JPH1181981A - Exhaust gas purifying device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust gas purifying device for an internal combustion engine, which can be miniaturized and decreased in weight. SOLUTION: An exhaust gas purifying device has such a structure that filter flanges 19a, 19b attached to a pair of particulate filters 4a, 4b are fastened to a partition plate 12 at the opening of the partition plate 12 with bolts and nuts 22 and to casing flanges 7 of a case part with bolts and nuts 9 for connecting the casing parts 5a, 5b, on the outer peripheral side of the casing parts 5a, 5b. With this arrangement, the filter flanges of the filters can be fixed to the partition panel 12 without requiring additional fixing space, with a minimum necessary number of bolts, while ensuring a high sealability, thereby the device can be miniaturize and decreased in weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying apparatus for an internal combustion engine that collects particulates contained in exhaust gas of the internal combustion engine by a particulate filter.

[0002]

2. Description of the Related Art Exhaust gas emitted from an internal combustion engine such as an automobile, particularly a diesel engine, contains particulates (exhaust particulates) mainly composed of carbon. Therefore, in a vehicle equipped with a diesel engine, an exhaust gas purifying device having a ceramic columnar particulate filter (hereinafter, simply referred to as a filter) is provided in an exhaust pipe (exhaust passage) of the diesel engine, and the exhaust gas is filtered by the filter. The collection of particulates inside is performed.

By the way, in a filter, when the collected particulates increase due to accumulation, the air permeability is gradually impaired. Therefore, regeneration of the filter is required. Accordingly, an exhaust gas purifying apparatus has been proposed in which a pair of (two) filters are housed in a common case so that the filters can be regenerated while continuing collection of particulates.

[0004] Such an exhaust gas purifying apparatus includes Japanese Patent Publication No.
As shown in JP-A-80962, a case is used which can be divided into an upstream side and a downstream side, and a partition for dividing the inside of the case into an inlet chamber and an outlet chamber at one of the divided openings of the divided case part. A structure is used in which a wall (partition plate) is mounted, filters are respectively installed in a pair of filter mounting openings formed in the partition wall, and each filter is housed in a case.

[0005] Specifically, a structure is used in which the open ends of the case portions are joined together by bolts via case flanges formed on the outer peripheral edge of each case portion.
Also, in the filter installation structure, a filter flange is attached to the outer periphery of each filter, and each part of the filter flange is fastened to the periphery of the opening for mounting each filter with a bolt different from the case joining bolt. The structure which fixes each filter to a partition wall is used.

[0006]

By the way, the exhaust gas purifying device is required to be reduced in size and weight like other devices. In particular, the demand for the exhaust gas purifying device is high because it is installed in the middle of an exhaust pipe of an automobile, which has many space restrictions.

However, as described above, the structure in which the joining of the case portion and the fixing of the filter are performed by separate bolts as fastening means is a space for disposing the filter fixing bolt between the peripheral wall of the case and the filter. Therefore, there is a problem that the case becomes large, that is, the device becomes large.

In addition, since the bolts for joining the case and the bolts for fixing the filter are separate from each other, there are considerably many places to be fastened, so that many bolts are required.

[0009] For this reason, there is a need to improve such points. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an exhaust gas purifying apparatus for an internal combustion engine which can realize a reduction in size and weight.

[0010]

In order to achieve the above object, in the exhaust gas purifying apparatus according to the present invention, the filter flange mounted on the pair of filters is connected with the first fastening means between the openings of the partition plate. In this case, a structure is adopted in which the outer peripheral side of the divided case portion is fastened and fixed to both case flanges of the case portion together by the second fastening means.

According to this structure, the fastening for joining the case portion is the fastening for fixing the filter as it is, that is, the fastening means for joining the case portion and fixing the filter is shared. It is fixed to the partition plate without requiring a separate fixing space between the peripheral wall and the filter. In addition, the number of fastening means such as bolts is reduced.

Further, since only the portion of the filter flange disposed between the openings of the partition plate, that is, the portion that cannot be sandwiched by the case flange, is fixed to the partition plate by another fastening means, the sealing performance at the portion is sufficiently improved. Secured. Of course, since the filter flange is fastened using the space between the openings, the case is not increased in size.

[0013] This makes it possible to reduce the size and weight of the exhaust gas purifying apparatus incorporating the pair of filters. In the exhaust gas purifying apparatus according to the second aspect, a partition plate is attached to the upstream case portion, and the filter is alternately regenerated by dividing the inlet chamber into chambers for each filter by a partition wall joined to the partition plate. In this case structure, the second fastening means is disposed at a corner formed by the peripheral wall of the upstream case portion forming the case structure and the end of the partition wall adjacent thereto.

[0014] With this structure, the filter flange is fastened to the plate surface of the partition plate, which is provided with high rigidity by the upstream case portion and the partition wall, so that the filter flange is firmly fixed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on one embodiment shown in FIGS. FIG. 1 (a),
(B) shows an exhaust gas purification device 2 installed in the middle of an exhaust pipe 1 (corresponding to an exhaust path of an internal combustion engine) extending from an internal combustion engine, for example, a diesel engine (not shown) mounted on an automobile (vehicle). Shows a plan sectional view and a front sectional view of
FIG. 2 shows an external view of the exhaust gas purifying apparatus 2, and FIG. 3 shows an exploded view of a part of the exhaust gas purifying apparatus 2.

In this exhaust gas purifying apparatus 2, a pair of (two: plural) cylindrical particulate filters 4a and 4b (hereinafter simply referred to as filters 4a and 4b) are accommodated in parallel in a common case. It is configured in one unit.

The structure of the exhaust gas purifying apparatus 2 will be described. In the drawing, reference numeral 5 denotes an accommodating case (corresponding to a case) formed in, for example, an elliptical cylindrical shape. For example, as shown in FIGS. 2 and 3, the housing case 5 has a structure in which an upstream case portion 5a and a downstream case portion 5b which are divided into an upstream side and a downstream side are joined.

Specifically, the upstream case portion 5a and the downstream case portion 5b are formed by a pair of long cylindrical body portions 6a, 6a.
A case flange 7 is attached to an outer peripheral edge of one of the openings b (corresponding to an outer peripheral edge of the divided opening), and an elliptical end wall 8 is attached to the other opening. . Then, a plurality of portions of the case flanges 7, 7 at the divided ends of the case portions 5a, 5b are fastened by first fastening means, for example, bolts and nuts 9, to form an elongated cylindrical case structure. However, reference numeral 7a denotes a bolt insertion hole formed in the case flanges 7, 7 for fixing the case (FIG. 3).
Only shown).

An inlet 10 communicating with the exhaust pipe portion 1a of the exhaust pipe 1 toward the engine is formed at the center of the end wall of the upstream case 5a, and is formed at the center of the end wall of the downstream case 5b. An outlet 11 is formed to communicate with an exhaust pipe portion 1b toward an exhaust port (not shown) of the exhaust pipe 1.

The inside of the storage case 5 includes a body portion 6a,
6b, for example, an oval partition plate 12 formed continuously from the case flange 7 on the upstream trunk portion 6a so as to close the opening of the trunk portion 6a.
Thus, an inlet chamber 13 and an outlet chamber 14 are defined.

Further, the partitioned inlet chamber 13 is divided into two parts in parallel by a partition wall 15 (partition wall) which is joined to the central portion of the partition plate 12 and extends to the central portion of the inlet 10.
The extending end of the partition wall 15 is joined to the center of a mounting plate 16 attached to the inflow port 10 to divide the inlet chamber 13 into chambers 13a and 13b for each filter. The mounting plate 16
Is connected to an exhaust gas introduction pipe 17 for introducing exhaust gas from the inlet 10 for each of the chambers 13a and 13b.

The partition plate 12 is formed with a pair of circular openings 18 for mounting a filter, which are opened for each of the chambers 13a and 13b (shown only in FIG. 3). And these openings 18
Each time, a pair of filters 4a and 4b (for example, formed of a cylindrical honeycomb filter having a partition made of a porous member such as ceramic) are installed in parallel.

When installing the filters 4a and 4b, the filter flanges 19a and 19b
And these filter flanges 19a, 19a
b is overlapped on the partition plate 12 and fixed.
A structure is used in which the ends of a and 4b protrude from a pair of openings 18.

The present invention is applied to a structure for fixing the filter flanges 19a and 19b. That is, the outer shape of each of the filter flanges 19a and 19b is, for example, as shown in FIG. Are formed in substantially the same shape as one side. Reference numeral 20 denotes a rectangular portion of the filter flanges 19a and 19b, and reference numeral 21 denotes a circular portion (shown only in FIG. 3).

Then, each filter flange 19a, 19
b of the upstream / downstream case portions 5a, 5b
Are fastened to both case flanges 7, 7 with bolts and nuts 9 which are sandwiched between the case flanges 7, 7 and fasten the two case portions 5a, 5b. Reference numeral 21a denotes a bolt insertion hole for co-fastening formed in the filter flanges 19a and 19b (shown only in FIG. 3).

Only the rectangular portions 20 of the filter flanges 19a, 19b which cannot be clamped by the case flanges 7, 7 are fixed by a second fastening means, for example, another bolt and nut 22,
The partition plate 12 is fastened to a plate surface portion between the openings 7,7.

In particular, this square portion 20 is
2, as shown by the broken line in FIG.
The partition wall 12 is fastened to a corner (a square plate surface portion) 12a formed by the peripheral wall a and the end of the partition wall 12 adjacent thereto. For this purpose, a dedicated bolt insertion hole 20a is formed on each side of the corner 12a and the square portion 20 overlapping the corner 12a.

In FIG. 1, reference numeral 23 denotes filters 4a, 4a installed upstream of the respective filters 4a, 4b.
an electric heater (heating means) for heating b for regeneration (alternate regeneration); 24, a heat reflecting plate installed upstream of each electric heater 23; 25, an inlet 10 and an exhaust pipe portion 1;
a valve unit interposed between the exhaust gas introduction pipe 17 and the exhaust gas introduction pipe 17 and controls the supply of the regeneration gas (part of the exhaust gas) to the exhaust gas introduction pipe 17 on the regeneration side.

The filter flanges 19a and 19b of the filters 4a and 4b are fastened and fixed to the two case flanges 7 on the outer peripheral side of the case portions 5a and 5b by bolt nuts 9 connecting the case portions. In the case where the upper and lower case portions 5a and 5b are fixed to the partition plate 12 with the bolts and nuts 22 between the 18 portions, the fixing for directly fixing the filters 4a and 4b is performed.

With this fastening structure, the size and weight of the device can be reduced while ensuring high sealing performance. That is, since the upper / downstream case portions 5a, 5b and the filters 4a, 4b are fixed by the common bolt / nut 9 (first fastening means), each filter 4a, 4b is connected to the upper / downstream case. The space between the peripheral walls of the portions 5a and 5b and the filters 4a and 4b can be fixed to the partition plate 12 without requiring a separate fixing space. In addition, the number of bolts and nuts 9 to be used is reduced.

In addition, only the square portions 20 of the filter flanges 19a and 19b disposed between the openings 18 and 18 of the partition plate 12, that is, the portions that cannot be sandwiched by the two case flanges 7, are provided with separate bolt nuts 22 (second bolt nuts 22). Since it is fixed to the partition plate 12 by the fastening means, it is possible to sufficiently secure the sealing performance at the relevant location. In addition, since the bolt nut 22 is disposed in the space between the openings 18, 18 which does not require a space for newly disposing the bolt nut, the filter flanges 19a, 19b are fastened by effectively utilizing the space. In addition, the size of the storage case 5 does not increase.

