JP2003120273A - Exhaust gas purification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a small-diameter tubular carrier at a low production cost in an exhaust gas purifying apparatus for purifying gas by installing a tubular catalyst body produced by applying a catalyst to a tubular carrier in an exhaust gas passage. In addition, it is possible to manufacture the exhaust gas purifying apparatus with high dimensional accuracy, and further improve the purification performance of the exhaust gas purifying apparatus by adding a new device to the shape. SOLUTION: As the tubular carrier, a tubular material obtained by cutting a steel pipe member formed by extrusion or the like into a predetermined length and having a large number of inwardly projecting deformed portions is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying apparatus for a small internal combustion engine used in a motorcycle or the like. In the present specification, a "tubular material" is a material for manufacturing a carrier by deformation processing, and a "tubular carrier" is a material obtained by subjecting a tubular material to processing such as deformation and perforation. The “catalyst body” means the above-mentioned tubular carrier coated with a catalyst.

[0002]

2. Description of the Related Art An exhaust gas purifying apparatus for a small internal combustion engine used in a motorcycle or the like has a structure in which a catalyst is applied to a carrier and carried, that is, a so-called catalyst body is installed in an exhaust gas flow to exhaust the exhaust gas. It is a device that purifies harmful components in gas. As the shape of the carrier, a tubular carrier 01 having punched holes 02 as shown in FIG. 26, which is coated with a catalyst and is arranged in parallel with the flow G of exhaust gas, is generally used (Japanese Patent Laid-Open No. Hei 10 (1999) -242242). No. 10-30432).

Conventionally, in such a tubular carrier with punching holes, as shown in FIG. 27, a roll-shaped metal plate material 03 is flattened, punched with a punching hole 04, and then cut 05 to a predetermined size. , U-bending 06, O-bending 07, etc. were bent to bring both edges into contact with each other, and welded 08 to finish the tubular carrier 01.

[0004]

The conventional method of manufacturing the tubular carrier 01 shown in FIG. 27 has the drawback that the number of processing steps is large and the manufacturing cost is high. Also, a small displacement, for example 4
When used in a motorcycle with a stroke of 125 cc or less, it is difficult to reduce the diameter so that it can be installed in a narrow exhaust device. Especially, when a tubular carrier having a diameter of less than 20 mm is manufactured by a conventional method, the dimensional accuracy is reduced. There was a problem.

Further, a conventional tubular carrier with punching holes 01
When the tubular catalyst body 09 with punching holes made by applying the catalyst to the inner and outer surfaces of the is placed in the exhaust gas flow, there is no unevenness on the surface of the pipe, so as shown in FIG. There is also a problem that the catalyst body becomes large in size in order to sufficiently bring the exhaust gas G into contact with the catalyst.

The present invention makes it possible to manufacture the above-mentioned small-diameter tubular carrier with a low manufacturing cost and high dimensional accuracy, and by adding a new device to the shape, the purification performance of the exhaust gas purifying apparatus. It is intended to improve the

[0007]

Means for Solving the Problems and Effects The present invention is to solve the above-mentioned problems, and the invention according to claim 1 is to exhaust a tubular catalyst body produced by coating a catalyst on a tubular carrier. In an exhaust gas purifying apparatus for purifying gas installed in a passage, the tubular carrier has a large number of inward projecting deformed portions formed on a tubular material obtained by cutting a steel tubular member formed by extrusion molding or the like into a predetermined length. It is characterized by being

Since the present invention is constructed as described above,
As the tube material, you can use a commercially available product that has already been molded as a tube, and since the inward protruding deformation part can be easily processed from the outside of the tube, you can reduce the number of manufacturing steps and the manufacturing cost. can do. Further, when using a commercially available pipe material, it is possible to accurately manufacture a small diameter product having a diameter of less than 20 mm. Further, by optimizing the shape of the projecting deformed portion, the exhaust gas flowing inside the tubular catalyst body is disturbed, so that the catalyst body can be downsized or the exhaust gas purification rate can be improved.

According to a second aspect of the present invention, in the exhaust gas purifying apparatus according to the first aspect, the tubular carrier is located inside the resonance pipe and is adjacent to the rear end of each of the inwardly projecting deformation portions. A communication hole that communicates the inside and outside of the pipe is formed.

Since the present invention is constructed in this way,
By optimizing the shape of the protruding deformation part with a communication hole, turbulence is given to the exhaust gas flowing inside the tubular catalyst body,
In addition, by reducing the amount of gas leaking to the outside, it is possible to reduce the effect on exhaust pulsation and improve the exhaust gas purification rate while improving the performance of the internal combustion engine.

According to a third aspect of the present invention, in the exhaust gas purifying apparatus according to the first or second aspect, the inwardly projecting deformation portion is between the original pipe wall and the inwardly projecting deformation portion. The cross-sectional area of the space formed in 1 is characterized in that there is a portion of a shape in which the cross-sectional area gradually increases from zero cross-sectional area from the upstream end of the exhaust gas toward the downstream side. By doing so, the present invention can reduce the increase in resistance to the gas flow.

According to a fourth aspect of the present invention, in the exhaust gas purification device according to the first or second aspect, the inwardly projecting deformation portion is between the original pipe wall and the inwardly projecting deformation portion. The cross-sectional area of the space formed gradually increases from zero cross-sectional area from the upstream end of the exhaust gas toward the downstream side, and the maximum cross-sectional area portion of the space becomes the rear end of the inwardly projecting deformed portion. It is characterized by being present. According to the present invention, by doing so, the exhaust gas behind the projecting deformation portion is disturbed, so that the exhaust gas purification rate can be improved.

