JP2822821B2 - Filter regeneration device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for collecting and regenerating particulates discharged from exhaust gas of an internal combustion engine mounted on an automobile or the like, and more particularly, to a particulate used in the above device. And a support structure for a filter that collects air.

[0002]

2. Description of the Related Art With respect to global environmental protection, measures against global warming, that is, measures against CO2 reduction, have been greatly highlighted today, but measures against acid rain that causes deforestation cannot be ignored.

[0003] Acid rain is a natural phenomenon caused by air pollutants such as sulfur oxides and nitrogen oxides as a polluting source.
There is a trend to strengthen stationary sources such as generation and mobile sources such as automobiles.

[0004] In an internal combustion engine using light oil as a fuel, regulations on the emission of particulates have been strengthened simultaneously with the nitrogen oxides emitted from the internal combustion engine. In response to this tightening of regulations, it is considered impossible to achieve the exhaust gas regulation value only by conventional measures to reduce pollutants in exhaust gas by improving combustion such as delaying fuel injection timing. It is indispensable to attach a processing unit. This post-processing apparatus requires a filter for collecting particulates and the like.

If this filter continues to collect particulates, clogging occurs and the flow of exhaust gas deteriorates, leading to a decrease in engine output or an engine stop. As a solution to this problem, technology development for regenerating the trapping ability of the ceramic filter has been promoted, but securing a durable performance is a major practical problem.

[0006] It is known that particulates burn at about 600 ° C. As means for generating energy for raising particulates to this high temperature range,
A burner method, an electric heater method, a microwave method, and the like have been considered.

As a filter function reproducing apparatus using a microwave, there is, for example, JP-A-59-122022. FIG. 8 shows an apparatus disclosed in the publication. In the figure, 1 is an engine, 2 is an exhaust manifold,
Reference numeral 3 denotes an exhaust pipe, 4 denotes an exhaust branch pipe, 5 denotes a ceramics filter (hereinafter referred to as a filter) as a matrix, 6 denotes a heating chamber which is a storage section that stores and supports the filter 5, 7 denotes microwave generating means, and 8 denotes a micro-wave. A waveguide for guiding the microwave generated by the wave generating means 7 to the heating chamber 6, 9 is a microwave reflecting plate, 10 is an air pump, 11 is an air supply path, 12 is a driving power supply of the microwave generating means 7, and 13 is a driving power supply. Muffler, 14
Is an air switching valve, and 15 is an exhaust gas flow switching valve.

In the above configuration, the outer periphery of the filter 5 is housed and supported in the heating chamber away from the inner wall of the heating chamber 6. The space created by the inner wall of the heating chamber 6 and the outer periphery of the filter 5 is an air layer. Further, the exhaust gas of the engine is guided to the filter 5 by the exhaust gas flow switching valve 15 or directly discharged to the atmosphere. In the particulate collection cycle, the exhaust gas is guided to the filter 5 and the particulates contained in the exhaust gas are collected by the filter 5, but the collection capacity of the filter 5 is limited as described above. When the trapping capacity reaches the limit, the exhaust gas flow switching valve 15 is controlled, the exhaust gas to the exhaust pipe 3 is shut off, and all of the exhaust gas is exhausted to the atmosphere via the exhaust branch pipe 4.
During this time, the regeneration of the filter 5 is performed. In this filter regeneration cycle, energy for heating the particulates is supplied from the microwave generation means 7 and air required for combustion is supplied from the air pump 10 at the same time. When the filter regeneration is completed after a predetermined time, the exhaust gas flow switching valve 15
Is controlled again, and exhaust gas is guided to the filter 5. This cycle of collection and regeneration is repeated.

[0009]

However, there are the following problems when regenerating particulates collected by a filter used in the above-mentioned conventional filter regeneration apparatus for an internal combustion engine.

The first problem is caused by the incompatibility between the heat insulating performance of the storage portion for storing the filter and the heating performance of the particulates collected on the outer peripheral portion of the filter. That is, in the above-described conventional configuration (details of the configuration in the filter storage section are not shown), the outer periphery of the filter is separated from the heating chamber also serving as the filter storage, and the air acting as a heat insulating layer between the filter and the heating chamber is provided. The filter was supported in a configuration having a layer.

In order to improve the heat insulation performance of the air layer, it is necessary to reduce the thickness of the air layer to such an extent that convection does not occur in the air layer by bringing the outer peripheral portion of the filter close to the inner wall of the heating chamber. The vicinity of the inner wall of the heating chamber is where the microwave energy is the smallest, and if the outer periphery of the filter is too close to the inner wall of the heating chamber, the particulates collected near the outer periphery of the filter will not be sufficiently heated by the microwave to reach the combustible temperature. Not reach. Further, simply forming an air layer cannot prevent heat radiation from the outer peripheral portion of the filter.

In order to increase the microwave energy near the outer periphery of the filter, it is better to keep the outer periphery of the filter and the inner wall of the heating chamber apart, but the thickness of the air layer between the outer periphery of the filter and the inner wall of the heating chamber is large. If this is the case, satisfactory heat insulating performance cannot be obtained due to the convection of air in this layer.
Further, the heating chamber becomes unnecessarily large.

Therefore, it is not possible to achieve both the heat insulating performance of the air layer and the heating performance of the particulates collected on the outer peripheral portion of the filter, so that the heat of the outer peripheral portion of the filter is transferred to the heating chamber which also serves as the filter housing. Since it cannot be suppressed, and the vicinity of the outer periphery of the filter is not sufficiently heated by the microwave, the particulates collected near the outer periphery of the filter cannot reach the combustible temperature and remain unburned. For this reason, the particulates collected by the filter cannot be sufficiently regenerated.

The second problem is that, as described in the description of the first problem, the particulates collected near the outer periphery of the filter do not burn, so that the thermal stress generated by the temperature gradient generated in the inside and outside of the filter causes the filter to fail. Is mechanically damaged.

Another object of the present invention is to ensure the vibration resistance of the filter by using a heat-expandable, fire-resistant holding material used for supporting a three-way catalyst carrier of a gasoline vehicle. It is conceivable to provide the space between the heating chamber also serving as a housing and the outer peripheral portion of the filter. However, this holding material has no effective heat insulating performance, and the heat of the outer peripheral portion of the filter is transferred to the heating chamber via this holding material, and the particulates collected near the outer peripheral portion of the filter are It cannot reach the flammable temperature and causes unburned residue.

Further, it is conceivable to support the filter only with a heat insulating material having excellent heat insulating performance. However, since the heat insulating material does not have sufficient heat expandability, stable support of the filter cannot be obtained.

The present invention solves the above-mentioned problems, and provides an improved storage and support structure of a filter through which exhaust gas flows, which is used in a device for purifying exhaust gas discharged from an internal combustion engine, and stably supports the filter. It is another object of the present invention to provide a device which improves basic performance of a filter by improving a heat insulating effect and improves durability performance by relaxing a temperature gradient generated in the filter.

[0018]

The present invention SUMMARY OF] In order to achieve the above object, a filter for collecting particulates contained in exhaust gas of an internal combustion engine, a housing tube for housing the filter, the housing tube Generate microwaves to be fed
Microwave generating means, and filter supporting means having at least a two-layer structure for supporting the filter in the storage tube , wherein at least one layer of the filter supporting means is provided .
Contains microwave absorbing material.

The filter supporting means comprises a holding material and a heat insulating material, and at least one layer of the filter supporting means comprises a holding material and a heat insulating material.

A protection means is provided for isolating at least the end face of the filter support means on the upstream side in the exhaust gas flow direction from the exhaust gas.

[0021]

In the above construction, when the filter supporting means has at least a two-layer structure, it becomes an imperfect layer bonding area having a notable air layer area between the layers, thereby suppressing the heat transfer between the layers, and also providing each layer with itself. Also, by providing a means for suppressing heat transfer, the transfer of heat inside the filter to the storage pipe can be suppressed to a minimum, and heat can be accumulated inside the filter. The filter provided between the filter and the storage tube
At least one layer constituting the filter support means has a relative dielectric constant.
By containing large microwave absorbing material,
Increase the electrical length between the filter and the storage tube, and
The area near the part can be a space with high microwave energy
And store microwave energy in the filter support
Can be trapped near the outer periphery of the filter.
Strengthening collected particulates by microwave
It can be heated well.

At least one layer of the filter supporting means is composed of a holding material and a heat insulating material. However, it is difficult to wind the filter as a heat insulating material without a gap between the filter and the heat insulating material due to the interposition of the heat expandable holding material. Even when a heat insulating material is used, the gap between the layers, the filter, and the storage pipe can be eliminated to prevent the exhaust gas from flowing through the support means, and also prevent the filter from being displaced due to the exhaust gas pressure of the filter. it can.

The protection means provided at least on the end face of the filter support means on the upstream side in the exhaust gas flow direction allows at least the end face on the upstream side in the flow direction of the exhaust gas of the holding material or the heat insulating material constituting the filter support means to move away from the exhaust gas. Can be isolated and protected.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an enlarged view of a main part of FIG.

In FIG. 1, exhaust gas discharged from an internal combustion engine (not shown) is supplied to a front exhaust pipe 16 and a valve A1.
7. The fuel gas is led to the filter 20 through the auxiliary gas discharge pipe 18 and the front connection pipe 19.

In FIG. 2, a filter support means having a three-layer structure is formed between the storage tube 21 and the filter 20, and an inner layer is formed in a portion of the filter 20 facing the inner wall of the storage tube 21 so that the exhaust gas flows therethrough. The first holding member 22 is provided in the vicinity of both ends in the direction, and the first heat insulating member 23 is provided in a portion where the first holding member 22 is not provided. Holding member 22 and second heat insulating material 24 provided at the portion of first heat insulating material 23 facing the inner wall of storage tube 21.
The outer layer has a second holding member 25 provided near both ends in the direction of exhaust gas flow in a portion of the second heat insulating material 24 facing the inner wall of the storage tube 21. A closed space 26 acting as an air heat insulating layer is formed between the storage tube 21, the second heat insulating material 24, and the second holding material 25. Further, the first holding member 22 and the second
Protection means 28 are provided on both end surfaces 27 of the heat insulating material 24 and the second holding material 25 in the exhaust gas flow direction.

In FIG. 1, the exhaust gas flowing through the filter 20 and collecting particulates by the filter 20 is supplied to the power supply pipe 29, the rear connection pipe 30, the auxiliary combustion gas supply pipe 3, and the like.
1. The gas is discharged into the atmosphere through a valve B32 and a rear exhaust pipe 33.

The microwaves generated by the microwave generating means 34 (particulate heating means) are supplied to the microwave working space 36 through the waveguide 35. Front connection pipe 1
9, a front microwave shielding means 37 having a punching hole configuration or a honeycomb configuration on the exhaust gas inflow side, and a rear microwave shielding means having a punching hole configuration or a honeycomb configuration between the power supply pipe 29 and the rear connection pipe 30. Means 38 is provided, and the microwave working space 3 is provided between the front connection pipe 19, the filter housing pipe 21, the feed pipe 29, the front microwave shielding means 37 and the rear microwave shielding means 38.
6 are formed. This microwave causes the filter 20
The particles collected in the chamber are dielectrically heated.

A valve C39 is provided on the auxiliary gas discharge pipe 18, and a valve D41 is provided between the auxiliary gas supply means 40 and the auxiliary gas supply pipe 31. Filter 2
At the time of regeneration, the valve A17 is switched to discharge exhaust gas to the atmosphere through the bypass pipe 42 and the muffler 43.

Valve A17, valve B32, valve C3
9. The valve D41 is controlled as shown in FIG. 1 at the time of particulate collection, as shown in FIG. 3 at the time of particulate heating, and as shown in FIG.

Hereinafter, the operation of the apparatus will be described. The exhaust gas discharged from the internal combustion engine flows through the front exhaust pipe 16, flows into the filter 20, and flows through the rear exhaust pipe 32. At this time, the valves A17, B32, C39, and D41 are controlled as shown in FIG. Filter 2
0 is configured with a wall flow type honeycomb structure,
It has a function of collecting particulates contained in exhaust gas. When the amount of particulates collected by this filter increases, the pressure loss of the filter increases, the load on the engine as the internal combustion engine increases, and in the worst case, the engine stops.

Therefore, it is necessary to remove the particulates collected by the filter at an appropriate time. The means for determining the appropriate timing is based on the detection of the pressure drop level of the filter, the detection of the amount of trapped particulates by electrical means, or the integrated value of the operating state of the engine. The particulate matter trapped in the filter is removed by heating and burning. This process is called filter regeneration.

Next, the filter regeneration process will be described.
When the amount of particulates collected by the filter 20 reaches the collection area where the filter is to be regenerated, the filter regeneration process starts.

This reproduction control command is issued from a control unit (not shown). The valve A1 is controlled based on a command from the control unit.
7, valve B32, valve C39 and valve D41 are shown in FIG.
And the exhaust gas flowing into the filter 20 is shut off. When the internal combustion engine is operating, exhaust gas is guided to the bypass pipe 42. Further, a driving voltage is supplied to the microwave generating means 34. The microwave generated by the microwave generating means 34 is transmitted through the waveguide 35 and fed into the microwave working space 36 including the filter 20 therein. As a result, the particulates collected by the filter 20 are dielectrically heated, and the heated area extends to the inside of the filter 20. As time elapses, the combustible temperature sequentially increases from the particulate present near the end face of the filter 20 on the microwave incident side, but the microwave power supply is continued. When the flammable temperature is reached, the particulates in that region glow red and partially burn, but the steam rises due to lack of oxygen and the temperature rise saturates. With the continuation of the microwave power supply, the region where the temperature at which the particulates can be burned is expanded to about の of the filter 20. At this time, the inflow of exhaust gas and other gases into the microwave working space 36 is almost completely blocked, so that the microwave-heated particulates efficiently rise in temperature toward the combustible temperature.

Thereafter, valve A17, valve B32,
The valve C39 and the valve D41 are controlled as shown in FIG.
The operation of the assisting gas supply means 40 is started. As a result, the auxiliary combustion gas containing oxygen is supplied to the filter 20 from the outside, and the high-temperature particulates in the filter 20 shift to the combustion state. The particulate combustion region expands toward the outer periphery of the filter while moving in the gas flow direction, and after an appropriate time, the particulates in almost the entire area of the filter 20 are burned and removed.

The operation of the microwave generating means 34 and the auxiliary gas supply means 40 is stopped, and the valves A17, B32, C39 and D41 are controlled again as shown in FIG. I do. After that, the exhaust gas can flow into the filter 20 to collect the particulates.

FIG. 5 is a graph showing the relationship between the amount of particulates collected by the filter 20, the weight regeneration rate, and the maximum temperature inside the filter during particulate regeneration. The weight regeneration rate is the ratio of the weight of the burned particulates to the weight of the collected particulates. According to FIG. 5, when the amount of trapped particulates increases, the weight regeneration rate increases, but the maximum temperature also increases. In addition, when the trapped amount of particulates decreases, the maximum temperature decreases, but the weight regeneration rate also decreases. In the latter, the particulates collected in the vicinity of the outer periphery of the filter 20 are not sufficiently heated by the microwaves, and the heat at the time of heating the particulates and the heat at the time of the burning of the particulates escape from the outer periphery of the filter 20. Therefore, the temperature of the particulates collected near the outer periphery of the filter 20 cannot reach the combustible temperature, and the particulates do not burn.

For this reason, when the filter 20 is regenerated, the filter 20 must be regenerated in a region where a large amount of particulates can be collected to obtain a somewhat high weight regeneration rate (required of 70% or more). And the filter 20 is mechanically damaged. Also, if the regeneration is performed with the particulate collection amount having a relatively low maximum temperature, the weight regeneration rate is too low, and many particulates are not regenerated and remain unburned, and the filter 20 is clogged. As a method for solving this problem, it is conceivable to significantly lower the maximum temperature in the collection region where the weight regeneration rate is originally high without significantly decreasing the weight regeneration rate. Another solution is to increase the weight regeneration rate without increasing the maximum temperature in the trapping region where the maximum temperature is originally low. The present invention belongs to the latter.

The method of supporting the filter 20 in the exhaust pipe can be roughly classified into a supporting method using a metal spring or the like and a supporting method using a holding material. When the filter is made of a material such as ceramics, direct joining between the filter and the metal has a high risk of causing mechanical damage to the filter due to a large difference in thermal expansion. For this reason, a method using a holding material is suitable for supporting the filter 20.
In the application field to which the present invention belongs, a ceramic mat having heat expansion properties is used as the holding material. It is conceivable that only such a holding material is provided between the outer peripheral portion of the filter 20 and the storage tube 21. However, in general, the heat-expandable mat (holding material) does not have sufficient heat insulating performance (typical heat expansion). The thermal conductivity of the mat is in the temperature range 2
0.2 to 0.43 kcal at 00 to 600 ° C
/ Mh ° C), and did not have satisfactory heat insulating performance for the purpose of the present invention, and the weight regeneration rate could not be increased. On the other hand, only a heat insulating material having an excellent heat insulating effect
Although it is conceivable to provide the heat insulating material between the outer peripheral portion and the storage tube 21, such a heat insulating material generally does not have a sufficient heat expandability, and the holding power of the filter 20 alone is not sufficient. Stable filter support cannot be obtained. When only a part of the heat insulating material 44 is wound around the entire outer peripheral portion of the filter 20, a depression 45 is formed as shown in FIG. 6, and even when the protection means 28 is provided, the depression 45 and the outer peripheral portion of the filter 20 or the storage tube are not provided. Exhaust gas leaks from the gap between the exhaust gas 21 and the exhaust gas.

The present inventors have proposed that the storage tube 21 and the filter 20
To constitute a filter support means having a three-layer structure,
First holding material 22 and second holding material 2 having heat expansion property
5, the first effect of the present embodiment is as follows.
The stable retention of the filter 20 was able to be obtained using the heat expansion property. As a second effect of this embodiment, even when the heat insulating material is double-wound, the expansion of the first and second holding means having heat expandability as shown in FIG. It is possible to eliminate a gap between the portion and the storage tube 21 to prevent leakage of exhaust gas from that portion.

Some commercially available heat insulating materials have a thermal conductivity lower than that of still air. Such an excellent heat insulating material is used for the first heat insulating material 23 and the second heat insulating material.
It is more effective when used as a heat insulating material 24. By forming a space portion 26 to the extent that convection does not occur and acting as an air heat insulating layer and combining the first and second heat insulating materials 23 and 24 to form a three-layer heat insulating structure, heat inside the filter 20 is reduced. Transmission to the storage tube 21 is minimized,
In particular, it is possible to prevent the temperature of the particulates collected near the outer peripheral portion of the filter 20 from decreasing. Further, by forming the filter supporting means in a multilayer structure, the clearance between the filter 20 and the storage tube 21 is increased, so that the vicinity of the outer periphery of the filter 20 can be arranged in a space where microwave energy is strong, and the collection near the outer periphery of the filter 20 is performed. The particulates thus burned can be more effectively heated by the microwaves and burned. Thus, the third embodiment of the present invention
As a result, the weight regeneration rate can be improved without increasing the maximum temperature inside the filter during particulate regeneration. Further, as a fourth effect of the present embodiment, the occurrence of cracks in the filter 20 can be prevented by relaxing the temperature gradient inside and outside the filter 20.

Further, the protection means 28 is provided on both end surfaces 27 of the first holding member 22, the second heat insulating member 24, and the second holding member 25 in the exhaust gas flow direction. As a fifth effect, leakage of exhaust gas can be more completely prevented, and as a sixth effect of the present embodiment, the performance of the holding material and the heat insulating material due to particulates or other substances contained in the exhaust gas. Deterioration can be prevented. Further, as a seventh effect of the present embodiment, displacement of the filter 20 due to exhaust gas, vibration, or the like can be completely prevented.

By selecting a material having a large relative dielectric constant of the heat insulating material, the equivalent thickness of the heat insulating material as viewed from the microwave increases. By utilizing this function, the clearance between the filter 20 and the storage tube 21 can be increased without increasing the actual thickness of the heat insulating material.

As a heat insulating material of this kind, a material containing a microwave absorbing material (for example, titanium oxide (TiO 2)) can be used.

In FIG. 5, the support structure of the filter is as follows.
Between the outer periphery of the filter 20 and the storage tube 21, there is a holding material having a thermal expansion property (the thermal conductivity is from
0.2 to 0.43 Kcal / mh ° C at 00 ° C)
The performance by the configuration using only the point A (the performance by the conventional configuration in which only the air layer is insulated is not shown in FIG. 5 but the weight regeneration rate is lower than that of the point A), the performance by the configuration according to the present invention. Is point B. Collection amount is 6.3g / l
In the case of, the weight regeneration rate is greatly improved from 42% to 65% by the configuration of the present invention. On the other hand, the maximum temperature inside the filter rose from 660 ° C to 680 ° C. With the support structure of the present invention, it is possible to combust particulates collected near the outer periphery of the filter 20 while suppressing a rise in the maximum temperature. In the case where collection and regeneration are repeated, if the weight regeneration rate in the first regeneration is about 70%, the newly collected particulates will be approximately 1 after the second regeneration.
The maximum temperature was about 100 ° C. higher than the first maximum temperature. This allows filter 2
At a temperature (900 ° C.) or lower at which cracks occur at 0, without causing cracks in the filter 20;
The stable regeneration of the filter 20 can be performed.

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 8 differs from the above-described embodiment in that the second holding member is omitted and the filter supporting means has a two-layer structure. In the case where a heat insulating material which does not form a depression even when wound in a cylindrical shape is used, a configuration as shown in FIG. 7 can be adopted.
In this case, by increasing the thickness of each layer, the same heat insulation performance as in the previous embodiment can be provided.

It is to be noted that, of the first holding members 22, those on the downstream side of the exhaust gas can be omitted. In this case, it is better to provide the first heat insulating material in a portion where the holding material is omitted.

Further, a second holding member may be provided so as to eliminate the space 26, and more stable support of the filter 20 can be obtained.

Further, a third heat insulating material may be newly provided in the space 26. The heat insulation effect is further enhanced, and the weight regeneration rate can be increased.

Further, the first heat insulating material 23 may be omitted, and a closed space (air heat insulating layer) may be formed by the filter 20, the first support member 22, and the second heat insulating material 24. Good.

When the heat insulating materials are integrally formed, the work of providing the heat insulating material on the filter 20 can be performed more easily.

In the case of a heat insulating material which does not contain a microwave absorbing material, a microwave absorbing material such as titanium oxide (TiO 2) may be applied to the heat insulating material, or silicon carbide (S) may be used.
A material having a large dielectric loss such as iC) may be applied to the heat insulating material to generate heat.

The structure of the means for transmitting microwaves to the microwave working space is not limited to the embodiment of the present invention, and for example, a coaxial transmission line can be used.

Further, as a means for heating the particulates, a microwave generation means has been described as an example, but the heating means may be, for example, an electric heater, a burner or the like.

The structure of the protection means for protecting the support means is not limited to the embodiment of the present invention. For example, the protection means and the storage tube may be integrated.

[0056]

As described above, according to the filter regeneration device for an internal combustion engine of the present invention, the following effects can be obtained.

(1) By forming the filter support means in at least a two-layer structure, an imperfect layer bonding area having a notable air layer area between the layers is formed, thereby suppressing heat transfer between the layers. Also, by providing a means for suppressing heat transfer, the transfer of heat inside the filter to the storage pipe can be suppressed to a minimum, and heat can be accumulated inside the filter. The filter provided between the filter and the storage tube
At least one layer constituting the support means has a large relative dielectric constant.
Filter by using a microwave absorbing material
Increase the electrical length between the filter and the storage tube, and
It can be a space with high microwave energy beside
And store microwave energy in the filter support
So that it can be collected near the outer periphery of the filter.
The applied particulates by microwave
Can be heated.

(2) Since at least one layer of the filter supporting means is composed of a holding material and a heat insulating material, a heat insulating material which is difficult to be wound without a gap between the filter and the heat insulating material as a heat insulating material due to the interposition of the holding material. Even when it is used, by using a holding material having a thermal expansion property, the gap between the layers, the layer, the filter, and the storage pipe is eliminated to prevent the exhaust gas from flowing through the support means portion, and at the same time, by the exhaust gas pressure of the filter. The displacement of the filter can be prevented.

(3) Exhaust gas is allowed to flow through the filter by a protecting means provided so as to isolate at least the end face of the holding member or the heat insulating material constituting the filter supporting means on the upstream side in the flowing direction of the exhaust gas from the exhaust gas. Leakage can be more completely prevented, and at the same time, the performance degradation of the holding material or the heat insulating material due to the particulates contained in the exhaust gas or other substances can be prevented,
Further, the displacement of the filter due to exhaust gas, vibration, or the like can be completely prevented.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a filter regeneration device for an internal combustion engine showing one embodiment of the present invention.

FIG. 2 is an enlarged configuration diagram of a main part of FIG. 1;

FIG. 3 is a configuration diagram of a filter regeneration device for an internal combustion engine showing one embodiment of the present invention.

FIG. 4 is a configuration diagram of a filter regeneration device for an internal combustion engine showing one embodiment of the present invention.

FIG. 5 is a filter regeneration characteristic diagram obtained according to an embodiment of the present invention.

FIG. 6 is a diagram showing a problem when the configuration of one embodiment of the present invention is not used.

FIG. 7 is a sectional view taken along line AA of FIG. 2;

FIG. 8 is an enlarged view of a main part of a filter regeneration device for an internal combustion engine showing another embodiment of the present invention.

FIG. 9 is a configuration diagram of a conventional filter regeneration device for an internal combustion engine.

[Explanation of symbols]

 Reference Signs List 20 filter 21 storage tube 22 first holding material 23 first heat insulating material 24 second heat insulating material 25 second holding material 28 protective means 34 microwave generating means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-126022 (JP, A) Japanese Utility Model Application 1-69112 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F01N 3/02 301-321

Claims (3)

(57) [Claims] 1. A filter for collecting particulates contained in exhaust gas of an internal combustion engine, a storage pipe for storing the filter, and a microwave for supplying power to the storage pipe.
Microwave generating means for generating, and filter supporting means having at least a two-layer structure for supporting the filter in the storage tube , wherein at least one of the filter supporting means is provided .
A filter regeneration device for an internal combustion engine whose layer contains a microwave absorbing material . 2. The filter regeneration device for an internal combustion engine according to claim 1, wherein said filter support means is constituted by a holding material and a heat insulating material, and at least one layer of said filter supporting means is constituted by a holding material and a heat insulating material. 3. The exhaust gas passage of at least the filter support means.
Protective means to isolate the end face on the upstream side in the flow direction from exhaust gas
The filter regeneration device for an internal combustion engine according to claim 1 or 2, further comprising: