JP3699209B2 - Exhaust gas purification device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust gas purification device used for an internal combustion engine of a motorcycle.
[0002]
[Prior art]
A technique for mounting an exhaust gas purification device on a vehicle for the purpose of preventing air pollution is known, and JP-A-3-85320 “Exhaust gas purification device for internal combustion engine” is one of them.
[0003]
In this apparatus, as shown in FIG. 1 of the publication, an inner pipe 5 in which a plurality of small holes are formed by punching is disposed in an exhaust pipe 3, and a catalyst is supported on the inner pipe 5 so as to be contained in the exhaust gas. It oxidizes unburned components.
[0004]
[Problems to be solved by the invention]
The exhaust pipe 3 is an exhaust pipe (that is, a bend pipe) bent into a substantially C shape as shown in FIG. 6, and includes an inner pipe 5 carrying a catalyst. The reason why the inner pipe 5 is built in the exhaust pipe 3 is to keep the exhaust gas purification performance high by reacting the catalyst carried on the inner pipe 5 with high-temperature exhaust gas.
However, if this is done, the inner pipe 5 having the punching hole is disposed near the exhaust port 2, so that the exhaust gas flow is disturbed by the punching hole, which greatly affects the output characteristics of the engine. This will also cause a decrease in output.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to provide an exhaust gas purification apparatus that efficiently reacts with a catalyst to maintain high exhaust gas purification performance and does not affect the output characteristics of the engine.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the first aspect of the present invention is to form a small-diameter and large-diameter exhaust gas purifying apparatus that is formed into a cylindrical shape with punching metal and carries a catalyst from the exhaust pipe rear portion of the exhaust pipe to the expansion chamber. The large-diameter exhaust gas purification device is arranged in series, and the large-diameter exhaust gas purification device is overlapped, and the overlapping portion of the large-diameter exhaust gas purification device includes a portion having no punching hole. It is characterized in that a reinforcing ring is attached to a portion having no gap.
[0007]
Since the two exhaust gas purifying devices are arranged in series from the rear part of the exhaust pipe exhaust pipe to the expansion chamber, each exhaust gas purifying apparatus is located near the exhaust port at the front part of the exhaust pipe part. I won't do it. Therefore, there is no concern that the output characteristics of the engine will be affected.
[0008]
In addition, since the oxidation reaction was carried out by the first-stage exhaust gas purification device and the oxidation reaction was continuously carried out by the second-stage exhaust gas purification device, the catalyst was placed at a position where the temperature of the exhaust gas was lowered. Even so, the second-stage exhaust gas purification device can be heated to a temperature at which the catalyst reacts efficiently, and the unburned components in the exhaust gas can be efficiently oxidized and converted into harmless components.
[0009]
Furthermore, if the large-diameter exhaust gas purification device becomes elliptical due to thermal deformation, there is a risk of contact with the inner small-diameter exhaust gas purification device. Therefore, a reinforcing ring is attached to the overlap portion of the large-diameter exhaust gas purification device so as to suppress inconvenient deformation and maintain the performance of the exhaust gas purification device.
[0010]
According to a second aspect of the present invention, a small-diameter and large-diameter exhaust gas purification device that is formed in a cylindrical shape with punching metal and that carries a catalyst is arranged in series from the rear portion of the exhaust pipe exhaust section to the expansion chamber, and the small-diameter exhaust gas The exhaust gas purification device having a large diameter is overlapped with the gas purification device, and the density of punching holes in the overlap portion is made coarser than other portions.
[0011]
Since the two exhaust gas purifying devices are arranged in series from the rear part of the exhaust pipe exhaust pipe to the expansion chamber, each exhaust gas purifying apparatus is located near the exhaust port at the front part of the exhaust pipe part. I won't do it. Therefore, there is no concern that the output characteristics of the engine will be affected.