According to a fifth aspect of the present invention, in the exhaust gas purifying apparatus according to the first or second aspect, the inwardly projecting deformation portion is between the original pipe wall and the inwardly projecting deformation portion. The cross-sectional area of the space formed gradually increases from zero cross-sectional area toward the downstream side from the upstream end of the exhaust gas, and the cross-sectional area relatively rapidly increases from the maximum cross-sectional area portion of the space toward the downstream side. Is reduced and the cross-sectional area becomes zero. Also in this invention, the exhaust gas behind the protruding deformation portion is disturbed, so that the exhaust gas purification rate can be improved.

According to a sixth aspect of the present invention, in the exhaust gas purifying apparatus according to the fourth to fifth aspects, the ridgeline of the inwardly projecting deformation portion and the original pipe wall surface of the inwardly projecting deformation portion are formed. It is characterized in that the corners are formed to be acute. Also in this invention, the exhaust gas behind the protruding deformation portion is disturbed, so that the exhaust gas purification rate can be improved.

According to a seventh aspect of the present invention, in the exhaust gas purifying apparatus according to the fourth to fifth aspects, the height of the inward projecting deformation portion is (17 ± 5)% of the inner diameter of the pipe material. It is characterized by being within the range. Since the present invention is configured in this way, as compared with the conventional tubular catalyst body with punching holes, the purification rate of harmful gas is kept substantially equal without increasing the flow path resistance of exhaust gas particularly. With excellent workability and easiness of manufacturing, the production efficiency can be increased.

According to an eighth aspect of the present invention, in the exhaust gas purifying apparatus according to the fourth to fifth aspects, the inwardly projecting deformed portions form rows at regular intervals in the axial direction of the tubular carrier. An interval between the inwardly projecting deformed portions that are formed and are adjacent to each other in the tube axis direction is 20 mm to 30 mm, and a plurality of rows are formed on one tubular carrier. . Since the present invention is configured in this way, the interval is too short, the rear inward projecting deformation portion is hidden in the wake of the front inward projecting deformation portion, the effect is reduced, or the interval is It is possible to avoid a decrease in the effect due to a shortage of the total number of inwardly projecting deformed portions because the length is too long, and it is possible to set an optimum interval.

According to a ninth aspect of the present invention, in the exhaust gas purifying apparatus according to the first to eighth aspects, the tubular catalyst body is coated with the catalyst only on the inner surface side of the tubular carrier. It is a feature. The present invention utilizes that the purification efficiency of the inner portion of the pipe is significantly higher than that of the outer portion due to the protruding deformed portion being on the inner surface of the pipe, and the catalyst is applied only on the inner side of the tubular carrier to reduce the cost of the catalyst. By halving it and allowing the exhaust to flow inside the pipe, the purification effect relative to the cost of the catalyst is relatively improved.

According to a tenth aspect of the present invention, in the exhaust gas purifying apparatus according to the first to ninth aspects, the tubular catalyst body of the exhaust gas purifying apparatus is installed in an exhaust gas passage in a muffler of a motorcycle. It is characterized by purifying gas. According to the present invention, by doing so, the exhaust gas can be purified without adding another device.

[0019]

FIG. 1 is a view showing an embodiment of a tubular carrier for an exhaust gas purifying apparatus according to the present invention, (a)
Is a view of the tubular carrier 1 as seen obliquely from the rear, and FIG. Around the pipe material, a large number of inward projecting deformation portions 2 are formed by projecting and deforming the pipe material inward. One side of each projecting deformation is sheared and punched to form the communication hole 3
The inside and outside of the pipe communicate at this part. Arrow G is the direction of exhaust gas flow.

FIG. 2 is a three-view drawing of the tubular carrier 1.
(A) is an external view seen from the side, (b) is BB of (a)
Sectional drawing, (c) is CC sectional drawing of (b) (view seen toward the front). The shape of the inwardly projecting deformed portion 2 is a triangular depression when viewed from the outer surface of the pipe, and when viewed from the rear to the front, a triangular shape is formed on one side of each inwardly projecting deformed portion due to shear punching of the pipe material. The communication hole 3 is visible. When this carrier is used, since the exhaust gas is arranged so as to flow from left to right, the inward projecting deformation portion 2 is formed so as to be inclined so that the triangular communication hole 3 opens rearward. Has been done. The inclination angle θ is preferably about 30 degrees.

FIG. 3 is a view showing a manufacturing process of the tubular carrier. To manufacture the carrier of the present embodiment, a commercially available stainless steel pipe material 4 cut into necessary dimensions is used.
The core material 5 with a relief groove, which is provided along the generatrix of the pipe material, is provided with a plurality of concave grooves corresponding to the rows of the inwardly projecting deformed portions, so-called relief grooves 5a. And in this state, it is inserted into a metal holding block 6 having a circular cross-section cavity 6a in the longitudinal direction at the center and a longitudinal opening 6b at the top, and the opening 6b at the top.
Then, the deformation tool 7 is brought into contact with the outer peripheral surface of the pipe material 4 corresponding to the position of the escape groove 5a and driven. When the processing 8 of the inwardly projecting deformed portion of one row is completed, the deforming tool 7 is pulled up, the tube material 4 is rotated 9 together with the core metal 5, and the inwardly projecting deformed portion machining 10 of the next row is performed. By repeating this process and processing the inwardly projecting deformed portion 2 around the entire circumference of the pipe material 4, the tubular carrier 1 is completed. When a catalyst is applied to this, a tubular catalyst body is completed.

FIG. 4 is a perspective view showing an inwardly projecting deforming portion 2 and a deforming tool 7 for processing the inwardly projecting deforming portion. FIG. 4A shows one inwardly projecting deforming portion 2. A view seen from the inside of the pipe, (b) is an external view of a deformation tool 7 used for deforming the inward protruding deformation portion 2. The ridgeline 2a of the inwardly projecting deformed portion 2 forms an acute angle θ with the original wall surface of the inwardly projecting deformed portion, and is preferably about 30 degrees.
In order to shear the rear edge 2b of the deforming portion 2 of the deforming tool 7,
A sharp blade is formed at the edge of the trailing edge shearing portion 7a of the deformation tool 7.

FIG. 5 shows a tubular catalyst body 11 with an inwardly projecting deformable portion 2 formed by applying a catalyst to the tubular carrier 1 of the above embodiment.
Is a streamline diagram in the case where is placed in the exhaust gas flow G. In the tubular catalyst body 11 with the inwardly projecting deformed portion, a strong turbulent flow occurs on the inner surface of the tube at the rear end of the inwardly projecting deformed portion, and the exhaust gas swirls and violently contacts the catalyst applied to the carrier. Compared with the conventional tubular catalyst body with punching holes 09 (see FIG. 28) in which the flow flows laminarly on the surface, the effect of purifying the exhaust gas is remarkably large.

Next, the tubular catalyst body with the inward protruding deformation portion
An embodiment when 11 is applied to an exhaust system of a motorcycle will be described. FIG. 6 is a side view of a muffler 12 of a motorcycle 4-stroke 125 cc internal combustion engine in which the catalyst body 11 is mounted, and FIG. 7 is a cross-sectional view of the muffler (VI in FIG. 6).
It is a view of the I-VII cross section viewed from the rear). Inside the muffler 12, as shown in FIG. 7, four pipelines A, B, C,
And D are provided. FIG. 8 is a vertical cross-sectional view (VIII-VIII cross-sectional view of FIG. 7) of the same muffler cut along a vertical plane. FIG. 9 is a horizontal sectional view (IX-IX sectional view in FIG. 7) of the muffler.

In FIGS. 8 and 9, the central portion of the body of the muffler 12 is a double body consisting of a body outer plate 13 and a body inner plate 14, and a partition plate 15 keeps a distance between them. Glass wool 16 is filled between them. The front part of the body is covered with a hemispherical front lid 17, and an exhaust pipe 18 connected to the internal combustion engine is inserted therethrough. The rear part of the body is covered with a back lid outer plate 19 and a back lid inner plate 20, and glass wool 21 is filled between them.
A rear end annular portion 22 is provided on the rear surface of the rear lid. Fuselage plate 14
A first partition 23 and a second partition 24 are provided in this order from the front inside, and the inside of the muffler 12 is divided into three chambers by these partitions. For the following description, these are named first chamber 25, second chamber 26, and third chamber 27 in order from the front. Inside the muffler, the four pipes A, which have different lengths and which connect the chambers 25, 26 and 27 in different combinations, respectively.
B, C and D are formed.

In FIG. 8, an inlet pipe 28 connected to an external exhaust pipe 18 constitutes an upper pipe A in the muffler.
A connection pipe 29 connected to the inlet pipe 28, a diffuser pipe / catalyst body 30 connected to the connection pipe 29, and a resonance pipe 31 that covers the outside of the diffuser pipe / catalyst body 30. The conduit A is provided so as to penetrate the first partition wall 23 and the second partition wall 24,
Exhaust gas discharged from the internal combustion engine is first injected into the third chamber 27 through the conduit A.

In FIG. 9, it is the communication pipe 32 that constitutes the conduit B on the right side of the muffler. This conduit B is the second
The exhaust gas is provided so as to penetrate the partition wall 24, and the exhaust gas previously injected into the third chamber 27 enters the second chamber 26 through the conduit B.

In FIG. 9, the communication pipe 33 constitutes the conduit C on the left side in the muffler. This conduit C is the first
The exhaust gas is provided so as to penetrate the partition wall 23, and the exhaust gas that has entered the second chamber 26 enters the first chamber 25 through the conduit C.

In FIG. 8, it is the front diffuser assembly 34 and the rear diffuser assembly 35 that make up the lower conduit D in the muffler, which are connected via a guide tube 36. The conduit D penetrates the first partition wall 23 and the second partition wall 24, and further penetrates the rear lid outer plate 19 and the rear lid inner plate 20 at the rear end of the rear diffuser assembly 35 to project to the outside. The exhaust gas that has entered the first chamber 25 earlier is discharged to the outside through the pipe line D. The muffler 12 is a device that reduces exhaust noise by combining the functions of the diffusers 30, 34, and 35 with discharging the exhaust gas of the internal combustion engine through the complicated path as described above.

A diffuser tube / catalyst body 30, which is one application form of the tubular catalyst body 11, is provided inside the muffler 12 as follows.
At the end of the conduit A directly connected to the exhaust pipe 18, at a position where a diffuser pipe having a large number of punching holes is conventionally provided, instead of the diffuser pipe, an inwardly projecting deformable portion shown in FIG. 1 is provided. A diffuser tube / catalyst body 30 is obtained by replacing the tubular catalyst body 11 with an inwardly projecting deformable portion, which is manufactured by coating a catalyst on the tubular carrier 1. The conventional diffuser tube has a large number of punched holes when exhaust gas flows out,
The pressure energy was attenuated, and the sound was suppressed by interacting with the resonance tube on the outside to reduce the volume. Since the tubular catalyst body 11 of the present embodiment is provided with a large number of communication holes 3 around it, it can function as a diffuser tube / catalyst body 30 that also has a sound deadening function in place of the conventional diffuser tube with punching holes. it can.

