WO2015037559A1

WO2015037559A1 - Diffusion plate and manufacturing method for same

Info

Publication number: WO2015037559A1
Application number: PCT/JP2014/073693
Authority: WO
Inventors: 好伸永田; 鈴木　誠
Original assignee: フタバ産業株式会社
Priority date: 2013-09-12
Filing date: 2014-09-08
Publication date: 2015-03-19
Also published as: JP6306306B2; JP2015055218A

Abstract

A method for manufacturing a diffusion plate shaped with a plurality of blades protruding from a cylindrical body, wherein the method has: a correction step for performing corrective machining on a single developing metal plate, on which are formed a belt part curved in an arc within a plane, and a plurality of the blades protruding from one lateral directional side of the belt part which is the side that contacts the outer side of the arc, the machining being performed so that the shape of the belt part is linear relative to the arc; and a cylinder formation step for forming the belt part into a cylinder to form the cylindrical body, the cylinder formation step following the correction step.

Description

Diffusion plate and manufacturing method thereof

Cross-reference of related applications

This international application claims priority based on Japanese Patent Application No. 2013-189664 filed with the Japan Patent Office on September 12, 2013, and is based on Japanese Patent Application No. 2013-189664. The entire contents are incorporated into this international application.

The present invention relates to a diffusion plate that diffuses exhaust gas in an exhaust passage.

The exhaust gas discharged from an internal combustion engine such as a diesel engine contains nitrogen oxides (NO _x ) that are air pollutants. As an exhaust gas purification system for purifying such exhaust gas, an exhaust gas purification system having a configuration in which an SCR (Selective Catalytic Reduction) type catalyst is provided in an exhaust flow path and urea water is injected into the exhaust gas upstream thereof. Are known. The urea water injected into the exhaust gas is hydrolyzed by the heat of the exhaust gas, and ammonia (NH ₃ ) generated by the hydrolysis is supplied to the catalyst together with the exhaust gas. Nitrogen oxides in the exhaust gas react with ammonia in the catalyst and are reduced and purified.

Further, in this type of exhaust purification system, a diffusion plate for diffusing the exhaust gas flowing through the exhaust passage is provided on the upstream side of the catalyst so that the distribution of the exhaust gas flowing into the catalyst is less likely to be biased. For example, as described in Patent Document 1, the diffusion plate has a shape in which a plurality of blades protrude from a cylindrical tubular body, and is formed from a single developed metal plate. The developed metal plate is formed with a linear belt portion and a plurality of blades protruding from one side in the width direction of the belt portion. The cylindrical body is formed by rounding the belt portion into a cylindrical shape. Moreover, in the diffusion plate described in Patent Document 1, a plurality of blades protrudes inward from the cylindrical body so as to leave a central passage inside the cylindrical body.

JP 2008-274951 A

In the diffusion plate described in Patent Document 1 described above, since the portion (opening portion) where the blades are not present is large inside the cylindrical body as viewed from the direction along the central axis of the cylindrical body, the flow of exhaust gas is the opening portion. The diffusibility of the exhaust gas becomes low. However, if the blades are simply formed so as to close the opening, the pressure loss in the exhaust passage becomes too large.

In one aspect of the present invention, it is desirable to provide a diffusion plate capable of suppressing an excessive increase in pressure loss in the exhaust passage while suppressing a decrease in the diffusibility of the exhaust gas in the exhaust passage.

One aspect of the present invention is a method of manufacturing a diffuser plate having a shape in which a plurality of blades protrude from a cylindrical body, and includes a correction step and a cylinder forming step. In the correction step, a band portion having an arcuate shape in one plane and a plurality of the blades projecting from the one side in the width direction of the band portion and corresponding to the outer side of the arc shape are formed. The process which correct | amends so that the shape of the said belt | band | zone part may become linear compared with the said arc shape with respect to one expansion | deployment metal plate is given. In the cylinder forming step, the cylindrical body is formed by forming the belt portion into a cylindrical shape after the correcting step.

According to such a manufacturing method, it is possible to manufacture a diffusion plate capable of suppressing an excessive increase in pressure loss in the exhaust passage while suppressing a decrease in the diffusibility of the exhaust gas in the exhaust passage.

In other words, in order to suppress a reduction in exhaust gas diffusibility in the exhaust flow path, the ratio of the opening where there is no blade inside the cylindrical body as viewed from the direction along the central axis of the cylindrical body is reduced. Is effective. However, the pressure loss of the exhaust passage tends to increase as the ratio of the opening portion decreases. On the other hand, in order to suppress the pressure loss in the exhaust passage, it is effective to reduce the angle (attack angle) of the facing surface facing the exhaust gas flow in the blades with respect to the central axis of the cylindrical body. However, the smaller the angle of attack of the blade, the smaller the area of the blade viewed from the direction along the central axis of the cylindrical body, and the higher the proportion of the opening.

Therefore, in a single developed metal plate that is a material of the diffusion plate, the belt portion forming the cylindrical body is formed into an arcuate shape in one plane, and a plurality of blades are projected from the arcuate outside. By doing in this way, compared with the case where a belt | band | zone part is linear shape, it becomes possible to enlarge the width | variety of the blade | wing in one plane (width | variety of the blade | wing which can be formed from one expansion | deployment metal plate). Therefore, it is possible to manufacture a diffusion plate that achieves both improvement in the diffusibility of exhaust gas in the exhaust passage and suppression of pressure loss in the exhaust passage.

The manufacturing method may include a bending step of partially bending the plurality of blades prior to the correction step. According to such a manufacturing method, it can be made hard to produce that a blade | wing approaches and interferes by a correction process.

In the above manufacturing method, the inner edge of the belt portion that corresponds to the inner side of the arc shape may have a shape in which M (M is an integer of 2 or more) line segments are connected in a broken line shape. According to such a manufacturing method, the inner edge of the band part after the correction process can be brought closer to a straight line by partially correcting the band part at a position connected in a polygonal line shape.

In the above manufacturing method, N blades (N is an integer of 1 or more) may be formed corresponding to each of the M line segments. According to such a manufacturing method, the arrangement of the plurality of blades after the correction process can be made difficult to vary.

In the manufacturing method, in the correction step, the band may be partially bent, or the band may be partially extended. Further, a part of the band part may be bent and the other part may be extended. According to such a manufacturing method, it is possible to make the belt-shaped band portion curved in an arc shape close to a straight line by relatively simple processing.

In the manufacturing method, the spread metal plate may be formed of a single metal plate, or may be formed as a single sheet by combining a plurality of metal plates (for example, tailored material).
Another aspect of the present invention is a diffusion plate for diffusing exhaust gas flowing through an exhaust passage, and includes a cylindrical body and a plurality of blades. The cylindrical body is fixed to an inner surface of a flow path member that forms the exhaust flow path. The plurality of blades protrude from the cylindrical body. The cylindrical body and the plurality of blades are formed of a single developed metal plate. The cylindrical body is formed into a cylindrical shape after correcting a strip portion bent in an arc shape in one plane so as to be straight compared with the arc shape. The plurality of blades are formed on the one side in the width direction of the belt and on the outer side of the arc shape.

According to such a diffusion plate, it is possible to suppress an excessive increase in pressure loss in the exhaust passage while suppressing a decrease in exhaust gas diffusibility in the exhaust passage. As described above, the band forming the cylindrical body is formed in an arcuate shape in one plane, and a plurality of blades are projected from the outer side of the arc, thereby making the blades larger than the linear band. This is because it can be formed. Therefore, it is possible to achieve both the improvement of the diffusibility of the exhaust gas in the exhaust passage and the suppression of the pressure loss in the exhaust passage.

In the diffusing plate, an opposed surface of the blade facing the exhaust gas flow is formed in a plane having an angle with respect to a central axis of the cylindrical body of 15 to 40 degrees, and the cylinder is viewed from a direction along the central axis. The ratio of the opening part where the blade does not exist inside the body may be 25% or less. According to such a diffusion plate, it is possible to suppress an excessive increase in pressure loss in the exhaust passage while suppressing a decrease in exhaust gas diffusibility in the exhaust passage.

Another aspect of the present invention is a diffusion plate for diffusing exhaust gas flowing through an exhaust passage, and includes a cylindrical body and a plurality of blades. The cylindrical body is fixed to an inner surface of a flow path member that forms the exhaust flow path. The plurality of blades protrude from the cylindrical body. The cylindrical body and the plurality of blades are formed of a single developed metal plate. An opposed surface of the blade facing the exhaust gas flow is formed in a plane having an angle of 15 to 40 degrees with respect to the central axis of the cylindrical body, and is located on the inner side of the cylindrical body as viewed from the direction along the central axis. The ratio of the opening part where the blade does not exist is 25% or less. According to such a diffusion plate, it is possible to suppress an excessive increase in pressure loss in the exhaust passage while suppressing a decrease in exhaust gas diffusibility in the exhaust passage.

FIG. 1A is a top view of the exhaust purification system of the first embodiment, and FIG. 1B is a side view of the exhaust purification system of the first embodiment. 2A is a cross-sectional view taken along the line IIA-IIA in FIG. 1A, FIG. 2B is a cross-sectional view taken along the line IIB-IIB in FIG. 1B, and FIG. 3A is a perspective view of the diffusion plate of the first embodiment, FIG. 3B is a side view of the diffusion plate of the first embodiment viewed from a direction orthogonal to the central axis, and FIG. 3C is the diffusion plate of the first embodiment. It is the rear view seen from the direction which becomes a downstream of an exhaust passage along a central axis. 4A is a diagram showing a flat developed metal plate as a material of the diffusion plate of the first embodiment, FIG. 4B is a diagram showing the developed metal plate after the bending process, and FIG. 4C is a developed metal plate after the correcting process. FIG. 4D is a view showing the developed metal plate (diffusion plate) after the cylinder forming step. FIG. 5A is a view showing an analysis model, FIG. 5B is a view showing a spray state when the diffusion plate of the comparative example is used, and FIG. 5C is a view showing uniformity of ammonia when the diffusion plate of the comparative example is used. is there. FIG. 6A is a diagram showing a spray state when the diffusion plate of the first embodiment is used, and FIG. 6B is a diagram showing the uniformity of ammonia when the diffusion plate of the first embodiment is used. 7A is a perspective view of the diffuser plate of the second embodiment, FIG. 7B is a side view of the diffuser plate of the second embodiment viewed from a direction orthogonal to the central axis, and FIG. 7C is the diffuser plate of the second embodiment. It is the rear view seen from the direction which becomes a downstream of an exhaust passage along a central axis. It is a figure which shows the planar expansion | deployment metal plate used as the material of the diffusion plate of 2nd Embodiment. 9A is a perspective view of the diffusion plate of the third embodiment, FIG. 9B is a side view of the diffusion plate of the third embodiment viewed from a direction orthogonal to the central axis, and FIG. 9C is the diffusion plate of the third embodiment. It is the rear view seen from the direction which becomes a downstream of an exhaust passage along a central axis. FIG. 10A is a diagram showing a flat developed metal plate as a material of the diffusion plate of the third embodiment, FIG. 10B is a diagram showing the developed metal plate after the bending process, and FIG. 10C is a developed metal plate after the cylinder forming process. It is a figure which shows (diffusion plate). 11A is a schematic diagram of the bending process, FIG. 11B is a schematic diagram of the stretching process, and FIG. 11C is a schematic diagram of the folding process and the stretching process.

DESCRIPTION OF SYMBOLS 1 ... Exhaust gas purification system, 2 ... 1st flow path member, 3 ... 2nd flow path member, 4 ... Catalyst, 5 ... Injection apparatus, 10, 20, 30 ... Diffusion plate, 10M, 20M, 30M ... Deployment metal Plate, 11, 21, 31 ... cylindrical body, 11M, 21M, 31M ... belt part, 12, 22, 32 ... guide part, 13, 23 ... inner edge, 121, 122, 221, 222, 321, 322 ... blade, C1 ... first axis, C2 ... second axis.

Embodiments to which the present invention is applied will be described below with reference to the drawings.
[1. First Embodiment]
[1-1. Constitution]
The exhaust purification system 1 shown in FIGS. 1A, 1B, and 2A is for purifying exhaust gas discharged from an internal combustion engine (for example, a diesel engine) of an automobile. The exhaust purification system 1 includes a first flow path member 2, a second flow path member 3, a catalyst 4, an injection device 5, and a diffusion plate 10. In the following description, the vertical and horizontal directions (vertical direction and horizontal direction) are expressed with reference to FIG. 2A. However, this is merely an expression for convenience of description, and the direction in which the exhaust purification system 1 is provided is not particularly limited.

The first flow path member 2 forms a part of the exhaust flow path for guiding the exhaust gas discharged from the internal combustion engine to the outside of the automobile, specifically, the exhaust flow path to the catalyst 4. The first flow path member 2 includes, in order from the upstream side (left side in FIG. 2A) in the exhaust flow path, the first pipe portion 2A, the second pipe portion 2B, the

third pipe portion

2C, 4 pipe part 2D and the 5th pipe part 2E are provided. The first to fifth pipe portions 2A to 2E are sections for convenience of explanation, and the sections of the parts constituting the first flow path member 2 are not particularly limited.

The first tube portion 2A is a straight circular tube portion.
The third tube portion 2C is a linear circular tube portion having the same inner diameter as the first tube portion 2A. However, the third pipe 2C is different from the first pipe 2A in the direction in which the exhaust gas flows. Specifically, the first pipe portion 2A forms a flow path where the exhaust gas flows obliquely downward, and the third pipe portion 2C forms a flow path where the exhaust gas flows in the horizontal direction. For this reason, the 1st pipe part 2A and the 3rd pipe part 2C are gently connected by the 2nd pipe part 2B of the shape curved in circular arc shape in the side view.

The second tube portion 2B is formed, for example, by bonding two exteriors up and down. As shown in FIG. 1A, the exhaust flow path formed by the second pipe part 2B (the part into which the second flow path member 3 is inserted) has a first pipe part 2A and a third pipe in top view. It is expanded so as to expand (swell) to both sides in the width direction (vertical direction in FIG. 1A) than the part 2C. The width direction here refers to a first direction that is a flow direction (an obliquely downward direction) of exhaust gas that collides with an outer surface (specifically, an upper surface) of the second flow path member 3, and a second flow path member. It is a direction orthogonal to both of the second direction (horizontal direction) which is the axial direction of 3. The first direction is a direction along the first axis C1, which is the central axis of the first pipe portion 2A. The second direction is a direction along the second axis C2, which is the central axis of the third pipe portion 2C. In the present embodiment, the first axis C1 and the second axis C2 are in a positional relationship where they intersect each other.

The fifth tube portion 2E is a straight circular tube portion that is coaxial with the third tube portion 2C (with the second axis C2 as a central axis). However, the fifth tube portion 2E is formed to have an inner diameter larger than that of the third tube portion 2C in order to accommodate the columnar catalyst 4 having an outer diameter larger than the inner diameter of the third tube portion 2C. . For this reason, the 3rd pipe part 2C and the 5th pipe part 2E are the circular pipes of the shape (in this embodiment frustoconical shape) which forms the diameter expansion flow path for enlarging the internal diameter of an exhaust flow path gradually. It is gently connected by a fourth tube portion 2D which is a portion. That is, an exhaust passage having an enlarged passage on the upstream side of the catalyst 4 is formed by the first passage member 2 as an exhaust passage leading to the catalyst 4.

The second flow path member 3 has a reducing agent flow path that guides the reducing agent injected by the injection device 5 (diffused from the small holes 5A outside the exhaust flow path) to the exhaust flow path upstream of the catalyst 4. It is a so-called dosing pipe to be formed. The second flow path member 3 is a circular pipe portion that is coaxial with the third pipe portion 2C (with the second axis C2 as a central axis). In the present embodiment, the second flow path member 3 is configured such that the inner diameter of the reductant flow path gradually increases toward the exhaust flow path so that the injected reductant is less likely to directly hit the inner surface (so as not to corrode). It is formed in an enlarged shape (in this embodiment, a truncated cone shape). The 2nd flow path member 3 is connected to the 2nd pipe part 2B in the 1st flow path member 2, and the reducing agent injected by the injection apparatus 5 is the waste gas which flows through the inside of the 2nd pipe part 2B. To join. Specifically, the second flow path member 3 passes through the side wall of the second pipe portion 2B and protrudes into the exhaust flow path (the end of the second flow path member 3 is the center of the exhaust flow path). Is inserted).

As described above, the portion where the second flow path member 3 is inserted in the exhaust flow path is expanded so as to spread to both sides in the width direction when viewed from above, as shown in FIG. 1A. For this reason, as shown in FIG. 2B, the exhaust flow path formed between the first flow path member 2 and the second flow path member 3 is wider at the side portions on both sides in the width direction than at the top. Is formed. Therefore, the exhaust gas flowing from the first pipe portion 2A is likely to flow around the region R shown in FIG. 2C (regions formed on both sides in the width direction of the second flow path member 3). A flow that scoops the reducing agent from the second flow path member 3 is generated.

The catalyst 4 is an SCR (Selective Catalytic) having a function of reducing nitrogen oxides (NO _x ).
Reduction: selective catalyst reduction) type catalyst, which is provided on the downstream side of the expanded diameter passage in the exhaust passage (specifically, in the fifth pipe portion 2E).

The injection device 5 injects a liquid reducing agent and reduces it to the upstream side of the diffusion plate 10 in the exhaust flow path (specifically, in the second pipe portion 2B) via the second flow path member 3. It functions as a supply device for supplying the agent. In this embodiment, urea water is injected as a reducing agent. Strictly speaking, the urea water injected into the exhaust gas is hydrolyzed by the heat of the exhaust gas to generate ammonia (NH ₃ ), and the ammonia thus generated functions as a reducing agent. However, the state before hydrolysis (urea water) is also referred to as a reducing agent.

The diffusing plate 10 is provided on the upstream side (inside the third pipe portion 2C) of the enlarged flow passage in the exhaust flow passage, and diffuses into the enlarged flow passage by guiding the exhaust gas that has flowed in to swirl (stir). And the bias of the exhaust gas flowing into the catalyst 4 is suppressed (approached uniformly). As shown in FIGS. 3A to 3C, the diffusing plate 10 includes a cylindrical body 11 and a guide portion 12. Note that an arrow F in FIGS. 3A and 3B indicates the flow direction (direction along the second axis C2) of the exhaust gas at the inflow position to the diffusion plate 10.

The cylindrical body 11 is a portion that is bonded and fixed to the inner peripheral surface of the first flow path member 2 (specifically, the third pipe portion 2C) by welding or the like, and has an inner diameter of the third pipe portion 2C. Corresponding (for example, the same or slightly smaller dimension than the inner diameter of the third tube portion 2C) is formed in a cylindrical shape having an outer diameter. The cylindrical body 11 is arranged so as to be coaxial with the third tube portion 2C (so that the second axis C2 becomes the central axis).

The guide unit 12 includes a plurality of

blades

121 and 122 provided so as to protrude from the cylindrical body 11 in order to guide the exhaust gas to swirl. In the present embodiment, the guide unit 12 includes five first-type blades 121 and five second-type blades 122. The second type blade 122 has a shorter length along the radial direction than the first type blade 121 (in other words, the distance from the second axis C2 to the tip is large). The first type blade 121 and the second type blade 122 are arranged at equal intervals along the circumferential direction of the cylindrical body 11, and the first type blade 121 and the second type blade 122 are one sheet. They are arranged alternately.

The plurality of

blades

121 and 122 are formed so as to extend from the downstream side of the exhaust passage in the cylindrical body 11 in a direction approaching the second axis C2. As shown in FIG. 3C, when viewed from the direction along the second axis C2, the tip portions of the blades 121 and 122 (portions close to the center of the cylindrical body 11) have a shape that narrows toward the center. . The plurality of

blades

121 and 122 do not overlap each other when viewed from the direction along the second axis C2, and a portion (opening portion) where the

blades

121 and 122 do not exist except for a slight gap between the blades. It is designed not to be formed. That is, in the guide portion 12, the ratio of the opening (opening area) inside the cylindrical body 11 is close to 0% (at least 25% or less) when viewed from the direction along the second axis C2. Designed to be

Moreover, as shown to FIG. 3B, the opposing surface which opposes the flow direction F of the exhaust gas in each of the some blade | wing 121,122 is an angle (attack angle) with respect to the central axis (2nd axis C2) of the cylindrical body 11. θ1 is formed on a plane of 15 to 40 degrees (30 degrees in this embodiment). This is a small angle compared to a conventional diffusion plate (for example, the configuration described in Patent Document 1 described above). That is, in the diffusing plate 10 of the present embodiment, the

blades

121 and 122 are formed at an angle at which it is more difficult to inhibit the flow of exhaust gas as compared with the conventional configuration.

Here, a method for manufacturing the diffusion plate 10 will be described. As shown in FIGS. 4A to 4D, the diffusion plate 10 (the cylindrical body 11 and the guide portion 12) is formed from a single developed metal plate 10M. The developed metal plate 10M is formed of a single metal plate (for example, a plate made of stainless steel).

Specifically, as shown in FIG. 4A, first, one flat development of a shape in which a band portion 11M for forming the cylindrical body 11 and a plurality of

blades

121 and 122 are integrated. A metal plate 10M is formed. This step is realized by, for example, a process of punching out the shape shown in FIG. 4A from a rectangular metal plate material by a press or a process of cutting out by a laser.

The belt portion 11M is a portion that forms the cylindrical body 11, but is not a straight belt shape, but is formed in a belt shape that is bent in an arc shape in one plane. The arc shape here includes not only a gentle curved shape such as an arc, but also a shape in which a plurality of line segments are connected in a broken line shape. In the present embodiment, the inner edge 13 (the lower edge in FIG. 4A) corresponding to the inner side of the arc shape in the belt portion 11M has a shape in which five line segments 13A to 13E are connected in a broken line shape (generally arc shape).

The plurality of

blades

121 and 122 are formed so as to protrude from one side (the upper side in FIG. 4A) which is one side in the width direction of the band portion 11 </ b> M and hits the outer side of the arc shape. By disposing the

blades

121 and 122 in the outward direction of the arc-shaped belt portion 11M (in this example, radially), the ratio of the opening portions in the state where the diffusion plate 10 is formed can be reduced. Specifically, two

blades

121 and 122 are formed corresponding to each of the five line segments 13A to 13E at the inner edge 13 of the belt portion 11M. For this reason, compared with the configuration in which the belt portion 11M is a straight belt shape, the plurality of

blades

121 and 122 are less likely to interfere with each other in one plane (high degree of freedom in shape), and the width of the

blades

121 and 122 is increased. Can be formed.

Subsequently, as shown in FIG. 4B, the developed metal plate 10M is subjected to a process of partially bending the

blades

121 and 122 at a desired angle (bending step). In the present embodiment, the angle α of the folding lines of the

blades

121 and 122 corresponding to the line segments 13A to 13E is designed to be 60 degrees, and the angle of attack is set to 30 degrees by being bent at 90 degrees along the folding lines. It is formed.

Subsequently, as shown in FIG. 4C, the developed metal plate 10M after the bending process is processed so as to correct the shape of the belt portion 11M to be a straight line (correction process). In the correction process, the belt portion 11M is partially bent (corrected) at a position connected in a broken line shape (connection positions 14A to 14D of the line segments 13A to 13E). As a result, the inner edge 13 of the band portion 11M is substantially linear. The plurality of

blades

121 and 122 have a shape that hardly interferes after the correction process by a bending process performed in advance.

Subsequently, as shown in FIG. 4D, the developed metal plate 10M after the correction process is subjected to a process of forming the cylindrical body 11 by rounding the belt portion 11M into a cylindrical shape (cylinder forming process). In this way, the diffusion plate 10 is manufactured.

[1-2. Action]
Next, the operation of the exhaust purification system 1 will be described. As shown in FIG. 2A, the exhaust gas discharged from the internal combustion engine is guided to the diffusion plate 10 by the exhaust passage, and is guided to the catalyst 4 after passing through the diffusion plate 10. On the other hand, the reducing agent injected from the injection device 5 is led to the central portion of the exhaust passage by the reducing agent passage and then merges with the exhaust gas.

The portion of the second flow path member 3 inserted into the exhaust flow path collides with the upper surface of the outer surface of the second flow path member 3 in the exhaust gas flowing from the first pipe portion 2A to the second pipe portion 2B. It has a function of guiding the exhausted gas so as to go around along the outer surface. For this reason, the reducing agent flowing out from the second flow path member 3 is scooped up and dispersed in the exhaust flow path. The exhaust gas that has flowed into the diffusion plate 10 is guided so as to turn by the plurality of

blades

121 and 122, flows out so as to diffuse into the enlarged diameter flow path, and flows into the catalyst 4 in a state where the bias is suppressed. Since the angle of attack of each of the plurality of

blades

121 and 122 is small, the flow of the exhaust gas is not easily inhibited. On the other hand, the ratio of the openings is small, so that the reducing agent is efficiently diffused.

[1-3. effect]
According to the first embodiment described in detail above, the following effects can be obtained.
[1A] In order to improve the diffusibility of the exhaust gas in the exhaust passage, it is effective to reduce the ratio of the opening of the diffusion plate 10. However, the pressure loss of the exhaust passage tends to increase as the ratio of the opening portion decreases. On the other hand, in order to suppress the pressure loss of the exhaust passage, it is effective to reduce the angle of attack of the

blades

121 and 122. However, the smaller the angle of attack, the smaller the areas of the

blades

121 and 122 viewed from the direction along the central axis of the cylindrical body 11, and the proportion of the opening tends to increase.

Therefore, in the first embodiment, in one developed metal plate 10M that is a material of the diffusion plate 10, the belt portion 11M that forms the cylindrical body 11 is bent in an arc shape in one plane, and the arc shape is formed from the outside. A plurality of

blades

121 and 122 are projected. By doing in this way, compared with the case where a belt | band | zone part is linear form, the width | variety (width | variety of the blade | wing which can be formed from one expansion | deployment metal plate 10M) of the blade | wing 121,122 in one plane can be enlarged. it can. Therefore, according to the manufacturing method of the diffusion plate 10 of the first embodiment, it is possible to manufacture the diffusion plate 10 that achieves both improvement in diffusibility of exhaust gas in the exhaust passage and suppression of pressure loss in the exhaust passage.

[1B] In the manufacturing method of the diffusing plate 10 of the first embodiment, the bending step of partially bending the plurality of

blades

121 and 122 is performed before the correction step. Therefore, according to the manufacturing method of the diffusing plate 10 of the first embodiment, it is possible to make it difficult for the

blades

121 and 122 to approach each other and interfere with each other by the correction process.

[1C] In the manufacturing method of the diffusing plate 10 of the first embodiment, the inner edge 13 corresponding to the arcuate inner side of the belt portion 11M has a shape in which five line segments 13A to 13E are connected in a broken line shape. Therefore, according to the manufacturing method of the diffusing plate 10 of the first embodiment, the inner edge 13 of the band portion 11M after the correction process is linearly corrected by partially correcting the band portion 11M at the position connected to the broken line. You can get closer.

[1D] In the manufacturing method of the diffusion plate 10 of the first embodiment, two

blades

121 and 122 are formed corresponding to each of the five line segments 13A to 13E. Therefore, according to the manufacturing method of the diffusing plate 10 of the first embodiment, the arrangement of the plurality of

blades

121 and 122 after the correction process can be made difficult to vary.

[1E] In the manufacturing method of the diffusion plate 10 of the first embodiment, the belt portion 11M is partially bent in the correction process. Therefore, according to the manufacturing method of the diffusing plate 10 of the first embodiment, it is possible to bring the belt portion 11M having an arcuate shape closer to a straight line by a relatively simple process.

[1F] In the diffusing plate 10 of the first embodiment, the opposed surfaces of the

blades

121 and 122 facing the exhaust gas flow are formed in a plane whose angle θ1 with respect to the central axis of the cylindrical body 11 is 15 to 40 degrees. . Moreover, in the diffusing plate 10 of the first embodiment, the ratio of the openings where the

blades

121 and 122 do not exist inside the cylindrical body 11 when viewed from the direction along the central axis is 25% or less. Therefore, according to the diffusion plate 10 of 1st Embodiment, it can suppress that the pressure loss of an exhaust flow path becomes large too much, suppressing the fall of the diffusibility of the exhaust gas in an exhaust flow path.

[1G] As in this embodiment, the configuration in which the second flow path member 3 (dosing pipe) is inserted so as to protrude into the exhaust flow path is compared with the configuration in which the dosing pipe does not protrude into the exhaust flow path. As a result, the pressure loss in the exhaust passage increases. In this respect, in the diffusing plate 10 of the first embodiment, the

blades

121 and 122 are formed at an angle at which the flow of the exhaust gas is more difficult to obstruct compared with the conventional configuration, and the pressure loss is small. It is also suitable for a configuration protruding into the flow path.

[1-4. Analysis result]
Next, an analysis result by CAE (Computer Aided Engineering) analysis will be described. In addition, the detection location of the pressure loss and the uniformity of ammonia described below is as in the CAE analysis model shown in FIG. 5A. That is, the point J represents the urea water injection position, the pressure loss represents the differential pressure ΔP between the upstream side and the downstream side with respect to the diffusion plate 10A, and the uniformity of ammonia is the upstream end face (VC−VC) of the catalyst 4. (Across section) represents the distribution of ammonia. Note that the diffusion plate 10A shown in FIG. 5A means the diffusion plate described in FIG. 7 of the above-mentioned Patent Document 1 (hereinafter referred to as “comparative diffusion plate”) or the diffusion plate 10 of the present embodiment.

According to the analysis results using the diffusion plate of the comparative example shown in FIG. 5B and FIG. 5C, the pressure loss is large because the blades are formed at an angle that obstructs the flow, and the flow rate of the exhaust gas is large because the ratio of the opening is large. Tends to be biased. On the other hand, according to the analysis results using the diffusion plate 10 of the present embodiment shown in FIGS. 6A and 6B, the blades are formed at an angle that does not obstruct the flow, so that the pressure loss is higher than that of the diffusion plate of the comparative example. Was reduced by 45%. Moreover, since the ratio of the opening portion is smaller than that of the diffusion plate of the comparative example, and the flow of the exhaust gas is not easily biased to the outer peripheral portion, the uniformity of ammonia (a value that increases as the uniformity increases) is improved by 1.9%. . That is, according to the diffusion plate 10 of the present embodiment, the pressure loss can be reduced while increasing the uniformity of ammonia as compared with the diffusion plate of the comparative example.

[2. Second Embodiment]
[2-1. Difference from the first embodiment]
The basic configuration of the second embodiment is the same as that of the first embodiment, and the diffusion plate 20 shown in FIGS. 7A to 7C is used in place of the above-described diffusion plate 10 (FIGS. 3A to 3C). Is different. In addition, about the common structure, description is abbreviate | omitted using the same code | symbol.

[2-2. Configuration of diffusion plate]
As shown in FIGS. 7A to 7C, the diffusion plate 20 includes a cylindrical body 21 and a guide portion 22.

The cylindrical body 21 is a portion that is joined and fixed to the inner peripheral surface of the first flow path member 2 by welding or the like, similarly to the cylindrical body 11 of the first embodiment, and is formed on the inner diameter of the third pipe portion 2C. It is formed in a cylindrical shape with a corresponding outer diameter, and is arranged so as to be coaxial with the third pipe portion 2C.

As with the guide unit 12 of the first embodiment, the guide unit 22 includes five first-type blades 221 and five second-type blades that are shorter in the radial direction than the first-type blades 221. The blades 222 are provided. The first type blade 221 and the second type blade 222 are arranged at equal intervals along the circumferential direction of the cylindrical body 11, and the first type blade 221 and the second type blade 222 are one sheet. They are arranged alternately.

The plurality of

blades

221 and 222 are formed so as to extend from the downstream side of the exhaust passage in the cylindrical body 21 in a direction approaching the second axis C2. As shown in FIG. 7C, when viewed from the direction along the second axis C2, each

blade

221, 222 has a shape that narrows in a triangular shape from the proximal end portion toward the distal end portion. The plurality of

blades

221 and 222 are designed so that they do not overlap each other when viewed from the direction along the second axis C2, and no opening is formed except for a slight gap between the blades. That is, the guide part 22 is designed so that the ratio of the opening part is close to 0% (at least 25% or less), like the guide part 12 of the first embodiment.

Further, as shown in FIG. 7B, an angle θ2 with respect to the central axis (second axis C2) of the cylindrical body 21 of the opposed surfaces facing each other in the exhaust gas flow direction F in each of the plurality of

blades

221 and 222 is 15˜. It is formed on a plane of 40 degrees (30 degrees in this embodiment).

Further, as shown in FIG. 8, the diffusion plate 20 (tubular body 21 and guide portion 22) of the second embodiment is a single (single) developed metal, like the diffusion plate 10 of the first embodiment. It is formed from a plate 20M. And the belt | band | zone part 21M for forming the cylindrical body 21 is formed in the belt | band | zone shape of the shape curved in the arc in one plane similarly to the belt | band | zone part 11M of 1st Embodiment. The plurality of

blades

221 and 222 are formed so as to protrude radially from one side (the upper side in FIG. 8) corresponding to the arcuate outer side on one side in the width direction of the band portion 21 </ b> M.

Specifically, the inner edge 23 (the lower edge in FIG. 8) corresponding to the inner side of the arc shape in the belt portion 21M has a shape in which ten line segments 23A to 23J are connected in a broken line shape (generally an arc shape). One

blade

221, 222 is formed corresponding to each of the ten line segments 23A to 23J. The diffusion plate 20 of the second embodiment is also manufactured by subjecting the developed metal plate 20M to the same folding process, correction process, and cylinder forming process as those of the first embodiment.

[2-3. effect]
According to the second embodiment described in detail above, the same effects as those of the first embodiment described above can be obtained.

[3. Third Embodiment]
[3-1. Difference from the first embodiment]
The basic configuration of the third embodiment is the same as that of the first embodiment, and the diffusion plate 30 shown in FIGS. 9A to 9C is used in place of the above-described diffusion plate 10 (FIGS. 3A to 3C). Is different. In addition, about the common structure, description is abbreviate | omitted using the same code | symbol.

[3-2. Configuration of diffusion plate]
As shown in FIGS. 9A to 9C, the diffusion plate 30 includes a cylindrical body 31 and a guide portion 32.

The cylindrical body 31 is a portion that is joined and fixed to the inner peripheral surface of the first flow path member 2 by welding or the like, similar to the cylindrical body 11 of the first embodiment, and is formed on the inner diameter of the third pipe portion 2C. It is formed in a cylindrical shape with a corresponding outer diameter, and is arranged so as to be coaxial with the third pipe portion 2C.

As with the guide unit 12 of the first embodiment, the guide unit 32 includes five first type blades 321 and five second type blades having a shorter length along the radial direction than the first type blades 321. Blade 322. The first type blades 321 and the second type blades 322 are arranged at equal intervals along the circumferential direction of the cylindrical body 11, and the first type blades 321 and the second type blades 322 are one piece. They are arranged alternately.

The plurality of

blades

321 and 322 are formed so as to extend from the downstream side of the exhaust passage in the cylindrical body 31 in a direction approaching the second axis C2. As shown in FIG. 9C, when viewed from the direction along the second axis C2, the tip portions of the blades 321 and 322 (portions close to the center of the cylindrical body 31) have a shape that narrows toward the center. . The plurality of

blades

321 and 322 are designed to be small (at least 25% or less) although they do not overlap each other when viewed from the direction along the second axis C2 and there are openings.

Further, as shown in FIG. 9B, the opposing surfaces of the plurality of

blades

321 and 322 facing the exhaust gas flow direction F each have an angle θ3 of 15 to 15 with respect to the central axis (second axis C2) of the cylindrical body 31. It is formed on a plane of 40 degrees (30 degrees in this embodiment).

As shown in FIGS. 10A to 10C, the diffusion plate 30 (cylindrical body 31 and guide portion 32) of the third embodiment is the same as the diffusion plate 10 of the first embodiment. Formed from. However, the diffusion plate 30 of the third embodiment is different from the diffusion plate 10 of the first embodiment in that the band portion 21M for forming the cylindrical body 31 is formed in a linear band shape. The plurality of

blades

321 and 322 are formed so as to protrude from one side (the upper side in FIG. 10A) in the width direction of the band portion 21M. The diffusion plate 30 of the third embodiment is also manufactured by performing the bending process (FIG. 10B) and the cylinder forming process (FIG. 10C) similar to the first embodiment on the developed metal plate 30M (the correction process is performed). Absent).

[3-3. effect]
According to the third embodiment described above in detail, the same effects as the effects [1F] to [1G] of the first embodiment described above can be obtained.

[4. Other Embodiments]
As mentioned above, although embodiment of this invention was described, it cannot be overemphasized that this invention can take a various form, without being limited to the said embodiment.

[4A] In the first embodiment and the second embodiment, as shown in the schematic diagram of FIG. 11A, in the correction process, the

belt portions

11M and 21M are partially bent at the positions connected in a broken line shape. However, the present invention is not limited to this. For example, as shown in FIG. 11B, in the correction step, a process of partially extending may be performed instead of a process of partially bending. Moreover, as shown to FIG. 11C, you may process so that a part (arc-shaped outer side) may be bent and the other part (arc-shaped inner side) may be extended.

[4B] The shape of the diffusion plate, for example, the number of blades, the shape, the angle of attack, and the like are not limited to those exemplified in the above embodiments. For example, in the above-described embodiments, two types of blades having different shapes are alternately arranged one by one, but the number of patterns to be arranged may be changed, such as alternating one and two blades. In each of the above embodiments, there are two types of blade shapes, but there may be one type or three or more types. Moreover, it is good also considering several angles of attack.

[4C] The shape of the inner edge of the belt portion (number of broken lines, angles, etc.) is not limited to that exemplified in the above embodiment. Moreover, it is good also considering the inner edge of a belt | band | zone part as shapes (for example, circular arc shape) other than a broken line.
[4D] The cross-sectional shapes of the

cylindrical bodies

11, 21, 31 are not limited to circles, and may be, for example, elliptical or polygonal.

[4E] One

spread metal plate

10M, 20M, 30M that is a material of the

diffusion plate

10, 20, 30 is formed by combining a plurality of types of metal plates into a single sheet, such as a tailored material. There may be. For example, using a single developed metal plate in which two types of metal plates having different plate thicknesses are combined as a material,

cylindrical bodies

11, 21, 31 are formed by thin portions, and guide portions are formed by thick portions. 12, 22, 32 may be formed. In this case, since the rigidity of the

blades

121, 122, 221, 222, 321, and 322 is increased, the

blades

121, 122, 221, 222, 321, and 322 are less likely to be deformed and the durability is improved.

[4F] The exhaust passage and the reducing agent passage in the above embodiment are merely examples, and the present invention is not limited thereto. For example, in the above embodiment, on the assumption that the second flow path member 3 protrudes into the exhaust flow path, a partial cross-sectional shape of the first flow path member 2 is a horizontally long shape. At least a part of the cross-sectional shape of the road member 3 may be a vertically long shape. Further, for example, the second flow path member 3 may be configured not to protrude into the exhaust flow path, and the cross-sectional shapes of the first flow path member 2 and the second flow path member 3 may be circular. Further, for example, the first tube portion 2A and the third tube portion 2C may have different inner diameters, and the third tube portion 2C, the fifth tube portion 2E, and the second flow path member 3 are It need not be coaxial. Further, for example, the exhaust flow path is not limited to having an enlarged diameter flow path, and may be an exhaust flow path not having an enlarged diameter flow path.

[4G] The reducing agent is not limited to urea water, and any substance that contributes to purification of exhaust gas in the catalyst may be used. The present invention may also be applied to an exhaust system other than an exhaust purification system using a reducing agent.

[4H] The functions of one constituent element in the above embodiment may be distributed as a plurality of constituent elements, or the functions of a plurality of constituent elements may be integrated into one constituent element. Further, at least a part of the configuration of the above embodiment may be replaced with a known configuration having the same function. Moreover, you may abbreviate | omit a part of structure of the said embodiment as long as a subject can be solved. In addition, at least a part of the configuration of the above embodiment may be added to or replaced with the configuration of the other embodiment. In addition, all the aspects included in the technical idea specified from the wording described in the claims are embodiments of the present invention.

[4I] The present invention can be realized in various forms such as the above-described diffusion plate, an exhaust purification system using the diffusion plate as a constituent element, and a method for suppressing the deviation of the flow of exhaust gas.

Claims

A method of manufacturing a diffuser plate having a shape in which a plurality of blades protrudes from a cylindrical body,
One piece of developed metal in which a band portion having an arcuate shape in one plane and a plurality of the blades protruding from the one side that is on one side in the width direction of the band portion and contacts the outer side of the arc shape are formed. A correction process for applying correction to the plate so that the shape of the belt portion is linear compared to the arc shape;
After the straightening step, a tube forming step of forming the tubular body by forming the belt portion into a tubular shape,
A method for producing a diffuser plate.
It is a manufacturing method of the diffusion plate according to claim 1,
The manufacturing method of a diffusion plate which has the bending process of partially bending the said several blade | wing before the said correction process.
It is a manufacturing method of the diffusion plate according to claim 1 or 2,
The inner edge which hits the inside of the said arc shape in the said belt | band | zone part is a manufacturing method of the diffusion plate which is the shape where the M (M is an integer greater than or equal to 2) line segment was connected in the shape of a broken line.
It is a manufacturing method of the diffusion plate according to claim 3,
A manufacturing method of a diffusion plate, wherein N blades (N is an integer of 1 or more) are formed corresponding to each of the M line segments.
It is a manufacturing method of the diffusion plate given in any 1 paragraph of Claims 1-4,
The diffusion plate manufacturing method, wherein in the correction step, the belt portion is partially bent.
It is a manufacturing method of the diffusion plate given in any 1 paragraph of Claims 1-5,
In the correction step, the diffusion plate is partially stretched, and the diffusion plate manufacturing method.
It is a manufacturing method of the diffusion plate given in any 1 paragraph of Claims 1-6,
The said expansion | deployment metal plate is a manufacturing method of the diffusion plate currently formed with the single metal plate.
It is a manufacturing method of the diffusion plate given in any 1 paragraph of Claims 1-6,
The said expansion | deployment metal plate is a manufacturing method of the diffusion plate currently formed in one sheet combining several metal plates.
A diffusion plate for diffusing the exhaust gas flowing through the exhaust passage,
A cylindrical body fixed to the inner surface of the flow path member forming the exhaust flow path;
A plurality of blades protruding from the tubular body;
With
The cylindrical body and the plurality of blades are formed of a single developed metal plate,
The cylindrical body is made into a cylindrical shape after correcting the belt portion of the shape bent in an arc shape in one plane to be linear compared to the arc shape,
The plurality of blades are diffusion plates that are formed on one side in the width direction of the belt portion and on the one side that contacts the arcuate outer side.
The diffusion plate according to claim 9,
The opposed surface of the blade facing the exhaust gas flow is formed in a plane having an angle of 15 to 40 degrees with respect to the central axis of the cylindrical body,
A diffuser plate in which the ratio of the openings where the blades do not exist is 25% or less inside the cylindrical body when viewed from the direction along the central axis.
A diffusion plate for diffusing the exhaust gas flowing through the exhaust passage,
A cylindrical body fixed to the inner surface of the flow path member forming the exhaust flow path;
A plurality of blades protruding from the tubular body;
With
The cylindrical body and the plurality of blades are formed of a single developed metal plate,
The opposed surface of the blade facing the exhaust gas flow is formed in a plane having an angle of 15 to 40 degrees with respect to the central axis of the cylindrical body,
A diffuser plate in which the ratio of the openings where the blades do not exist is 25% or less inside the cylindrical body when viewed from the direction along the central axis.