layered structure 11, for example, when molding the muffler body 2 using the mixture 9, it may be attached at the same time, or by fitting a metal tube (for example, a stainless steel tube) into the mixture 9. Alternatively, ready-made sheet-shaped ceramics or paper may be rolled up and fixed inside, and further, a ceramic lining process may be applied.

Further, a highly compressed tube made of ceramic powder or the like can also be used. When ceramic is used as the layered structure 11, the heat resistance temperature is approximately 1700°C to 2500°C.
The density of the silencer body 2 is approximately 173 to 1/2 that of a copper plate or stainless copper plate, excluding CeO and wc.
The weight can be reduced.

On the other hand, as a method for molding the silencer main body 2 using a thermosetting resin, for example, a glass cloth is soaked in the thermosetting resin and pre-cured to create a prepreg, and then this prepreg is formed into a metal layered structure. 11 and press-forming it into a cylindrical muffler. After creating the cylindrical silencer main body 2 from the above prepreg, a ready-made thin sheet-like ceramic paper containing silica and alumina as main components and a product with a thickness of 0.5 mm to 5 mm is processed using a rigidizer. It can also be treated and fixed as a layered structure 11 on the inner surface of the silencer body 2.

The thus formed automobile exhaust system muffler has the muffler main body 2 having a predetermined volume disposed within the space 7 of the rear bumper 4, so that the muffler main body 2 is not disposed in the conventional manner. Since it does not need to be installed on the underside of the floor, there is no space restriction due to other parts, and the vehicle height can be freely set without being affected by the silencer body 2. becomes. Furthermore, by forming the muffler body 2 from resin, the shape can be set more freely than when it is made of metal, so it can be molded into a shape that fits within the space 7 of the rear bumper 4. This space 7 can be utilized to the fullest. Furthermore, this muffler main body 2 includes an outer 5 and an inner 6 of the rear bumper 4.
, so even if a stone etc. jumps up from the ground, it will not be damaged.Furthermore, the silencer body 2 and rear bumper 4 have a double structure, so the sound deadening effect is improved. will further improve.

In addition, the silencing effect of this muffler is based on the principle that when the heat-resistant resin changes from a glass region to a viscoelastic region and then to a rubber region due to overheating, the elastic modulus changes and absorbs noise at a specific frequency. is used. The temperature range of the exhaust gas that most efficiently absorbs the noise is approximately ±50° C. of the thermal deformation temperature of the heat-resistant resin or the Tg point. In particular, heat-resistant resins generally have lower thermal conductivity than copper plates or stainless steel, so the gradient of the temperature difference inside and outside the muffler is made of steel plates.

By utilizing this appropriate temperature difference, which is larger than that of a stainless steel muffler, it is possible to match the exhaust gas temperature and the Tg point of the heat-resistant resin at any part, and at the outlet of the exhaust pipe 3, Exhaust noise can be reduced.

Also, in general, heat-resistant resins, especially epoxy resins.

Phenol resin, unsaturated polyester resin, diallyl phthalate resin, thermosetting polycarbodiimide resin, etc.
It has higher corrosion resistance to acids and various impurities than steel plates or stainless steel, and has the effect of preventing corrosion of the muffler body 2 caused by condensed impurities contained in high-temperature exhaust gas and impurities and salt in the atmosphere. Ceramic or mica are also inherently corrosion-resistant materials.

Further, when the layered structure 11 is made of a metal material such as stainless steel, the thickness of the material is 0°01 mm to 2 μm.
It is desirable that it is, more preferably 0.1a~
The thickness of the layered structure 11 is preferably 2u.
If it exceeds 0, weight reduction cannot be achieved and
．． If the thickness is less than 0.1 m, the heat of the high-temperature exhaust gas cannot be sufficiently dissipated, and the physical strength of the heat-resistant resin decreases, which may cause damage or deformation of the muffler body 2 due to impact or the like.

In the case where the layered structure 11 is a paper or sheet-like structure formed of at least one type of ceramic,
It is preferable that the thickness is 0.5 mm to 5 mm, and if it is more than that, weight reduction cannot be achieved.