In the diffuser pipe / catalyst body 30 of the present embodiment, the exhaust gas is connected to the connecting pipe 29 so that the gas flows inside the pipe.
Has been introduced from. The main stream of gas flows inside the tube and some small amount of gas flows outside the tube. Therefore, even if the catalyst is applied only to the inside of the tube, the effect comparable to that of the catalyst applied to both inside and outside can be exhibited. By doing so, the cost of the catalyst can be halved, and a great effect on the cost can be obtained.

FIG. 10 shows a second exhaust gas purifying apparatus according to the present invention.
FIG. 6 is a view showing a tubular carrier 37 according to the embodiment. The inwardly projecting deformable portion 38 of this embodiment has a rounded front portion and a communication hole 39 linearly sheared and punched at the rear end. The function and effect of this embodiment are almost the same as those of the tubular carrier of the first embodiment.

FIG. 11 shows an exhaust gas purifying apparatus according to a third embodiment of the present invention.
FIG. 3 is a view showing a tubular carrier 40 according to the embodiment. The inwardly projecting deformable portion 41 of the present embodiment has a shear punched hole 42 that is long in the tube axis direction.
While forming the, the pipe material piece is bent inward of the pipe centering on one side which is not punched. The gas inside and outside the pipe is communicated with each other by the shear punch hole 42 that is long in the pipe axial direction. In the tubular carrier of the present embodiment, the catalyst can be applied to both inner and outer surfaces of the tube so that the gas can be effectively contacted on both surfaces.

FIG. 12 shows the fourth embodiment of the exhaust gas purifying apparatus of the present invention.
FIG. 6 is a view showing a tubular carrier 43 according to the embodiment. The inwardly projecting deformation portion 44 of this embodiment has a round shape like a part of a spherical surface, and is not provided with a hole for communicating the inside and outside of the pipe. The tubular carrier of the present embodiment can be applied to an exhaust gas purifying device of a type in which exhaust gas is allowed to flow only on the inner surface of the pipe.

FIG. 13 shows the fifth embodiment of the exhaust gas purifying apparatus of the present invention.
It is a three-sided view of the tubular carrier 45 which concerns on embodiment, (a) is an external view seen from the side, (b) is BB sectional drawing of (a),
(C) is a CC cross-sectional view of (b) (a view looking forward). The shape of the inwardly projecting deformation portion 46 is an insular quadrangular depression with rounded corners when viewed from the outer surface of the pipe, and no hole that communicates the inside and outside of the pipe is provided. When viewed from the rear to the front, the inward projecting deformation portion 46 caused by the deformation of the pipe material can be seen. When this carrier is used, the exhaust gas is
It is arranged to flow in the tube in the direction of.

FIG. 14 is a perspective view showing the shape of a deforming tool 47 for machining the inward projecting deformed portion 46 and the inward projecting deformed portion of the tubular carrier 45 of the fifth embodiment. The figure which looked at each inward projecting deformation part 46 from the inside of the pipe, (b) is a deformation tool used for deforming this inward projecting deformation part 46
It is an external view of 47.

The inwardly projecting deformation portion 46 of this embodiment is shown in FIG.
As shown in (a), the bottom surface is unequal and has a pyramid shape that is long in the gas flow G direction, and of the ridge lines extending in the front-rear direction, the slope of the ridge line in front of the apex toward the gas flow with respect to the pipe wall. Is gentler than the inclination of the ridgeline behind the apex with respect to the tube wall. The inclination angle θ of the ridgeline on the front side of the apex with respect to the tube wall is an acute angle, and is preferably about 30 degrees. The vicinity of the apex is the maximum cross-sectional area portion, and the cross-sectional area decreases relatively rapidly from the maximum cross-sectional area portion toward the downstream side and becomes zero. In the figure, the vertices and ridges are drawn with sharp lines, but the real thing is manufactured in a rounded shape.

FIG. 14B is an external perspective view of a deforming tool 47 for processing the inward protruding deforming portion 46. In a practical deformation tool, the top and the edge of the ridge are rounded so as not to damage the pipe material. As described above, the inclination of the ridgeline on the front side with respect to the tube wall is preferably about 30 degrees.
The manufacturing process of the tubular carrier 45 using the deformation tool 47 is the same as the manufacturing process of the tubular carrier 1 shown in FIG.

FIG. 15 is an external perspective view of the tubular carrier according to the fifth embodiment, which is provided with inwardly projecting deformable portions having various numbers of rows.
In the present embodiment, the inwardly projecting deformable portions can be formed in two to six rows or a plurality of other rows at regular intervals in the tube axis direction of the tubular carrier. If the number of rows is an even number, opposite rows are provided at symmetrical positions with respect to the center line of the tube, and if appropriate tools are provided for the inward projecting deformation processing of the rows facing each other, The efficiency of manufacturing the carrier is improved.

FIG. 16 shows the case where the exhaust gas flow G is introduced into the inside of the tubular catalyst body 48 formed by applying the catalyst to the inner surface of the tubular carrier 45 with the holeless inward projecting deformation portion 46 of the above embodiment. FIG. In the illustrated example, the tubular catalyst body 48 is held in a cantilever state, and no exhaust gas flows outside the tube.
In this tubular catalyst body 48, the cross-sectional area relatively rapidly decreases from the maximum cross-sectional area portion of the inward projecting deformation portion 46 toward the downstream side, and finally the cross-sectional area of the projecting portion becomes zero. Violent turbulence occurs on the inner surface of the tube at the rear end of the deformed deformed portion. Due to this turbulent flow phenomenon, the exhaust gas violently contacts the catalyst coated on the inner surface of the carrier, so that the conventional tubular catalyst body with punching holes 09 (FIG. 28) in which the gas flow flows laminarly on the surface.
Compared with the above, the effect of purifying exhaust gas is remarkably large.

In the tubular catalyst body 11 with the inwardly projecting deformation portion 2 having a hole shown in FIG. 5, the catalyst is applied to the inside and outside of the pipe, and exhaust gas is circulated through the hole to the inside and outside of the pipe. Although the amount of gas flowing on the outer surface of the pipe is smaller than that on the inner surface, the catalyst is applied in the same way as the inner surface, so the outer surface has the same amount of catalyst used as the inner surface, which is highly effective in terms of cost efficiency. I can't get it. The tubular catalyst body 48 with a holeless inward projecting deformation portion 46 of the fifth embodiment shown in FIG. 16 is a solution to this improvement, in which the catalyst is applied only to the inner surface of the pipe and the exhaust gas is circulated only inside the pipe. It was made to let. The securing of the contact area between the exhaust gas and the catalyst is adjusted by, for example, slightly increasing the length of the pipe.

The higher the height of the inwardly projecting deformed portion, the higher the purification rate of harmful substances. At the same time, however, since the inwardly projecting deformed portion blocks the gas passage, the passage resistance becomes large, and the output of the internal combustion engine is increased. Cause a decrease in. In practical use of the present invention, at least the conventional tubular catalyst body with punching holes 09 (Fig. 28)
It is necessary to achieve the same level of purification rate and flow path resistance.
For this reason, an experiment was conducted to find the optimum mutual relationship between the inner diameter of the pipe material and the height of the inwardly projecting deformed portion while comparing with the conventional technique. Some of them are described below.

FIG. 17 is a diagram showing the definition of the inner diameter of the tubular material of the tubular carrier 45 of the fifth embodiment and the height of the inward projecting deformed portion after processing. FIG. 18 is a plot of the gas purification rate (%) of the tubular catalyst body 48 in which a tube material having an inner diameter of 23.4 mm is provided with inwardly projecting deformed portions having heights of 1 mm, 4 mm, and 7 mm,
FIG. 19 shows a curve obtained by plotting the flow path resistance (Pa) in the tubular catalyst body 48 under the same conditions, and showing the curve obtained by joining the curves. In both of these figures, for comparison, the gas purification rate (%) and the flow path resistance (Pa) of the tubular catalyst body 09 with punching holes having the same inner diameter as the tubular catalyst body 48 are shown in the respective figures. . In the case of the tubular catalyst body 09 with punching holes, it is shown as a constant value because it has nothing to do with the height of the inwardly projecting deformed portion.

From these figures, when the tubular material having the inner diameter of 23.4 mm is used, the tubular catalyst body 48 having the height of the inwardly projecting deformed portion of 4 mm shows the exhaust gas purification rate (%) and the flow passage resistance (Pa). 2) is substantially equivalent to the tubular catalyst body 09 with a punching hole having the same inner diameter, and the exhaust gas purification rate (%) does not increase so much when the height of the inwardly deformed portion exceeds 4 mm. However, the flow path resistance (Pa) suddenly increases, and when the height of the inwardly projecting deformed portion becomes lower than 4 mm, the exhaust gas purification rate (%) drops sharply, but the flow path resistance (Pa) decreases significantly. The result is not to. From this experimental result, in consideration of the allowable range, it was concluded that the height of the inwardly projecting deformed portion is appropriately within the range of (17 ± 5)% of the inner diameter of the pipe material. The range of the height of the inwardly projecting deformed portion when the pipe having the inner diameter of 23.4 mm is used is about 2.8 mm.
The range is up to 5.2 mm.

As a result of conducting the same experiment for other tubular catalyst bodies having some inner diameters, even if the inner diameters of the pipe materials are different, the height of the inwardly projecting deformed portion is (17 ±
It was found that the conclusion that the range of 5)% is appropriate applies. FIG. 20 collectively shows the results of these experiments, in which the horizontal axis represents the pipe inner diameter (mm) and the vertical axis represents the height of the inwardly projecting deformed portion (mm). The thick solid line shows the limit of the allowable range with the thin solid line. Since the present embodiment is configured in this way,
Compared to conventional tubular catalysts with punched holes, the production efficiency is greatly improved, while maintaining the same purification rate of harmful gases without increasing the flow resistance of exhaust gas. The efficiency can be increased.

Further, in the tubular catalyst body of this embodiment, the inwardly projecting deforming portions are arranged in a row in the tube axial direction, and the interval L between the inwardly projecting deforming portions 46 adjacent in the tube axial direction (see FIG. 15). reference)
It has been found that 20 to 30 mm is suitable. If the interval is too short, the rearward inward projecting deformation part is hidden in the wake of the forward inward projecting deforming part, reducing the effect.If the interval is too long, the total number of inward projecting deforming parts is insufficient. The effect is reduced due to. If the above interval is adopted, this problem can be avoided.

The above experiment was also conducted on the inwardly projecting deformed portion having a hole as shown in FIG. 2, and the height of the inwardly projecting deformed portion was within the range of (17 ± 5)% of the inner diameter of the pipe material. The conclusion obtained from the above-mentioned experiment that the inside is suitable, and the dimension between the inwardly projecting deformed portions adjacent to each other in the pipe axis direction are 20 to 30.
It was confirmed that the conclusion that mm is suitable is also applicable to inwardly projecting deformed portions of other shapes.

FIG. 21 is a side view of a motorcycle 50 equipped with the tubular catalyst body of this embodiment. A head pipe 52 is provided at a front end portion of a vehicle body frame 51, a handle 53 and a front fork 54 are rotatably held here, and a front wheel 55 is rotatably supported by the front fork 54. The upper end of the shock absorber 56 is attached to the rear part of the body frame 51, the power unit 57 is suspended between the center part of the body frame 51 and the lower end of the shock absorber 56, and the rear wheel 58 is attached to the rear part of the power unit 57.
Is rotatably attached. A carburetor 62 and an air cleaner 63 are connected via an intake pipe 61 to a cylinder head 60 of an internal combustion engine 59 forming the front part of the power unit 57, and a muffler 65 is connected to the cylinder head 60 via an exhaust pipe 64. ing. In the figure, since the exhaust pipe 64 and the muffler 65 are arranged on the other side of the vehicle body, they are hatched with broken lines to clearly show their positions. Body frame 51,
The internal combustion engine 59 and the like are covered with a front cover 66, a body cover 67 and the like. A seat 68 is provided above the body cover 67. A spare tire 69 is provided at the rear of the body cover 67.

FIG. 22 is a side view of the exhaust pipe 64 and the muffler 65, and FIG. 23 is a plan view thereof. At the front end of the exhaust pipe 65,
A flange portion 70 for connecting to the cylinder head 60 is provided, and the muffler 65 is provided with two brackets 71, 72 for attaching to the structural portion of the power unit 57.
A heat shield plate 73 is provided on the side surface of the muffler.

FIG. 24 is a side view showing the inside of the muffler 65, and FIG. 25 is a plan view showing the inside of the muffler. The muffler 65 is covered with a case 74, and the inside thereof is separated by a partition wall 75 into a first chamber 76 and a second chamber 77. A first pipe line 79 is connected to an inlet pipe 78 that is connected to the exhaust pipe 64 shown in FIG. 22 and that penetrates through the case 74. 1st line 79
As shown in FIG. 16, the tubular catalyst body 48 with a holeless inward projecting deformation portion is mounted in a cantilever state in the large-diameter portion 79a close to the inlet. The first conduit 79 is bent in the second chamber 77, passes through the first chamber 76 more largely, and opens into the first chamber 76. A straight tubular second conduit 80 penetrates through the partition wall 75 in the central portion of the case 74 to form a first chamber 76 and a second chamber 77.
Is connected to. Further, there is provided a third conduit 81 that penetrates the case 74 from the second chamber 77 and opens to the outside.

The exhaust gas that has entered the muffler 65 from the inlet pipe 78 is purified while passing through the tubular catalyst body 48 in the first pipeline. The purified exhaust gas is sequentially fed to the first pipe 79 and the first chamber.
76, the second conduit 80, the second chamber 77, and the third conduit 81 are cooled and decompressed, the exhaust noise is reduced, and the gas is discharged into the atmosphere through the outlet 82 of the third conduit 81. It

Incidentally, FIGS. 24 and 25 show an example in which the tubular catalyst body 48 with a holeless inward projecting deformation portion is mounted in the muffler 65. Needless to say, even if the other type of the above-mentioned tubular catalyst body with a hole-forming type or a hole-free type having an inwardly projecting deformation portion is mounted, the same exhaust gas purification effect as that of this example can be obtained.

As described above in detail based on a plurality of embodiments, in the exhaust gas purifying apparatus of the present invention, a commercially available stainless steel pipe material is used as the catalyst carrier, and a deforming tool is used to form the inside of the pipe from the outside. A plurality of deformed portions projecting toward one side or projecting deformed portions with communication holes are processed and a catalyst is applied to form a catalyst body. As a result, the following advantages can be obtained. (1) Since a commercially available pipe material is used, the manufacturing method is simple and the manufacturing cost can be reduced as compared with the conventional method in which a flat plate is punched and then processed into a pipe. (2) Since a commercially available pipe material is used, a small diameter product having a diameter of less than 20 mm can be accurately manufactured. (3) By optimizing the shape of the inwardly projecting deformed portion with a communication hole or the inwardly projecting deformed portion without a hole, appropriate turbulence can be given to the exhaust gas flowing inside the tubular carrier. The exhaust gas purification rate can be improved as compared to the punched hole processed product. (4) In the tubular catalyst body of the present invention, the height of the inwardly projecting deformed portion is within the range of (17 ± 5)% of the inner diameter of the pipe material, or the interval between the inwardly projecting deformed portions adjacent to each other in the pipe axial direction. 20 to
By setting it to 30 mm, the best effect can be obtained. (5) In the tubular catalyst body of the present invention, the purification efficiency of the inner surface of the tube is much higher than that of the outer surface of the tube, so that a tubular catalyst body in which the catalyst is applied only to the inside of the pipe is prepared, and the catalyst application amount is reduced by half. Cost is reduced, exhaust gas is introduced inside the catalyst,
Or make the exhaust gas flow only inside,
The cost effect can be enhanced. Particularly, in the case of a tubular catalyst body having a holeless inward projecting deformation portion, the cost effect is great.

[Brief description of drawings]

FIG. 1 is a view showing a first embodiment of a tubular carrier 1 according to an exhaust gas purifying apparatus of the present invention, (a) is a rear perspective view of the tubular carrier 1, and (b) is a rear view.

FIG. 2 is a three-view drawing of the tubular carrier 1, where (a) is a side view, (b) is a BB sectional view of (a), and (c) is a CC sectional view of (b). is there.

FIG. 3 is a manufacturing process diagram of the tubular carrier.

FIG. 4 is a perspective view showing a shape of an inwardly projecting deformed portion 2 and a deforming tool 7 for processing the inwardly projecting deformed portion of the tubular carrier 1 according to the first embodiment, and FIG. Inward projecting deformation part 2
FIG. 6B is a view of the inside of the pipe, FIG.
It is an external view of the deformation | transformation tool 7 used in order to deform | transform deformation.

FIG. 5 is a streamline diagram in the case where a tubular catalyst body 11 having an inwardly projecting deformation portion, which is made by applying a catalyst to the tubular carrier, is placed in an exhaust gas flow.

FIG. 6 is a side view of a muffler 12 of a motorcycle 4-stroke 125 cc internal combustion engine in which the catalyst body 11 is mounted.

FIG. 7 is a transverse sectional view of the muffler.

FIG. 8 is a vertical sectional view of the muffler.

FIG. 9 is a horizontal sectional view of the muffler.

FIG. 10 is a view showing a second embodiment of the tubular carrier according to the exhaust gas purifying apparatus of the present invention, (a) is a rear perspective view of the tubular carrier, and (b) is a rear view.

FIG. 11 is a diagram showing a third embodiment of the tubular carrier according to the exhaust gas purifying apparatus of the present invention, (a) is a rear perspective view of the tubular carrier, and (b) is a rear view.

FIG. 12 is a view showing a fourth embodiment of the tubular carrier according to the exhaust gas purifying apparatus of the present invention, (a) is a rear perspective view of the tubular carrier, and (b) is a rear view.

FIG. 13 is a trihedral view of a tubular carrier according to a fifth embodiment of the exhaust gas purifying apparatus of the present invention, (a) is a side view, and (b) is a side view.
7A is a sectional view taken along the line BB of FIG. 7A, and FIG.

FIG. 14 is an inward protruding deformation portion 46 of the tubular carrier 45 according to the fifth embodiment, and a deformation tool for processing the inward protruding deformation portion.
47A is a perspective view showing the shape of 47, FIG. 14A is a view of one inward projecting deformation portion 46 seen from the inside of the pipe, and FIG. Deformed tools 47
FIG.

FIG. 15 is an external perspective view of the tubular carrier according to the fifth embodiment including the inwardly projecting deformable portions having various numbers of rows.

FIG. 16 is a holeless inward protruding deformation portion 46 of the fifth embodiment.
FIG. 7 is a streamline diagram in the case where an exhaust gas flow G is introduced into the inside of a tubular catalyst body 48 formed by applying a catalyst to the inner surface of the attached tubular carrier 45.

FIG. 17 is a diagram showing the definition of the inner diameter of the tubular carrier and the height of the inwardly projecting deformed portion of the fifth embodiment.

FIG. 18: Tube material with an inner diameter of 23.4 mm, height of 1 mm, 4
FIG. 7 is an experimental result diagram of the gas purification rate (%) of the tubular catalyst body 48 provided with the inwardly projecting deformation portions of mm and 7 mm. The gas purification rate (%) of the tubular catalyst body 09 with punching holes having the same inner diameter is also shown.

19 is an experimental result diagram of flow path resistance (Pa) in the tubular catalyst body 48 under the same conditions as FIG. 18. The channel resistance (Pa) of the tubular catalyst body 09 with punching holes having the same inner diameter is also shown.

FIG. 20 is a diagram collectively showing the experimental results, in which a suitable height (m) of the inward projecting deformed portion with respect to the inner diameter (mm) of the pipe material is shown.
It is the figure which showed m) and its allowable range.

FIG. 21 is a side view of a motorcycle 50 including the tubular catalyst body according to the fifth embodiment.

FIG. 22 is a side view of the exhaust pipe 64 and the muffler 65.

FIG. 23 is a plan view.

FIG. 24 is a side view showing the inside of the muffler 65.

FIG. 25 is a plan view showing the inside of the muffler.

FIG. 26 is a view showing a tubular carrier with punching holes used in a conventional exhaust gas purifying apparatus, (a) is a rear perspective view of the tubular carrier, and (b) is a rear view.

FIG. 27 is a manufacturing process diagram of the conventional tubular carrier with punching holes.

FIG. 28 is a streamline diagram in the case where a tubular catalyst body with punching holes made by applying a catalyst to the conventional tubular carrier is placed in an exhaust gas flow.

[Explanation of symbols]

A ... Pipe line, B ... Pipe line, C ... Pipe line, D ... Pipe line, G ... Exhaust gas flow, L ... Pipe axial direction interval of inwardly projecting deformed portion, .theta .... Front edge ridge inclination angle, DESCRIPTION OF SYMBOLS 1 ... Tubular carrier (1st Embodiment), 2 ... Inward projecting deformation part, 2a ... Ridge line, 2b ... Rear edge,
3 ... Communication hole, 4 ... Stainless steel pipe material, 5 ... Escape groove core metal, 5a ... Escape groove, 6 ... Metal holding block, 6a ... Circular cross-section cavity, 6b ... Upper longitudinal opening, 7 ... Deformation tool , 7a ... Trailing edge shearing part, 8 ... Machining of inward projecting deformed part in one row, 9 ... Rotation, 10 ... Machining of inward projecting deformed part in next row, 11 ...
Tubular catalyst body with inward protruding deformation part, 12 ... muffler, 13 ... fuselage outer plate, 14 ... body plate, 15 ... partition plate, 16 ... glass wool, 17 ... front lid, 18 ... exhaust pipe, 19 ... outside of rear lid Plate, 20 ... Rear lid inner plate, 21 ... Glass wool, 22 ... Rear end annular portion, 23 ... First partition wall, 24 ... Second partition wall, 25 ... First chamber, 26 ... Second chamber, 27 ... Third
Chamber, 28 ... Inlet pipe, 29 ... Connection pipe, 30 ... Diffuser pipe / catalyst body, 31 ... Resonance pipe, 32 ... Communication pipe, 33 ... Communication pipe, 34 ... Front diffuser assembly, 35 ... Rear diffuser assembly, 36
... Guide tube, 37 ... Tubular carrier (second embodiment), 38 ... Inward projecting deformation portion, 39 ... Communication hole, 40 ... Tubular carrier (third embodiment), 41 ... Inward projecting deformation portion, 42 ... Communication Holes, 43 ... Tubular carrier (fourth embodiment), 44 ... Inward protruding deformation portion (without holes), 45
... tubular carrier (fifth embodiment), 46 ... inwardly projecting deformed portion (no hole), 47 ... deformation tool, 48 ... tubular catalyst body, 50 ... motorcycle, 51 ... vehicle body frame, 52 ... head pipe, 53 ... steering wheel, 54 ... front fork, 55 ... front wheel, 56 ... shock absorber, 57 ... power unit, 58 ... rear wheel, 59 ... internal combustion engine, 60
… Cylinder head, 61… Intake pipe, 62… Carburettor, 63…
Air cleaner, 64 ... Exhaust pipe, 65 ... Muffler, 66 ... Front cover, 67 ... Body cover, 68 ... Seat, 69 ... Spare tire, 70 ... Flange part, 71 ... Bracket, 72 ... Bracket, 73 ... Heat shield, 74 ... Muffler case, 75 ... Partition, 76 ...
First chamber, 77 ... Second chamber, 78 ... Inlet pipe, 79 ... First pipe line, 79a
... Large-diameter portion of the first conduit, 80 ... Second conduit, 81 ... Third conduit, 82
… Exit part, 01… Tubular carrier, 02… Punching hole, 03… Roll metal plate, 04… Punching hole processing, 05… Cutting, 06…
U vent processing, 07 ... O vent processing, 08 ... Welding, 09 ... Tubular catalyst body with punching holes.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koji Egawa             1-4-1 Chuo Stock Market, Wako City, Saitama Prefecture             Inside Honda Research Laboratory F-term (reference) 3G091 AA03 AB01 BA39 GA16 GB01X                       HA05                 4D048 BA39X BB02 BB05 BB12                       BB13

Claims (10)

[Claims] 1. An exhaust gas purifying apparatus for purifying gas by installing a tubular catalyst body produced by coating a catalyst on a tubular carrier in an exhaust gas passage, wherein the tubular carrier is molded by extrusion molding or the like. An exhaust gas purifying device, comprising: a tubular member obtained by cutting a steel pipe member into a predetermined length and having a large number of inward projecting deformed portions. 2. The tubular carrier is located inside the resonance tube, and a communication hole is formed adjacent to the rear end of each of the inwardly projecting deformation portions so as to communicate the inside and outside of the tube. The exhaust gas purifying apparatus according to Item 1. 3. The inwardly projecting deformed portion has a cross-sectional area of a space formed between the original pipe wall and the inwardly projecting deformed portion that crosses from the upstream end of the exhaust gas toward the downstream side. The exhaust gas purifying apparatus according to claim 1, wherein there is a portion having a shape that gradually increases from zero area. 4. The inwardly projecting deformed portion has a cross-sectional area of a space formed between the original pipe wall and the inwardly projecting deformed portion that crosses from the upstream end of the exhaust gas toward the downstream side. The exhaust gas purifying apparatus according to claim 1 or 2, wherein the area gradually increases from zero, and the maximum cross-sectional area portion of the space is the rear end of the inwardly projecting deforming portion. 5. The inwardly projecting deformed portion has a cross-sectional area of a space formed between the original pipe wall and the inwardly projecting deformed portion that crosses from the upstream end of the exhaust gas toward the downstream side. 3. The cross-sectional area gradually increases from zero area to the downstream side from the maximum cross-sectional area portion of the space, and the cross-sectional area becomes zero, whereby the cross-sectional area becomes zero. Exhaust gas purification device described. 6. The method according to claim 4, wherein the ridgeline of the inwardly projecting deformed portion and the original wall surface of the inwardly projecting deformed portion form an acute angle. Exhaust gas purification device. 7. The exhaust gas purifying apparatus according to claim 4, wherein the height of the inward projecting deformed portion is within the range of (17 ± 5)% of the inner diameter of the pipe material. . 8. The inwardly projecting deformed portions are formed in rows at regular intervals in the tube axis direction of the tubular carrier, and the inwardly projecting deformable portions adjacent to each other in the tube axis direction have an interval of 20 mm to 30 m.
The exhaust gas purifying apparatus according to any one of claims 4 to 5, wherein a plurality of rows are formed on one tubular carrier. 9. The exhaust gas purifying apparatus according to claim 1, wherein the tubular catalyst body is coated with a catalyst only on the inner surface side of the tubular carrier. 10. The exhaust gas according to claim 1, wherein the tubular catalyst body of the exhaust gas purifying device is installed in an exhaust gas passage in a muffler of a motorcycle to purify the gas. Purification device.