[0012]
In addition, since the oxidation reaction was carried out by the first-stage exhaust gas purification device and the oxidation reaction was continuously carried out by the second-stage exhaust gas purification device, the catalyst was placed at a position where the temperature of the exhaust gas was lowered. Even so, the second-stage exhaust gas purification device can be heated to a temperature at which the catalyst reacts efficiently, and the unburned components in the exhaust gas can be efficiently oxidized and converted into harmless components.
[0013]
Furthermore, if the large-diameter exhaust gas purification device becomes elliptical due to thermal deformation, there is a risk of contact with the inner small-diameter exhaust gas purification device. Therefore, the density of the punching holes in the overlap portion of the large-diameter exhaust gas purification device is made coarser than other portions so as to suppress inconvenient deformation and maintain the performance of the exhaust gas purification device.
[0014]
Embodiment
Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a side view of a motorcycle equipped with an exhaust gas purifying apparatus according to the present invention. The motorcycle 1 supports a front fork 4 on a front portion of a main frame 2 via a head pipe 3, and this front fork. A front wheel 5 and a front fender 6 are attached to 4, a two-cycle engine 8 is attached to the lower side of the main frame 2 via engine hanger parts 7, 7, an exhaust pipe 50 is extended from the two-cycle engine 8, and the main frame 2 A cantilever swing arm 11 is pivotally supported via a pivot 9 at the rear end portion, and a rear wheel 12 is attached to the swing arm 11.
[0015]
In the figure, 14 is a fuel tank, 15 is an air cleaner, 16 is a vaporizer, 17 is a seat, 18 and 19 are seat rails, 20 is a passenger seat, 21 is a rear suspension, 22 is a drive chain, and 23 is a silencer. .
Also, 25 is a meter, 26 is a headlight, 27 is a winker provided in the left and right openings of the cowling 28, 30 is a brake disk, 31 is a caliper, 32 is a radiator, 33 is an upper edge of the exhaust port of the engine 8 An exhaust timing control valve drive pulley provided, 34 an exhaust timing control valve drive motor, 35 an intake chamber, 36 a battery, 36 an oil tank, 38 a taillight, 39 a seat cowl, and 40 a rear axle .
[0016]
FIG. 2 is a plan view of a motorcycle equipped with an exhaust gas purifying device according to the present invention. After the exhaust pipe 50 extends rearward from the center of the vehicle body, it bypasses the rear suspension 21 and the cantilever swing arm 11, Extend the vehicle's right side backwards as viewed from the passenger.
In the figure, 42 and 42 are rider steps, 43 is a brake pedal, 44 is a change pedal, and 45 is a steering handle.
[0017]
FIG. 3 is a side view of an exhaust pipe provided with the exhaust gas purifying apparatus according to the present invention.
The exhaust pipe 50 described in FIG. 1 incorporates an exhaust gas purification device 60 and includes a curved tubular exhaust part 51, an expansion chamber 52, and a tail pipe part 56. The expansion chamber 52 includes a diver part 53 whose flow path cross-sectional area gradually increases in the gas flow direction, a straight part 54 whose cross-sectional area is substantially constant, and a converter part 55 whose cross-sectional area gradually decreases. Diver portion 53 may be formed from the rear portion of exhaust portion 51 as indicated by a two-dot chain line. The exhaust gas purification device 60 will be described with reference to FIG.
The exhaust pipe is an abbreviation for an exhaust pipe, but here refers to only a bent pipe directly under the engine, not the entire exhaust pipe. Diver is an abbreviation for divergent, and convert is an abbreviation for convergent.
Reference numeral 58 denotes a hanging metal fitting.
[0018]
FIG. 4 is a cross-sectional view of an essential part of the exhaust gas purifying apparatus according to the present invention.
The exhaust gas purification device 60 includes a small-diameter first catalyst-equipped cylinder member (small-diameter exhaust gas purification device) 61 disposed at the rear end of the exhaust pipe 51 and a large-diameter second catalyst disposed in the expansion chamber 52. The cylinder member (large-diameter exhaust gas purification device) 71 is connected to the first catalyst-equipped cylinder member 61 and the second catalyst-equipped cylinder member 71 from the rear portion of the exhaust pipe 51 of the exhaust pipe 50 to the expansion chamber 52. Are arranged in series and substantially on a straight line.
The second cylinder member with catalyst 71 has a front end portion overlapped with the rear end portion of the first cylinder member with catalyst 61. The overlapped portions (hereinafter referred to as “overlap portions”) 94 of the first and second catalyst-equipped tubular members 61 and 71 are regions where the density of punching holes is coarser than other portions.
[0019]
That is, the overlap portion 94 of the first catalyst-equipped tubular member 61 is an area of the low-density hole-equipped portion 103 and the hole-less portion 101b, and the second catalyst-equipped tubular member 71 has an overlap portion 94 of low-density. This is a region of the holed portion 87 and the holeless portion 85a. The second catalyst-equipped tubular member 71 is obtained by fitting a reinforcing ring 93 into the holeless portion 85 a of the overlap portion 94.
The non-hole portions 101b and 85a are regions without punching holes, and the low-density hole portions 103 and 87 are regions where the density of punching holes is coarser than other portions.
[0020]
As the reinforcing ring 93, a member fitted into the overlap portion 94 of the second catalyst-equipped cylinder member 71 is used. As other members, for example, a member wound around the second catalyst-equipped cylinder member 71, It is good also considering the protruding item | line member formed in the outer periphery of the cylindrical member 71 with a catalyst of 2 as a reinforcement ring.
In addition, the small-diameter first catalyst-equipped cylinder member 61 is arranged on the upstream side and the large-diameter second catalyst-equipped cylinder member 71 is arranged on the downstream side, but the large-diameter second catalyst-equipped cylinder is arranged on the upstream side. It is also possible to arrange the member 71 and arrange the first catalyst-equipped cylinder member 61 having a small diameter on the downstream side.
[0021]
5 is a cross-sectional view taken along line 5-5 of FIG. 4 and shows the structure of the support stay that supports the first catalyst-equipped cylinder member 61. FIG.
The support stay 62 includes a W-shaped support fitting 63 and an outer ring 64 welded to the support fitting 63. The outer ring 64 is divided into two parts in the vertical direction for the convenience of assembly. An annular elastic member 65 is provided between the outer ring 64 and the inner ring 109 (see also FIG. 6). Like the elastic material 75, the elastic material 65 is preferably stainless wool having heat resistance and cushioning properties.
[0022]
The exhaust pipe 51 is composed of a right half cylinder 51R and a left half cylinder 51L, and the right half cylinder 51R is a member that fixes the support fitting 63 of the support stay 62 by welding.
The support stay 62 is a member that supports the first catalyst-equipped cylinder member 61 at the center of the cross section of the exhaust pipe 51.
[0023]
FIG. 6 is a side view of the first tubular member with catalyst according to the present invention.
The first catalyst-equipped cylinder member 61 is formed by forming a punching metal carrying a catalyst in a cylindrical shape, butting the end portions 105 and 106 and welding the butted portions.
In this first tubular member 61 with a catalyst, the region 101a in which the center inner rings 109, 109 are inserted and the region 101b at the right end portion are formed as a holeless portion, and along the butt weld portion 107 of the end portions 105, 106. A region having a constant width is formed as holeless portions 101c and 101c.
[0024]
In the first tubular member 61 with catalyst, the edge portion connected to the non-hole portions 101a and 101b is a low density hole portion 103 (... indicates a plurality. The same applies hereinafter), and the other portion is a hole portion 102a. , 102b.
The non-hole portions 101a, 101b, 101c, and 101c are regions where the punching holes 90 are not formed, and the low-density hole portions 103 are regions where the punching holes 90 are opened in a low density (ie, “rough” state). is there. The holes 102a and 102b are areas where the punching holes 90 are opened at a relatively high density.
Open arrows indicate the flow direction of the exhaust gas.
[0025]
7 is a cross-sectional view taken along the line 7-7 in FIG. 4 and shows the configuration of the front support stay that supports the second catalyst-equipped cylinder member 71. FIG.
The front support stay 72F includes a W-shaped support fitting 73F and an outer ring 74 welded to the support fitting 73F. The outer ring 74 is divided into two parts on the left and right for the convenience of assembly. An annular elastic member 75 is provided between the outer ring 74 and the inner ring 92. The elastic material 75 is preferably stainless wool having heat resistance and cushioning properties.
[0026]
The expansion chamber 52 is a member formed by combining the upper divided tube body 52T and the lower divided tube body 52B, and is used to stop the W-shaped support fitting 73F of the front support stay 72F by welding only on the upper divided tube body 52T. .
By welding the W-shaped support fitting 73F of the front support stay 72F to the upper divided tubular body 52T, the front support stay 72F supports the second catalyst-equipped tubular member 71 at the substantially cross-sectional center of the expansion chamber 52. It is a member.
[0027]
8 is a cross-sectional view taken along line 8-8 in FIG. 4 and shows the configuration of the rear support stay that supports the second catalyst-equipped cylinder member 71. FIG.
The rear support stay 72R is basically the same structure as the front support stay 72F except that the shape of the W-shaped support fitting 73R is slightly different from that of the front support stay 72F. The description is omitted.
[0028]
FIG. 9 is a side view of the second tubular member with catalyst according to the present invention.
The second tubular member 71 with catalyst is formed by forming a punching metal carrying a catalyst into a tubular shape, butting the end portions 81 and 82 and welding the butted portions.
The second catalyst-equipped cylinder member 71 has a hole-free portion in each of the regions 85a, 85b, and 85c into which the reinforcing ring 93 at the left end, the inner ring 92 at the center, and the inner ring 92 at the right end are fitted. , 82 are welded to the constant width region along the butt welded portion 91 as holeless portions 85d and 85d.
[0029]
The second cylindrical member 71 with a catalyst is such that the edge connected to the non-hole portions 85a, 85b, 85c is a low density hole portion 87, and the other portions are hole portions 86a, 86b.
The holeless portions 85a, 85b, 85c, 85d, and 85d are regions where the punching holes 90 are not formed, and the low density hole portions 87 are regions where the punching holes 90 are opened at a low density. The holed portions 86a and 86b are regions in which the punching holes 90 are opened at a relatively high density.
The reinforcing ring 93 described above is a member that suppresses thermal deformation that occurs at the left end of the catalyst-equipped cylinder member 71 when the catalyst-equipped cylinder member 71 is heated with exhaust gas.
Open arrows indicate the flow direction of the exhaust gas.
[0030]
The manufacturing process of the first catalyst-equipped tubular member 71 will be described in the order of FIG. 10 → FIG. 6 → FIG. 5 → FIG.
FIG. 10 is a first manufacturing explanatory view of the exhaust gas purifying apparatus according to the present invention, and shows a punching metal 100 for manufacturing the first catalyst-equipped tubular member 61.
First, a plurality of punching holes 90 are punched in a predetermined area of the rectangular punching metal 100 to a low density or high density state, and the punching metal 100 has holes 101a, 101b, 101c, 101c and low density holes. Part 103 ... and holes 102a, 102b.
[0031]
The non-hole portions 101a, 101b, 101c, 101c, and 101c are provided at the center portion, the right end portion, and the upper and lower end portions of the punching metal 100. The low density hole portions 103 are provided around the hole portions 102a and 102b.
[0032]
Next, the punching metal 100 is rounded and the end portion 105 and the end portion 106 are butt welded as shown in FIG. 6 to form the first cylindrical member 61a. Next, a thin film of activated alumina is formed on the inner and outer peripheral surfaces of the first cylinder member 61a, and a catalyst component is supported on the activated alumina layer to obtain a second cylinder member 61 with a catalyst.
Next, the inner rings 109, 109 are arranged and welded to the left holeless portion 101a of the first catalyst-equipped tubular member 61.
[0033]
Subsequently, as shown in FIG. 5, heat-resistant elastic members 65 and 65 are fitted to the inner rings 109 and 109 (only one of them is shown), and the elastic members 65 and 65 are held by the outer ring 64 divided in half. Next, the first catalyst-equipped tubular member 61 is disposed in the exhaust pipe 51 with the outer ring 64, 64 using the support fitting 63 (see FIG. 4).
[0034]
Next, the manufacturing process of the second catalyst-equipped tubular member 71 will be described in the order of FIG. 11 → FIG. 12 → FIG. 9 → FIG. 6 → FIG.
FIG. 11 is a second production explanatory view of the exhaust gas purifying apparatus according to the present invention, and shows a punching metal 80 forming the second tubular member 71 with catalyst.
First, a plurality of punching holes 90 are punched in a predetermined area of the rectangular punching metal 80 to a low density or high density state, and the punching metal 80 has no holes 85a, 85b, 85c, 85d, 85d and low density. It has hole portions 87... And hole portions 86 a and 86 b.
[0035]
The holeless portions 85a to 85d are provided at the left end portion, the center portion, the right end portion, and the upper and lower end portions of the punching metal 80, respectively. The low density hole portions 87 are provided on the upper, lower, left and right edges connected to the hole portions 86a and 86b.
[0036]
FIG. 12 is a third production explanatory view of the exhaust gas purifying apparatus according to the present invention, and shows a state where the second catalyst-equipped tubular member 71 is rounded into a tubular shape.
The rectangular punching metal 80 described with reference to FIG. 11 is rounded, and the upper end portion 81 and the lower end portion 82 are butt welded to form the second cylindrical member 71a. Next, a thin film of activated alumina is formed on the inner and outer peripheral surfaces of the second cylindrical member 71a, and a catalyst component is supported on the activated alumina layer to obtain a second cylindrical member 71 with a catalyst.
[0037]
Next, the inner ring 92, 92 is put on the hole-less portion 85b and the hole-less portion 85c at the right end of the second catalyst-equipped cylinder member 71, the notch bottom portion 92a of the center inner ring 92 and the second catalyst-carrying cylinder. The member 71 is welded. 92b and 92b are butt welds of the inner rings 92 and 92.
Subsequently, the reinforcing ring 93 is placed on the hole-less portion 85a at the left end of the second catalyst-equipped cylinder member 71, and the left end of the second catalyst-equipped cylinder member 71 and the left end of the reinforcement ring 93 are welded.
[0038]
As a result of the manufacturing process described above, as shown in FIG. 9, the reinforcing ring 93 and the inner rings 92, 92 are disposed in the holeless portions 85a, 85b, 85c of the second catalyst-equipped cylinder member 71, respectively.
[0039]
Next, as shown in FIGS. 6 and 7, heat-resistant elastic materials 75 and 75 are fitted to the inner rings 92 and 92, and the elastic materials 75 and 75 are held by the outer rings 74 and 74 divided in two. Next, the support fittings 73F and 73R are welded into the expansion chamber 52, and the second catalyst-equipped cylinder member 71 is disposed in the expansion chamber 52 (see FIG. 4).
[0040]
Next, the operation of the exhaust gas purification device 60 according to the present invention will be described.
Exhaust gas that has entered the exhaust pipe 51 of the exhaust pipe 50 shown in FIG. 4 (the white arrow indicates the flow direction of the exhaust gas) is discharged from the first catalyst-equipped cylinder member 61 and the second catalyst-equipped cylinder member 71. Passes in and out.
[0041]
Here, the first catalyst-equipped cylinder member 61 and the second catalyst-equipped cylinder member 71 are arranged in series and in a substantially straight line from the rear portion of the exhaust pipe 51 of the exhaust pipe 50 to the expansion chamber 52. Therefore, each of the cylinder members 61 and 71 with catalyst does not disturb the exhaust gas at a position close to the exhaust port (the front portion of the exhaust section 51 in FIG. 3). This does not affect the output characteristics of the engine.
[0042]
In addition, since the rear end portion of the first catalyst-equipped cylinder member 61 and the front end portion of the second catalyst-equipped cylinder member 71 are overlapped, the first catalyst-equipped cylinder member 61 undergoes an oxidation reaction, and continues. The oxidation reaction was continuously carried out by the cylindrical member 71 with two catalysts. Therefore, even if the second catalyst-equipped cylinder member 71 is disposed at a position where the temperature of the exhaust gas is lowered, the second catalyst-equipped cylinder member 71 can be heated to a temperature at which the catalyst reacts efficiently, The combustion component can be efficiently oxidized and converted into a harmless component.
[0043]
By the way, if the second catalyst-equipped cylinder member 71 becomes an ellipse due to thermal deformation, there is a risk of contact with the inner first catalyst-equipped cylinder member 61. Therefore, a reinforcing ring 93 is attached to the overlap portion 94 of the second catalyst-equipped cylinder member 71, and the density of the punching holes 90 in the overlap portion 94 of the second catalyst-equipped cylinder member 71 is coarser than other portions. Thus, inconvenient deformation is suppressed and the performance of the exhaust gas purification device 60 is maintained.
It should be noted that the reinforcing ring 93 is attached to the overlap portion 94 of the second catalyst-equipped cylinder member 71 and the density of the punching holes 90 in the overlap portion 94 of the second catalyst-equipped cylinder member 71 is higher than that of other portions. Even if only one of the roughening methods is performed, the same effect can be obtained.
[0044]
On the other hand, in the second catalyst-equipped cylinder member 71 shown in FIG. 9, the side portions of the holeless portions 85a, 85b, and 85c are adjacent to the low density hole portions 87, respectively. Accordingly, when the second catalyst-equipped cylinder member 71 is heated with the exhaust gas, the heat distribution in the region connecting from the left holeless portion 85a to the low density hole portion 87 changes gradually, so that cracks occur from the punching holes 90. There is no worry that will occur.
[0045]
Similarly, the heat distribution in the region connected from the central holeless portion 85b to the holed portions 86a and 86b changes gently, and the heat distribution in the region connected from the right holeless portion 85c to the holed portion 86b changes gently. To do. Therefore, there is no concern that cracks will occur from the punching holes 90 in these regions.
Moreover, since the butt weld part 91 is adjacent to the holeless parts 85d and 85d, the butt weld part 91 can be separated from the holed part. Therefore, when the second catalyst-equipped tubular member 71 is heated with exhaust gas, there is no concern that a crack will occur from the holed portion toward the butt weld portion 91.
[0046]
In this embodiment, the exhaust gas purification device is used for an exhaust pipe of a motorcycle. However, the exhaust gas purification device of the present invention may be used for an exhaust pipe of another internal combustion engine such as an industrial machine. Of course.
[0047]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
Since the first exhaust gas purifying device is arranged in series from the rear portion of the exhaust pipe exhaust section to the expansion chamber, each exhaust gas purifying device has the exhaust gas disturbance at a position close to the exhaust port. I won't do it. Therefore, there is no concern that the output characteristics of the engine will be affected.
[0048]
In addition, since the oxidation reaction is performed in the first stage exhaust gas purification device and the oxidation reaction is continuously performed in the second stage exhaust gas purification device, the catalyst is placed at a position where the temperature of the exhaust gas becomes low. Even if it arrange | positions, the exhaust gas purification apparatus of a 2nd stage can be heated to the temperature which a catalyst reacts efficiently, and the unburned component in exhaust gas can be oxidized efficiently, and can be converted into a harmless component.
[0049]
Furthermore, if the large-diameter exhaust gas purification device becomes elliptical due to thermal deformation, there is a risk of contact with the inner small-diameter exhaust gas purification device. Therefore, a reinforcing ring is attached to the overlap portion of the large-diameter exhaust gas purification device so as to suppress inconvenient deformation and maintain the performance of the exhaust gas purification device.
[0050]
According to the second aspect, since the two exhaust gas purifying devices are arranged in series from the rear portion of the exhaust pipe exhaust pipe to the expansion chamber, each exhaust gas purifying device is arranged to turbulent exhaust gas at a position close to the exhaust port. I won't do it. Therefore, there is no concern that the output characteristics of the engine will be affected.
[0051]
In addition, since the oxidation reaction was carried out by the first-stage exhaust gas purification device and the oxidation reaction was continuously carried out by the second-stage exhaust gas purification device, the catalyst was placed at a position where the temperature of the exhaust gas was lowered. Even so, the second-stage exhaust gas purification device can be heated to a temperature at which the catalyst reacts efficiently, and the unburned components in the exhaust gas can be efficiently oxidized and converted into harmless components.
[0052]
Furthermore, if the large-diameter exhaust gas purification device becomes elliptical due to thermal deformation, there is a risk of contact with the inner small-diameter exhaust gas purification device. Therefore, the density of punching holes in the overlap portion of the large-diameter exhaust gas purification device is made coarser than other portions so as to suppress inconvenient deformation and maintain the performance of the exhaust gas purification device.
[Brief description of the drawings]
FIG. 1 is a side view of a motorcycle equipped with an exhaust gas purification apparatus according to the present invention. FIG. 2 is a plan view of a motorcycle equipped with an exhaust gas purification apparatus according to the present invention. FIG. 4 is a cross-sectional view of the main part of the exhaust gas purifying apparatus according to the present invention. FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. 4. FIG. FIG. 7 is a sectional view taken along line 7-7 in FIG. 4. FIG. 8 is a sectional view taken along line 8-8 in FIG. 4. FIG. 9 is a sectional view of the second tubular member with catalyst according to the present invention. Side view FIG. 10 is a first production explanatory diagram of an exhaust gas purification device according to the present invention. FIG. 11 is a second production explanatory diagram of an exhaust gas purification device according to the present invention. FIG. 12 is an exhaust gas purification device according to the present invention. 3rd manufacturing explanatory drawing [Explanation of symbols]
60 ... exhaust gas purification device, 61 ... first catalyst-equipped cylinder member (small-diameter exhaust gas purification device), 71 ... second catalyst-equipped cylinder member (large-diameter exhaust gas purification device), 80, 100 ... punching metal , 85a, 101b ... No hole part, 87,103 ... Low density hole part, 90 ... Punching hole, 93 ... Reinforcing ring, 94 ... Overlapping part.

Claims (2)

A small-diameter and large-diameter exhaust gas purification device that is formed in a cylindrical shape with a punching metal and is arranged in series across the expansion chamber from the exhaust pipe rear portion of the exhaust pipe, and is large in the small-diameter exhaust gas purification device. The exhaust gas purification device of the diameter,
An exhaust gas purification apparatus comprising: a portion having no punching hole in an overlap portion of the large-diameter exhaust gas purification device; and a reinforcing ring attached to the portion having no punching hole . A small-diameter and large-diameter exhaust gas purification device that is formed in a cylindrical shape with a punching metal and is arranged in series across the expansion chamber from the exhaust pipe rear portion of the exhaust pipe, and is large in the small-diameter exhaust gas purification device. An exhaust gas purifying apparatus characterized in that the exhaust gas purifying apparatus having a diameter is overlapped, and the density of punching holes in the overlap portion is made coarser than other portions.

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