Furthermore, when an inorganic substance is added to the heat-resistant resin, the thickness of the silencer main body 2 is generally desirably 0.1au* to 10cm, more preferably 0.5aIIl to 5cm thick.
It is better to set fI1. If the thickness exceeds 101 lm, it is impossible to reduce the weight of the muffler, and the weight of the muffler cannot be reduced.
．． If it is less than 1 mm, the physical strength of the silencer will be low under high-temperature loads, and it will be damaged by impact, etc. There is a drawback that it may cause deformation, etc. Further, FIG. 3 shows a second embodiment of the present invention. In this embodiment, the inner 6 of the rear bumper 4 is used, and the inner 6 and the intermediate panel 13 constitute the outer shape of the muffler main body 2, and a layered structure 11 is provided on the inner surface of the muffler main body 2. By using the inner 6 of the rear pumper 4 in this way, the material cost can be reduced to form the muffler main body 2.

The other configurations and operations are the same as those in the first embodiment, so their explanations will be omitted.

Furthermore, FIG. 4 shows a third embodiment of the present invention. In this embodiment, the outer shape of the muffler main body 2 is formed by the outer 5 and inner 6 of the rear bumper 4, and the outer 5
A layered structure 11 is provided on the inner surface of the inner layer 6. In this way, the rear bumper 4 itself can be used as a muffler, so that the material cost can be further reduced compared to the second embodiment. The other configurations and operations are the same as those in the first embodiment, so their explanation will be omitted. Furthermore, FIG. 5 shows a fourth embodiment of the present invention. In this embodiment, the outer shape of the muffler main body 2 is formed by the outer 5 of the rear bumper 4 and the intermediate panel 13, and these two members 5. A layered structure 11 is arranged inside 13. Even in this way, material costs can be reduced.

Further, FIG. 6 shows a fifth embodiment of the present invention. This embodiment has a muffler main body 2 having a structure similar to that of the first embodiment.
is disposed inside the front bumper 14 instead of the rear bumper 4, unlike the above embodiments. And the silencer body 2
A discharge pipe 3 is extended toward the rear. The other configurations and operations are the same as those in the first embodiment, so their explanation will be omitted. In each of the above embodiments, the muffler main body is made of heat-resistant resin, but it is not limited to this, and can of course be made of metal such as iron, copper, or aluminum. [Effects of the Invention] As explained above, according to the present invention, by setting the silencer main body within the space of the bumper, there is no need to arrange it on the lower surface side of the floor panel as in the conventional case.
There are no restrictions on the base due to relationships with other parts. Furthermore, if the main body of the muffler is made of resin, it can be shaped into any shape compared to a metal muffler body, so the space inside the bumper can be used more effectively. Furthermore, if a silencer body is installed separately within the space of the bumper, the silencer body can be protected by the outer and inner parts of the bumper, so it can be protected against rocks thrown up from the road surface when the vehicle is running. This can prevent damage to the silencer body. Furthermore, if the muffler main body is configured using at least one of the inner and outer bumpers, a practically beneficial effect can be achieved in that material costs can be effectively reduced when constructing the muffler main body. Demonstrate.

[Brief explanation of the drawing]

1 and 2 are views showing a first embodiment of the automobile exhaust system silencer of the present invention, FIG. 1 is a sectional view taken along line I-1 in FIG. 2, and FIG. 3 to 5 are sectional views corresponding to FIG. 1 showing the second to fourth embodiments of the present invention, and FIG. 6 is a perspective view of the fifth embodiment of the present invention. FIG. 3 is a sectional view of the front bumper shown in FIG. 1... Inflow pipe 2... Silencer body 3...
・Exhaust pipe 4...Rear bumper 5...Outer 6...Inner 7...Space
14...Front bumper E...Engine (internal combustion engine)

Claims (1)

[Scope of Claims] (1) In an exhaust system muffler for an automobile, in which exhaust gas from an internal combustion engine is guided to a muffler main body via an inflow pipe, and is exhausted from the muffler main body to the outside via an exhaust pipe. . An automobile exhaust system muffler, characterized in that the muffler main body is set within a space of a bumper. (2) An automobile exhaust system muffler, wherein the muffler main body is made of metal such as iron, copper, or aluminum. (3) The silencer body is made of a heat-resistant resin or a mixture of a heat-resistant resin and an inorganic substance, and a heat-resistant layered structure is attached to the inner surface of the silencer body. The automobile exhaust system muffler according to claim 1. (4) The automobile exhaust system muffler according to claim 1 or 2, wherein the muffler main body is separately disposed within a space of a bumper comprising an inner and an outer. (5) The automobile exhaust system muffler according to claim 1 or 2, wherein the muffler main body is constructed using at least one of an inner and an outer bumper.