JP2002138817A - Exhaust emission control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the scavenging surface area without increasing ventilation resistance of exhaust gas and without deteriorating mounting performance to a vehicle. SOLUTION: Plural particulate filters 4 are arranged in series in the almost parallel direction to the axial direction of an exhaust pipe 3, the exhaust gas 2 is distributed to the respective filters 4 via respective introducing spaces 12 from an introducing jacket 14, and is extracted and exhausted to an exhaust jacket 15 via an exhaust space 13 after purifying the exhaust gas by passing the exhaust gas through the respective filters 4 by one path to realize a flow of the exhaust gas 2 similar to a case of parallelly arranging the respective filters 4.

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 component
F (Soluble Organic Fraction: Soluble Organic Component) as a main component, and also contains a small amount of sulfate (mist-like sulfuric acid component). As a measure to reduce this type of particulates, FIG. As shown in FIG. 1, an exhaust pipe 3 through which exhaust gas 2 from a diesel engine 1 flows
It is considered that a particulate filter 4 is provided in the middle of the process.

As shown in FIG. 5, the particulate filter 4 has a porous honeycomb structure made of a ceramic such as cordierite, and the inlets of the respective 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. Exhaust gas 2
The inside particulates are collected on the inner surface of the porous thin wall 6.

[0004] Such a particulate filter 4 requires a large amount of collecting surface area so as to be able to meet the strict regulation values in recent years. However, if the particulate filter 4 is simply extended in the axial direction, the exhaust gas will not be exhausted. This greatly increases the gas 2 ventilation resistance.

On the other hand, as shown in FIGS. 6 and 7, as means for increasing the trapping surface area while suppressing an increase in the ventilation resistance of the exhaust gas 2, a plurality of particulate filters 4 are used in the flow direction of the exhaust gas 2. It is conceivable to increase the total entrance area by disposing them in parallel.

In FIG. 1, reference numeral 7 denotes a cushion material provided outside each particulate filter 4, reference numeral 8 denotes a sealing material provided at an intermediate portion of the cushion member 7 in the axial direction, and reference numeral 9 denotes a cushion member for each particulate filter 4. An inner cylinder 10 accommodated via the material 7 and the sealing material 8 is a holding plate for fixing the respective inner cylinders 9 in the flow direction of the exhaust gas 2, and 11 collectively holds all the particulate filters 4. The outer cylinder is shown.

[0007]

However, when, for example, four particulate filters 4 are arranged in parallel as in the example shown here, the outside of the outer cylinder 11 holding each of these particulate filters 4 is determined. There is a problem that the diameter becomes large, which hinders mounting on a vehicle.

That is, the place where the particulate filter 4 of this type is mounted is located near the lower surface of the chassis frame on one of the right and left sides. There is naturally a limit to the height dimension that can be secured while taking into account the minimum clearance with the ground in the part (road clearance), and also between the center propeller shaft in the vehicle width direction and the outer tire periphery. Since there is a limit to the width dimension that can be achieved, it has been substantially difficult to expand the outer diameter of the outer cylinder 11 in the height direction or the width direction.

Further, in manufacturing the outer cylinder 11 having a distorted cross-sectional shape as shown in FIG. 7, it is difficult to use the conventional plate winding method for producing a conventional cylindrical or elliptical cylindrical muffler cylinder as it is. However, even if the outer cylinder 11 can be manufactured by using a sheet winding method, the outer diameter of the outer cylinder 11 is several times larger than that of the conventional muffler cylinder, so that there is a problem that a new processing machine has to be installed.

[0010] The present invention has been made in view of the above-mentioned circumstances, and it is possible to increase the trapping surface area without increasing the ventilation resistance of exhaust gas or deteriorating the mountability on a vehicle. It is an object of the present invention to provide an exhaust gas purifying apparatus which can be easily manufactured by a plate winding method by directly using a processing machine for producing a muffler cylinder.