Therefore, it is possible to provide the exhaust gas purifying device 2 which is excellent in sealing performance and excellent in size and weight reduction. In addition, by utilizing a structure in which the filters 4a and 4b can be alternately regenerated by dividing the inlet chamber 13 into chambers 13a and 13b for each filter by a partition wall 15, the peripheral wall of the upstream case portion 5a and a partition close thereto are used. Corner 1 of partition plate 12 formed with the end of wall 15
2a, the square portions 2 of the filter flanges 19a, 19b
0 is fastened by the bolt nut 22, so that the filters 4a and 4b can be fixed with high supporting strength.

This is because the corner 12a of the partition plate 12 formed by the peripheral wall of the upstream case portion 5a and the end of the partition wall 15 adjacent thereto has high rigidity due to the upstream case portion 5a and the partition wall 15. This is because the filter flanges 19a and 19b can be firmly fixed by fastening the rectangular portions 20 of the filter flanges 19a and 19b to the same.

In the above-described embodiment, the example in which the partition plate is mounted on the upstream case portion has been described. However, it goes without saying that the same effect can be obtained when the partition plate is mounted on the downstream case portion. Further, in the above-described embodiment, the bolt and the nut are used as the first fastening means and the second fastening means, but other fastening means may be used.

[0035]

As described above, according to the first aspect of the present invention, a high sealing property can be ensured with no additional fixing space required and with a minimum necessary number of fastening means. In addition, the filter flange of the filter can be fixed to the partition plate.

Therefore, it is possible to realize an exhaust gas purifying apparatus which is excellent in sealing performance and small in size and weight. According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, the partition between the openings between the openings of the filter flange is provided with high rigidity by the upstream case portion and the partition wall. Since the filter flange is fastened to the surface portion, the filter flange can be fixed with high support rigidity.

[Brief description of the drawings]

FIG. 1A is a side sectional view showing a structure of an exhaust gas purifying apparatus according to an embodiment of the present invention. FIG. 2B is a cross-sectional plan view of the exhaust gas purifying apparatus taken along line A-A in FIG.

FIG. 2 is a perspective view showing the appearance of the exhaust gas purifying apparatus.

FIG. 3 is a partially exploded perspective view for explaining a mounting structure of a filter flange of the exhaust gas purifying apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Diesel engine exhaust pipe (exhaust path) 2 ... Exhaust gas purifier 4a, 4b ... Particulate filter 5 ... Housing case (case) 5a ... Upstream case part 5b ... Downstream case part 7 ... Case flange 9 ... Bolt Nut (first fastening means) 12 ... partition plate 13 ... inlet chamber 14 ... outlet chamber 15 ... partition wall (partition wall) 18 ... opening 19a, 19b ... filter flange 22 ... bolt nut (second fastening means).

Claims (2)

[Claims] 1. An exhaust gas purifying apparatus for an internal combustion engine, comprising a case interposed in an exhaust path of the internal combustion engine, and a pair of particulate filters accommodated in parallel in the case. A partition plate that divides the inside of the case into an inlet chamber and an outlet chamber is formed at the divided opening of one of the case portions while being divided into an upstream case portion and a downstream case portion that are connected to the upper / downstream. The partition plate is formed with a pair of openings for mounting each of the particulate filters, and a case flange is formed on an outer peripheral edge of the divided opening of each of the case portions. A filter flange is formed on an outer peripheral side of the filter, and the filter flange is provided between the pair of openings.
The fixing means is fastened and fixed to the partition plate, and the outer peripheral sides of the two case portions are fixed together with the two case flanges by the second fastening means so as to be sandwiched between the case flanges. An exhaust gas purifying device for an internal combustion engine. 2. The partition plate is mounted on the upstream case portion, and the upstream case portion is provided with a partition wall which divides the inlet chamber into a chamber for each filter and is joined to the partition plate. Second fastening means for fastening and fixing the filter flange between the pair of openings is disposed at a corner formed by a peripheral wall of the upstream case portion and an end of the partition wall adjacent thereto. The exhaust gas purifying apparatus for an internal combustion engine according to claim 1, characterized in that: