JPS5928008A - Exhaust device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust system for exhausting combustion gas from an internal combustion engine, and more particularly to an exhaust system for exhausting combustion gas from an internal combustion engine of a vehicle.

Exhaust gas produced by an internal combustion engine, such as that installed in a vehicle, is discharged through an exhaust system. The exhaust system includes a relatively small diameter tube extending from the exhaust manifold to an opening to the atmosphere and having one or more silencers along it. The oscilloscope is a heavy, bulky device that is much larger in diameter than the rest of the exhaust system.

Silencers are used to cancel, within a relatively short distance, the acoustic shock waves created by the explosive release of the combusted air-fuel mixture from the cylinder. This shock wave contains sound waves at the frequency of the seed line. The muffler is designed to attenuate sound waves at the seed line frequency by structures well known in the art.

Large silencers are extremely susceptible to road damage and are limited by the space that must be accommodated in the vehicle. When the exhaust system cools, moisture condenses in the large partitioned space inside the muffler, causing rust and deterioration of the muffler. Silencers are relatively complex in construction and require a plurality of different metal pieces that must be treated in different ways. Silencers are therefore relatively expensive and heavy.

In recent years, exhaust systems have also been required to eliminate unburned hydrocarbons from the exhaust gas. This function is performed by a separate catalytic converter. Converters are additions to conventional exhaust systems and form relatively bulky containers. The exhaust containing unburned hydrocarbons entered the converter and was all plated on alumina. ” pass through a catalyst from noble metals of the platinum group, including gold, palladium and rhodium. Alumina is
Form into pellets or coat onto a substrate of extruded ceramic material. The converter works by oxidizing hydrocarbons and reducing pollutants in the atmosphere. The volume of the converter also requires that the structure of the vehicle be particularly adapted to receive the converter. The oxidation of unburned hydrocarbons generates significant heat and the converter reaches high temperatures. Vehicles must also be constructed to ensure that they do not suffer damage from these high temperatures.

Conventional mufflers, converters, interconnect pipes, exhaust pipes and end tail pipes are connected to the vehicle by flanges and are mounted via brackets. These have a relatively complex structure, so it takes a lot of effort to assemble them! 7 The cost will also be higher.

There is a need for an improved exhaust system that retains the muffling and oxidizing properties of conventional mufflers and converters, yet reduces its size, cost and weight. In this case, the flexibility of the vehicle structure increases. There is also a need to develop new exhaust systems that have equal or increased durability in use and reduced assembly time and material costs. Recent proposals that seek to achieve some of these goals include d'e Ca
rdenas), US Pat.

According to the present invention, an exhaust system for exhausting gas from an internal combustion engine having an exhaust manifold of a vehicle is obtained.

The exhaust system includes a uniform diameter tube section extending from an engine exhaust manifold to an opening to the atmosphere. This tube section carries exhaust gases from the engine to the atmosphere. A plurality of porous filters are positioned within the tube section along its length to muffle exhaust noise. The porous filter is formed from at least one section of expanded metal. Each section is folded at preselected locations along its length to form an individual filter between each fold, each filter being spaced a predetermined distance from the filter formed by the common fold. “It should be noted that according to the invention, the predetermined distance between each filter is varied along the tube section to enhance the muffling effect in the range of acoustic frequencies.
At least one section along the tube section is unfiltered to form a mixing chamber in which isolated sections of shock waves cancel each other out.

Each filter has a rectangular (including square) cross section and forms four arcuate passages between each filter and the inner wall of the tube section that serve to dissipate shock waves.

Each filter may have an oval (including circular) cross-section between each fold to allow each filter to contact the inner wall of the tube section about approximately its inner circumference.

The filter piece may be twisted in a helical manner with the filter piece edge contacting the inner surface of the tube piece to form a filter.

According to the invention, the porous material can be selected from the group consisting of metals, ceramic materials or high temperature resistant silanic materials. Each hole in the porous material can be sized to enhance sound deadening over a range of acoustic frequencies, and can have an airfoil cross-section to enhance sound deadening. Each hole can be created by stretching the material, or by weaving together linear materials, or by other suitable dimensions.

According to the invention, each section of porous material is coated with alumina and also a metal from the platinum group and positioned along its length within the tube section to oxidize unburned hydrocarbons in the exhaust gas. The tube section is continuous along its entire length, and the porous material extends within the tube section along substantially its entire length or is concentrated in one or more locations.

Further, according to the present invention, there is provided an exhaust system for discharging gas from an internal combustion engine having an exhaust manifold of a vehicle. The exhaust system has a uniform diameter tube section extending from an engine exhaust manifold to an opening to the atmosphere. This tube section conveys the discharged gas therein to the opening. At least one section of liner is positioned within the tube section during formation of the tube section. This section includes a plurality of airfoil baffles extending into the gas stream to muffle the exhaust air.

According to the invention, the airfoil baffle is selected from the group consisting of metal, high temperature plastic material and ceramic material. The liner is constructed from a continuous strip, the airfoil baffle is stamped from the strip, and the edges of the strip are folded and welded to form the tube section itself within the exhaust pipe section. During this process, a cylindrical body to be welded is formed.

The airfoil deflector has a length, cross section, and thickness along the length of the liner.
The silencing effect of this exhaust system can be strengthened by changing the angle of attack and frequency.

In accordance with the invention, an exhaust system is provided which includes a tube section of uniform diameter containing a wire fabric to muffle the exhaust gas. This wire may have a wire diameter and cross section,
The resulting fabric extends along the length of the tube section and provides enhanced muffling in the exhaust acoustic frequency range.

Embodiments of the exhaust system of the present invention will be described in detail below with reference to the accompanying drawings.

Like reference numerals represent similar or corresponding parts throughout the accompanying drawings. FIG. 1 shows a vehicle 10 with associated internal combustion engine 12 for propulsion.

Engine 12 includes an exhaust manifold 14 that collects combustion exhaust from engine 12 from one or more cylinders for disposal to the atmosphere.

The parts shown in dashed lines represent a conventional muffler 20, a conventional converter 18 and a conventional clamp 21.

The converter 18 and the muffler 20 are interconnected by a tube section 22. It is clear that the structure of the vehicle 10 must be particularly able to accommodate the relatively bulky converter 18 and muffler 20. It is also clear that a typical exhaust system consists of many parts that must be assembled at the same time or prior to assembling the vehicle on the assembly line.

The exhaust system 24 illustrated in FIG. 1 constitutes a first embodiment of the present invention. As shown, the exhaust system 24 of the present invention includes a continuous tube section 26 having a uniform outer diameter and a flange 28 at one end for connection to the exhaust manifold 14. The opposite end of the tube piece 26 is provided with an opening 30 near the rear of the vehicle 10 for venting combustion gases from the engine 12 to the atmosphere. The tube section 26 has pendants 32, 34, 36, 38, 40, 42, 43 along its length to accommodate the structure of the vehicle 10, including the rear axle and other components. As will be discussed in more detail below, the exhaust system 24 serves to muffle the exhaust of the engine 12 and also includes catalytic conversion elements to oxidize unburned hydrocarbons and reduce air pollution.

Details of the interior of the exhaust system 24 will be described with reference to FIGS. 2, 6, and 4. FIG. 2 shows a piece 44 of expanded porous material 46. FIG. Piece 44 may be folded along fold line 48 and any number of spaced apart rectangular filters 50 may be folded sufficiently to form a square filter as shown. The mesh piece 52 of each filter 50 defines a plurality of holes 54 through which exhaust gas can pass through each filter 50. The mesh piece 52 absorbs the sweat acoustic frequencies created in the exhaust by the explosive release of the combusted air-fuel mixture from the engine 12.
Attenuates and destroys several shock waves.

The bending angle 56 of the fold 48 is selected to provide an optimal cross section for the filter 50. In the embodiments of FIGS. 2, 6, and 4, the material 46 has an angle 56 close to 18o0.
to form a square filter 50 in the direction transverse to the exhaust flow indicated by arrow 58. In the second variant shown in FIGS. 6A, 6B and 6C, the bending angle 56 is 180
A rectangular filter 60 is formed by bending and stretching the piece at a smaller angle than . Filter 60 is not transverse to the direction of gas flow. The bend angle 56 can be varied along the length of the section to enhance the muffling effect in the range of acoustic frequencies of the exhaust flow. Steel would be a preferred material to form the wrought material.

However, high temperature resistant plastics, ceramics or other materials may also be used.

It has been found that an exhaust system constructed in accordance with the present invention using a hole 54 having dimensions of 1/4 in.

In a rectangular filter 50 (including the square filter 50 shown), there are four arcuate passages 62.64, 66.68 between the inner wall 70 of the tube piece 26 and the outer edge 72 of the filter 50.
form. Some of the shock waves in the exhaust enter these passages. The turbulent imbalance between the gas flow between each passage and the gas filtering through filter 50 enhances the decomposition of acoustic frequency shock waves and enhances the muffling effect.

Although the segment 44 fills the entire length of the tube section 26, the preferred construction is to incorporate one or more mixing chambers 74 along the length of the tube section 26, as shown in FIG. Mixing chamber 74
is formed between the two pieces 44, 44, or in a single quick-reading piece, as shown in the first variant of the invention according to FIG. may be provided.

Each mixing chamber 74 mixes separate portions of the decomposed shock wave,
These parts cancel each other out and further strengthen the sound deadening effect.

By providing the straight section 76, the section 44 is connected to the tube section 2.
It extends in the form of a continuous strip over the entire length of 6 to facilitate manufacturing. Ideally, to attenuate the maximum range of acoustic frequencies, the exhaust system 24 includes a series of filters and mixing chambers with line type sized holes in each filter to attenuate shock waves.

This pattern repeats along the length of the exhaust system to create a targeted multi-stage acoustic decomposition effect for each frequency. Reticulated piece 5
2 is also formed with a wire airfoil cross-sectional shape to move the gas within the tube section 26 and enhance the damping action.

Exhaust system 24 also acts as a catalytic converter. Common catalytic converters are constructed in two basic ways. One method involves preparing a number of alumina pellets coated with a platinum group metal. The platinum group includes platinum, palladium and rhodium. In the second method, the ceramic material is coated with alumina and then a catalyst from the platinum group is added. The catalyst facilitates the oxidation of unburned hydrocarbons in the exhaust gas.

The mesh piece 52 is coated with alumina 78 and a platinum group metal 80, as shown in FIG. 3A, and subjected to catalytic conversion in an exhaust system 24. When a steel material is used as the wrought material 46, it is desirable to coat the steel material with a ceramic material before coating the alumina 78 and platinum group metal 80.

A sixth modification of the exhaust device 24 is illustrated in FIGS. 7A, 7B, and 7C. This variant of the exhaust system includes a piece 82 formed from expanded material 46 with a circular filter 84 . The folds 48 between each filter 84 are folded approximately 180 degrees so that each circular filter 84 is generally transverse to the gas flow. The peripheral edge 86 of the circular filter 84 contacts the inner wall 70 such that each filter 84
extends over the entire internal cross-section of. Therefore, the arcuate passage 62
．． 64, 66.68 will disappear.

A fourth variation of the exhaust system 24 provides a section 88 formed from wrought metal 46 and partitioning an oval filter 90, as shown in FIGS. 8A, 8B and 8C. Each fold 4
The material at 8 is bent at an angle of less than 1800 88
expand. Due to the oval shape of the filter 90, each oval filter 90 can contact the inner wall 7o of the tube piece 26 along the inner circumference obliquely to the longitudinal direction of the tube piece 26.

Each filter 9o is therefore not transverse to the direction of flow. The passages 62.64, 66.68 are eliminated so that the entire gas flow must pass through each filter 9o.

The distance between each filter 90 can also be adjusted according to the length of the ellipse.

Figures 9A, 9B, 9c and 15 and 16
A fifth modification of the exhaust device 24 is illustrated in the figures. In this variant, a piece 94 of a continuous strip of expanded material 46 of uniform width is twisted in a helical manner, so that the outer edge 96 of the piece 94 follows the helical winding 98,100 of the tube piece 26. Contact the inner wall 70. The gas is passed through each filter 10-? formed by a helical piece 94. flows through. Each filter 102
A plurality of porous cross-sections extending around the entire circumference of the interior 970 are provided for gas flow.

FIG. 15 shows the placement of a portion of section 94 within tube section 26. FIG. FIG. 16 shows a section 94 sufficient to span the entire circumference of the inner wall.
FIG. 3 is an end view of an exhaust system 24 having one filter 102 formed by a length of .

This exhaust system 24 has many advantages. Exhaust device 24
The tube section 26 is formed as a continuous silencer tube. In fact, by experiment,
It has been found that substantially the same silencing effect as the ordinary exhaust system 16 can be obtained by the pipe section 26 having approximately the same outer diameter as the connecting station 22 in the ordinary exhaust system 16 and extending the length of the ordinary exhaust system 16. . A bulky silencer is therefore unnecessary. If the exhaust system 24 has a catalytic converter function, the catalytic converter 18 will also be unnecessary. Therefore, the exhaust device 24 is
Reducing the size and weight of the exhaust system body increases flexibility in vehicle construction, including lower profiles and more streamlined lighter vehicles. In this case, fuel can be saved. The smoother and less bulky profile of the exhaust quarters 24 means that the exhaust system is also less susceptible to road damage.

Furthermore, the continuous tubing section 26 does not require the clamps normally used with conventional exhaust systems 16. The simplicity of the exhaust system 24 saves material costs on the assembly line and allows for lower back pressures for the desired level of muffling.

If it is made to have a catalytic converter function, the exhaust system 24
Further, it has the advantage of dissipating heat generation from the contacting action along the length of the exhaust system 24 with catalytic converter action.

In this case, heat generation in any particular part of the vehicle is reduced, and greater flexibility in the construction of the vehicle is obtained. The exhaust system 24 can perform six functions within a given length and minimum diameter, whereas the tube section 22 of a conventional exhaust system 16 of similar diameter only passes gas. The tubing section 26 not only carries away gas, but also muffles exhaust noise and removes contaminants.

Due to the presence of the passages 62, 64, 66, 68, the exhaust system 2
When 4 is not activated, it increases the ``Shiki'' effect within it.

In this way, the corrosion (@) level is reduced below the levels found in ordinary mufflers, making the exhaust system 24 more durable during operation.The exhaust system 24 is also designed to fit the vehicle structure. For example, FIG. 14 shows an internal longitudinal section of the exhaust system 24 at bends 40, 42. Since the muffling effect occurs over a substantial length of the exhaust system 24, the Limited distortion or disassembly of each filter does not significantly affect the operation of the exhaust system.A small number of filters 60 are pressed closer together at the inner diameter of the bend and fan out at the outer diameter of this bend. distortion has no practical effect on the exhaust system.A small number of filters 59 are pressed closer together 9 due to the shortening of the tube sections when forming the 7 flange 53, but in this case too. There are no practical adverse effects.

Material 46 can be formed from an extruded ceramic material having a variety of pores and shapes that can be sized and configured to fit into tube section 26 prior to forming tube section 26 and welding the radius seams. When bending the tube piece 26,
The ceramic material piece breaks at the flange and can be bent without significantly reducing the muffling ability of the exhaust system.

The exhaust system 24 is designed to suit the displacement of the internal combustion engine for which it is to be used, the length of the pipe section to be installed, the desired muffling characteristics, the degree of acceptable backpressure, and the level of pollution control required. Can be made into different grades. Since the muffling and catalytic converter functions are separate, the exhaust system 24 can be used solely for muffling or for pollution control only. However, the functions of noise reduction and catalytic conversion are the same as the exhaust system 2.
42 I can make you eat needles.

Further, it is desirable that the exhaust device 24 is configured in a plurality of sections. This is desirable for ease of assembly. Furthermore, it is possible in this case to combine an exhaust system section that is used exclusively for noise reduction with a further section that is used exclusively as a catalytic converter.

In this case, the silencing section and the conversion section can be replaced independently of each other. Also, the muffling section and the catalytic conversion section do not occupy the entire length of the tube section 26. Exhaust device 240 heavy oil pipe piece 2
This can be reduced by eliminating unnecessary materials within 6. It is also possible to use an evacuation device expansion material made of multiple types of materials. For example, steel is used for the sound deadening section, but ceramic material is used for the catalytic converter section. The ideal production system would be to have the pipe sections that perform the functions of sound deadening and catalytic conversion in a series, in a linearly continuous configuration, or in a series of continuously repeating configurations, and that all parts would have a long service life. can be designed to reach the terminal stage simultaneously.

No. 3 U.S. Pat.
．． A comparison was made between an exhaust system incorporating a muffler, such as that described in the specification of 746,126, and an exhaust system constructed according to the present invention. We also conduct sound level tests on a single 5 ft.
The test was carried out using an empty tube section with a length of 100 mm and without a silencer or tube section. All tests were conducted on a General Motors engine with an exhaust volume of 283 in3.
) The test was carried out using a V8 type engine made by the company. Genrad
) A 1985 model sound level meter with a rapid response method was used for all measurements.

All tests were conducted under the same conditions in a home garage.

The sound level meter was mounted on a tripod mount approximately midway between the side of the vehicle and one wall of the garage and approximately 4 feet from the open end of the exhaust system. The exhaust system tested in each case was installed after a Y-shaped or cross-shaped joint joining each exhaust pipe section from the two exhaust manifolds to a common pipe just forward of the conventional muffler location.

A silencer constructed in accordance with Patent No. 7 Annex to de Carbonas was constructed from a length of galvanized steel plate, such as that used for roofing, by cutting a strip to a width equal to the inside diameter of an exhaust pipe with an outside diameter of 2 inches. Had made. The steel plate was 5 ft long and twisted into a 5 ft long piece of 2 inch outside diameter tubing.

Table 1 summarizes the sound level readings from a conventional silencer at various engine speeds with the automatic transmission installed on the test vehicle in the parked and driven positions.

Ordinary silencer Table 1 R, P, M, Parking dB (A) Driving dB (A) 500 68 600 70 71 800 72 73 1000 73 78 1200 77 - 2000 80 - 2500 84 - The acoustic readings for a silencer constructed according to the patent specification are recorded in Table 2.

dB(A) when parking dB(A) when driving 500 78 600 76 81 800 80 88 10008294 1200 84 - 2000 88 2500 90, one piece The sound level results of the silencer constructed according to the invention are shown in Table 3.

Table 3 of the present invention R, P, M, aB (A) when parking dB (A) when driving 500 71 600 72 74 800 75 78 1000 77 841200
78 -2000 81
, -2500 84 - Sound level measurements from a 5 ft long piece of hollow or hollow tubing are given in Table 4.

5 ft long, from Table 4 R, P, M, Parked dB(A) Driving dB(A) 500 80 600 77 83 800 80 89 1000 85 95 1200 85 - 2000 89 - 2500 90 - The measured sound levels without a pipe piece or muffler after the Y-junction are given in Table 5.

Table 5 R, P, M without pipe piece or muffler dB(A) when parked dB(A) when driven 500 796
00 78 84800
80 901000 81
961200 83 -
2000 90 -2500
92 -3.00 The sound level measured when rapidly accelerating to ORPM is as follows.

The exhaust system 110 illustrated in FIGS. 10, 11, 12, and 13 forms a second embodiment of the invention. The exhaust system 110 includes a tube section 26 having a substantially uniform outside diameter over its entire length. However, within the tube segment 26 is a liner 112't-positioned. The liner 112 includes a plurality of airfoil baffles 114 that project inwardly from the liner 112 into the gas flow to attenuate and break up acoustic shock waves.

Liner 112 is preferably constructed from a metal such as steel.

The airfoil baffle 114 is constructed from a continuous strip of liner material as shown in FIG. iis
, 120 and bending the resulting baffle plate 114 in one direction so that all the baffle plates 114 extend from one side 122 of the liner 112.

The tube section 26 and liner 112 are then rolled into a tube shape as shown in FIG. When rolled, the tube sections 26 meet along the joint surface 124 to form an airtight evacuation system. Tube section 26 and liner 112 may be welded together if desired.

The baffle plate 114 within the rolled liner 112 is
2, it extends radially inward toward the center of the exhaust device 110. The baffle plate 114 can extend entirely across the inner diameter of the rolled liner 112 or any shorter distance desired.

A number of baffles 114 are shaped to form an airfoil surface as seen in FIG. The airfoil surface dampens the gas flow and attenuates the acoustic frequencies of the shock waves. Each deflecting plate 114
can vary the frequency along the length of the exhaust device along with its airfoil I':fr surface, length, thickness and angle of attack θ relative to the gas flow. If a catalytic conversion function is desired, the baffle plate 114 can be coated with alumina and platinum metallization to perform the conversion function.

Exhaust system 110 has the advantages described above with respect to exhaust system 24. Exhaust system 110 can also be used in much the same manner as exhaust system 24 described above.

The exhaust system 130 shown in FIG. 17 is a third embodiment of the present invention. In the exhaust device 130, the wire fabric 1 is attached to the pipe piece 26.
It's packed with 32. The wire fabric 132 is connected to the device 24 described above.
, 110, it acts to weaken the acoustic frequency of shock waves in the exhaust gas. The warp yarns of this fabric may be wires with various cross sections.

The weft within the fabric can also be varied as well.

The open spaces between wires within fabric 132 vary in size and shape along the length of fabric 132 to increase attenuation across a range of acoustic frequencies. Exhaust device 130 also includes devices 24,1 described above.
It yields 10 benefits and uses.

Although the present invention has been described in detail with reference to its embodiments, it is obvious that the present invention can be modified in various ways without departing from its spirit.

[Brief explanation of the drawing]

FIG. 1 shows a first embodiment of the exhaust system of the present invention, shown in solid lines, and a conventional exhaust system with a conventional muffler, a conventional catalyst co/parter, and a flange, shown in broken lines. FIG. 3 is a front view of the vehicle. 2 is a partial perspective view showing the exhaust system of the present invention shown in FIG. 1 with a portion cut away and enlarged; FIG. 6 is a cross-sectional view taken along line 6-3 in FIG. 2; and FIG. Slow A-3A
FIG. 4 is a scaled-down horizontal sectional view taken along line 4-4gJ in FIG. 2; FIG. 5 is a horizontal sectional view of the first modification of FIG. 4, and FIGS. 6A, 6B, and 6C are cross-sectional views and filter portions of the second modification of the present exhaust system. Single plan view and side view, Figures 7A, 7B, and 7
Figure C is a cross-sectional view, a plan view of a filter section, and a side view, respectively, of a sixth variant of the present exhaust system, and Figures 8A, 8B, and 8C are respective views of a fourth variant of the present exhaust system. iL cross-sectional view, filter part plan view and side view, Figure 9A, Figure 9
Figures B and 9C are a cross-sectional view, a plan view of a filter section, and a side view, respectively, of a fifth variant of the exhaust device. FIG. 10 is a side view showing a second embodiment of the present exhaust system together with an unbent part to illustrate the inside, and FIG. Figure 12 is an enlarged 1@ side view along line 12-12 of Figure 10.
FIG. 6 is an enlarged sectional view taken along line 13-13iIi1 in FIG. 12. Fig. 14 is a horizontal sectional view showing the first embodiment of the present exhaust system as it is attached to an exhaust manifold;
The figure is a partially cutaway side view showing a fifth modification of the first embodiment of the present exhaust system, and FIG. 16 is a sectional view taken along line 16--16 in FIG. 15. FIG. 17 is a partially cutaway perspective view of the sixth embodiment of the present exhaust system. DESCRIPTION OF SYMBOLS 10... Vehicle 3.12... Internal combustion engine, 14... Exhaust manifold, 26... Pipe piece, 30... Opening, 44
... Piece, 48... Fold line, 50... Fill drawing 5, 11; (No change in content) 3 1' -Procedure
Supplementary +l(+': (Method) September 1982 61
1 Director General of the Japan Patent Office 1, Indication of the case Patent Application No. 95888 of 1982
No. 3 Person making the amendment Relationship to the case Patent applicant Nail, Laurence, Cali - 4th Administrator Tameike Tokyu Pill 5, 1-14 Akasaka, Minato-ku, Tokyo Date of amendment order August 1, 1982
0 days (shipped on August 30, 1982) 6 Number of inventions increased by amendment

Claims (1)

[Claims] (11) An exhaust system for discharging gases from an internal combustion engine having a double exhaust manifold; diameter tube section and at least one section of porous material, the plurality of expanded porous materials being positioned within said tube section along its length to muffle exhaust noise. a filter, folding said piece at preselected locations along its length to form individual filters between these folds, each of these folds being a predetermined distance from its adjacent filter. An exhaust system characterized by separated intervals. (2) A predetermined distance between adjacent filters is varied along the length of the pipe section to strengthen the silencing effect in the acoustic frequency range inside the exhaust system. The device according to claim (1). (3) The tube section is provided with at least one section along its length that is not provided with a filter, and the acoustic frequencies subdivided by the preceding six filters are filtered. Claim (1) wherein a mixing chamber is formed in which the shock wave portions cancel each other out.
Exhaust device as described in section. (4) Each filter has a rectangular cross-section forming four arcuate passages along the length of the tube section between its inner wall and the edge of each said filter to aid in the dissipation of acoustic frequency shock waves. An exhaust system according to claim (1). <5) The filter according to claim (1), wherein each filter has an oval horizontal 1#fr surface so that each filter can contact the inner wall of the tube piece around its entire circumference. Exhaust device. (6) at least one section is constituted by a strip of porous material having a uniform width equal to the inner diameter of the tube section;
Twist the piece into a helical shape and insert it into the tube piece.
An exhaust system according to claim 1, wherein the exhaust system forms a filter. (8) The exhaust device according to claim 1, wherein the porous material is made of a material selected from the group consisting of metal, ceramic material, and high temperature resistant plastic material. X]/?l n
Claim No. 1 (exhaust device according to claim 11) using a wrought steel material having holes of Exhaust device according to claim 1. 00) Exhaust according to claim 1, using a continuous tube extending from the exhaust manifold to the opening to the atmosphere as a tube section of uniform diameter. Device. (1) The exhaust device according to claim (1), wherein each hole in the porous material is dimensioned along the length of the tube section to attenuate a range of acoustic frequency shock waves. The exhaust device according to claim (1), wherein a catalytic converter is formed inside the exhaust device using a mesh piece plated with alumina and platinum metal as materials. (13) The porous material: Exhaust device according to claim (1), plated with a material selected from the group consisting of alumina and platinum group metals. !J4) Exhaust for discharging gas from an internal combustion engine having an exhaust manifold of a vehicle. In the apparatus, the tube is formed of a uniform diameter piece extending from an engine exhaust manifold to an opening to the atmosphere and conveying exhaust gases from the engine to the atmosphere, and at least one piece of porous material. a plurality of porous material filters having through-holes positioned within the piece to muffle exhaust noise along its length, said piece being folded and alternated at preselected positions along its length; forming individual filters between adjacent folds and creases, each filter sharing a common crease being spaced a predetermined distance from the formed filter on each side thereof; An exhaust system characterized in that each part of the exhaust gas is coated with alumina and a platinum group metal to form a catalytic converter section that oxidizes unburned hydrocarbons in exhaust gas. (1ω) The exhaust device according to claim (+4), wherein the predetermined distance between each filter is changed to strengthen the silencing effect in the range of acoustic frequency shock waves inside the exhaust device. mixing the separate parts of the shock wave within at least one part without providing a filter;
07) The exhaust device according to claim 1 is arranged so as to form a mixing chamber from which the parts cancel each other out. Form a folded rectangular cross section fill,
Four arcuate passages are formed in said piece between the edge of each filter and the inner wall of the tube piece through which the exhaust gas flows, and each of said filters and each passage Exhaust device according to claim 14J, which further attenuates acoustic frequency shock waves due to the pressure and imbalance between the flow through the Ql. An exhaust device according to claim 14, characterized in that filters are formed in cross-section, and the edges of these filters are in contact with the inner wall of the pipe section along an elliptical curve. Claim 14 wherein the width is uniform and the tube piece is twisted to form a helical shape contained within the tube piece.
Exhaust device as described in section. (The exhaust device according to claim (14), wherein the 2υ porous material is selected from the group of materials consisting of metal, ceramic material, and high temperature resistant plastic material. 121) The mesh piece forming each filter The exhaust device according to claim 1, having an airfoil-shaped cross section exposed to the air, to further attenuate acoustic frequency shock waves. (2) The exhaust device according to claim (14), in which wrought copper is used as the wrought material, and each piece of the wrought copper has dimensions of about 4X%, n.123) An exhaust system according to claim 14, characterized in that the tube section of uniform diameter is continuous from the exhaust manifold to the opening to the atmosphere. (2) Each hole in the porous material is arranged along the length of the tube section. An exhaust system according to claim 14, characterized in that the target frequency over a range of acoustic frequency shock waves is attenuated by changing the technique.
The exhaust system according to claim 14, wherein the section primarily muffles exhaust gas, while the second section mainly reduces hydrocarbons in the exhaust gas. 126) The exhaust device according to claim 17, wherein the pieces are bent to form a filter having a square cross section. (2η) An exhaust system according to claim 1, in which the pieces are bent to form a filter having a circular cross section. In an exhaust system for discharging air, from a uniform diameter tube section extending from an engine exhaust manifold to an opening to the atmosphere and conveying exhaust from the engine to the atmosphere, and at least one elongated strip of wrought metal. a plurality of porous metal filters formed within said tube section along its length and with a plurality of perforated metal filters positioned between each hole; said section being folded at preselected locations along its length; All the individual filters are formed between the 9th fold, the adjacent filters are separated by the folds, and the mesh piece of the filter selected from among the filters is coated with alumina and platinum group metal. A filter and a partition having a rectangular cross section are formed by bending the pieces with a uniform width so as to perform a contact conversion function, and four strips are formed between the inner wall of the tube piece and the edge of each filter. An exhaust system characterized in that an arcuate passage is formed to further attenuate acoustic frequency shock waves, and each hole between the mesh pieces of each filter is approximately 4/2 inch. In an exhaust system for discharging fumes from an internal combustion engine having an exhaust manifold, a piece of tubing of uniform diameter extending from the engine exhaust manifold to an opening to the atmosphere and carrying the fumes from the engine, muffles the exhaust noise. +f in the gas flow so that
c. at least one lie force section within said tube section having a plurality of airfoil-shaped baffles extending in the air. (7) The exhaust device according to claim 29i, wherein the lie is made of a material from the group consisting of metal, high temperature resistant plastic material, and ceramic material. A deflecting plate is punched out from the lie force, and the lie force and the pipe piece are rolled and welded along the seam to form the exhaust apparatus main body. (3) Each deflector plate has an openwork section along the length of the tube section,
29. The exhaust system according to claim 29, wherein the length, thickness, and exhaust angle of attack and frequency relative to the gas flow are varied to maximize exhaust sound muffling effect. (33) Selected deflecting plates among the deflecting plates are coated with alumina and platinum group metal to perform a catalytic conversion function inside the exhaust system and reduce hydrocarbon pollution. Exhaust device. (34) An exhaust system according to claim 1, in which a selected deflector plate is coated with a substance made of alumina and a platinum group metal. Exhaust device according to claim C21, characterized in that an internal part is provided to form a mixing chamber and to form an acoustic frequency shock wave. an engine exhaust 7--a neck piece of uniform diameter extending from the hold to an opening to the atmosphere and conveying the exhaust gas, and at least a section of neck piece having a plurality of airfoil baffles punched through and provided in said pipe piece. a metal liner, and the lie and tube sections are rolled and welded together to form the exhaust system body, each of the airfoil-shaped baffles extending radially inwardly into the exhaust stream to generate acoustic shock waves. An exhaust system characterized by attenuating, mutually mixing and destroying. +37) Cross-section of the airfoil deflector along the length of the lie force,
Exhaust device according to claim 1 (column) in which the length, thickness, angle of attack with respect to gas flow, and frequency are changed to attenuate the range of body-frequency sound waves. (Blue) Selection of airfoil-shaped deflectors Exhaust device according to Claim No. 4t2, in which alumina and platinum group interstices are coated on a deflector plate to perform a catalytic conversion function. In an exhaust system for use in an engine exhaust system, a piece of tubing of uniform diameter extending from an engine exhaust manifold to an opening to the atmosphere carries the exhaust air, and a wire disposed within the piece of tubing and extending along substantially its entire length to muffle the exhaust air. (40) The diameter of the i'fF+ surface of the wires in the wire fabric is changed to attenuate the range of acoustic frequency shock waves, and the holes between each wire are also changed in size to reduce the acoustic frequency. Claim 3 (claim 3) is an exhaust system that attenuates the range of frequency shock waves. Device.