JP2009197695A - Exhaust emission control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device which is installed even in a narrow space, capable of introducing exhaust emission in a substantially uniform manner in an oxidation catalyst or a filter in the exhaust emission control device, sufficiently demonstrating the purifying performance, and suppressing occurrence of breakage or the like caused by explosive combustion. <P>SOLUTION: In the exhaust emission control device 1 storing oxidation catalyst 4 and a filter 5 for purifying exhaust emission from a diesel engine in cylindrical cases 10, 20, an introduction chamber 2 is formed on the upstream side of the cylindrical case 10, the oxidation catalyst 4 and the filter 5 are stored on the downstream side, one end of the exhaust emission introduction pipe 6 is connected to an exhaust manifold, and the other end of the exhaust emission introduction pipe 6 is inserted in the introduction chamber so that the exhausting direction is orthogonal to the center axis of the introduction chamber 2, and offset therefrom. Alternatively, the exhaust introduction pipe 6 is inserted in the direction orthogonal to the center axis of the introduction chamber 2, and a plurality of exhaust holes 6b are opened around the exhaust emission introduction pipe 6 in the introduction chamber 2. In addition, a partition 50 for partitioning a purification chamber 30 is provided, and a plurality of communication holes 55 are opened in the partition plate 50. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technology of an exhaust gas purification device, and more particularly to a technology for uniformly introducing exhaust gas into the exhaust gas purification device.

In recent years, environmental issues and health effects are concerned, so particulate matter (hereinafter referred to as PM) and nitrogen oxides (NOX) in exhaust gas discharged from diesel engines such as automobiles, ships, and generators. Development of a device that removes etc. is underway. As technical methods for dealing with these, there are a method for preventing black smoke emission by measures such as fuel injection timing and mixing ratio on the engine side, and a method for dealing with exhaust system post-treatment. As a method for dealing with exhaust system post-treatment, for example, a technology for attaching an exhaust gas purification device to an exhaust device such as a diesel engine is already known. The ceramic filter method is the mainstream. Although various methods for regenerating the accumulation of particulate matter have been studied for these apparatuses, they are still not technically sufficient.
Conventionally, in automobiles, trucks, etc. that have adopted exhaust gas purification devices ahead of industrial diesel engines, it is possible to arrange these devices at the bottom of the chassis, so it is possible to use a relatively large space. there were.
For example, as described in Patent Document 1, when exhaust gas is introduced into the exhaust gas purification device, the heat of the exhaust gas is raised by using a tapered pipe and an exhaust throttle valve, etc., and introduced into the oxidation catalyst and filter (DPF). Techniques that can be made are known.
JP 2007-40220 A

Further, in the case of an industrial diesel engine engine, there are various mounting forms of the exhaust gas purification device, and the space of the mounting part is limited.
In an industrial diesel engine, it is impossible for a construction machine or an agricultural machine used off-road to dispose an exhaust gas purification device at the bottom of a chassis of a work machine. In addition, since the same engine is mounted on various working machines, when it is placed outside the engine room, naturally, different specifications of piping and the like are generated, and there is a concern that the purification performance may be reduced due to a change in exhaust temperature.
Therefore, it is required to place an aftertreatment device in the vicinity of the engine, but it must be a narrow space, so it is difficult to introduce exhaust gas into the oxidation catalyst and the filter substantially uniformly, and the performance cannot be fully exhibited. In addition, damage such as erosion of the filter due to runaway combustion (a phenomenon in which PM of a predetermined concentration or more accumulates in the filter, burns continuously, and partially becomes high temperature) has occurred.

  Therefore, the present invention has been made in view of the above problems, and the object of the present invention is that it can be installed even in a narrow space near the engine, and exhaust gas is substantially uniformly applied to an oxidation catalyst and a filter in the exhaust gas purification device. The purpose of the present invention is to provide an exhaust gas purifying apparatus that is introduced and exhibits its purification performance sufficiently to suppress the occurrence of breakage due to runaway combustion.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

  That is, in claim 1, in an exhaust gas purifying apparatus in which an oxidation catalyst and a filter for purifying exhaust gas from a diesel engine are housed in a cylindrical case, an introduction chamber is formed on the upstream side of the cylindrical case, and an oxidation is performed on the downstream side. The catalyst and filter are accommodated, one end of the exhaust introduction pipe is connected to the exhaust manifold, and the other end of the exhaust introduction pipe is in a position perpendicular to the central axis of the introduction chamber and eccentric. It is inserted into the introduction chamber.

  According to claim 2, in the exhaust gas purification apparatus in which an oxidation catalyst or filter for purifying exhaust gas from a diesel engine is housed in a cylindrical case, an introduction chamber is formed on the upstream side of the cylindrical case, and an oxidation catalyst or A filter is accommodated, one end of the exhaust introduction pipe is connected to the exhaust manifold, and the other end of the exhaust introduction pipe is inserted in a direction perpendicular to the central axis of the introduction chamber, and is formed in the exhaust introduction pipe Is opened to the antioxidation catalyst side.

  According to claim 3, in the exhaust gas purification apparatus in which an oxidation catalyst or filter for purifying exhaust gas from a diesel engine is housed in a cylindrical case, an introduction chamber is formed on the upstream side of the cylindrical case, and an oxidation catalyst or The filter is accommodated, one end of the exhaust introduction pipe is connected to the exhaust manifold, the other end of the exhaust introduction pipe is inserted in a direction perpendicular to the central axis of the introduction chamber, and the periphery of the exhaust introduction pipe in the introduction chamber A plurality of discharge holes are opened, and the number of discharge holes is increased toward the center of the introduction chamber.

  According to claim 4, in the exhaust gas purification apparatus in which an oxidation catalyst or filter for purifying exhaust gas from a diesel engine is housed in a cylindrical case, an introduction chamber is formed on the upstream side of the cylindrical case, and an oxidation catalyst or The filter is accommodated, one end of the exhaust introduction pipe is connected to the exhaust manifold, the other end of the exhaust introduction pipe is inserted in a direction perpendicular to the central axis of the introduction chamber, and the periphery of the exhaust introduction pipe in the introduction chamber A plurality of discharge holes are opened, and the area of the discharge holes is increased toward the center of the introduction chamber.

  In Claim 5, the partition plate which partitions off the purification chamber which stores an oxidation catalyst and a filter is provided in the downstream of the introduction chamber, a plurality of communication holes are opened in the partition plate, and the number of the communication holes is introduced. The smaller the number, the closer to the center of the room.

  According to a sixth aspect of the present invention, a partition plate for partitioning the oxidation chamber and the purification chamber for storing the filter is provided downstream of the introduction chamber, a plurality of communication holes are opened in the partition plate, and the area of the communication hole is introduced. It is made smaller toward the center of the room.

  In claim 7, in the exhaust gas purification apparatus in which an oxidation catalyst or filter for purifying exhaust gas of a diesel engine is housed in a cylindrical case, an introduction chamber is formed on the upstream side of the cylindrical case, and an oxidation catalyst or The filter is housed, one end of the exhaust introduction pipe is connected to the exhaust manifold, and the other end of the exhaust introduction pipe is inserted so as to be substantially coincident with the central axis of the introduction chamber, and the exhaust gas discharge direction from the exhaust introduction pipe A rectifying plate is provided in a direction perpendicular to the rectifying plate, a plurality of passage holes are opened in the rectifying plate, and the number of the passage holes is reduced toward the center of the introduction chamber.

  According to claim 8, in the exhaust gas purification apparatus in which an oxidation catalyst or filter for purifying exhaust gas from a diesel engine is housed in a cylindrical case, an introduction chamber is formed on the upstream side of the cylindrical case, and an oxidation catalyst or A filter is housed, and an exhaust introduction pipe connected to an exhaust manifold is inserted so as to substantially coincide with the central axis of the introduction chamber, and a rectifying plate is provided in a direction perpendicular to the exhaust gas discharge direction from the exhaust introduction pipe. A plurality of passage holes are opened in the current plate, and the area of the passage holes is reduced toward the center side of the introduction chamber.

  In claim 9, in the exhaust gas purification apparatus in which an oxidation catalyst or filter for purifying exhaust gas from a diesel engine is housed in a cylindrical case, an introduction chamber is formed upstream of the cylindrical case, and an oxidation catalyst or A filter is housed, one end of the exhaust introduction pipe is connected to the exhaust manifold, and the other end of the exhaust introduction pipe is inserted so as to be substantially coincident with the central axis of the introduction chamber, thereby closing the tip of the exhaust introduction pipe in the introduction chamber. A plurality of discharge holes are opened in the periphery, and the number of discharge holes is smaller as the oxidation catalyst side.

  According to claim 10, in the exhaust gas purification apparatus in which an oxidation catalyst or filter for purifying exhaust gas from a diesel engine is housed in a cylindrical case, an introduction chamber is formed on the upstream side of the cylindrical case, and an oxidation catalyst or The filter is housed, one end of the exhaust introduction pipe is connected to the exhaust manifold, the other end of the exhaust introduction pipe is inserted so as to substantially coincide with the central axis of the introduction chamber, and the tip of the exhaust introduction pipe in the introduction chamber is inserted. A plurality of discharge holes are opened around the plug, and the area of the discharge holes is made smaller toward the oxidation catalyst side.

  As effects of the present invention, the following effects can be obtained.

  In claim 1, the exhaust gas is introduced as a swirling flow along the wall surface of the introduction chamber, and can be introduced substantially uniformly into the oxidation catalyst and the filter. Therefore, the performance of the oxidation catalyst can be fully exerted to avoid runaway combustion. Further, the exhaust introduction pipe can be easily attached to the introduction chamber, the taper pipe and the swirl flow generator are not required, and a swirl flow can be obtained in a space-saving manner.

  According to the second aspect, the exhaust gas is discharged in the reverse direction with respect to the oxidation catalyst and the filter, so that the exhaust gas is bypassed and can be introduced into the oxidation catalyst and the filter substantially uniformly. Therefore, the performance of the oxidation catalyst can be fully exerted to avoid runaway combustion. Further, the exhaust introduction pipe can be easily attached to the introduction chamber.

  According to the third aspect, the exhaust gas can be discharged substantially uniformly from the exhaust introduction pipe into the introduction chamber, and can be introduced substantially uniformly into the oxidation catalyst and the filter. Therefore, the performance of the oxidation catalyst can be fully exerted to avoid runaway combustion. Further, the exhaust introduction pipe can be easily attached to the introduction chamber, and the discharge hole can be easily opened.

  According to the fourth aspect of the present invention, the exhaust gas can be discharged almost uniformly from the exhaust introduction pipe into the introduction chamber, and can be introduced almost uniformly into the oxidation catalyst and the filter. Therefore, the performance of the oxidation catalyst can be fully exerted to avoid runaway combustion. Occasionally, the exhaust introduction pipe can be easily attached to the introduction chamber, and the discharge hole only needs to be changed in size.

  In the fifth aspect, in addition to the effects of the first to fourth aspects, unevenness when introduced into the oxidation catalyst or the filter can be further reduced. Noise can be reduced by the partition plate. The communication hole can be easily opened.

  In the sixth aspect, in addition to the effects of the first to fourth aspects, unevenness when introduced into the oxidation catalyst or the filter can be further reduced. Moreover, noise can be reduced by the partition plate, and the discharge hole only needs to be changed in size.

  According to the seventh aspect of the present invention, it is possible to discharge the exhaust gas from the exhaust introduction pipe into the introduction chamber substantially uniformly by simply providing a rectifying plate, and to introduce it into the oxidation catalyst and the filter substantially uniformly. Therefore, the performance of the oxidation catalyst can be fully exerted to avoid runaway combustion. Further, the length in the central axis direction can be shortened, and the passage hole can be easily opened.

  According to the eighth aspect of the present invention, the exhaust gas can be discharged from the exhaust introduction pipe into the introduction chamber substantially uniformly by simply providing the current plate, and can be introduced into the oxidation catalyst and the filter substantially uniformly. Therefore, the performance of the oxidation catalyst can be fully exerted to avoid runaway combustion. Further, the length in the central axis direction can be shortened, and substantially uniformity can be easily obtained by simply changing the size of the passage hole.

  According to the ninth aspect, the exhaust gas can be discharged substantially uniformly from the exhaust introduction pipe into the introduction chamber, and can be introduced substantially uniformly into the oxidation catalyst and the filter. Therefore, the performance of the oxidation catalyst can be fully exerted to avoid runaway combustion. Further, the length in the central axis direction can be shortened, and the discharge hole can be easily opened.

  According to the tenth aspect, the exhaust gas can be discharged substantially uniformly from the exhaust introduction pipe into the introduction chamber, and can be introduced substantially uniformly into the oxidation catalyst and the filter. Therefore, the performance of the oxidation catalyst can be fully exerted to avoid runaway combustion. In addition, the length in the central axis direction can be shortened, and substantially uniformity can be easily obtained simply by changing the size of the discharge hole.

Next, embodiments of the invention will be described.
FIG. 1 is a schematic perspective view showing an exhaust gas purification apparatus according to Embodiment 1 of the present invention, FIG. 2 is a cutaway view in the exhaust gas flow direction showing the exhaust gas purification apparatus according to Embodiment 1 of the present invention, and FIG. Fig. 4 is a schematic perspective view showing an exhaust gas purifying apparatus according to Example 2, Fig. 4 is a cutaway view of an exhaust gas flow direction showing an exhaust gas purifying apparatus according to Example 2 of the present invention, and Fig. 5 (a) is related to Example 3 of the present invention. FIG. 5B is a schematic perspective view showing an exhaust gas purification apparatus according to Embodiment 4 of the present invention, and FIG. 6 is an exhaust gas purification apparatus according to Embodiments 3 and 4 of the present invention. FIG. 7 is a schematic perspective view showing an exhaust gas purifying apparatus according to Example 5 and Example 6 of the present invention, and FIG. 8A is Example 5 and Example of the present invention. FIG. 8B is a schematic diagram showing a partition plate and a rectifying plate according to FIG. 7, and FIG. FIG. 9 is a schematic perspective view showing an exhaust gas purifying apparatus according to Example 7 and Example 8 of the present invention, and FIG. 10 is Example 9 and Example of the present invention. 11 is a schematic perspective view showing an exhaust gas purifying apparatus according to Example 10, FIG. 11 (a) is a schematic perspective view showing an exhaust introduction pipe according to Example 9 of the present invention, and FIG. 11 (b) is according to Example 10 of the present invention. It is a schematic perspective view which shows an exhaust introduction pipe.

  The overall configuration of the exhaust gas purifying apparatus according to all the embodiments of the present invention will be outlined with reference to FIG.

An exhaust gas purification apparatus 1 for diesel engines (hereinafter simply referred to as an exhaust gas purification apparatus) includes an exhaust introduction pipe 6, an introduction chamber 2, an oxidation catalyst 4, a filter 5 (DPF), and an outlet portion 3. Moreover, the thick arrow in each figure represents the flow of exhaust gas.
The oxidation catalyst 4 is formed in a cylindrical case 10 as a casing, and similarly, the filter 5 is formed in a cylindrical case 20 as a casing. The upstream side of the exhaust gas is defined as the introduction chamber 2, and the introduction chamber 2, the cylindrical case 10, the cylindrical case 20, and the outlet portion 3 are arranged in series in this order. In addition, as shown in FIG. 2, spaces 30 a, 30 b, and 30 c having predetermined intervals are provided on the upstream side, the downstream side, and the downstream side of the filter 5 of the oxidation catalyst 4 disposed in the purification chamber 30.
Both the downstream end of the introduction chamber 2 and the upstream end of the cylindrical case 10 are formed with a flange-like flange portion 15. Similarly, the downstream end of the cylindrical case 10 and the upstream end of the cylindrical case 20 are A flange portion 15 is formed on both sides, and an annular gasket (not shown) is sandwiched between the flange portions 15 to maintain airtightness, and both are integrally fixed with a bolt (not shown) or the like. Yes. Also, a flange-like flange portion 15 is formed at the downstream end of the cylindrical case 20, and an annular gasket (not shown) is provided with a disc-shaped outlet portion provided with an opening at the substantially central portion of the flange portion 15. 3 is kept airtight by being sandwiched between 3 and is fixed integrally with a bolt (not shown) or the like. Here, the disc-shaped outlet portion 3 is fixed to the downstream end of the cylindrical case. However, the outlet portion 3 may be formed integrally with the cylindrical case 20, and the space portion 30c may be formed in the downstream portion. It is not limited.
The oxidation catalyst 4 and the filter 5 are detachable from the cylindrical cases 10 and 20.

  An exhaust introduction pipe 6 that guides exhaust gas from the engine through an exhaust manifold (not shown) is disposed in the introduction chamber 2. Details of the insertion direction of the exhaust introduction pipe 6 with respect to the introduction chamber 2 will be described in each embodiment. An opening is provided at the tip or circumference of the exhaust introduction pipe 6 in the introduction chamber 2. That is, the exhaust gas is introduced into the introduction chamber 2 from the openings of the exhaust introduction pipe 6.

  The entire oxidation catalyst 4 at the rear stage of the introduction chamber 2 has a substantially cylindrical shape, and has a monolithic carrier (not shown) in which a grid-like (honeycomb-like) passage is formed in the direction in which the exhaust gas flows. A catalytic metal such as platinum, rhodium or palladium is supported on the monolith support. Oxidizing power is imparted to nitric oxide (NO), carbon monoxide (CO), hydrocarbon (HC) and the like by the oxidation catalyst 4 by supporting the catalytic metal. In addition, although the material of the monolith carrier is cordierite in this embodiment, it is not particularly limited, and silicon carbide, stainless steel, or the like can be used.

Further, the downstream filter 5 is a substantially cylindrical honeycomb filter having a polygonal cross section partitioned by porous partition walls made of ceramics such as cordierite. Further, the filter 5 is configured by alternately sealing exhaust gas inlets and outlets of a large number of through holes formed in parallel with each other by these partition walls. The partition wall carries a catalyst metal such as platinum. Similar to the oxidation catalyst 4 described above, it has a catalytic function.
In this embodiment, platinum is used as the catalyst metal, but there is no particular limitation, and palladium, rhodium, iridium, or the like can also be used.
In each embodiment to be described later, the oxidation catalyst 4 and the filter 5 are arranged in the exhaust gas purification device 1, but only the filter 5 having a catalytic function is arranged in the purification chamber 30 of the exhaust gas purification device 1. Also good.

Next, an exhaust gas flow and a purification method in the exhaust gas purification apparatus 1 will be described.
In the above configuration, the exhaust gas is introduced into the introduction chamber 2 through an opening (details will be described later in each embodiment) provided in the exhaust introduction pipe 6 in the introduction chamber 2. Subsequently, the exhaust gas passes through the space 30 a in a substantially uniform state in the introduction chamber 2 in the preceding stage, and is introduced into the oxidation catalyst 4. The introduced exhaust gas is imparted with oxidizing power by the oxidation catalyst 4 to generate NO ₂ from NO (oxidizing power is also imparted to CO, HC, etc.). PM is collected by the DFP 5 from the exhaust gas that has passed through the oxidation catalyst 4. The collected PM is continuously oxidized and burned off using the oxidizing power of NO _{2 and the} like generated by the oxidation catalyst 4 and DFP 5 in the previous stage and the high temperature of the exhaust gas near the engine. That is, the PM accumulated in the filter 5 is burned and removed, and the removing power of the filter 5 is regenerated. The exhaust gas from which PM has been removed by the filter 5 is discharged out of the exhaust gas purification apparatus 1 through a pipe (not shown) from an opening provided in the approximate center of the outlet portion 3.
That is, accumulation of PM in the filter 5 in the oxidation catalyst 4 is prevented, and in addition to the removal of PM, there are effects of reducing carbon monoxide, hydrocarbons, and the like. Further, in each of the embodiments described later, the concentrated deposition near the center of the conventional DFP 5 can be avoided by introducing the exhaust gas substantially uniformly.

Up to this point, the basic configuration of the exhaust gas purification apparatus 1 and the exhaust gas purification method are common to the embodiments described later.
Here, the exhaust introduction method, which is a feature of the present invention, will be described in detail in each embodiment.

A first embodiment of the present invention will be described with reference to FIGS.
The exhaust gas discharged from the engine passes through the exhaust manifold and is introduced into the exhaust introduction pipe 6 having one end connected to the exhaust manifold. The other end of the exhaust introduction pipe 6 is inserted into the introduction chamber 2 so that the discharge direction is perpendicular to the central axis of the introduction chamber 2 and is eccentric. It is extended to. Further, the other end (tip) of the exhaust introduction pipe 6 is an opening 6a, and the exhaust gas is swirled along the wall surface in the introduction chamber 2 from the opening 6a into the introduction chamber 2. be introduced. More specifically, the other end of the exhaust introduction pipe 6 is parallel to the tangential direction of the cylindrical introduction chamber 2, and the central axis of the exhaust introduction pipe 6 does not pass through the center of the introduction chamber 2. Inserted into. However, the central axis of the exhaust introduction pipe 6 may be inclined toward the purification chamber 30 so that a swirling flow is generated. Further, the opening 6a is disposed so as to be positioned at the center in the vertical direction of the introduction chamber 2 in FIG. However, the opening 6 a is a surface perpendicular to the central axis of the exhaust introduction pipe 6.

  With the above configuration, when the exhaust gas enters the introduction chamber 2 through the opening 6a, it is guided by the inner wall of the introduction chamber 2 to form a swirling flow, and the exhaust gas is introduced into the introduction chamber 2 and the space 30a before being introduced into the oxidation catalyst 4. The exhaust gas can be introduced into both the oxidation catalyst 4 and the filter 5 substantially uniformly. As a result, the performance of the oxidation catalyst 4 can be sufficiently exerted, and runaway combustion or the like can be avoided. In addition, a tapered tube or a swirl flow generator that previously required a space is not required, and a swirl flow can be obtained in a space-saving manner. Further, since the swirling flow can be obtained only by changing the insertion position of the exhaust introduction pipe 6 into the introduction chamber 2 and the exhaust introduction pipe 6 is simply inserted into the introduction chamber 2, it can be easily attached.

A second embodiment of the present invention will be described with reference to FIGS.
The exhaust gas discharged from the engine passes through the exhaust manifold and is introduced into the exhaust introduction pipe 6 having one end connected to the exhaust manifold. The other end of the exhaust introduction pipe 6 is in a direction perpendicular to the central axis of the introduction chamber 2 and enters the introduction chamber 2 so that the central axis of the exhaust introduction pipe 6 and the central axis of the introduction chamber 2 intersect. The end of the exhaust introduction pipe 6 is inserted and fixed so that the exhaust introduction pipe 6 is closed on the inner wall opposite to the insertion port through which the exhaust introduction pipe 2 is inserted. A plurality of exhaust holes 6b, which are openings, are formed on the anti-oxidation catalyst 4 side of the exhaust introduction pipe 6, that is, on the surface opposite to the outlet.

  3 and 4, the exhaust gas discharged from the discharge hole 6b hits the inner wall on the opposite side to the outlet side of the introduction chamber 2 and bypasses the exhaust introduction pipe 6 as shown in FIGS. 2 The exhaust gas becomes substantially uniform at the downstream side and the space 30a, and is introduced into the oxidation catalyst 4 and the filter 5 substantially uniformly. As a result, the performance of the oxidation catalyst 4 can be sufficiently exerted, and runaway combustion or the like due to uneven deposition of PM can be avoided. Further, since no accessories such as valves are involved, the exhaust introduction pipe 6 can be easily attached to the introduction chamber 2.

A third embodiment of the present invention will be described with reference to FIGS.
The exhaust gas discharged from the engine passes through the exhaust manifold and is introduced into the exhaust introduction pipe 6 having one end connected to the exhaust manifold. The other end of the exhaust introduction pipe 6 is in a direction perpendicular to the central axis of the introduction chamber 2 and enters the introduction chamber 2 so that the central axis of the exhaust introduction pipe 6 and the central axis of the introduction chamber 2 intersect. The end of the exhaust introduction pipe 6 is inserted and fixed so that the exhaust introduction pipe 6 is closed on the inner wall opposite to the insertion port through which the exhaust introduction pipe 2 is inserted. A plurality of discharge holes 6 b are opened around the exhaust introduction pipe 6 in the introduction chamber 2. The size of the discharge holes 6b is the same, and the number of the discharge holes 6b is set so as to increase as the center side 10a of the introduction chamber 2 decreases as the outer peripheral side 10b. That is, the number of discharge holes 6 b proportional to the opening area of the space 30 a is opened on the outer periphery of the exhaust introduction pipe 6 in the introduction chamber 2.

  With the above configuration, as shown in FIG. 6, a large amount of exhaust gas discharged from the exhaust introduction pipe 6 is exhausted from the center side of the introduction chamber 2 and gradually decreases toward the periphery, and from the central axis of the exhaust introduction pipe 6. In proportion to the length to the wall surface of the introduction chamber 2 in the perpendicular direction, that is, in FIG. 5A, an amount of exhaust gas proportional to the opening area of the space 30a is discharged from the discharge hole 6b. Therefore, the exhaust gas becomes substantially uniform in the vicinity of the space 30 a and can be introduced into the oxidation catalyst 4 and the filter 5 almost uniformly. As a result, the performance of the oxidation catalyst 4 can be sufficiently exerted, and runaway combustion or the like can be avoided. The exhaust introduction pipe 6 can be easily attached to the introduction chamber 2. Further, the exhaust hole 6b of the exhaust introduction pipe 6 can be easily opened with a drill or the like.

A fourth embodiment of the present invention will be described with reference to FIGS.
The exhaust introduction pipe 6 is inserted and fixed in the introduction chamber 2 as in the third embodiment. In the present embodiment, the plurality of discharge holes 6b provided in the entire peripheral wall of the exhaust introduction pipe 6 in the introduction chamber 2 are arranged substantially uniformly, and the opening area thereof is larger toward the center side 10a and gradually toward the peripheral side. It is small. In other words, the opening area of the discharge hole 6b is larger at the central side 10a of the introduction chamber 2 and smaller at the outer peripheral side 10b. That is, the discharge holes 6b are opened at a constant interval on the outer periphery of the exhaust introduction pipe 6 in the introduction chamber 2, and the opening area of the discharge holes 6b is proportional to the opening area of the space 30a where the holes are located. Has been.

  With the above configuration, as shown in FIG. 6, a large amount of exhaust gas discharged from the exhaust introduction pipe 6 is exhausted from the center side of the introduction chamber 2 and gradually decreases toward the periphery, and from the central axis of the exhaust introduction pipe 6. In proportion to the length to the wall surface of the introduction chamber 2 in the perpendicular direction, that is, in FIG. 5A, an amount of exhaust gas proportional to the opening area of the space 30a is discharged from the discharge hole 6b. Therefore, the exhaust gas becomes substantially substantially uniform in the space 30 a and can be introduced almost uniformly into the oxidation catalyst 4 and the filter 5. Therefore, the performance of the oxidation catalyst 4 can be sufficiently exerted to avoid runaway combustion or the like. Further, the exhaust introduction pipe 6 can be easily attached to the introduction chamber 2. The size of the discharge hole 6b only needs to change the diameter of the drill.

A fifth embodiment of the present invention will be described with reference to FIGS. 7 and 8 (a).
The exhaust gas discharged from the engine passes through the exhaust manifold and is introduced into the exhaust introduction pipe 6 having one end connected to the exhaust manifold. The other end of the exhaust introduction pipe 6 is in a direction perpendicular to the central axis of the introduction chamber 2 and enters the introduction chamber 2 so that the central axis of the exhaust introduction pipe 6 and the central axis of the introduction chamber 2 intersect. The end of the exhaust introduction pipe 6 is inserted and fixed so that the exhaust introduction pipe 6 is closed on the inner wall opposite to the insertion port through which the exhaust introduction pipe 2 is inserted. A plurality of discharge holes 6 b having the same area are opened at equal intervals around the exhaust introduction pipe 6 in the introduction chamber 2.
In the fifth embodiment, in addition to the basic configuration, as shown in FIG. 7, a partition plate 50 is provided between the introduction chamber 2 and the purification chamber 30 that houses the oxidation catalyst 4 and the filter 5. ing. That is, a partition plate 50, which is a circular plate in plan view, is provided near the downstream end of the introduction chamber 6 so as to be fixed to the flange portion 15 at the upstream end of the cylindrical case 10.
A plurality of communication holes 55 are opened in the partition plate 50 in a substantially radial manner, and the number of the communication holes 55 is smaller at the center side of the introduction chamber 2 and more at the outer peripheral side.

  By configuring in this way, it is possible to reduce the unevenness of the exhaust gas when the exhaust gas is introduced into the oxidation catalyst 4 or the filter 5 through the communication hole 55 of the partition plate 50 provided on the downstream side of the introduction chamber 2. Moreover, the communication hole 55 which is the opening part of the partition plate 50 plays the role of a silencer, and can reduce the noise by which exhaust gas flows. Further, the communication hole 55 that is an opening of the partition plate 50 can be easily opened by drilling or punching.

A sixth embodiment of the present invention will be described with reference to FIGS. 7 and 8B.
The exhaust introduction pipe 6, the introduction chamber 2 and the like have the same configuration as in the fifth embodiment, and the size of the plurality of communication holes 55 provided in the partition plate 50 is smaller toward the center side and larger toward the outer periphery side. That is, the plurality of communication holes 55 provided in the partition plate 50 are opened concentrically at regular intervals, and the opening area of the communication holes 55 is smaller toward the center of the introduction chamber 2 and gradually toward the outer periphery. It is provided to be larger.

When the exhaust gas substantially uniformized by this configuration is introduced into the oxidation catalyst 4 and the filter 5 through the communication hole 55 of the partition plate 50 provided on the downstream side of the introduction chamber 2, the unevenness of the exhaust gas can be further reduced. . In addition, the communication hole 55 that is an opening of the partition plate 50 serves as a silencer and can reduce noise caused by the exhaust gas flowing. Moreover, the communication hole 55 which is an opening part of the partition plate 50 should just change magnitude | sizes, such as a drill or punching.
In addition, the partition plate 50 of the said Example 5 or Example 6 can also be set as the structure arrange | positioned between the introduction chamber 2 and the purification | cleaning chamber 30 in any of the said Example 1 thru | or Example 4. With this configuration, the unevenness of the exhaust gas can be further reduced when being introduced into the oxidation catalyst 4 and the filter 5 through the communication hole 55.

A seventh embodiment of the present invention will be described with reference to FIGS.
The exhaust gas discharged from the engine passes through the exhaust manifold and is introduced into the exhaust introduction pipe 6 having one end connected to the exhaust manifold. The other end of the exhaust introduction pipe 6 is inserted so that the introduction chamber 2 and the central axis substantially coincide with each other. A rectifying plate 60 is provided between the introduction chamber 2 and the purification chamber 30 to partition the chamber. A plurality of passage holes 65 are opened in the rectifying plate 60, and the number of passage holes 65 is smaller toward the center side of the introduction chamber 2 and larger toward the outer peripheral side.

  With the above configuration, the exhaust gas discharged from the exhaust introduction pipe 6 has a small number of passage holes 65 in the portion that directly contacts the rectifying plate 60, so that the exhaust gas discharge amount on the center side is suppressed, and the surrounding passage holes 65 Although it is discharged around, the number of passage holes 65 is large, so that it can be introduced almost uniformly into the oxidation catalyst 4 and the filter 5 on the downstream side of the rectifying plate 60. As a result, the performance of the oxidation catalyst 4 can be exhibited sufficiently, and runaway combustion or the like can be avoided. When the introduction chamber 2 of the present invention is compared with the conventional tapered introduction chamber, the length in the central axis direction can be shortened, and the overall length of the exhaust gas purification apparatus 1 can be shortened. The passage hole 65 provided in the current plate 60 can be easily opened by drilling or punching.

An eighth embodiment of the present invention will be described with reference to FIGS. 8B and 9.
In the eighth embodiment, similarly to the exhaust introduction pipe 6 of the seventh embodiment, the introduction chamber 2 and the central axis are inserted so as to substantially coincide with each other, and a rectifying plate 60 is provided between the introduction chamber 2 and the purification chamber 30. . A plurality of passage holes 65 are opened in the rectifying plate 60 at substantially constant intervals, and the opening area of the passage holes 65 is reduced toward the center of the introduction chamber 2 and is increased toward the outer periphery.

With the above-described configuration, the exhaust gas discharged from the exhaust introduction pipe 6 has a small opening area of the passage hole 65 in the portion that directly contacts the rectifying plate 60, so that the exhaust gas discharge amount on the center side is suppressed, and the surrounding passage hole 65 However, since the opening area of the passage hole 65 is large, it can be introduced almost uniformly into the oxidation catalyst 4 and the filter 5 on the downstream side of the rectifying plate 60.
As a result, the performance of the oxidation catalyst 4 can be exhibited sufficiently, and runaway combustion or the like can be avoided. When the introduction chamber 2 of the present invention is compared with the conventional tapered introduction chamber, the length in the central axis direction can be shortened, and the overall length of the exhaust gas purification apparatus 1 can be shortened. Further, it is possible to easily obtain substantially uniformity by simply changing the size of the passage hole.
However, the rectifying plate 60 may be provided in the opening 6 a at the end of the exhaust introduction pipe 6. With this configuration, the exhaust gas discharged from the rectifying plate 60 is gradually diffused up to the oxidation catalyst 4 and can be made substantially uniform on the downstream side (space portion 30a) of the introduction chamber 2. .

A ninth embodiment of the present invention will be described with reference to FIGS. 10 and 11 (a).
The exhaust gas discharged from the engine passes through the exhaust manifold and is introduced into the exhaust introduction pipe 6 having one end connected to the exhaust manifold. The other end of the exhaust introduction pipe 6 is inserted so as to substantially coincide with the central axis of the introduction chamber 2. The tip of the exhaust introduction pipe 6 in the introduction chamber 2 is closed by a bottom plate, and a plurality of discharge holes 6 b of the same size are opened on the outer periphery of the exhaust introduction pipe 6 in the introduction chamber 2. The number of the discharge holes 6b is smaller on the side of the oxidation catalyst 4 and is increased as the distance from the oxidation catalyst 4 increases.

  With the above configuration, the exhaust gas from the exhaust introduction pipe 6 is exhausted more on the upstream side and less on the downstream side, and bypasses the end of the exhaust introduction pipe 6 on the downstream side of the introduction chamber 2. This makes it possible to make the exhaust gas substantially uniform in the space 30 a and introduce it into the oxidation catalyst 4 and the filter 5 almost uniformly. The performance of the oxidation catalyst 4 and the filter 5 can be fully exerted to avoid runaway combustion. Further, when the introduction chamber 2 of the present invention and the conventional tapered introduction chamber 2 are compared, the length in the central axis direction can be shortened, and the overall length of the exhaust gas purification apparatus 1 can be shortened. The exhaust hole 6b of the exhaust introduction pipe 6 can be easily opened by a drill or the like.

A tenth embodiment of the present invention will be described with reference to FIGS. 10 and 11 (b).
One end of the exhaust introduction pipe 6 is connected to an exhaust manifold, and the other end of the exhaust introduction pipe 6 is inserted so as to be substantially coincident with the central axis of the introduction chamber 2, and the tip of the exhaust introduction pipe 6 in the introduction chamber 2 is inserted. Is closed by a bottom plate, and a plurality of exhaust holes 6 b are opened on the outer periphery of the exhaust introduction pipe 6 in the introduction chamber 2. The opening area of the discharge hole 6b is made smaller toward the oxidation catalyst 4 side and larger as it goes away from the oxidation catalyst 4.

With the above configuration, the exhaust gas from the exhaust introduction pipe 6 is exhausted more on the upstream side and less on the downstream side, and bypasses the end of the exhaust introduction pipe 6 on the downstream side of the introduction chamber 2. This makes it possible to make the exhaust gas substantially uniform in the space 30 a and introduce it into the oxidation catalyst 4 and the filter 5 substantially uniformly. The performance of the oxidation catalyst 4 and the filter 5 can be fully exerted to avoid runaway combustion. Further, when the introduction chamber 2 of the present invention is compared with the conventional tapered introduction chamber, the length in the central axis direction can be shortened, and the overall length of the exhaust gas purification apparatus 1 can be shortened. In addition, substantially uniform uniformity can be easily obtained simply by changing the size of the opening area of the exhaust hole 6b of the exhaust introduction pipe 6 with a drill or the like.
However, in Example 9 and Example 10, when the amount of exhaust gas on the center side is not enough, a discharge hole is appropriately opened in the bottom plate.

1 is a schematic perspective view showing an exhaust gas purification apparatus according to Embodiment 1 of the present invention. 1 is a cross-sectional view in the exhaust gas flow direction showing an exhaust gas purification apparatus according to Embodiment 1 of the present invention. The schematic perspective view which shows the exhaust gas purification apparatus which concerns on Example 2 of this invention. Fig. 6 is a cutaway view of an exhaust gas flow direction showing an exhaust gas purification apparatus according to Embodiment 2 of the present invention. (A) The schematic perspective view which shows the exhaust gas purification apparatus which concerns on Example 3 of this invention, (b) The schematic perspective view which shows the exhaust gas purification apparatus which concerns on Example 4 of this invention. The exhaust gas flow direction cut surface schematic perspective view showing the exhaust gas purifying apparatus according to Example 3 and Example 4 of the present invention. The schematic perspective view which shows the exhaust gas purification apparatus which concerns on Example 5 and Example 6 of this invention. (A) The schematic which shows the partition plate and rectifier plate which concern on Example 5 and Example 7 of this invention, (b) The schematic which shows the partition plate and rectifier plate which concern on Example 6 and Example 8 of this invention. The schematic perspective view which shows the exhaust gas purification apparatus which concerns on Example 7 and Example 8 of this invention. The schematic perspective view which shows the exhaust gas purification apparatus which concerns on Example 9 and Example 10 of this invention. (A) The schematic perspective view which shows the exhaust introduction pipe | tube which concerns on Example 9 of this invention, (b) The schematic perspective view which shows the exhaust introduction pipe | tube which concerns on Example 10 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exhaust gas purification apparatus 2 Introduction chamber 3 Outlet part 4 Oxidation catalyst 5 Filter (DPF)
6 Exhaust pipe 10 Cylindrical case 20 Cylindrical case 50 Partition plate 60 Rectifier plate

Claims (10)

In an exhaust gas purification device in which an oxidation catalyst and filter for purifying exhaust gas from a diesel engine are housed in a cylindrical case,
An introduction chamber is formed on the upstream side of the cylindrical case, an oxidation catalyst and a filter are accommodated on the downstream side, one end of the exhaust introduction pipe is connected to an exhaust manifold, and the other end of the exhaust introduction pipe is connected to the exhaust direction. An exhaust gas purification apparatus, wherein the exhaust gas purification apparatus is inserted into the introduction chamber in a direction perpendicular to the central axis of the introduction chamber and in an eccentric position. In an exhaust gas purification device in which an oxidation catalyst and filter for purifying exhaust gas from a diesel engine are housed in a cylindrical case,
An introduction chamber is formed on the upstream side of the cylindrical case, an oxidation catalyst and a filter are accommodated on the downstream side, one end of the exhaust introduction pipe is connected to an exhaust manifold, and the other end of the exhaust introduction pipe is connected to the introduction chamber. An exhaust gas purifying apparatus, wherein the exhaust gas purification apparatus is inserted in a direction perpendicular to a central axis, and a discharge hole formed in the exhaust introduction pipe is opened to the antioxidation catalyst side. In an exhaust gas purification device in which an oxidation catalyst and filter for purifying exhaust gas from a diesel engine are housed in a cylindrical case,
An introduction chamber is formed on the upstream side of the cylindrical case, an oxidation catalyst and a filter are accommodated on the downstream side, one end of the exhaust introduction pipe is connected to an exhaust manifold, and the other end of the exhaust introduction pipe is connected to the introduction chamber. Exhaust gas purification characterized by being inserted in a direction perpendicular to the central axis, opening a plurality of exhaust holes around the exhaust introduction pipe in the introduction chamber, and providing a larger number of exhaust holes toward the center of the introduction chamber apparatus. In an exhaust gas purification device in which an oxidation catalyst and filter for purifying exhaust gas from a diesel engine are housed in a cylindrical case,
An introduction chamber is formed on the upstream side of the cylindrical case, an oxidation catalyst and a filter are accommodated on the downstream side, one end of the exhaust introduction pipe is connected to an exhaust manifold, and the other end of the exhaust introduction pipe is connected to the introduction chamber. An exhaust gas purification apparatus, wherein the exhaust gas purification apparatus is inserted in a direction perpendicular to the central axis, and a plurality of exhaust holes are opened around the exhaust introduction pipe in the introduction chamber, and the area of the discharge holes is increased toward the center side of the introduction chamber. .   A partition plate is provided downstream of the introduction chamber to partition the purification chamber for storing the oxidation catalyst and the filter. A plurality of communication holes are opened in the partition plate, and the number of the communication holes is smaller toward the center of the introduction chamber. The exhaust gas purification device according to any one of claims 1 to 4, wherein the exhaust gas purification device is provided.   On the downstream side of the introduction chamber, there is provided a partition plate that partitions the purification chamber that houses the oxidation catalyst and the filter, and a plurality of communication holes are opened in the partition plate, and the area of the communication hole is smaller toward the center side of the introduction chamber. The exhaust gas purifying apparatus according to any one of claims 1 to 4, wherein the exhaust gas purifying apparatus is any one of claims 1 to 4. In an exhaust gas purification device in which an oxidation catalyst and filter for purifying exhaust gas from a diesel engine are housed in a cylindrical case,
An introduction chamber is formed on the upstream side of the cylindrical case, an oxidation catalyst and a filter are accommodated on the downstream side, one end of the exhaust introduction pipe is connected to an exhaust manifold, and the other end of the exhaust introduction pipe is connected to the introduction chamber. Inserted so as to be substantially coincident with the central axis, provided with a flow straightening plate in a direction perpendicular to the exhaust gas discharge direction from the exhaust introduction pipe, opened a plurality of passage holes in the flow straightening plate, the number of passage holes introduced An exhaust gas purifying apparatus, characterized in that the exhaust gas purifying apparatus is provided less at the center side of the chamber. In an exhaust gas purification device in which an oxidation catalyst and filter for purifying exhaust gas from a diesel engine are housed in a cylindrical case,
An introduction chamber is formed on the upstream side of the cylindrical case, an oxidation catalyst and a filter are accommodated on the downstream side, and an exhaust introduction pipe connected to an exhaust manifold is inserted so as to substantially coincide with the central axis of the introduction chamber, A rectifying plate is provided in a direction perpendicular to the exhaust gas discharge direction from the exhaust pipe, and a plurality of passage holes are opened in the rectifying plate, and the area of the passage hole is made smaller toward the center side of the introduction chamber. Exhaust gas purification device. In an exhaust gas purification device in which an oxidation catalyst and filter for purifying exhaust gas from a diesel engine are housed in a cylindrical case,
An introduction chamber is formed on the upstream side of the cylindrical case, an oxidation catalyst and a filter are accommodated on the downstream side, one end of the exhaust introduction pipe is connected to an exhaust manifold, and the other end of the exhaust introduction pipe is connected to the center of the introduction chamber Exhaust gas characterized by being inserted substantially in line with the shaft, closing the tip of the exhaust introduction pipe in the introduction chamber and opening a plurality of discharge holes around it, the number of the discharge holes being smaller as the oxidation catalyst side Purification equipment. In an exhaust gas purification device in which an oxidation catalyst and filter for purifying exhaust gas from a diesel engine are housed in a cylindrical case,
An introduction chamber is formed on the upstream side of the cylindrical case, an oxidation catalyst and a filter are accommodated on the downstream side, one end of the exhaust introduction pipe is connected to an exhaust manifold, and the other end of the exhaust introduction pipe is connected to the introduction chamber. Exhaust gas characterized by being inserted so as to substantially coincide with the central axis, closing the tip of the exhaust introduction pipe in the introduction chamber and opening a plurality of discharge holes around it, and reducing the area of the discharge holes toward the oxidation catalyst side Purification equipment.

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