[0011]

SUMMARY OF THE INVENTION The present invention relates to an exhaust gas purifying apparatus which is provided in the middle of an exhaust pipe and removes particulates in exhaust gas, and which is connected in series in a direction substantially parallel to the axis of the exhaust pipe. A plurality of particulate filters, an introduction space formed on one side in the axial direction of each of the particulate filters, and an introduction space formed on the other side in the axial direction of each of the particulate filters. Exhaust space, an introduction jacket extending in the direction in which the particulate filters are arranged so that the exhaust gas can be guided from the upstream side of the exhaust pipe and distributed to the introduction spaces, and the exhaust gas can be exhausted from the exhaust spaces. A discharge jacket extending in the direction in which the particulate filters are arranged so that the filter can be extracted and sent to the downstream side of the exhaust pipe. A.

Therefore, according to the present invention, the exhaust gas introduced from the upstream side of the exhaust pipe is introduced into the introduction jacket and distributed from the introduction jacket to the respective introduction spaces, and then from the respective introduction spaces to the respective particulates. While being introduced into the filter and passing through each of the particulate filters, the particulates are collected and purified.

Further, the exhaust gas purified by passing through each of the particulate filters is discharged to each of the discharge spaces, extracted from each of the discharge spaces to a discharge jacket, and is discharged from the discharge jacket to a downstream side of the exhaust pipe. Is discharged to

Then, the exhaust gas is distributed from the discharge jacket through the respective introduction spaces and introduced into the respective particulate filters, and the purified exhaust gas passing through the respective particulate filters is passed through the respective discharge spaces. According to the system of collecting and discharging in the discharge jacket, even if the arrangement of each particulate filter is in series, substantially the same flow of exhaust gas as when each of the particulate filters is arranged in parallel is realized. This makes it possible to increase the total area of the inlet by distributing the exhaust gas to a plurality of particulate filters and pass the exhaust gas through one pass, thereby increasing the trapping surface area while suppressing an increase in exhaust gas ventilation resistance. It becomes possible.

When the exhaust gas purifying apparatus of the present invention is concretely constructed, for example, each particulate filter is loaded in series at a required interval in a cylindrical inner cylinder, so that the inside of the inner cylinder is reduced. The introduction space and the discharge space are alternately formed at the front and rear positions sandwiching each of the particulate filters, and the outer cylinder is externally arranged so that the cross-sectional shape forms a closed curve around the inner cylinder, thereby being isolated from each other. By forming a pair of introduction jacket and discharge jacket respectively, and forming a communication hole at an appropriate position in the circumferential direction at the place where the introduction space and discharge space of the inner cylinder are formed, between the introduction space and the introduction jacket. What is necessary is just to make it communicate with each said discharge space and discharge jacket.

In this way, it is possible to use the conventional sheet winding method for producing a conventional cylindrical or elliptical cylindrical muffler cylinder, and the outer diameter thereof is not much different from that of the conventional muffler cylinder. Since it falls within the range, it becomes possible to divert a conventional processing machine for producing a muffler cylinder as it is.

[0017]

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

FIGS. 1 and 2 show an example of an embodiment of the present invention, and the portions denoted by the same reference numerals as those in FIGS. 4 to 7 represent the same components.

As shown in a plan sectional view seen from above in FIG. 1, in the present embodiment, two cylinders extend in a direction substantially parallel to the axial direction of the exhaust pipe 3 and are formed in a cylindrical inner cylinder 9. Particulate filters 4 are mounted in series at required intervals, and a front part of the front side (left side in FIG. 1) of the particulate filter 4 in the vehicle front-rear direction (left-right direction in FIG. 1) in the inner cylinder 9. An introduction space 12 is formed on the rear side (the right side in FIG. 1) of the particulate filter 4, and a discharge space 13 is formed between the two particulate filters 4. ing.

The exhaust gas 2 is introduced from the upstream side of the exhaust pipe 3 to the outer peripheral portion on the left side (the lower side in FIG. 1) of the inner cylinder 9 in the vehicle width direction (vertical direction in FIG. 1). Each introduction space 1
An introduction jacket 14 extends in the direction in which the particulate filters 4 are arranged so as to be able to distribute the particles 2 to each other. On the other hand, the right side in the vehicle width direction of the inner cylinder 9 (the upper side in FIG.
The exhaust jacket 1 is arranged in the direction in which the particulate filters 4 are arranged so that the exhaust gas 2 can be extracted from the exhaust space 13 and sent to the downstream side of the exhaust pipe 3.
5 is extended.

Here, as shown in FIG. 2, the introduction jacket 14 and the discharge jacket 15 are formed by encasing the outer cylinder 11 by a plate winding method so as to form an elliptical cylinder around the inner cylinder. It is designed to be manufactured as being separated from each other by forming a cross-sectional shape of a mold, and between the introduction space 12 and the introduction jacket 14 and between the discharge space 13 and the discharge jacket 15. Are communication holes 16 and 17 formed at appropriate positions in the circumferential direction at the positions where the introduction space 12 and the discharge space 13 of the inner cylinder 9 are formed.
The communication is established.

In the example shown here, a case where a conventional muffler is provided as an exhaust gas purifying device having a silencing function in place of the conventional muffler is illustrated. An inlet pipe 18 projecting forward at the front end of the exhaust pipe 3 is connected to a substantial end of the exhaust pipe 3, and a tail pipe 19 projecting rearward at the rear end of the discharge jacket 15. Has become.

Thus, the exhaust gas 2 guided from the upstream side of the exhaust pipe 3 is introduced into the introduction jacket 14 and is distributed from the introduction jacket 14 to each of the introduction spaces 12. The particulates are introduced from each of the introduction spaces 12 to each of the particulate filters 4, and are collected and purified while passing through each of the particulate filters 4.

Further, the exhaust gas 2 that has been purified by passing through each particulate filter 4 is discharged to each exhaust space 13, extracted from each exhaust space 13 to an exhaust jacket 15, and discharged outside the vehicle. You.

Then, the exhaust gas 2 is distributed from the discharge jacket 15 through each of the introduction spaces 12 and introduced into each of the particulate filters 4, and the exhaust gas 2 that has been purified by passing through each of the particulate filters 4. Is collected in the discharge jacket 15 via the discharge space 13 and discharged, even if the arrangement of the particulate filters 4 is in series, it is practically the case where the particulate filters 4 are arranged in parallel. The same flow of the exhaust gas 2 can be realized, and the exhaust gas 2 is distributed to a plurality of particulate filters 4 and passed through one pass, thereby increasing the total inlet area and reducing the airflow resistance of the exhaust gas 2. It is possible to increase the collection surface area while suppressing the increase.

Therefore, according to the above embodiment, since the plurality of particulate filters 4 are arranged in series in a direction substantially parallel to the axial direction of the exhaust pipe 3, the outer cylinder 11
It is possible to avoid a significant increase in the outer diameter of the filter in the height and width directions, and even if the arrangement of the particulate filters 4 is in series, the respective particulate filters 4 are substantially connected in parallel. Exhaust gas 2 as in the case of
Therefore, the trapping surface area can be increased without increasing the ventilation resistance of the exhaust gas 2 or deteriorating the mountability on the vehicle.

Further, the conventional plate winding method for producing a cylindrical or elliptical cylindrical muffler cylinder can be used as it is,
In addition, since the outer diameter of the muffler cylinder can be kept within a range that is not much different from that of the conventional muffler cylinder, it is possible to easily produce the conventional muffler cylinder by the sheet winding method using the processing machine for producing the same.

FIG. 3 shows another embodiment of the present invention.
This embodiment shows an example in which at least three or more particulate filters 4 are arranged in series. Except that the number of the particulate filters 4 is increased, FIGS. It is almost the same as the two.

When the number of the particulate filters 4 is increased to three or more, the length of the outer cylinder 11 in the axial direction becomes longer.
The extension of the outer cylinder 11 in the axial direction does not greatly affect the mountability to the vehicle, and can be handled by a conventional processing machine for forming a muffler cylinder. As in the case of the embodiment, the trapping surface area can be further increased without increasing the ventilation resistance of the exhaust gas 2 and deteriorating the mountability on the vehicle, and further, a processing machine for forming a conventional muffler cylinder Can be easily manufactured by a plate winding method by diverting as it is.

It should be noted that the exhaust gas purifying apparatus of the present invention is not limited to the above-described embodiment, but may be variously modified without departing from the gist of the present invention.

[0031]

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 first aspect of the present invention, the plurality of particulate filters are arranged in series in a direction substantially parallel to the axial direction of the exhaust pipe. It is possible to avoid significant expansion of the outer diameter of the filter in the height and width directions, and even if the arrangement of each particulate filter is in series, the respective particulate filters are substantially arranged in parallel Since the same flow of exhaust gas as in the case described above can be realized, the trapping surface area can be increased without increasing the ventilation resistance of the exhaust gas or deteriorating the mountability on the vehicle.

(II) According to the second aspect of the present invention, the conventional sheet-winding method for producing a cylindrical or elliptical cylindrical muffler cylinder can be used as it is, and the outer diameter thereof can be reduced. Since the dimensions can be kept within a range that is not much different from that of the conventional muffler cylinder, the processing machine for producing the conventional muffler cylinder can be used as it is and can be easily manufactured by the plate winding method.

[Brief description of the drawings]

FIG. 1 is a cross-sectional plan view showing an example of an embodiment of the present invention.

FIG. 2 is a view in the direction of arrows II-II in FIG. 1;

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

FIG. 4 is a schematic diagram showing a conventional example.

FIG. 5 is a sectional view showing details of the particulate filter of FIG. 4;

FIG. 6 is a plan sectional view showing an example in which a plurality of particulate filters are arranged in parallel.

7 is a view in the direction of arrows VII-VII in FIG. 6;

[Explanation of symbols]

 2 exhaust gas 3 exhaust pipe 4 particulate filter 9 inner cylinder 11 outer cylinder 12 introduction space 13 discharge space 14 introduction jacket 15 discharge jacket 16 communication hole 17 communication hole

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshiki Oya 3-1-1, Hinodai, Hino-shi, Tokyo Inside Hino Motor Co., Ltd. (72) Inventor Osamu Tsuchiya 3-1-1, Hinodai, Hino-shi, Tokyo Hino Motors Co., Ltd. (72) Inventor Hiroshi Funabashi 3-1-1, Hinodai, Hino-shi, Tokyo Hino Motor Co., Ltd. F-term (reference) 3G090 AA04 BA01 EA01 4D058 JA32 KA01 KA16 KA25 KA27 KB05 QA01 QA03 QA11 QA15 SA08

Claims (2)

[Claims] 1. An exhaust gas purifying apparatus provided in the middle of an exhaust pipe for removing particulates in exhaust gas, comprising a plurality of particulates arranged in series in a direction substantially parallel to an axial direction of the exhaust pipe. A filter, an introduction space formed on one side in the axial direction of each of the particulate filters, a discharge space formed on the other side in the axial direction of each of the particulate filters, and an exhaust pipe. An introduction jacket extending in the direction in which the particulate filters are arranged so that exhaust gas can be guided from the upstream side and distributed to each of the introduction spaces, and exhaust gas is extracted from each of the exhaust spaces and downstream of the exhaust pipe. A discharge jacket extending in a direction in which the particulate filters are arranged so that the particulate filters can be sent out. 2. An introduction space and a discharge space are placed in front and rear positions of the particulate filter in the inner cylinder by inserting the particulate filters in series at required intervals in a cylindrical inner cylinder. By alternately forming the outer cylinder so as to form a closed curved cross section around the inner cylinder, a pair of mutually separated introduction jackets and discharge jackets are formed, and the introduction of the inner cylinder is performed. By forming a communication hole at an appropriate position in the circumferential direction at the location where the space and the discharge space are formed, it is possible to communicate between the introduction space and the introduction jacket and between the discharge space and the discharge jacket. The exhaust gas purifying apparatus according to claim 1, wherein: