JP2000104530A - Exhaust emission control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust emission control system to perform assembly of a filter to a filter container with high-efficiency and prevent movement and breakage of a filter during operation. SOLUTION: The diameter of the rear end part of a filter container 5a to contain a filter 1 arranged in an exhaust emission control system is equal or larger than the sectional diameter of a filter 4 and smaller than the sectional diameter of the filter 4 containing a heating expandable ceramic 6 wound around the filter 4. The exhaust emission control system is provided to perform assembly of the filter 4 to the filter container 5a with high-efficiency, prevent movement and breakage of the filter 4 during operation from occurring without worsening assembly efficiency, and improve reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for collecting particulates (combustible fine particles such as soot) and the like contained in exhaust gas discharged from an internal combustion engine such as a diesel engine using a filter. The present invention relates to an exhaust gas purifying apparatus that regenerates a filter by removing it by combustion or high pressure gas injection or other means.

[0002]

2. Description of the Related Art In recent years, particulates (combustible fine particles such as soot) discharged from diesel engines and the like have been regulated for environmental protection and health reasons. In order to remove the exhaust gas and purify the exhaust gas of the diesel engine, there is a method of attaching a cylindrical filter (hereinafter referred to as a filter) made of ceramic honeycomb in the middle of the flow path of the exhaust pipe to filter the particulates. The feature of this method is that when particulates are collected and accumulated to a certain extent in the filter, they are ignited and burned, converted to carbon dioxide and released into the atmosphere, and the filter is regenerated cleanly and used repeatedly. It is. This operation is called combustion regeneration. In general, since the exhaust gas of diesel engines is lower than the ignition temperature of particulates, the particulates do not burn in this state, but only accumulate on the filter, excessively increasing the exhaust pressure and deteriorating the engine and emission performance. . Therefore, for combustion regeneration, it is necessary to raise the exhaust gas temperature or the filter temperature by some method. In recent years,
There has been proposed a system in which two filters are provided in an exhaust system to purify exhaust gas alternately. Combustion regeneration is not performed during exhaust gas filtration, but after particulates have accumulated to some extent, exhaust gas purification is performed with the other filter.
Combustion regeneration is performed. As the temperature raising means, regeneration is performed by heating the filter with an electric heater, a burner, a microwave, or the like, raising the temperature of the filter, and burning the particulates.

Conventionally, when manufacturing such an exhaust gas purifying apparatus, the filter is housed in a filter container and used in an integrated state in order to facilitate attachment and detachment of the filter during maintenance and to improve workability.

Hereinafter, a conventional diesel exhaust gas purifying apparatus will be described with reference to the drawings. FIG. 4 is a schematic sectional view of a conventional exhaust gas purifying apparatus for a diesel engine.
In FIG. 4, 101 is a main body container, 102 is a front lid,
03 is a rear lid, 104 is a filter, 105 is a metal filter container, 106 is a heat-expandable ceramic, 1
07 denotes a heater, 108 denotes exhaust gas, and 109 denotes a stopper. The function of the conventional diesel exhaust gas purification device configured as described above will be described.

First, exhaust gas 108 discharged from a diesel engine (not shown) flows in from a front cover 102 of a diesel exhaust gas purification device, passes through a filter 104, and flows out of a rear cover 103. The filter 104 has a large number of cells, and the cells are alternately closed on the inflow side and the outflow side of the exhaust gas 108 in the filter 104.
A filter called a wall flow type that passes through the cell wall of No. 4 and collects particulates in the exhaust gas 108 at that time is used. And this filter 10
In the gap between 4 and the filter container 105, for the purpose of preventing leakage of the exhaust gas 108 and the purpose of fixing the filter,
The heat-expandable ceramic 106 is filled. In this assembly, first, the heat-expandable ceramic 106 is wrapped around the filter 104 without any gap, and then the filter 104 is press-inserted or pressed into the filter container 105 in the axial direction by an oil pressure or the like, and then subjected to a heat treatment. The expandable ceramic 106 is expanded to fix and seal the filter. Further, a stopper 109 is attached to the filter container 105 in order to prevent the rear lid 103 from blocking the flow path due to the movement of the filter 104. In addition, the particulates to some extent are
When collected and deposited on the filter 4, the fuel is ignited and burned by the heater 107, the combustion regeneration for regenerating the filter 104 is performed, the function is restored, and the filter 104 is used repeatedly. If two similar devices are installed and exhaust gas purification and filter regeneration are performed alternately, continuous operation can be performed without stopping the diesel engine.

[0006]

However, in the above-described conventional configuration, the filter 104 and the filter container 10 are not provided.
5 and when the heat-expandable ceramic 106 is assembled, since the filter container 105 is straight, the frictional force between the filter container 105 and the heat-expandable ceramic 106 must be pressed against the friction force between the start of insertion and the insertion. Work takes time and efficiency is poor. There is also a problem that a jig and a large oil pressure are required. Further, since the fixing of the filter 104 and the filter container 105 is based on the expansion pressure acting on the center of the filter 104 due to the expansion of the heat-expandable ceramic 106 and the frictional force resulting therefrom, the heat of combustion of particulates during filter regeneration, Alternatively, the temperature change of the filter portion due to the high-temperature exhaust gas during the operation of the diesel engine is caused by the fact that the thermal expansion coefficients of the filter 104 and the filter container 105 are largely different, and thus the respective expansion amounts are different and the density change of the heat-expandable ceramic 106 is different. Because of this, the fixing force between the filter 104 and the filter container 105 is reduced. For this reason, the filter 104 may move rearward due to an increase in the exhaust pressure accompanying the particulate deposition on the filter 104, and may block the flow path of the rear lid 103. In order to prevent the movement, the filter 104 is brought into contact with the stopper 109 to prevent the movement. However, in this case, since the filter 104 is in contact with the stopper 109, the filter 104 is gradually cut by the exhaust pressure and the vibration from the engine or the like. There is a problem that it is damaged.
If a portion of the filter 104 is damaged, the exhaust gas 108 leaks and the filter 104 does not function. Also,
In order to prevent the movement of the filter 104, a method of increasing the packing density of the heat-expandable ceramic 106 has been proposed. However, if the packing density is too high, the filter 104 will be damaged, and there is a limit. However, there is a problem that the assembly efficiency is deteriorated, such as increase in the size of the press-fitting jig and the difficulty of the operation.

An object of the present invention is to solve the above-mentioned conventional problems by efficiently assembling the filter 104 into the filter container 105 and preventing movement and breakage of the filter 104 during operation without deteriorating the assembly efficiency. It is an object of the present invention to provide an exhaust gas purifying apparatus capable of performing the following.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an exhaust gas purifying apparatus in which a rear end diameter of a filter container for storing a filter is equal to or larger than a cross-sectional diameter of the filter. In addition, the filter is configured to be smaller than the cross-sectional diameter of the filter including the heat-expandable ceramic wound around the filter.

As a result, it is possible to obtain an exhaust gas purifying apparatus capable of efficiently assembling a filter into a container and preventing movement and breakage of the filter during operation without deteriorating assembly efficiency.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Claims 1 and 5 of the present invention
The invention described in (1) is provided in the exhaust path of the exhaust gas, a cylindrical filter that allows the exhaust gas to pass through and collects particulates and the like in the exhaust gas, and a unit that removes the particulates and the like attached to the filter. In the exhaust gas purifying apparatus provided, a rear end inner diameter of a filter container that accommodates the filter provided in the apparatus is equal to or larger than a cross-sectional diameter of the filter, and includes a heat-expandable ceramic wound around the filter. It is configured to be smaller than the filter cross-sectional diameter,
According to the initial filling density of the heat-expandable ceramic, the filter can be fixed and sealed, and the filter does not come into contact with the filter container even when the filter moves during operation.

According to a second aspect of the present invention, in the exhaust gas purifying apparatus, a filter container provided in the apparatus has a tapered shape in which an inner diameter in a cross section in an axial direction gradually decreases from a front portion to a rear portion. The filter is fixed and sealed according to the initial filling density of the heat-expandable ceramic, and the filter container itself serves as a guide when the filter is inserted. When the filter moves during operation, the packing density of the heat-expandable ceramic increases in accordance with the movement. Further, the filter has an effect that the filter does not come into contact with the filter container even if the movement proceeds.

According to a third aspect of the present invention, in the exhaust gas purifying apparatus, an inner diameter of a cross section in the axial direction of a filter container that accommodates the filter provided in the device extends from the front part to the middle part and from the middle part. It is configured so that it gradually decreases toward the rear part, and the reduction rate of the cross-sectional inner diameter from the front part to the middle part is smaller than the reduction rate from the middle part to the rear part, depending on the initial filling density of the heat-expandable ceramic. In addition to fixing and sealing the filter, the filter container itself serves as a guide when the filter is inserted. When the filter moves during operation, the packing density of the heat-expandable ceramic increases in accordance with the movement. Further, the filter has an effect that the filter does not come into contact with the filter container even if the movement proceeds.

According to a fourth aspect of the present invention, in the exhaust gas purifying apparatus, an inner diameter of a cross section in an axial direction of a filter container for accommodating the filter provided in the device is gradually reduced from a middle part to a rear part. According to the initial packing density of the heat-expandable ceramic,
The filter can be fixed and sealed. When the filter moves during operation, the packing density of the heat-expandable ceramic increases in accordance with the movement. Further, the filter has an effect that the filter does not come into contact with the filter container even if the movement proceeds.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a schematic sectional view showing an exhaust gas purifying apparatus for a diesel engine according to Embodiment 1 of the present invention. In FIG. 1, the source side of the flow path is referred to as front, and the downstream side is referred to as rear, 1 is a main body container, 2 is a front lid, 3 is a rear lid,
Reference numeral 4 denotes a filter, 5a denotes a metal filter container, 6 denotes a heat-expandable ceramic, 7 denotes a heater, and 8 denotes exhaust gas.

A front lid 2 and a rear lid 3 are fastened to the main body container 1 in front and behind thereof by bolts or the like via gaskets, thereby forming a sealed structure. Further, pipes are welded to the front lid 2 and the rear lid 3 so that the exhaust gas 8 flows in and out. The material of the conduit is preferably made of metal because of its heat resistance, and is particularly preferably made of corrosion-resistant stainless steel or the like.

The filter 4 is preferably made of a heat-resistant and corrosion-resistant material such as cordierite and mullite and has a honeycomb structure having a small pressure loss. In addition, this filter 4
May carry an oxidation catalyst.

The filter container 5a is a corrosion-resistant metal container such as stainless steel formed in a tapered shape in which the cross-sectional inner diameter in the axial direction gradually decreases from the front part to the rear part. A flange is welded for mounting to the main body container 1 via a gasket together with a rear lid 3 as shown in FIG. The filter 4 around which the heat-expandable ceramic 6 is wound is press-fitted into the filter container 5a. The heat-expandable ceramic 6 is a ceramic mat (for example, an interlam mat manufactured by Sumitomo 3M Limited) containing a material that expands by heat such as vermiculite.

When inserting the filter 4 into the filter container 5a, first, the heat-expandable ceramic 6 formed into a band shape is wound around the filter 4 without gaps. At this time, the butted portion at the end of the heat-expandable ceramic 6 is formed in a stepped or uneven shape to prevent the exhaust gas 8 from leaking in the axial direction of the butted filter 4 so that they are combined. Thereafter, the filter 4 around which the heat-expandable ceramic 6 is wound is inserted under pressure from the front of the filter container 5a.

The thickness of the heat-expandable ceramic 6 is thicker than the clearance between the filter 4 and the filter container 5a, and decreases with the insertion into the filter container 5a. The required sealing distance in the axial direction of the filter 4 determined by the exhaust gas pressure is determined. Is determined so as to have a predetermined packing density in the region of. In pressurized insertion, a press or the like using hydraulic pressure is often used. According to the present embodiment, since the filter container 5a is formed in a tapered shape, the container itself serves as a guide at the time of insertion and at the same time the frictional force gradually increases. Easy press fitting and efficient assembly. After the assembly is completed, a heat treatment is performed to expand the heat-expandable ceramic 6 to fix and seal the filter 4.

The heater 7 is preferably one in which, for example, a nichrome wire or a Kanthal wire, which is a heating element, is wound in a ceramic-support portion in a winding manner having high thermal efficiency. Note that a sheath-type heating element in which the heating element is housed for improving corrosion resistance may be used.

The function of the exhaust gas purifying method using the exhaust gas purifying apparatus configured as described above will be described. First, the exhaust gas 8 discharged from the diesel engine (not shown) flows in from the front cover 2 of the diesel exhaust gas purification device, passes through the filter 4 and flows out from the rear cover 3. The filter 4 has a large number of cells, and the cells are alternately closed on the inflow side and the outflow side of the exhaust gas 8 in the filter 4.
Pass through the cell wall and collect particulates in the exhaust gas 8 at that time. When particulates are trapped and accumulated to some extent in the filter 4, the heater 7 ignites and burns the particulates, and the regeneration of the filter 4 is carried out to recover the function, and the filter 4 is recovered and used repeatedly.

As described above, while the purification of the exhaust gas and the combustion regeneration are repeated, the filter 4 and the filter container 5 a are fixed by the expansion of the heat-expandable ceramic 6.
And the frictional force resulting therefrom. The change in the temperature of the filter due to the heat of combustion of the particulates during combustion regeneration or the high temperature exhaust gas during operation of the diesel engine greatly differs in the thermal expansion coefficients of the filter 4 and the filter container 5a. Since the respective expansion amounts are different from each other and the density of the heat-expandable ceramic 6 is changed, the fixing force between the filter 4 and the filter container 5a is reduced. For this reason, the filter 4 moves rearward due to an increase in the exhaust pressure accompanying the particulate accumulation on the filter 4.

At this time, the frictional force between the heat-expandable ceramic 6 and the filter 4 is larger than the frictional force between the heat-expandable ceramic 6 and the filter container 5a due to the difference in surface roughness. Although the heat-expandable ceramic 6 moves at the same time, according to the present embodiment, the inner diameter of the rear end of the filter container 5a is equal to or larger than the cross-sectional diameter of the filter 4, and the heating wound around the filter 4 is performed. The filter 4 and the filter container 5a are formed in a tapered shape whose cross-sectional diameter is smaller than the cross-sectional diameter of the filter including the expandable ceramic 6 and gradually decreases from the front part to the rear part.
Because the gap of the heat-expandable ceramic 6 increases and the frictional force increases, the movement stops before reaching the rear lid 3. Therefore, it is not necessary to increase the packing density of the heat-expandable ceramic 6 when the filter 4 is inserted into the filter container 5a for the purpose of preventing the filter 4 from moving, so that the assembling efficiency is not deteriorated and the inserting operation is simple. Also, even if the rear lid 3
Since only the end face does not come into contact with the filter container 5a, it does not break, does not leak the exhaust gas, and the filter can be reused.

(Embodiment 2) FIG. 2 is a schematic sectional view showing an exhaust gas purifying apparatus for a diesel engine according to Embodiment 2 of the present invention. In FIG. 2, 1 is a main body container, 2 is a front lid, 3 is a rear lid, 4 is a filter, 6 is a heat-expandable ceramic, 7 is a heater, and 8 is an exhaust gas. Since these are the same as those described in the first embodiment, the same reference numerals are given and the description is omitted.

The filter container 5b is made of a corrosion-resistant metal such as stainless steel formed in a two-stage tapered shape, in which the sectional diameter in the axial direction gradually decreases from the front part to the middle part and from the middle part to the rear part. A flange is welded to the rear end of the container for attachment to the main body container 1, and is fastened to the main body container 1 via a gasket together with the rear lid 3 by a bolt or the like as shown in FIG. 1. . The filter 4 around which the heat-expandable ceramic 6 is wound is press-fitted into the filter container 5b.

When the filter 4 is inserted into the filter container 5b, first, the heat-expandable ceramic 6 formed in a band shape is wound around the filter 4 without gaps. At this time, the butted portion at the end of the heat-expandable ceramic 6 is formed in a stepped or uneven shape to prevent the exhaust gas 8 from leaking in the axial direction of the butted filter 4 so that they are combined. Thereafter, the filter 4 around which the heat-expandable ceramic 6 is wound is inserted under pressure from the front of the filter container 5b. The thickness of the heat-expandable ceramic 6 is thicker than the clearance between the filter 4 and the filter container 5b, and decreases with the insertion into the filter container 5b. It is determined so as to have a predetermined packing density. In pressurized insertion, a press or the like using hydraulic pressure is often used. According to the present embodiment, since the filter container 5b is formed into a tapered shape, the container itself serves as a guide for insertion and at the same time the frictional force gradually increases. Easy press fitting and efficient assembly. After the assembly is completed, a heat treatment is performed to expand the heat-expandable ceramic 6 to fix and seal the filter 4.

The function of the exhaust gas purifying method using the exhaust gas purifying apparatus configured as described above will be described. First, the exhaust gas 8 discharged from the diesel engine (not shown) flows in from the front cover 2 of the diesel exhaust gas purification device, passes through the filter 4 and flows out from the rear cover 3. The filter 4 has a large number of cells, and the cells are alternately closed on the inflow side and the outflow side of the exhaust gas 8 in the filter 4.
Pass through the cell wall and collect particulates in the exhaust gas 8 at that time. When particulates are trapped and accumulated to some extent in the filter 4, the heater 7 ignites and burns the particulates, and the regeneration of the filter 4 is carried out to recover the function, and the filter 4 is recovered and used repeatedly.

As described above, while the purification of the exhaust gas and the combustion regeneration are repeated, the filter 4 and the filter container 5b are fixed by the expansion of the heat-expandable ceramic 6.
And the frictional force resulting therefrom. The change in the temperature of the filter due to the heat of combustion of the particulates during combustion regeneration or the high temperature exhaust gas during operation of the diesel engine causes the filter 4 and the filter container 5b to have significantly different coefficients of thermal expansion. Since the expansion amounts are different from each other and the density of the heat-expandable ceramic 6 is changed, the fixing force between the filter 4 and the filter container 5b is reduced. For this reason, the filter 4 moves rearward due to an increase in the exhaust pressure accompanying the particulate accumulation on the filter 4.

At this time, the frictional force between the heat-expandable ceramic 6 and the filter 4 is larger than the frictional force between the overheat-expandable ceramic 6 and the filter container 5b due to the difference in surface roughness. Although the heat-expandable semi-rack 6 moves at the same time, according to the present embodiment, the cross-sectional diameter in the axial direction of the filter container 5b gradually decreases from the front part to the middle part and from the middle part to the rear part. In addition, since the inner diameter of the rear end of the filter container 5b is equal to or larger than the cross-sectional diameter of the filter 4 and smaller than the cross-sectional diameter of the filter including the overheat-expandable ceramic 6 wound around the filter 4, the filter is in the middle of movement. Filter 4 and filter container 5b
Because the gap of the heat-expandable ceramic 6 increases and the frictional force increases, the movement stops before reaching the rear lid 3.

Therefore, it is not necessary to increase the packing density of the heat-expandable ceramic 6 when the filter 4 is inserted into the filter container 5b for the purpose of preventing the filter 4 from moving. is there. In addition, since the end face of the filter 4 is in contact with the rear lid 3 even if it reaches the rear lid 3, the filter is not damaged, does not leak exhaust gas, and can be reused.

The inner diameter of the cross section of the filter container 5b gradually decreases from the front part to the middle part and from the middle part to the rear part. The inside diameter of the part can be set small. For this reason, there is also an effect that the outer diameter of the main body container 1 can be reduced and the size of the apparatus can be reduced.

(Embodiment 3) FIG. 3 is a schematic sectional view showing an exhaust gas purifying apparatus for a diesel engine according to Embodiment 3 of the present invention. 3, reference numeral 1 denotes a main body container, 2 denotes a front lid, 3 denotes a rear lid, 4 denotes a filter, 6 denotes a heat-expandable ceramic, 7 denotes a heater, and 8 denotes exhaust gas. Since these are the same as those described in the first embodiment, the same reference numerals are given and the description is omitted.

