JP2002364337A - Exhaust emission control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of improving a flow of exhaust gas in a flow passage switching valve, and drastically reducing pressure loss. SOLUTION: Each communication port 17, 18 opening to both right and left sides of a flow passage switching portion of a main pipe 13 is directed in the axial direction (a right and left direction in Fig. 1) of the main pipe 13, and expanded so as to be larger than the inner diameter d of communication pipe 11, 12 and not more than 1.5 times the inner diameter D of the main pipe 13. Therefore, when exhaust gas 2 returning through a particulate filter turns back in a flow passage switching valve 10, the minimum flow passage cross section restricted between a rearmost portion of the communication port 17 and a valve element 19 of the flow passage switching valve 10, is more expanded than before so that a backward turning flow of the exhaust gas 2 is improved to drastically reduce the pressure loss.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust emission control device.

[0002]

2. Description of the Related Art Particulate matter (particulate matter) emitted from a diesel engine is:
Soot composed of carbonaceous material and SO composed of high-boiling hydrocarbon components
F (Soluble Organic Fraction: soluble organic component) as a main component, and also contains a small amount of sulfate (mist-like sulfuric acid component), but as a measure to reduce this kind of particulates, FIG. As shown in FIG. 1, an exhaust pipe 3 through which exhaust gas 2 from a diesel engine 1 flows
Is equipped with a particulate filter 4 in the middle of the process.

As shown in FIG. 6, the particulate filter 4 has a porous honeycomb structure made of a ceramic such as cordierite, and the inlets of the flow paths 5 partitioned in a lattice are alternately plugged. The outlets of the flow passages 5 whose inlets are not plugged are plugged, and only the exhaust gas 2 that has passed through the porous thin wall 6 that defines each flow passage 5 is located on the downstream side. And the particulates in the exhaust gas 2 are collected on the inner surface of the porous thin wall 6.

Further, as shown in FIGS. 7 to 11, an exhaust gas purifying apparatus which has been developed in recent years oxidizes NOx during a lean combustion operation in which the oxygen concentration in the exhaust gas 2 is high, and temporarily oxidizes NOx in a state of nitrate. A NOx storage reduction catalyst that has the property of decomposing and releasing NOx by reducing and purifying NOx due to the presence of hydrocarbons and carbon monoxide in the exhaust gas 2 during operation at a rich air-fuel ratio that stores and has a low oxygen concentration in the exhaust gas 2 There is a case in which two particulate filters 4 which are supported in an axial direction of the exhaust pipe 3 are accommodated in the casing 7 in a state where they are laid side by side in a direction substantially perpendicular to the axis of the exhaust pipe 3.

The flow paths 5 of the particulate filters 4 are respectively connected to supply / discharge spaces 8 and 9 formed on both right and left sides of the casing 7, and the exhaust gas 2 is moved in the lateral direction (left and right direction) of the casing 7. So that the particulates can be collected.

[0006] Further, a passage switching valve is provided in the passage switching portion at an intermediate portion of the main pipe 13 connected to the exhaust pipe 3 on the upstream side. The supply / discharge spaces 8 and 9 are connected to each other via communication pipes 11 and 12, and the exhaust gas 2 is supplied to one of the supply / discharge spaces 8 and 9 by the flow path switching valve 10.
To the other end, and the collected exhaust gas 2 is again introduced into the front end of the casing 7 through the main pipe 13 via the flow path switching valve 10 and secured at the upper and lower portions in the casing 7. Casing 7 through exhaust passage 14
It is guided to the rear chamber 15 (muffling space) at the rear end and discharged to the tail pipe 16 on the downstream side.

When the exhaust gas 2 guided from the upstream side of the exhaust pipe 3 is introduced into the supply / discharge space 8 through the communication pipe 11 by switching the flow path switching valve 10 as shown in FIG.
The exhaust gas 2 is distributed and introduced from the supply / discharge space 8 to each of the particulate filters 4, and while the exhaust gas 2 passes through each of the particulate filters 4, the particulates are collected and purified. The exhaust gas 2 is discharged to the supply / discharge space 9 and returned to the flow path switching valve 10 via the communication pipe 12. The exhaust gas 2 is introduced into the casing 7 from the flow path switching valve 10 via the main pipe 13. The air is guided to the rear chamber 15 through the upper and lower exhaust passages 14 in the casing 7 and is discharged to the tail pipe 16 on the downstream side.

In the lean burn operation in which the oxygen concentration in the exhaust gas 2 is high, while the exhaust gas 2 passes through each of the particulate filters 4, the NOx occlusion carried on the particulate filters 4 is integrated. N by reduction catalyst
Ox is oxidized and temporarily stored in a state of nitrate, and NOx is removed from the exhaust gas 2.

At this time, the particulate matter collected in each particulate filter 4 is formed by the highly reactive active oxygen generated during the NOx occlusion reaction and the normal oxygen which is largely contained in the exhaust gas 2. The oxidation reaction of the curate is promoted, and efficient and continuous burning and removal of the particulate can be achieved.

On the other hand, for example, when the operation is instantaneously switched to the rich air-fuel ratio operation in which the oxygen concentration in the exhaust gas 2 is low, the exhaust gas 2
NOx is decomposed and released from the NOx storage reduction catalyst using hydrocarbons, carbon monoxide, and the like remaining unburned therein as a reducing agent, and is immediately reduced and purified.

At this time, the oxidation reaction of the particulates collected in each particulate filter 4 is promoted by the active oxygen generated at the time of the decomposition and release reaction of NOx, and the particulates are continuously burned with high efficiency. Removal is achieved.

As shown in FIG. 10, when the exhaust gas 2 guided from the exhaust pipe 3 is introduced into the supply / discharge space 9 through the communication pipe 12 by switching the flow path switching valve 10 as necessary, the exhaust gas 2 is The exhaust gas 2 that has passed through each of the particulate filters 4 is discharged to the supply / exhaust space 8 in a direction opposite to the previous direction, and is passed through the communication pipe 11 so that the flow path switching valve 10 And is introduced into the casing 7 from the flow path switching valve 10 via the main pipe 13, is guided to the rear chamber 15 through the upper and lower exhaust passages 14, and is discharged to the tail pipe 16 on the downstream side.

That is, as described above, the flow path switching valve 1
0, the flow direction of the exhaust gas 2 is reversed so that a new particulate having the back surface of the porous thin wall 6 defining each flow path 5 of the particulate filter 4 as a collecting surface can be obtained. Is collected, and a slight unburned residue on the front side surface of the porous thin wall 6 is removed by backwashing to achieve good regeneration of the collecting surface. Thus, the utilization efficiency of the NOx storage reduction catalyst supported on the catalyst is improved, and the particulates can be quickly burned and removed.

[0014]

However, in the conventional exhaust gas purifying apparatus, as shown in an enlarged view in FIG. 17 and 1 on both sides
8, and the connecting pipe 11 extends from one of the connecting ports 17 while bending backward and is connected to the supply / discharge space 8.
Since the connecting pipe 12 extends from the other connecting port 18 while bending toward the rear and is connected to the supply / discharge space 9, the connecting pipe 12 passes through each particulate filter 4 and is connected to the flow path switching valve 10. The returned exhaust gas 2 is turned back by about 180 ° from a forward flow to a backward flow, and the exhaust gas 2 introduced from a direction substantially perpendicular to the axial direction of the main pipe 13 is immediately returned. As a result of colliding with the butterfly type valve body 19 of the flow path switching valve 10 at a required angle and narrowing down the flow path cross-sectional area by the valve body 19 (the point indicated by the one-dot chain line arrow in FIG. 11). Where the flow path has the minimum cross-sectional area), there is a problem that the flow of the exhaust gas 2 is deteriorated and the pressure loss is significantly increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides an exhaust gas purifying apparatus capable of improving the flow of exhaust gas in a flow path switching valve to greatly reduce pressure loss. It is an object.

[0016]

According to the present invention, there is provided a main pipe for connecting exhaust gas introduced from a front exhaust pipe to a rear tail pipe, and a flow path switching section in the middle of the main pipe. First and second communication ports opened on both left and right sides of the filter, and a particulate filter disposed rearward from the flow path switching unit and configured to capture particulates in exhaust gas, A first supply / discharge space formed on one side in the axial direction of the particulate filter; a second supply / discharge space formed on the other side in the axial direction of the particulate filter; A first communication pipe bent and extended rearward from the communication port and the tip of which is connected to the first supply / discharge space;
A second connecting pipe, which is bent and extends rearward from the second connecting port and has a distal end connected to the second supply / drain space, and a butterfly type provided in a flow path switching portion of the main pipe; The exhaust gas from the exhaust pipe is selectively introduced into one of the first and second communication pipes by the valve body, and the exhaust gas returned from the other of the first and second communication pipes is tailed. An exhaust gas purification device comprising a flow path switching valve configured to be able to return to the pipe side and discharge the first and second communication ports in an axial direction of the main pipe; And is expanded to be 1.5 times or less the inner diameter of the main pipe.

Therefore, according to the present invention, when the exhaust gas introduced from the exhaust pipe is introduced into the first supply / discharge space through the first communication port and the first communication pipe by the flow path switching valve, the first supply / discharge space is reduced. Exhaust gas is introduced from the supply / discharge space to the particulate filter, and while the exhaust gas passes through the particulate filter, the particulate is collected and purified, and the purified exhaust gas is supplied to the second supply / discharge space. Is returned to the flow path switching valve via the second communication pipe and the second communication port, and is discharged from the flow path switching valve to the tail pipe on the downstream side via the main pipe.

On the other hand, the particulate matter collected by the particulate filter is removed by self-combustion in an operation region where the exhaust gas temperature becomes high during a high load operation or the like. By heating or taking appropriate measures to raise the exhaust gas temperature, more reliable burning and removal of particulates may be achieved.

Further, the flow path is switched by the flow path switching valve, and the exhaust gas guided from the exhaust pipe is transferred to the second supply / discharge space via the second communication port and the second communication pipe by the flow path switching valve. When introduced, the exhaust gas will pass through the particulate filter in the opposite direction to the previous one, and a new particulate with the back side of the porous thin wall that separates each flow path of the particulate filter as a collecting surface While the curates are collected, a slight unburned residue on the front side surface of the porous thin wall is removed by backwashing, so that a good collection surface can be regenerated.

In the present invention, since the first and second communication ports extend in the axial direction of the main pipe and are larger than the inner diameters of the first and second communication pipes, the first and second communication ports pass through the particulate filter. The smallest flow path narrowed between the last end of one of the first and second communication ports and the valve body of the flow path switching valve when the returned exhaust gas turns back in the flow path switching valve. The cross-sectional area will be expanded as compared with the conventional one, and the return flow of exhaust gas that has passed through the particulate filter and returned to the flow path switching valve will be improved and pressure loss will be significantly reduced. become.

Here, if the first and second communication ports are excessively expanded in the axial direction of the main pipe,
The tilt angle of the valve body with respect to the axis of the main pipe becomes too shallow, and the angle at which exhaust gas returning to the flow path switching valve through the particulate filter collides with the valve body becomes deep, and conversely, the pressure loss In order to avoid such an increase in pressure loss, expansion of the first and second communication ports in the axial direction of the main pipe is performed to increase the inner diameter of the main pipe to 1. 5 or less.

If the first and second communication ports are expanded in the axial direction of the main pipe, exhaust gas from the exhaust pipe is introduced from the main pipe into one of the first and second communication pipes. At this time, the minimum flow passage cross-sectional area narrowed between the other foremost end portions of the first and second communication ports and the valve body of the flow passage switching valve is also expanded as compared with the related art. The flow of exhaust gas introduced into either of the first and second connecting pipes is also improved, and pressure loss is reduced.

Further, in the present invention, instead of extending the first and second communication ports in the axial direction of the main pipe, the outer peripheral sides of the bent portions of the first and second communication pipes are moved forward. The first and second connecting pipes are formed by swelling with a gentle curved surface that does not cause separation of the exhaust gas flow toward the main pipe side at the outer peripheral end of the bent portion of the first and second connecting pipes. The direction may be set to be backward.

With this arrangement, when the exhaust gas returned through the particulate filter flows through one of the first and second communication pipes and flows into the flow path switching valve, the flow becomes substantially perpendicular. Exhaust gas flows at the bent portions of the first and second connecting pipes to be changed in a proper direction along the outer peripheral side of the bent portion, and the exhaust gas is separated without causing separation. Since the direction of the exhaust gas returned to the flow path switching valve is made small, the collision angle with respect to the valve body becomes shallow, and the flow along the valve body is easily formed, since the flow direction is changed to the flow smoothly flowing backward. The backflow of the exhaust gas is improved and the pressure loss is greatly reduced.

Here, when the exhaust gas from the exhaust pipe is introduced from the main pipe to one of the first and second connecting pipes, the introduced exhaust gas is supplied to the first and second connecting pipes. Since the gas flows toward the inner peripheral side of the bent portion that is separated from the outer peripheral side, there is no possibility that the shape of the bent portion on the outer peripheral side affects the flow of the exhaust gas.

Further, in the present invention, a guide curved surface is formed on both sides of the rear end of the valve body in the flow path switching valve so as to be warped and spread to the left and right sides, and the exhaust gas guided from the exhaust pipe by the guide curved surface. Flow smoothly toward one of the first and second communication ports and direct the flow of exhaust gas returning to the other of the first and second communication ports toward the tail pipe side of the main pipe. You may comprise so that a direction can be changed smoothly.

With this configuration, when the exhaust gas from the exhaust pipe strikes the valve body and forms a flow along the surface of the valve body, the guide curved surface formed at the rear end of the valve body forms The flow of the exhaust gas is smoothly diverted toward one of the first and second communication ports, and the exhaust gas returning to the other of the first and second communication ports strikes the valve body and When the flow along the surface of the body is formed, the flow of the exhaust gas is smoothly changed to the tail pipe side of the main pipe by the guide curved surface formed at the rear end of the valve body. Therefore, the flow of the exhaust gas flowing into and out of the flow path switching valve is improved, and the pressure loss is greatly reduced.

In the present invention, the catalyst may be integrally carried on the particulate filter.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a first embodiment of the present invention, and the portions denoted by the same reference numerals as those in FIGS. 7 to 11 represent the same components.

As shown in FIGS. 1 and 2, the present embodiment relates to an exhaust gas purifying apparatus having substantially the same structure as that of FIGS. Each of the communication ports 17 and 18 opened in the axial direction of the main pipe 13 (left and right direction in FIG. 1)
Are expanded so as to be larger than the inside diameter d of the communication pipes 11 and 12 and 1.5 times or less the inside diameter D of the main pipe 13.

Here, when expanding the communication ports 17 and 18 in the axial direction of the main pipe 13, the communication ports 17 and 18 are made oblong in the axial direction of the main pipe 13 as shown in FIG. The inner diameter d of the connecting pipes 11 and 12
It is also possible to make the main pipe 13 expand in the axial direction as a result of a larger circle.

Further, each of the communication ports 1 expanded in this manner.
When connecting the communication pipes 11 and 12 to the connection pipes 7 and 18, the connection ports 17 and 1 of the connection pipes 11 and 12 are connected.
What is necessary is just to connect gradually by gradually increasing the diameter of the connection end part with respect to 8.

In this embodiment, each communication port 1
Since the exhaust pipes 7 and 18 extend in the axial direction of the main pipe 13 and are larger than the inner diameter d of the connecting pipes 11 and 12, the exhaust gas 2 returning through the particulate filter 4
When the valve is turned back in the flow path switching valve 10, each communication port 1
The minimum flow path cross-sectional area narrowed between the last end of any one of the flow paths 7 and 18 and the valve element 19 of the flow path switching valve 10 is expanded as compared with the conventional case, and the particulate filter 4
Exhaust gas 2 that has passed through and returned to the flow path switching valve 10
And the pressure drop is greatly reduced.

That is, the smallest flow path narrowed between the last end of one of the communication ports 17 and 18 (the communication port 17 in the operating state of FIG. 1) and the valve element 19 of the flow path switching valve 10. The cross-sectional area is the location indicated by the dashed-dotted arrow in FIG. 1, and this location is compared with the location having the conventional minimum flow path cross-sectional area (see the location indicated by the dashed-dotted arrow in FIG. 11). As a result, the position is shifted to the side where the valve element 19 is open, so that the minimum flow path cross-sectional area is expanded as compared with the conventional case.

If the connecting ports 17 and 18 are excessively expanded in the axial direction of the main pipe 13, the tilt angle of the valve body 19 with respect to the axial center of the main pipe 13 becomes too shallow. The exhaust gas 2 returning to the flow path switching valve 10 through the particulate filter 4
9, the collision angle becomes deep, which may cause an increase in pressure loss. Therefore, in order to avoid such an increase in pressure loss, the shaft of the main pipe 13 of each of the communication ports 17, 18 is required. The main pipe 13 is expanded toward the center.
Of 1.5 or less.

The communication ports 17 and 18 are connected to the main pipe 13
, The exhaust gas 2 from the exhaust pipe 3 (see FIG. 7) is
When introducing to any one of 1, 12
The minimum flow path cross-sectional area narrowed between the foremost end of the other (the communication port 18 in the operating state of FIG. 1) and the valve element 19 of the flow path switching valve 10 is also expanded as compared with the related art, so that the main pipe The flow of the exhaust gas 2 introduced into any one of the connection pipes 11 and 12 from 13 is also improved, and the pressure loss is reduced.

Therefore, according to the first embodiment described above, the minimum flow to be constricted between the rearmost end of one of the communication ports 17 and 18 and the valve element 19 of the flow path switching valve 10. The flow path cross-sectional area and the minimum flow path cross-sectional area narrowed between the other foremost end of each of the communication ports 17 and 18 and the valve element 19 of the flow path switching valve 10 are expanded to increase the flow path switching valve 10. Since the flow of the exhaust gas 2 can be improved and the pressure loss can be greatly reduced, it is possible to realize a flow path switching type exhaust purification device with a small pressure loss.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, the connecting pipes 17 and 18 are expanded in the axial direction of the main pipe 13 and the connecting pipes 11 and 18 are replaced with each other. , 12 are bent forward (see FIG. 3).
To the left (in the left direction in FIG. 3), the exhaust gas 2 is formed by bulging with a gentle curved surface that does not cause separation, that is, by forming the cross hatched portion in FIG. 3 to bulge. The direction of the tangential direction A toward the main pipe 13 at the end on the outer peripheral side of the bent portions of the connecting pipes 11 and 12 is set to be backward (to the right in FIG. 3).

In this manner, the exhaust gas 2 returned through the particulate filter 4 is
12 (the connecting pipe 1 in the operating state of FIG. 3).
When flowing into the flow path switching valve 10 after passing through 1),
The connecting pipes 11 and 12 whose flow is changed to a substantially right angle direction (the connecting pipe 11 in the operating state of FIG. 3).
The exhaust gas 2 flows in a main flow along the outer peripheral side of the bent portion at the bent portion, and the exhaust gas 2 forms a laminar flow without causing separation, and is smoothly turned to the backward direction. Therefore, the collision angle of the exhaust gas 2 returning to the flow path switching valve 10 with respect to the valve body 19 becomes shallow, so that the flow along the valve body 19 is easily formed, and the return flow of the exhaust gas 2 backward. Is improved and the pressure loss is greatly reduced.

Here, when the exhaust gas 2 from the exhaust pipe 3 is introduced from the main pipe 13 to the other of the connecting pipes 11 and 12 (the connecting pipe 12 in the operation state of FIG. 3), the introduced exhaust gas 2 But the connecting pipes 11 and 1
2 (in the operating state of FIG. 3, the connecting pipe 12) flows toward the inner peripheral side which is separated from the outer peripheral side in the bent portion, so that the shape of the bent portion on the outer peripheral side affects the flow of the exhaust gas 2. There is no fear.

FIG. 4 shows a third embodiment of the present invention. In this embodiment, both sides of the rear end of the valve element 19 in the flow path switching valve 10 are warped and spread to the left and right outside. The guide curved surfaces 20 and 21 are formed, and the guide curved surfaces 20 and 21 are formed.
The flow of the exhaust gas 2 guided from the exhaust pipe 3 by 21 smoothly changes to one of the communication ports 17 and 18 and returns to the other of the communication ports 17 and 18. Of the main pipe 13 (FIG. 7)
(See Reference) side.

As shown in FIG. 7, when the main pipe 13 has a circular shape, the side surface of the valve element 19 has an elliptical shape. The curved surfaces 20 and 21 may be formed in the rear half of the outer peripheral portion of the valve body 19, but usually, the flow of the exhaust gas 2 from the exhaust pipe 3 forms a main flow at the axial center of the main pipe 13. The height direction of the valve body 19 (FIG. 4)
The shape may be such that the vicinity of the middle portion (in the direction perpendicular to the drawing in the middle) particularly protrudes greatly left and right outward.

Thus, when the exhaust gas 2 from the exhaust pipe 3 strikes the valve body 19 and forms a flow along the surface of the valve body 19, the rear end of the valve body 19 The flow of the exhaust gas 2 is caused by one of the guide curved surfaces 20 and 21 (the guide curved surface 21 in the operation state of FIG. 4) formed in the portion, to one of the communication ports 17 and 18 (the communication port 18 in the operation state of FIG. 4). The exhaust gas 2, which has been smoothly turned in the direction of the arrow and returned to the other of the communication ports 17, 18, is
When the flow along the surface of the valve body 19 is formed by contacting the valve body 19, the other of the guide curved surfaces 20 and 21 formed at the rear end of the valve body 19 (the guide curved surface 20 in the operation state of FIG. 4). As a result, the flow of the exhaust gas 2 is smoothly changed toward the tail pipe 16 (see FIG. 7) of the main pipe 13, so that the flow of the exhaust gas 2 entering and exiting the flow path switching valve 10 is improved. The pressure loss will be greatly reduced.

It should be noted that the exhaust gas purifying apparatus of the present invention is not limited to the above embodiment, and the particulate filter does not always need to carry a catalyst.
Even if the catalyst is supported, the present invention is not limited to the NOx storage reduction catalyst, and it is needless to say that various changes can be made without departing from the gist of the present invention.

[0046]

According to the exhaust gas purifying apparatus of the present invention described above, the following various excellent effects can be obtained.

(I) According to the exhaust gas purifying apparatus of the first, second and third aspects of the present invention, it is possible to improve the flow of the exhaust gas in the flow path switching valve to greatly reduce the pressure loss. Accordingly, it is possible to realize a flow path switching type exhaust gas purification apparatus with a small pressure loss.

(II) According to the exhaust gas purifying apparatus of the fourth aspect of the present invention, the particulate filter is provided with an oxidation catalyst for assisting the oxidation reaction of the collected particulates, or a catalyst contained in the exhaust gas. An additional function can be provided by integrally supporting a NOx selective reduction catalyst, a NOx storage reduction catalyst, or the like for removing NOx.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrows II-II in FIG.

FIG. 3 is a sectional view showing a second embodiment of the present invention.

FIG. 4 is a sectional view showing a third embodiment of the present invention.

FIG. 5 is a schematic view showing a conventional example.

FIG. 6 is a sectional view showing details of the particulate filter of FIG. 5;

FIG. 7 is a perspective view showing another conventional example.

8 is a sectional view taken along the line VIII-VIII in FIG. 7;

9 is a sectional view taken along the line IX-IX in FIG. 7;

FIG. 10 is a cross-sectional view showing a state where the flow path switching valve of FIG. 9 is switched.

FIG. 11 is an enlarged view showing details of a flow path switching unit in the main pipe.

[Explanation of symbols]

 2 Exhaust gas 3 Exhaust pipe 4 Particulate filter 8 Supply / discharge space (first supply / discharge space) 9 Supply / discharge space (second supply / discharge space) 10 Flow path switching valve 11 Communication pipe (first communication pipe) 12 Connecting pipe (first connecting pipe) 13 main pipe 16 tail pipe 17 connecting port (first connecting port) 18 connecting port (second connecting port) 19 valve body 20 guide curved surface 21 guide curved surface

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) F01N 3/08 F01N 3/24 H 4D058 3/24 3/28 301C 7/08 B 3/28 301 F16K 11 / 052 Z 7/08 B01D 53/36 103C F16K 11/052 ZAB 103B (72) Inventor Osamu Tsuchiya 3-1-1 Hinodai, Hino-shi, Tokyo Hino Motor Co., Ltd. F-term (reference) 3G004 BA03 BA06 DA06 DA00 DA01 DA24 EA00 3G090 AA01 BA01 CB23 CB25 EA01 3G091 AA18 AB02 AB06 AB13 BA00 BA14 BA38 HA14 HB01 HB02 3H067 AA05 CC13 DD03 DD12 EA13 FF12 FF17 FF22 GG02 4D048 AA06 AA13 AA14 AA18 CC01 JA02 CC04

Claims (4)

[Claims] 1. A main pipe for connecting exhaust gas guided from a front exhaust pipe to a tail pipe on the rear side, and a main pipe which is opened on both left and right sides of the flow path switching part with a part of the main pipe being a flow path switching part. A first and a second communication port, a particulate filter disposed behind the flow path switching unit and configured to collect particulates in exhaust gas, and an axial direction of the particulate filter. A first supply / discharge space formed on one side, a second supply / discharge space formed on the other side in the axial direction of the particulate filter, and a bent rearward from the first communication port. And a first connecting pipe whose tip is connected to the first supply / drain space, and extends rearwardly from the second communication port, and the tip of which extends in the second supply / drain space. The second connected to A communication pipe, and exhaust gas from an exhaust pipe is selectively introduced into one of the first and second communication pipes by a butterfly type valve body provided in a flow path switching unit of the main pipe; An exhaust gas purification device comprising: a flow path switching valve configured to return and exhaust exhaust gas returned from the other of the first and second communication pipes to the tail pipe side; Characterized in that the communication port is extended in the axial direction of the main pipe so as to be larger than the inner diameters of the first and second connection pipes and 1.5 times or less the inner diameter of the main pipe. apparatus. 2. A main pipe for connecting exhaust gas introduced from a front exhaust pipe to a tail pipe on the rear side, and a main pipe which is opened on both left and right sides of the flow path switching section, with a middle part of the main pipe serving as a flow path switching section. A first and a second communication port, a particulate filter disposed behind the flow path switching unit and configured to collect particulates in exhaust gas, and an axial direction of the particulate filter. A first supply / discharge space formed on one side, a second supply / discharge space formed on the other side in the axial direction of the particulate filter, and a bent rearward from the first communication port. And a first connecting pipe whose tip is connected to the first supply / drain space, and extends rearwardly from the second communication port, and the tip of which extends in the second supply / drain space. The second connected to A communication pipe, and exhaust gas from an exhaust pipe is selectively introduced into one of the first and second communication pipes by a butterfly type valve body provided in a flow path switching unit of the main pipe; An exhaust gas purification device comprising: a flow path switching valve configured to return and exhaust exhaust gas returned from the other of the first and second communication pipes to the tail pipe side; The outer peripheral side of the bent portion of the first and second connecting pipes is formed by expanding the outer peripheral side of the bent portion of the connecting pipe forward with a gentle curved surface that does not cause separation of the exhaust gas flow. An exhaust gas purification apparatus characterized in that a tangential direction toward the main pipe at the end of the exhaust pipe is set to be backward. 3. A main pipe for connecting exhaust gas introduced from a front exhaust pipe to a tail pipe on the rear side, and a middle part of the main pipe serving as a flow path switching section, and a second pipe opened on both right and left sides of the flow path switching section. A first and a second communication port, a particulate filter disposed behind the flow path switching unit and configured to collect particulates in exhaust gas, and an axial direction of the particulate filter. A first supply / discharge space formed on one side, a second supply / discharge space formed on the other side in the axial direction of the particulate filter, and a bent rearward from the first communication port. And a first connecting pipe whose tip is connected to the first supply / drain space, and extends rearwardly from the second communication port, and the tip of which extends in the second supply / drain space. The second connected to A communication pipe, and exhaust gas from an exhaust pipe is selectively introduced into one of the first and second communication pipes by a butterfly type valve body provided in a flow path switching unit of the main pipe; A flow path switching valve configured to return the exhaust gas returned from the other of the first and second communication pipes to the tail pipe side and discharge the exhaust gas. A guide curved surface is formed on both side surfaces of the rear end portion of the valve body so as to be warped and spread outward to the left and right, and the flow of exhaust gas guided from the exhaust pipe by the guide curved surface is applied to one of the first and second communication ports. And the exhaust gas returning to the other of the first and second communication ports can be smoothly turned to the tail pipe side of the main pipe. Exhaustion Air purifier. 4. The particulate filter according to claim 1, wherein the catalyst is integrally carried on the particulate filter.
An exhaust gas purification device according to item 1.