JP4024078B2 - Exhaust gas purification device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust gas purification device for a small internal combustion engine used in a motorcycle or the like. In this specification, “pipe material” is a material for deforming and manufacturing a carrier, “tubular carrier” is a tube material that has been subjected to processing such as deformation and drilling, an object to be coated with a catalyst, “tubular” The “catalyst body” means that the catalyst is applied to the tubular carrier.
[0002]
[Prior art]
Exhaust gas purification devices for small internal combustion engines used in motorcycles, etc., have a catalyst coated on a carrier and a supported structure, a so-called catalyst body, is installed in the exhaust gas flow, and harmful components in the exhaust gas It is a device to purify. As the shape of the carrier, a catalyst carrier is generally applied to a tubular carrier 01 having a punched hole 02 processed as shown in FIG. No. 10-30432).
[0003]
Conventionally, as shown in FIG. 27, such a tubular carrier with punched holes is obtained by extending a roll-shaped metal plate 03 into a flat plate shape, performing punching hole processing 04 thereon, then cutting 05 into a predetermined dimension, and U-bending. Bending processing such as processing 06 and O-bending processing 07 was applied to bring both edges into contact with each other, and welding 08 was performed to finish the tubular carrier 01.
[0004]
[Problems to be solved]
The conventional method for manufacturing the tubular carrier 01 shown in FIG. 27 has the disadvantage that the number of processing steps is large and the manufacturing cost is high. In addition, when used for a motorcycle having a small displacement, for example, a 4-stroke motorcycle of 125 cc or less, it is difficult to reduce the diameter for mounting in the thin exhaust device. In particular, a tubular carrier having a diameter of less than 20 mm is used in a conventional manner. When made, there was a problem that the dimensional accuracy was lowered.
[0005]
Further, when the tubular catalyst body 09 with punching holes made by applying a catalyst to the inner and outer surfaces of the conventional tubular carrier 01 with punching holes is placed in the exhaust gas flow, there is no irregularity on the surface of the pipe, As shown in FIG. 28, there is also a problem that the size of the catalyst body is increased in order to make the gas flow less turbulent and to sufficiently contact the exhaust gas G with the catalyst.
[0006]
The present invention makes it possible to manufacture a small-diameter tubular carrier as described above with low manufacturing cost and high dimensional accuracy, and further improves the purification performance of the exhaust gas purification device by adding a new device to the shape. It is intended to be illustrated.
[0007]
  The present invention solves the above problems, and the invention according to claim 1 is an exhaust gas for purifying gas by installing a tubular catalyst body manufactured by applying a catalyst to a tubular carrier in an exhaust gas passage. In the purification apparatus, the tubular carrier has a large number of inwardly projecting deformed portions in a pipe material obtained by cutting a steel pipe member formed by extrusion or the like into a predetermined length.Formed continuously with the pipe wall, forming an unequal square when viewed from the outside of the inwardly projecting deformed portion, and the exhaust gas upstream side of the unequal square is gradually inclined with respect to the pipe axis, and the exhaust gas downstream side The side slopes sharply with respect to the tube axis, and the cross-sectional area of the steam inward projecting deformation formed between the original tube wall gradually increases from zero, and reaches the downstream side from the maximum cross-sectional area of the space. The cross-sectional area becomes zero relatively rapidly towardIt is characterized by this.
[0008]
Since the present invention is configured as described above, a commercially available product that has been molded in advance as a tube can be used as the tube material, and the inwardly projecting deformation portion can be easily processed from the outside of the tube. Therefore, the number of manufacturing steps can be reduced, and the manufacturing cost can be reduced. In addition, when a commercially available pipe material is used, a small diameter product having a diameter of less than 20 mm can be manufactured with high accuracy. Furthermore, by optimizing the shape of the projecting deformation 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.
[0009]
  Furthermore, in the invention according to claim 1 of the present application, the inwardly projecting deformed portion has a space cross-sectional area formed between the original tube wall and the inwardly projecting deformed portion so that the upstream end of the exhaust gas is upstream. Since the cross-sectional area is gradually increased from zero toward the downstream side, an increase in resistance to gas flow is reduced.
In addition, the inward projecting deformed portion has a relatively rapid decrease in the cross sectional area from the maximum cross section area of the space formed between the original tube wall and the inward projecting deformed portion toward the downstream side, Since the cross-sectional area is formed to be zero, the exhaust gas behind the projecting deformed portion is disturbed, so that the exhaust gas purification rate is improved.
[0010]
  In the invention according to claim 2, since the angle formed by the ridge line of the inward projecting deformed portion and the original tube wall surface of the inward projecting deformed portion is formed at an acute angle, the exhaust gas behind the projecting deformed portion is disturbed. Therefore, the exhaust gas purification rate is improved.
[0011]
  In the invention described in claim 3, the inwardly projecting deformed portion is a pyramid type that is long in the exhaust gas flow direction, and the inclination of the ridge line on the front side of the apex in the exhaust gas flow direction with respect to the pipe wall in the exhaust gas flow direction is Since the slope of the ridge line behind the apex is gentler than the inclination of the tube wall, intense turbulence occurs on the inner surface of the tube at the rear end of the inward projecting portion, and this turbulence phenomenon causes exhaust gas to be applied to the carrier. As a result of violent contact with a certain catalyst, the exhaust gas purification effect is greater than that of a conventional tubular catalyst body with punched holes in which the gas flow flows laminarly on the surface.
[0012]
  Invention of Claim 4Then, the fact that the projecting deformed part is on the inner surface of the pipe makes it possible to use the fact that the purification efficiency of the inner part of the pipe is much higher than that of the outer side. The exhaust gas is allowed to flow into the inside of the pipe, so that the purification effect relative to the cost of the catalyst can be improved.
[0014]
  Invention of Claim 6Then, the height of the inward projecting deformed portion is in the range of (17 ± 5)% of the inner diameter of the tube material. Since the present invention is configured as described above, it can be remarkably maintained while maintaining the purification rate of harmful gas at the same level without particularly increasing the exhaust gas flow resistance as compared with the conventional tubular catalyst body with punching holes. The production efficiency can be increased by excellent processability and ease of manufacture.
[0015]
  Invention of Claim 7Then, the inwardly projecting deformed portions are formed in a row at regular intervals in the tube axis direction of the tubular carrier, and the interval between the inwardly projecting deformed portions adjacent in the tube axis direction is 20 mm to 30 mm, and Since a plurality of the above-mentioned rows are formed on one tubular carrier, the interval is too short, and the rearward inward projecting deformed portion is hidden in the wake of the front inward projecting deformed portion, which is effective. It is possible to avoid a decrease in the effect due to a decrease in the number of inward projecting deformed portions due to the decrease or the interval being too long, and an optimum interval can be obtained.
[0016]
  Invention of Claim 8Then, by installing the tubular catalyst body of the exhaust gas purification device in the exhaust gas passage in the muffler of the motorcycle to purify the gas, the exhaust gas is purified without adding another device. be able to.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
1A and 1B are views showing an embodiment of a tubular carrier for an exhaust gas purifying apparatus according to the present invention, wherein FIG. 1A is a view of the tubular carrier 1 viewed obliquely from the rear, and FIG. is there. A large number of inwardly projecting deformed portions 2 are formed around the tube material by projecting and deforming the tube material inwardly. One side of each protruding deformation is sheared out to form a communication hole 3, and the inside and outside of the tube communicate with each other at this portion. Arrow G is the direction of the exhaust gas flow.
[0020]
2A and 2B are three views of the tubular carrier 1, wherein FIG. 2A is an external view seen from the side, FIG. 2B is a cross-sectional view taken along the line BB in FIG. 2A, and FIG. It is C sectional drawing (figure which looked forward). The shape of the inwardly projecting deformed portion 2 is a triangular recess when viewed from the outer surface of the tube, and when viewed from the rear to the front, the shape of the triangular shape generated on one side of each inwardly projecting deformed portion by shear punching of the tube material. The communication hole 3 can be seen. When this carrier is used, the exhaust gas is arranged so as to flow from left to right. Therefore, the inwardly projecting deformed portion 2 is formed so as to be inclined so that the triangular communication hole 3 opens rearward. Has been. The inclination angle θ is preferably about 30 degrees.
[0021]
FIG. 3 is a view showing a manufacturing process of the tubular carrier. For production of the carrier of the present embodiment, a stainless steel pipe material 4 such as a commercial product cut to a required size is used as a material. A plurality of concave grooves corresponding to the rows of the inwardly projecting deformed portions, which are to be provided along the generatrix of the pipe material, the core metal 5 with a relief groove provided with a row of so-called relief grooves 5a, and the above-described cut pipe material 4 In this state, it is inserted through a metal holding block 6 having a circular cross-sectional cavity 6a in the longitudinal direction in the center and having a longitudinal opening 6b in the upper part. The deforming tool 7 is driven into contact with the outer peripheral surface of the pipe material 4 corresponding to the position of the escape groove 5a. When the processing 8 of the inward projecting deformed portions in one row is completed, the deforming tool 7 is pulled up, the tube material 4 is rotated 9 together with the cored bar 5, and the inward projecting deformed portion processing 10 in the next row is performed. When this process is repeated to process the inward projecting deformed portion 2 around the entire circumference of the tube material 4, the tubular carrier 1 is completed. When a catalyst is applied to this, a tubular catalyst body is completed.
[0022]
FIG. 4 is a perspective view showing an inward projecting deformable portion 2 and a deforming tool 7 for processing the inward projecting deformed portion, and FIG. 4A shows one inward projecting deformed portion 2 inside the pipe. FIG. 5B is an external view of the deformation tool 7 used for deforming the inward projecting deformable portion 2. An angle θ formed by the ridge line 2a of the inward projecting deformable portion 2 and the original tube wall surface of the inward projecting deformable portion is formed at an acute angle, and about 30 degrees is preferable. In order to shear the rear edge 2b of the deformable portion 2 of the deformation tool 7, a sharp blade is formed on the edge of the rear edge shearing portion 7a of the deformation tool 7.
[0023]
FIG. 5 is a flow diagram when the tubular catalyst body 11 with the inwardly projecting deformable portion 2 made by applying the catalyst to the tubular carrier 1 of the above embodiment is placed in the exhaust gas flow G. In the tubular catalyst body 11 with the inward projecting deformed portion, intense turbulence occurs on the inner surface of the tube at the rear end of the inward projecting deformed portion, and the exhaust gas swirls and vigorously contacts the catalyst applied to the carrier. Compared with the conventional punched-hole tubular catalyst body 09 (see FIG. 28) in which the flow flows in a laminar flow on the surface, the effect of exhaust gas purification is remarkably large.
[0024]
Next, an embodiment in which the tubular catalyst body 11 with the inwardly projecting deformed portion is applied to an exhaust system of a motorcycle will be described. FIG. 6 is a side view of a muffler 12 of a four-stroke 125 cc internal combustion engine for a motorcycle to which the catalyst body 11 is mounted, and FIG. 7 is a transverse sectional view of the muffler (cross-section VII-VII in FIG. 6 from the rear). It is a view). Inside the muffler 12, four pipes A, B, C, and D are provided as shown in FIG. FIG. 8 is a longitudinal sectional view (sectional view taken along line VIII-VIII in FIG. 7) of the muffler taken along a vertical plane. FIG. 9 is a horizontal sectional view of the muffler (cross-sectional view taken along the line IX-IX in FIG. 7).
[0025]
8 and 9, the center portion of the body of the muffler 12 is a double body made up of the body outer plate 13 and the body plate 14, and the space is held between the partition plates 15, with the glass wool in between. 16 is filled. 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. The rear part of the body is covered with a rear lid outer plate 19 and a rear 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. A first partition wall 23 and a second partition wall 24 are provided in order from the front inside the fuselage body plate 14, and the inside of the muffler 12 is partitioned into three chambers by these partition walls. For the following explanation, these are named first chamber 25, second chamber 26, and third chamber 27 in order from the front. Inside the muffler, the four pipe lines A, B, C, and D having different lengths that communicate the chambers 25, 26, and 27 in different combinations are formed.
[0026]
The pipe A in the upper part of the muffler is composed of an inlet pipe 28 connected to the external exhaust pipe 18, a connecting pipe 29 connected to the inlet pipe 28, and a diffuser pipe serving as the connecting pipe 29 in FIG. The resonance tube 31 covers the medium 30 and the outside of the diffuser tube / catalyst body 30. The pipe A is provided through the first partition wall 23 and the second partition wall 24, and the exhaust gas discharged from the internal combustion engine first passes through the pipe line A to the third chamber 27. Be injected.
[0027]
In FIG. 9, the communication pipe 32 constitutes the pipe line B on the right side in the muffler. The pipe B is provided through the second partition wall 24, and the exhaust gas previously injected into the third chamber 27 enters the second chamber 26 through the pipe B.
[0028]
In FIG. 9, the communication pipe 33 constitutes the pipe line C on the left side in the muffler. The pipe C is provided through the first partition wall 23, and the exhaust gas that has entered the second chamber 26 enters the first chamber 25 through the pipe C.
[0029]
In FIG. 8, it is a front diffuser assembly 34 and a rear diffuser assembly 35 that constitute a pipe line D at the lower part in the muffler, and are connected via a guide pipe 36. The pipe D passes through the first partition wall 23 and the second partition wall 24, and further protrudes outside through the rear cover outer plate 19 and the rear cover inner plate 20 at the rear end portion of the rear diffuser assembly 35. The exhaust gas that has entered the first chamber 25 first is discharged to the outside through the pipe D. The muffler 12 is a device that reduces exhaust noise by combining exhaust gas of the internal combustion engine through the complicated path as described above and the action of the diffusers 30, 34, and 35.
[0030]
A diffuser pipe / catalyst body 30 which is one application form of the tubular catalyst body 11 is a conventional diffuser pipe provided with a number of punching holes at the end portion of the pipe A directly connected to the exhaust pipe 18 inside the muffler 12. In place of the diffuser pipe, the tubular catalyst body 11 with the inwardly projecting deformed portion produced by applying the catalyst to the tubular carrier 1 with the inwardly projecting deformed portion shown in FIG. This is a tube and catalyst body 30. The conventional diffuser tube attenuates pressure energy when exhaust gas flows out from a large number of punching holes, and exerts a silencing effect by interaction with the outer resonance tube 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 pipe / catalyst body 30 that also has a silencing function instead of the conventional diffuser pipe with punching holes. it can.
[0031]
In the diffuser pipe / catalyst body 30 of the present embodiment, exhaust gas is introduced from the connection pipe 29 so that the gas flows inside the pipe. 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, an effect comparable to that applied to the catalyst both inside and outside can be exhibited. If it does in this way, the cost concerning a catalyst can be halved and a big effect can be acquired to cost.
[0032]
FIG. 10 is a view showing a tubular carrier 37 according to the second embodiment of the exhaust gas purifying apparatus of the present invention. The inwardly projecting deformed portion 38 of the present embodiment is round at the front and has a communication hole 39 that is linearly sheared and punched at the rear end. The effect of this embodiment is substantially the same as that of the tubular carrier of the first embodiment.
[0033]
FIG. 11 is a view showing a tubular carrier 40 according to a third embodiment of the exhaust gas purifying apparatus of the present invention. The inward projecting deforming portion 41 of the present embodiment has a shape in which a tube piece is bent inward of a tube around one side not punched while forming a long shear punching hole 42 in the tube axis direction. The gas inside and outside the tube communicates with the shear punching hole 42 which is long in the tube axis direction. In the tubular carrier of this embodiment, the catalyst can be applied to both the inner and outer surfaces of the tube, and the gas can be effectively brought into contact with both surfaces.
[0034]
FIG. 12 is a view showing a tubular carrier 43 according to a fourth embodiment of the exhaust gas purifying apparatus of the present invention. The inwardly projecting deformable portion 44 of this embodiment is round like a part of a spherical surface, and no hole is provided for communication between the inside and outside of the tube. The tubular carrier of this embodiment is
The present invention can be applied to an exhaust gas purification device of a type in which exhaust gas is circulated only on the inner surface of a pipe.
[0035]
FIG. 13 is a three-sided view of a tubular carrier 45 according to a fifth embodiment of the exhaust gas purifying apparatus of the present invention, (a) is an external view seen from the side, and (b) is BB of (a). Sectional drawing, (c) is a CC sectional view of (b) (viewed forward). The shape of the inwardly projecting deformed portion 46 is a dent of an unequal side quadrilateral with rounded corners when viewed from the outer surface of the tube, and no hole is provided to communicate the inside and outside of the tube. When viewed from the rear to the front, the inwardly projecting deformed portion 46 caused by the deformation of the tube material can be seen. When this carrier is used, the exhaust gas is arranged to flow in the pipe in the direction of arrow G.
[0036]
FIG. 14 is a perspective view showing the shape of the inward projecting deformed portion 46 of the tubular carrier 45 of the fifth embodiment and the shape of a deforming tool 47 for machining the inward projecting deformed portion. FIG. The figure which looked at the direction protrusion deformation | transformation part 46 from the inner side of the pipe | tube, (b) is an external view of the deformation | transformation tool 47 used in order to carry out the deformation process of this inward protrusion deformation | transformation part 46.
[0037]
As shown in FIG. 14A, the inwardly projecting deformed portion 46 of the present embodiment is a pyramid type having a bottom surface that is unequal and long in the gas flow G direction. The inclination of the ridge line ahead of the vertex with respect to the tube wall toward the flow is gentler than the inclination of the ridge line behind the vertex with respect to the tube wall. The inclination angle θ of the ridge line ahead of the apex with respect to the tube wall is an acute angle, and about 30 degrees is preferable. The vicinity of the apex is the maximum cross-sectional area, the cross-sectional area decreases relatively rapidly from the maximum cross-sectional area toward the downstream side, and the cross-sectional area becomes zero. In the figure, vertices and ridge lines are drawn with sharp lines, but the actual product is manufactured in a rounded shape.
[0038]
FIG. 14B is an external perspective view of the deformation tool 47 for processing the inward projecting deformable portion 46. In a practical deformation tool, the top and ridge edges are rounded so as not to damage the tubing. As described above, the inclination of the front ridge line 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.
[0039]
FIG. 15 is an external perspective view of a tubular carrier according to the fifth embodiment provided with inwardly projecting deformed 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, the opposing rows are provided at symmetrical positions with respect to the center line of the tube, and the inward projecting deformation processing of the facing rows is performed with an appropriate tool, for example, simultaneously from above and below, tubular The production efficiency of the carrier is improved.
[0040]
FIG. 16 shows streamlines when the exhaust gas flow G is introduced into the tubular catalyst body 48 formed by applying a catalyst to the inner surface of the tube of the tubular carrier 45 with the hole-less inwardly projecting deformed 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 decreases relatively abruptly from the maximum cross-sectional area portion of the inward projecting deformed portion 46 toward the downstream side, and finally the cross-sectional area of the projecting portion becomes zero. Vigorous turbulence occurs on the inner surface of the tube at the rear end of the projecting deformation. Due to this turbulent flow phenomenon, the exhaust gas is in vigorous contact with the catalyst coated on the inner surface of the carrier, so that the gas flow is compared with the conventional punched hole tubular catalyst body 09 (FIG. 28) which flows laminarly on the surface. The effect of exhaust gas purification is much greater.
[0041]
In the tubular catalyst body 11 with the bored inwardly projecting deformed portion 2 shown in FIG. 5, the catalyst is applied to the inside and outside of the tube, and the exhaust gas is circulated inside and outside of the tube through the hole. Although the amount of gas flowing through is small compared to 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, and a high effect cannot be obtained from the viewpoint of cost effectiveness. . The tubular catalyst body 48 with the hole-less inwardly projecting deformed portion 46 of the fifth embodiment shown in FIG. 16 is an improvement measure. The catalyst is applied only to the inner surface of the pipe, and the exhaust gas is circulated only inside the pipe. It is made to let you. The contact area between the exhaust gas and the catalyst is adjusted by slightly increasing the length of the pipe.
[0042]
The higher the height of the inwardly projecting deformed part, the higher the purification rate of harmful substances, but at the same time, the inwardly projecting deformed part blocks the gas flow path, so that the flow path resistance increases and the internal combustion engine output decreases. Arise. In practical application of the present invention, it is necessary to realize at least the same purification rate and flow path resistance as the conventional tubular catalyst body 09 with punching holes (FIG. 28). For this reason, an experiment for obtaining an optimum correlation between the inner diameter of the pipe material and the height of the inward projecting deformed portion was performed in comparison with the prior art. Some of them are described below.
[0043]
FIG. 17 is a view showing the definition of the inner diameter of the tube material of the tubular carrier 45 of the fifth embodiment and the height of the inward projecting deformed portion after processing. FIG. 18 shows a curve obtained by plotting the gas purification rate (%) of a tubular catalyst body 48 in which an inward projecting deformed portion having a height of 1 mm, 4 mm, and 7 mm is provided on a tube material having an inner diameter of 23.4 mm, and connecting them. FIG. 19 plots the flow resistance (Pa) in the tubular catalyst body 48 under the same conditions, and shows a curve connecting them. In these figures, 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 for comparison. . In the case of the tubular catalyst body 09 with the punching holes, it is displayed as a constant value because it is irrelevant to the height of the inward projecting deformed portion.
[0044]
From these figures, when a tube material having an inner diameter of 23.4 mm is used, the tubular catalyst body 48 having an inward projecting deformed portion having a height of 4 mm has a performance related to the exhaust gas purification rate (%) and the flow resistance (Pa). However, when the height of the inward projecting deformed portion exceeds 4 mm, the exhaust gas purification rate (%) does not increase so much, but the flow rate is almost the same as that of the tubular catalyst body 09 with punching holes having the same inner diameter. As a result, the path resistance (Pa) suddenly increases, and when the inward projecting deformation height becomes lower than 4 mm, the exhaust gas purification rate (%) suddenly decreases, but the flow path resistance (Pa) does not decrease so much. It has become. From this experimental result, in consideration of the allowable range, it was concluded that the height of the inward projecting deformed portion is appropriate within the range of (17 ± 5)% of the inner diameter of the tube material. The range of the height of the inward projecting deformed portion when using the tube material having the inner diameter of 23.4 mm is in the range of about 2.8 mm to 5.2 mm.
[0045]
The same experiment was conducted on several other tubular catalyst bodies having an inner diameter. As a result, the height of the inward projecting deformed portion was (17 ± 5)% of the inner diameter of the pipe, even though the inner diameter of the pipe was different. It was found that the conclusion that the range is appropriate applies. FIG. 20 collectively shows the results of these experiments. The horizontal axis is the inner diameter (mm) of the tube material, and the vertical axis is the height of the inward projecting deformed portion (mm). The bold solid line indicates the allowable limit, and the thin solid line indicates. Since the present embodiment is configured in this way, as compared with the conventional tubular catalyst body with punching holes, without particularly increasing the flow resistance of the exhaust gas, while keeping the purification rate of harmful gas equal, The production efficiency can be increased by remarkably superior processability and manufacturability.
[0046]
Further, in the tubular catalyst body of the present embodiment, inward projecting deformed portions are provided in a row in the tube axis direction, and an interval L (see FIG. 15) between the inward projecting deformed portions 46 adjacent to each other in the tube axis direction. It has been found that 20-30 mm is suitable. If the interval is too short, the effect of the rearward inward projecting deformed part is hidden in the wake of the forward inward projecting deformed part, and the effect is reduced.If the interval is too long, the total number of inward projecting deformed parts is insufficient. Because of the effect is reduced. If this interval is adopted, this problem can be avoided.
[0047]
The above experiment was also performed on the hole-shaped inwardly protruding deformed portion shown in FIG. 2 and the like, and the height of the inwardly projecting deformed portion is suitably within the range of (17 ± 5)% of the inner diameter of the tube material. The conclusion obtained from the above-described experiment, and the conclusion that the size between the inwardly projecting deformed portions adjacent to each other in the tube axis direction is preferably 20 to 30 mm. It was confirmed that it can also be applied to deformed parts.
[0048]
FIG. 21 is a side view of a motorcycle 50 provided with the tubular catalyst body of the present embodiment. A head pipe 52 is provided at the front end of the vehicle body frame 51. A handle 53 and a front fork 54 are rotatably held therein, 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 portion of the vehicle body frame 51, the power unit 57 is suspended between the center portion of the vehicle body frame 51 and the lower end of the shock absorber 56, and the rear wheel 58 is rotatably attached to the rear portion of the power unit 57. Yes. A carburetor 62 and an air cleaner 63 are connected to the cylinder head 60 of the internal combustion engine 59 constituting the front portion of the power unit 57 via an intake pipe 61, and a muffler 65 is also 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 disposed on the other side of the vehicle body, broken line hatching is added to clearly indicate their positions. The vehicle 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 on the upper portion of the body cover 67. A spare tire 69 is provided at the rear of the body cover 67.
[0049]
22 is a side view of the exhaust pipe 64 and the muffler 65, and FIG. 23 is a plan view thereof. A flange portion 70 for connection to the cylinder head 60 is provided at the front end of the exhaust pipe 65, and two brackets 71 and 72 for attachment to the structure portion of the power unit 57 are provided on the muffler 65. A heat shield 73 is provided on the side surface of the muffler.
[0050]
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 is separated into a first chamber 76 and a second chamber 77 by a partition wall 75. A first pipe 79 is connected to an inlet pipe 78 that is continuous with the exhaust pipe 64 shown in FIG. In the large-diameter portion 79a close to the inlet of the first conduit 79, the tubular catalyst body 48 with a hole-less inwardly projecting deformable portion is mounted in a cantilever state as shown in FIG. The first conduit 79 is bent in the second chamber 77, further bent in the first chamber 76, and opened in the first chamber 76. A straight tubular second conduit 80 passes through the partition wall 75 in the central portion of the case 74 and connects the first chamber 76 and the second chamber 77. Further, a third pipe 81 is provided through the case 74 from the second chamber 77 and opening to the outside.
[0051]
Exhaust gas entering the muffler 65 from the inlet pipe 78 is purified while passing through the tubular catalyst body 48 in the first pipe line. The purified exhaust gas is sequentially cooled through the first pipe 79, the first chamber 76, the second pipe 80, the second chamber 77, and the third pipe 81 to reduce the exhaust noise. Then, it is discharged into the atmosphere through the outlet 82 of the third pipe 81.
[0052]
24 and 25 show an example in which the tubular catalyst body 48 with a hole-less inwardly projecting deformed portion is mounted in the muffler 65. However, the muffler 65 of this type includes other parts described in this specification. Needless to say, the exhaust gas purification effect similar to that of the present example can be obtained even if the tubular catalyst body with the inwardly projecting deformed portion of the type with holes or without holes is mounted.
[0053]
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 the deformation tool is used to direct the pipe from the outside to the inside. A plurality of projecting deformed portions 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 of punching a flat plate and then processing the pipe.
(2) Since a commercially available pipe material is used, a small diameter product having a diameter of less than 20 mm can be manufactured with high accuracy.
(3) By optimizing the shape of the inwardly projecting deformed part with communication holes or the inwardly projecting deformed part without holes, it is possible to give appropriate disturbance to the exhaust gas flowing inside the tubular carrier. The exhaust gas purification rate can be improved from the punched hole processed product.
(4) In the tubular catalyst body of the present invention, the height of the inward projecting deformed portion is set within the range of (17 ± 5)% of the inner diameter of the tube material, or the interval between the inward projecting deformed portions adjacent in the tube axis direction. By setting the thickness to 20 to 30 mm, the best effect can be obtained.
(5) The tubular catalyst body of the present invention has a purification efficiency on the inner surface of the pipe that is much higher than the purification efficiency on the outer surface of the pipe. The cost can be reduced, and exhaust gas can be introduced inside the catalyst body, or the exhaust gas can be circulated only inside, thereby increasing the cost effect. In particular, in the case of a tubular catalyst body having a holeless inward projecting deformable portion, the effect on cost is great.
[Brief description of the drawings]
FIG. 1 is a view showing a first embodiment of a tubular carrier 1 according to an exhaust gas purification apparatus of the present invention, wherein (a) is a rear perspective view of the tubular carrier 1 and (b) is a rear view.
FIG. 2 is a three-side view of the tubular carrier 1, wherein (a) is a side view, (b) is a BB cross-sectional view of (a), and (c) is a CC cross-sectional view of (b). is there.
FIG. 3 is a manufacturing process diagram of the tubular carrier.
4 is a perspective view showing the shape of a deforming tool 7 for machining the inwardly projecting deformed portion 2 and the inward projecting deformed portion 2 of the tubular carrier 1 of the first embodiment, and FIG. The figure which looked at the inward protrusion deformation | transformation part 2 from the inner side of the pipe | tube, (b) is an external view of the deformation | transformation tool 7 used in order to carry out the deformation process of this inward protrusion deformation | transformation part 2. FIG.
FIG. 5 is a streamline diagram when a tubular catalyst body 11 with an inwardly projecting deformed portion 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 four-stroke 125 cc internal combustion engine for a motorcycle on which the catalyst body 11 is mounted.
FIG. 7 is a cross-sectional view of the muffler.
FIG. 8 is a longitudinal 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, wherein (a) is a rear perspective view of the tubular carrier, and (b) is a rear view.
11A and 11B are views showing a tubular carrier according to a third embodiment of the exhaust gas purifying apparatus of the present invention, wherein FIG. 11A is a rear perspective view of the tubular carrier, and FIG. 11B is a rear view.
12A and 12B are views showing a tubular carrier according to a fourth embodiment of the exhaust gas purifying apparatus of the present invention, in which FIG. 12A is a rear perspective view of the tubular carrier, and FIG. 12B is a rear view.
FIGS. 13A and 13B are three side views of a tubular carrier according to a fifth embodiment of the exhaust gas purifying apparatus of the present invention, wherein FIG. 13A is a side view, FIG. 13B is a cross-sectional view along line BB in FIG. ) Is a sectional view taken along the line CC of FIG.
FIG. 14 is a perspective view showing the shapes of an inwardly projecting deformed portion 46 of the tubular carrier 45 according to the fifth embodiment and a deforming tool 47 for machining the inwardly projecting deformed portion. FIG. The figure which looked at the inward protrusion deformation | transformation part 46 from the inner side of the pipe | tube, (b) is an external view of the deformation | transformation tool 47 used in order to carry out deformation processing of this inward protrusion deformation | transformation part 46. FIG.
FIG. 15 is an external perspective view of a tubular carrier according to a fifth embodiment provided with inward projecting deformable portions with various numbers of rows.
FIG. 16 introduces an exhaust gas flow G into the inside of a tubular catalyst body 48 formed by applying a catalyst to the inner surface of a tubular carrier 45 having a hole-less inwardly projecting deformable portion 46 according to the fifth embodiment. FIG.
FIG. 17 is a view showing the definition of the inner diameter of the tubular carrier of the fifth embodiment and the height of the inward projecting deformed portion.
FIG. 18 is an experimental result diagram of a gas purification rate (%) of a tubular catalyst body 48 in which an inward projecting deformed portion having a height of 1 mm, 4 mm, and 7 mm is provided on a tube material having an inner diameter of 23.4 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 in FIG. The flow path resistance (Pa) of the tubular catalyst body 09 with punching holes having the same inner diameter is also shown.
FIG. 20 collectively shows the experimental results, and is a diagram showing a preferable height (mm) of the inwardly projecting deformed portion and its allowable range with respect to the inner diameter (mm) of the pipe material.
FIG. 21 is a side view of a motorcycle 50 including the tubular catalyst body according to the fifth embodiment.
22 is a side view of the exhaust pipe 64 and the muffler 65. FIG.
FIG. 23 is a plan view.
24 is a side view showing the inside of the muffler 65. FIG.
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 device, (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 when a tubular catalyst body with punching holes produced by applying a catalyst to the conventional tubular carrier is placed in an exhaust gas flow.
[Explanation of symbols]
A ... pipe, B ... pipe, C ... pipe, D ... pipe, G ... flow of exhaust gas, L ... pipe axis interval of inwardly projecting deformed parts, θ ... tilt ridge angle on the front side of the apex, DESCRIPTION OF SYMBOLS 1 ... Tubular support | carrier (1st Embodiment), 2 ... Inward projecting deformation part, 2a ... Ridge line, 2b ... Rear edge, 3 ... Communication hole, 4 ... Stainless steel pipe material, 5 ... Core metal with a relief groove, 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 ... One row of inward projecting deformation parts, 9 ... Rotation, 10 ... Process of inward projecting deformation in the next row, 11 ... Tubular catalyst body with inward projecting deformation, 12 ... Muffler, 13 ... Body outer plate, 14 ... Body inner plate, 15 ... Partition plate, 16 ... Glass wool, 17 ... front lid, 18 ... exhaust pipe, 19 ... rear lid outer plate, 20 ... rear lid inner plate, 21 ... glass wool, 22 ... rear end annular portion, 23 ... first partition, 24 ... second partition, 25 ... 1st room, 26 ... 2nd 27 ... 3rd chamber, 28 ... Inlet pipe, 29 ... Connection pipe, 30 ... Diffuser pipe / catalyst, 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 deformed portion, 39 ... communication hole, 40 ... tubular carrier (third embodiment), 41 ... inward projection Deformation part, 42 ... communicating hole, 43 ... tubular carrier (fourth embodiment), 44 ... inward projecting deformation part (no hole), 45 ... tubular carrier (fifth embodiment), 46 ... inward projecting deformation part ( No holes), 47 ... Deformation tool, 48 ... Tubular catalyst, 50 ... Motorcycle, 51 ... Body frame, 52 ... Head pipe, 53 ... Handle, 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 ... carburetor, 63 ... air cleaner, 64 ... exhaust pipe, 65 ... muffler 66 ... Front cover, 67 ... Body cover, 68 ... Seat, 69 ... Spare tire, 70 ... Flange, 71 ... Bracket, 72 ... Bracket, 73 ... Heat shield, 74 ... Muffler case, 75 ... Bulkhead, 76 ... No. 1 chamber, 77 ... 2nd chamber, 78 ... inlet pipe, 79 ... 1st pipe line, 79a ... large diameter part of 1st pipe line, 80 ... 2nd pipe line, 81 ... 3rd pipe line, 82 ... outlet part , 01 ... Tubular carrier, 02 ... Punching hole, 03 ... Rolled metal plate, 04 ... Punching hole processing, 05 ... Cutting, 06 ... U vent processing, 07 ... O vent processing, 08 ... Welding, 09 ... Tubular with punching hole Catalyst body.

Claims (10)

In an exhaust gas purification apparatus for purifying a gas by installing a tubular catalyst body manufactured by applying a catalyst to a tubular carrier in an exhaust gas passage, the tubular carrier is formed by extruding a steel pipe member formed by extrusion molding or the like. A large number of inwardly projecting deformed portions are formed continuously with the tube wall on the pipe cut into a length, forming an unequal square in the tube outer view of the inward projecting deformed portion, and the exhaust gas upstream side of the unequal square The side gradually inclines with respect to the tube axis, the exhaust gas downstream side inclines sharply with respect to the tube axis, and the cross-sectional area of the inwardly projecting deformation formed between the original tube wall gradually increases from zero. The exhaust gas purifying apparatus is characterized in that the cross-sectional area becomes zero relatively rapidly from the maximum cross-sectional area portion of the space toward the downstream side . 2. The exhaust gas purifying apparatus according to claim 1, wherein an angle formed by the ridge line of the inward projecting deformable portion and the original pipe wall surface of the inward projecting deformable portion is formed as an acute angle . The inward projecting deformed portion is a pyramid type long in the exhaust gas flow direction, and the inclination of the ridge line ahead of the apex in the exhaust gas flow direction with respect to the tube wall of the ridge line in the front-rear direction is that of the ridge line behind the apex. The exhaust gas purification device according to claim 2, wherein the exhaust gas purification device is gentler than the inclination with respect to the tube wall . The exhaust gas purification device according to any one of claims 1 to 3, wherein the tubular catalyst body is coated with a catalyst only on the inner surface side of the tubular carrier . 5. The exhaust gas purifying apparatus according to claim 2 , wherein a plurality of inward protruding portions are formed at positions symmetrical with respect to the tube axis . The exhaust gas purifying device according to any one of claims 4 to 5, wherein a height of the inwardly projecting deformable portion is in a range of (17 ± 5)% of an inner diameter of the pipe material . The inwardly projecting deformed portions are formed in a row at regular intervals in the tube axis direction of the tubular carrier, and the interval between the inwardly projecting deformed portions adjacent to each other in the tube axis direction is 20 mm to 30 mm. The exhaust gas purification device according to any one of claims 4 to 6, wherein a plurality of the rows are formed on the tubular carrier . The exhaust gas purification apparatus according to any one of claims 1 to 7 , wherein the exhaust gas purification apparatus purifies gas by installing a tubular catalyst body of the exhaust gas purification apparatus in an exhaust gas passage in a muffler of a motorcycle . 2. The exhaust gas purifying apparatus according to claim 1, wherein the tubular carrier is positioned inside the resonance tube and is cantilevered by a pipe line inside the resonance tube . A step of cutting the pipe material to the required dimensions, a step of inserting a core metal with a relief groove having a plurality of relief groove rows into the above-mentioned pipe, a longitudinal circular section cavity at the center, and a longitudinal opening at the top Manufacturing the exhaust gas purifying apparatus, comprising: holding the pipe material in a holding block having a portion; and driving the deforming tool into contact with the outer peripheral surface of the pipe material corresponding to the position of the escape groove from the upper open portion Method.

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