The filter container 5c is a corrosion-resistant metal container such as stainless steel formed in a tapered shape such that the cross-sectional inner diameter in the axial direction gradually decreases from the middle part to the rear part. A flange is welded for attachment to the main container 1 via a gasket together with the rear lid 3 as shown in FIG.
Are fastened by bolts or the like. The filter 4 around which the heat-expandable ceramic 6 is wound is press-fitted into the filter container 5b.

When the filter 4 is inserted into the filter container 5c, first, the heat-expandable ceramic 6 formed into a band shape is wound around the filter 4 without gaps. At this time, the butted portion at the end of the heat-expandable ceramic 6 is formed in a stepped or uneven shape to prevent the exhaust gas 8 from leaking in the axial direction of the butted filter 4 so that they are combined. Thereafter, the filter 4 around which the heat-expandable ceramic 6 is wound is inserted under pressure from the front of the filter container 5c. The thickness of the heat-expandable ceramic 6 is larger than the clearance between the filter 4 and the filter container 5c, and decreases with the insertion into the filter container 5c. It is determined so as to have a predetermined packing density. In pressurized insertion, a press or the like using hydraulic pressure is often used. After the assembly is completed, a heat treatment is performed to expand the heat-expandable ceramic 6 to fix and seal the filter 4.

The function of the exhaust gas purifying method using the exhaust gas purifying apparatus configured as described above will be described. First, the exhaust gas 8 discharged from the diesel engine (not shown) flows in from the front cover 2 of the diesel exhaust gas purification device, passes through the filter 4 and flows out from the rear cover 3. The filter 4 has a large number of cells, and the cells are alternately closed on the inflow side and the outflow side of the exhaust gas 8 in the filter 4.
Pass through the cell wall and collect particulates in the exhaust gas 8 at that time. When particulates are trapped and accumulated to some extent in the filter 4, the heater 7 ignites and burns the particulates, and the regeneration of the filter 4 is carried out to recover the function, and the filter 4 is recovered and used repeatedly.

As described above, while the purification of the exhaust gas and the combustion regeneration are repeated, the filter 4 and the filter container 5 c are fixed by the expansion of the heat-expandable ceramic 6.
And the frictional force resulting therefrom. The change in the temperature of the filter due to the heat of combustion of the particulates during combustion regeneration or the high temperature exhaust gas during operation of the diesel engine greatly differs in the thermal expansion coefficients of the filter 4 and the filter container 5c. Since the expansion amounts are different from each other and the density of the heat-expandable ceramic 6 is changed, the fixing force between the filter 4 and the filter container 5c is reduced. For this reason, the filter 4 moves rearward due to an increase in the exhaust pressure accompanying the particulate accumulation on the filter 4.

At this time, the frictional force between the heat-expandable ceramic 6 and the filter 4 is larger than the frictional force between the heat-expandable ceramic 6 and the filter container 5c due to the difference in surface roughness. Although the heat-expandable ceramic 6 moves at the same time, according to the present embodiment, the inner diameter of the cross section in the axial direction of the filter container 5c gradually decreases from the middle part to the rear part.
The rear end inner diameter of the filter container 5c is equal to or larger than the cross-sectional diameter of the filter 4 and smaller than the cross-sectional diameter of the filter including the heat-expandable ceramic 6 wound on the filter 4, so that the filter 4
Since the gap between the filter and the filter container 5c becomes smaller, the filling density of the heat-expandable ceramic 6 increases, and the frictional force increases, the movement stops before reaching the rear lid 3.

Therefore, it is not necessary to increase the packing density of the heat-expandable ceramic 6 when the filter 4 is inserted into the filter container 5c for the purpose of preventing the filter 4 from moving. is there. In addition, since the end face of the filter 4 is in contact with the rear lid 3 even if it comes to the rear lid 3, the filter is not damaged, does not leak the exhaust gas, and can be reused.

Since the inner diameter of the cross section of the filter container 5c gradually decreases from the middle to the rear,
The inner diameter of the front end portion can be set smaller than that of a continuous tapered shape from the front portion to the rear portion. For this reason, there is also an effect that the outer diameter of the main body container 1 can be reduced and the size of the apparatus can be reduced.

[0040]

As described above, according to the exhaust gas purifying apparatus of the present invention, the inner diameter of the rear end portion of the filter container housing the filter provided in the apparatus is equal to or larger than the cross-sectional diameter of the filter. Since the filter has a configuration smaller than the cross-sectional diameter of the filter including the wound heat-expandable ceramic, the advantageous effect that the filter can be prevented from being damaged due to contact with the filter container due to the movement of the filter during operation. Having.

The filter container for accommodating the filter provided in the apparatus has a tapered shape in which the cross-sectional inside diameter in the axial direction gradually decreases from the front part to the rear part, and is provided in the apparatus. The cross-sectional inner diameter in the axial direction of the filter container storing the filter gradually decreases from the front part to the middle part, and from the middle part to the rear part, and the reduction rate of the cross-sectional inner diameter from the front part to the middle part is from the middle part to the rear part. The filter is configured to be smaller than the reduction rate of the filter, so the filter can be inserted and assembled into the container efficiently, and the filter movement and breakage during operation can be prevented without lowering the assembly efficiency due to the increase in difficulty of assembly Has the advantageous effect of being able to

Further, since the inner diameter of the cross section in the axial direction of the filter container for accommodating the filter provided in the apparatus is gradually reduced from the middle part to the rear part, the assembling efficiency is increased due to an increase in difficulty of assembling. There is an advantageous effect that the filter movement and breakage during operation can be prevented without deterioration.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an exhaust gas purifying apparatus for a diesel engine according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view of an exhaust gas purifying apparatus for a diesel engine according to a second embodiment of the present invention.

FIG. 3 is a schematic sectional view of an exhaust gas purifying apparatus for a diesel engine according to a third embodiment of the present invention.

FIG. 4 is a schematic sectional view of a conventional exhaust gas purifying apparatus for a diesel engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1,101 Main body container 2,102 Front lid 3,103 Rear lid 4,104 Filter 5a, 5b, 5c, 105 Filter container 6,106 Heat-expandable ceramic 7,107 Heater 8,108 Exhaust gas 109 Stopper

Claims (5)

[Claims] 1. A cylindrical filter provided in an exhaust path of exhaust gas for passing the exhaust gas and collecting particulates and the like in the exhaust gas, and means for removing the particulates and the like attached to the cylindrical filter. In the exhaust gas purifying apparatus provided with, a rear end inner diameter of a filter container for accommodating the cylindrical filter provided in the apparatus is equal to or larger than a cross-sectional diameter of the cylindrical filter, and is wound around the cylindrical filter. An exhaust gas purifying apparatus having a diameter smaller than a cross-sectional diameter including the thermally expandable ceramic. 2. The exhaust gas purifying apparatus according to claim 1, wherein an inner diameter of a cross section in an axial direction of a filter container for accommodating the cylindrical filter provided in the device is tapered so as to gradually decrease from a front portion to a rear portion. The exhaust gas purifying apparatus according to claim 1, wherein 3. The exhaust gas purifying apparatus according to claim 1, wherein an inner diameter of a cross section in the axial direction of the filter container for accommodating the cylindrical filter provided in the device gradually decreases from a front part to a middle part and from a middle part to a rear part. 2. The exhaust gas purifying apparatus according to claim 1, wherein the reduction rate of the cross-sectional inner diameter from the front part to the middle part is smaller than the reduction rate from the middle part to the rear part. 4. The exhaust gas purifying apparatus according to claim 1, wherein an inner diameter of a cross section in an axial direction of a filter container for accommodating the cylindrical filter provided in the device gradually decreases from a middle part to a rear part. 2. The exhaust gas purifying apparatus according to claim 1. 5. An exhaust gas purifying apparatus provided with a filter means in an exhaust gas flow path, wherein an outer periphery of the filter means is wound around a packaging means having a different coefficient of thermal expansion from the filter means and stored in a storage container. An exhaust gas purifying apparatus, wherein the inner diameter of the flow path of the storage container on the source flow side is larger than the inner diameter of the flow path of the storage container on the downstream side.