DE19538810C2 - Exhaust Particle Oxidation Device - Google Patents

Description

The invention relates to an exhaust gas particle oxidation device for combustion Mung motor, comprising: a filter housing for arrangement in an exhaust passage of the internal combustion engine, a filter element which is arranged in the filter housing, to filter out particles from the exhaust gas emitted by the internal combustion engine tern, a switchable heating element for heating and burning the filtered out Particles for regeneration of the filter element, the filter housing an Ab gas inflow space on the upstream side of the filter element in the exhaust gas streams direction and an exhaust gas outflow space on the downstream side of the filter element in the exhaust gas flow direction.

So far, there are many different exhaust particle treatments directions have been proposed and used in practice come to ver from the point of view of environmental protection prevent particles (suspended particles) such as wise soot contained in exhaust gas from an internal combustion engine are expelled into the ambient air. More in one The engine is isolated on its exhaust system with an exhaust gas particle treatment device provided, which a Fil formed of a ceramic material or the like terelement, and in which exhaust gas through the filter element is passed so that particles in the exhaust gas be filtered or captured by the filter element.

When using such a particle treatment for a long time The captured particles are directed towards and in the fil terelement accumulated, and therefore the filter element comes in a constipated state and develops a high flow resistance in an exhaust gas passage, in which the Particle treatment device is arranged, whereby the  Exhaust gas back pressure of the engine is increased. Consequently, that will be Performance and fuel economy of the engine worsened. This has usually been done to heat and burn the captured particles using a heater such as a heating element or a burner, whereby the filter element is regenerated.

However, there are difficulties in such a conventional one result in exhaust gas particle treatment device in the an insufficient amount of air (oxygen) in the particle particles action device is supplied or present in it is so that the combustion of the particles is insufficient where ver through the regeneration efficiency of the filter element gets worse.

An exhaust gas particle oxidation device of the type mentioned at the outset is known from DE A1-35 38 155 known. This discloses a process for removing soot particles from a filter through the temporary supply of secondary energy. The essential The teaching is to bring the concentration of the particles to a value within the To increase the ignition limits of a particle-exhaust gas mixture. For this, the on the Filters deposited particles whirled up by the exhaust gas for a short period of time is blown back with the help of compressed air or compressed air, which is why Pressure source is required. Furthermore, DE-A1-35 38 155 teaches the supply of Compressed air upstream of the filter near a heating element, which in turn a compressed air source is required. Instead of a separate compressed air source, there can be after charge air can also be used. Chargers are usually over-atmospheric creates spherical pressure.

As an alternative to the idea of whirling up the particles using compressed air, DE-A1-35 38 155 further proposed the whirling up with the help of vibrations by egg to bring about a suitable vibration generator.  

All of these measures to whirl up the particles require auxiliary units for example a compressed air generator, a charger or a vibration generator, which are based on the supply of additional energy. These solutions are technical complex and affect the freedom of design due to their space requirements of an exhaust system with an oxidation filter.

Furthermore, DE-A-37 11 101 is a catalytic oxidation process in one Particulate filter known, in which secondary air is blown. According to DE-A-37 11 101, the filter temperature is kept at a high level in order to maintain a continuous to allow the particles to burn off. To the filter on a sufficient Maintaining temperature is described in DE-A-37 11 101 upstream of the filter with the aid of a Blown in additional air.

Furthermore, EP-A-0 244 061 discloses an intermittent and direct filter to heat, but here too, additional air is supplied by a compressor or another suitable air or oxygen source supplied.

In contrast, the invention is based on the object of To improve the oxidation device of the type mentioned, such that a sufficient air supply to burn off soot particles deposited in a filter is guaranteed for regeneration of the filter in a particularly simple manner.

This object is achieved in the exhaust gas particle oxidation device mentioned at the beginning solved in that an air inlet device is provided on the filter housing hen is for the effective introduction of air into the filter housing through natural con vention inside the filter housing during the combustion of the filtered out Particle is generated during the regeneration of the filter element.

Through the targeted use of convection in the area of the filter housing, Start of the combustion of the filtered particles in a regeneration phase the combustion itself creates a sufficient train through which the required Combustion air (or oxygen) is sucked in. There are no additional Auxiliary units or auxiliary lines are required in the area of the exhaust system.  

In such an exhaust gas particle oxidation device, hereinafter also the exhaust part Chen treatment device is called if the regeneration of the filter element when the Motor activity is carried out by natural convection Air inside the filter housing develops under the we combusted gas generated in the housing. Under Ver Using this natural convection, air becomes effective in the filter housing initiated so that they around the Filterele ment is fed around. In this way, air to the Re generation can be effectively fed to the burning of the in to promote particles collected in the filter element. Hence can effectively keep the particles burning avoiding an interruption in the burning, without a complicated air introduction device such as assign a motor-driven air pump or the like turn.

In the following the invention based on the embodiment shown in the drawing examples described in more detail, with the same reference numerals in all figures the same Identify parts and elements. The drawing shows:  

Fig. 1 is a schematic sectional view of a first example of a first embodiment of an exhaust gas particle treatment device;

Fig. 2 is a schematic sectional view of a modified example of the first example of Fig. 1;

Fig. 3 is a schematic sectional view of a second example of the first embodiment of the exhaust gas chen treatment device;

Fig. 4 is a schematic sectional view of a modified example of the second example of Fig. 3;

Fig. 5 is a schematic sectional view of another modified example of the second example of Fig. 3;

Fig. 6 is a schematic sectional view of a third example of the first embodiment of the exhaust gas chen treatment device;

Fig. 7 is a schematic sectional view of a modified example of the third example of Fig. 6;

Fig. 8 is a schematic sectional view of another modified example of the third example of Fig. 6;

Fig. 9 is a schematic sectional view of a fourth case of the game to the first embodiment of the exhaust part chen-treatment apparatus;

Fig. 10 is a schematic sectional view of a modified example of the fourth example of Fig. 9;

Fig. 11 is a schematic sectional view of another modified example of the fourth example of Fig. 9;

Fig. 12 is a schematic sectional view of another modified example of the fourth example of Fig. 9;

FIG. 13 is a schematic sectional view of another modified example of the fourth example of FIG. 9;

Fig. 14 is a schematic sectional view of another modified example of the fourth example of Fig. 9;

Fig. 15 is a schematic sectional view of another modified example of the fourth example of Fig. 9;

FIG. 16 is a schematic sectional view of a first case of the game to a second embodiment of the exhaust part of chen-treatment apparatus;

Fig. 17 is a section in the direction of arrows substantially along the line 17-17 of Fig. 16;

FIG. 18 is a flowchart of a control for power supply to electrical heating elements in the Abgasteilchen- treatment apparatus of FIG. 16 and 17;

Fig. 19 is a diagram of a temperature characteristic of filters in a conventional exhaust particle treatment device;

FIG. 20 is a diagram showing a temperature characteristic of filters in the exhaust particulate treatment apparatus of FIG. 16 and 17;

FIG. 21 is a schematic sectional view of a second case of the game of the second embodiment of the exhaust part chen-treatment apparatus;

Fig. 22 is a vertical sectional view of a filter element (with heating elements) of the exhaust particle treatment device of Fig. 21;

Fig. 23 is a flowchart of control for electric power supply to the heating elements of the exhaust particle treatment device of Figs. 21 and 22;

Fig. 24 is a schematic sectional view of a third embodiment of the exhaust particle treatment device;

Fig. 25 is a section in the direction of arrows substantially along the line 25-25 of Fig. 24; and

Fig. 26 is a flowchart of a control for power supply to electrical heating elements in the Abgasteilchen- treatment apparatus of FIG. 24 and 25.

In FIGS. 1 to 16, a first example is an exhaust particulate-treating device shown by numeral P. A first example of the first embodiment is discussed with reference to FIG. 1. A filter housing 102 is arranged in an exhaust passage 101 , which is connected to a manifold (not shown) of an internal combustion engine. In this example, the filter housing 102 is arranged generally horizontally and has a generally cylindrical portion (no reference number), the axis of which extends generally horizontally. A cylindrical and hollow filter element 104 is arranged in the housing 102 . The filter element 104 is porous and is formed from a heat-resistant filter material such as ceramic fiber, ceramic porous material including ceramic foam (ceramic foam), metallic porous material including metal foam (foam metal), and glass wool. The filter housing 102 is manufactured by shaping the heat-resistant filter material into a cylindrical shape. The filter element 104 can be produced as a monolith from the heat-resistant filter material.

A heater 105 is formed into a generally cylindrical shape and is porous to allow exhaust gas from the engine to flow through the heater 105 . The heating element 105 is arranged along the inner peripheral surface of the cylindrical filter element 104 . In this context, the filter element 104 can be formed by wrapping the sheet-shaped heat-resistant filter material around the heating element 105 . The heating element 105 is made of stainless steel or an electrical heating element material of the Fe-Cr-Al system or the Ni-Cr-Fe system.

An electrode 105 a is electrically connected to a metallic end part 105 b, which in turn is electrically connected to the heating element 105 and the downstream end section 104 b of the cylindrical filter element 104 tightly closes. The end part 105 b is formed from a sheet metal or the like. The electrode 105 a is electrically insulated from the filter housing 102 and protrudes from the filter housing 102 in front. The end part 105 b is generally bowl-shaped and is attached to its outer peripheral surface on the inner circumferential surface of a downstream end portion (including the end portion 104 b) of the cylindrical filter element 104 . A metallic annular Ab gas inlet part 105 c is arranged sealingly between the filter housing 102 and the filter element 104 . From the gas inlet part 105 c is formed from a sheet or the like. Specifically, the outer peripheral portion of the exhaust gas introduction part 105 c is fixedly attached to the inner peripheral surface of the filter housing 102 , while the inner peripheral portion of the exhaust gas introduction part 105 c is fixedly connected to the inner peripheral surface of an upstream end portion (including a current end 104 a) of the filter element 104 .

In this way, a combined body of the filter element 104 , the end part 105 b and the exhaust gas inlet part 105 c defines an exhaust gas inflow space S1 which communicates with an exhaust gas inlet 102 a, and an exhaust gas outflow space S2 which has an exhaust gas outlet 102 b is connected. The exhaust gas inlet 102 a is in communication with the exhaust gas passage 101 . The exhaust gas outlet 102 b is connected to an exhaust pipe 103 . Accordingly, exhaust gas introduced into the gas inflow space S1 flows through the filter element 104 to the exhaust gas outflow space S2 and then flows through the exhaust pipe 103 to be discharged into the atmosphere or ambient air. As the exhaust gas flows through the filter element 104 , particulate matter in the exhaust gas is filtered or trapped by the filter element 104 . The heating element 105 functions to be heated upon supply of electric current, thereby burning the trapped particles on and in the filter element 104 . Electric current is supplied to the heating element 105 through the electrode 105 a. It goes without saying that the electrode 105 a is electrically connected via the heating element 105 to the exhaust gas introduction part 105 c, which is grounded via the filter housing 102 .

An exhaust gas pressure sensor 111 is built into the filter housing 102 and is arranged such that it projects into the exhaust gas inflow space S1 upstream of the filter element 104 in order to sample an exhaust gas pressure in the space S1. The exhaust gas pressure sensor 111 forms part of a filter regeneration time determination device (no reference number) for determining a point in time at which regeneration of the filter element 104 is required. More specifically, the filter regeneration time determining device serves to determine a pressure (in the space S1) which represents a clogged state of the filter element 104 , which is closely related to reaching the point in time at which regeneration of the filter element 104 is required.

A heater driver 106 is rationszeitgeber- for vorgese hen to control the heating element 105, and includes a Regene and relay or control circuit 106 a, through which the exhaust pressure sensor 111 is electrically connected with a regeneration b warning lamp 106th The electrode 105 a is also electrically connected via the circuit 106 a with a battery BT. A regeneration switch 106 c is electrically connected to the circuit 106 a.

In this heater driver 106, and the exhaust gas pressure sensor 111, when the sensed by the exhaust pressure sensor 111 pressure does not reach a value below a predetermined level, it is judged that the time has come, in which a regeneration of the filter element is required 104 so that the circuit 106 operates to turn on the regeneration warning lamp 106 b. Then turns Bedie voltage man or the like while seeing the illuminated Rege nerationswarnlampe 106 b the regeneration switch 106 c a, thereby allowing electrical current from the bat tery BT flows through the circuit 106 a to the electrode 105 a. It goes without saying that the circuit 106 a can be arranged in such a way that when the pressure sensed by the exhaust pressure sensor 111 does not reach the value below the predetermined value, the electric current from the battery BT through the circuit 106 a flows to the electrode 105 a.

In this example, the filter housing 102 is provided with a connection hole or passage 107 through which the exhaust gas outflow space S2 communicates with the atmosphere or ambient air. The connection hole 107 is formed through the wall of the cylindrical portion of the filter housing 102 . The connection hole 107 is located near the exhaust gas line part 105 c and upstream of the exhaust outlet 102 b of the filter housing 102 . It should be noted that the connection hole 107 is positioned near a lower portion (not identified) of the filter element 104 and located at the bottom part of the cylindrical portion of the filter case 102 in a state of FIG. 1 in which the filter case 102 is generally arranged horizontally. It is understood that the exhaust gas outlet 102 b or the exhaust pipe 103 also serves as a communication hole or passage (such as the communication hole 107 ) through which the exhaust gas outflow space S2 communicates with the ambient air.

Although the filter element 104 has been shown as cylindrical and has been described, it will be understood that it suffices that the filter element is hollow, and therefore it is not limited to the cylindrical shape.

Although the single filter element 104 has been shown and described arranged in the filter housing 102 , it is clear that a plurality of filter elements arranged in parallel or aligned in the filter housing 102 can be arranged.

The following is the operation of the first example of Exhaust particle treatment device P according to the above arrangement described.

In order to trap exhaust gas particles through the filter element 104 , exhaust gas flows into the exhaust gas inflow space S1 and reaches the inside of the cylindrical filter element 104 . Then, the exhaust gas flows through the filter element 104 and flows into the exhaust gas outflow space S2. During the passage of gas from the filter element 104 particles are filtered or trapped by this exhaust gas. After that, the exhaust gas flows through the exhaust gas outlet 102 b of the filter housing 102 and is introduced into the exhaust gas exhaust pipe 103 to be discharged into the ambient air.

If the time has come, in which a regeneration of the filter element is required 104, the engine operation is to adjust the heater driver conducts be 106 to cause so that electrical current from the battery BT through the Regenerationszeitgeber- and -Relaisschaltung 106 a flows to the electrode 105 a. Then electric current flows to the heating element 105 during a regeneration time (e.g. 10 minutes), which is set by a timer in the circuit 106 a. From the point of view of the electrical energy saving and the durability of the filter element 104 and the heating element 105 , it is preferable to set the regeneration time to a period of time which has previously been confirmed by experiments or the like.

When electrical current passes through the heating element 105 , this generates heat to ignite and burn the exhaust gas particles accumulated on and in the filter element 104 . In this example, the heating element 105 is in contact with the inner peripheral surface of the filter element 104 , and therefore the combustion basically spreads from the inner peripheral side to the outer peripheral side of the filter element 104 . In addition, the combustion does not spread in the axial direction of the cylindrical filter element 104 , since the heating element 105 extends over the entire length of the filter element 104 and is in contact with it. During the combustion of the exhaust gas particles, air is allowed to flow through the communication hole 107 into the exhaust gas outflow space S2 to assist the combustion of the exhaust gas particles.

In this connection, the function and the effect of the connection hole 107 will be discussed.

• a) The communication hole 107 is provided in order to burn the exhaust gas particles accumulated on and in the filter element 104 (that is, to regenerate the exhaust gas particles) under the effect of natural convection, in which heated air rises.
• b) More specifically, when natural convection of air near the filter element 104 occurs during combustion of the exhaust gas particles, heated air rises within the filter housing 102 , which leads to the introduction of ambient air to the inside of the filter housing 102 through the communication hole 107 and to a downward movement of cold air, which was not used in the combustion of the exhaust gas particles. So a convection of air is generated near the Filterele element 104 , so that ambient air from the outside of the filter housing 102 through the connection hole 107 is supplied to the corresponding parts of the filter element 104 , while the air which has not been used also the corresponding one Parts of the filter element 104 is supplied.
• c) In this way, ambient air outside the filter housing 102 and the unused air serve as the air for regeneration of the filter element 104 . Accordingly, the exhaust gas particles accumulated on and in the filter element 104 can be effectively burned out without equipping the exhaust gas particle treatment device P with an air pump or the like.

While there has been only the sole connection hole 107 housing in the Filterge 102 shown embodied and described, a plurality of communication holes 107 may be formed so that they are arranged along the axis of the filter housing 102 disposed on or of the filter housing 102 in the circumferential direction of the cylindrical portion are.

FIG. 2 shows a modified example of the exhaust particle treatment device P of FIG. 1, which is the same as that of FIG. 1, except that the filter housing 102 with the filter element 104 is positioned generally vertically. In this example, a plurality of communication holes may be formed to be arranged in the circumferential direction of the cylindrical portion of the filter case 102 and to be located at a low level of the filter case 102 , as indicated by a broken line, because of the possibility of rain water or The like through the communication hole 107 is small compared to the case of FIG. 1 in which the filter housing 102 is generally horizontal. This can further promote the natural convection of air through the inside of the filter housing 102 and around the filter element 104 , whereby the regeneration process of the filter element 104 is achieved more effectively. In this example, a flap 107 a can be provided, as indicated by a broken line, in order to prevent rain water or the like from penetrating through the connection hole 107 into the filter housing 102 .

Thus, according to the examples of FIGS. 1 and 2, when the filter element 104 is regenerated when the engine operation is stopped, natural convection of air is generated around the filter element 104 under the action of heated air. The heated air rises within the filter housing 102 , and part of the heated air is discharged from the exhaust pipe 103 . As a result, low temperature air which has not yet been used to burn exhaust particles is supplied around the filter element 104 for use in burning the exhaust particles, accompanying the inflow of ambient air through the communication hole or holes 107 . Thus, air for regeneration of the filter element 104 can be effectively supplied to the inside of the filter housing 102 , whereby the combustion of exhaust gas particles is constantly achieved without causing an interruption in the combustion of exhaust gas particles. This further improves the regeneration efficiency of the filter element 104 of the gas particle treatment device P.

Fig. 3 shows a second example of the first embodiment of the exhaust particle treatment device P, which he is the first example of Fig. 1 similar to the exception that a further communication hole or a passage 108 additional Lich through the wall of the cylindrical portion of the filter housing 102 is formed and is located near the exhaust outlet 102 b of the filter housing 102 . More specifically, the communication hole 108 is positioned on the opposite side of the axis of the filter housing 102 relative to the communication hole 107 , that is, on the upper side of the cylindrical portion of the filter housing 102 .

The function and the effect of the connection hole 108 are described.

• a) In order to improve the effect of natural convection during the regeneration of the filter element 104 beyond the effect in the first example, heated air is to be emitted directly from the filter housing 102 , whereby the introduction of ambient air is promoted through the connection hole 107 . In other words, a regeneration-improving effect due to natural convection of air can be expected to some extent, even with the single communication hole 107 as in the first example. If air with low oxygen concentration that has already been used in the combustion can be effectively discharged from the housing 102 (for example, if a flow resistance of air in the exhaust passage 101 is high, or if a muffler (not shown) or the like Chen is arranged in the exhaust gas discharge channel downstream of the filter housing 102 ), however, there is a tendency that only the air of low oxygen concentration, which has already been used, remains in the filter housing 102 , whereby the regeneration effect of the filter element 102 is deteriorated. In order to avoid the above disadvantage from occurring, the low oxygen concentration air which has already been used is definitely discharged through the communication hole 108 at the top, while fresh ambient air is to be introduced through the communication hole 107 on the lower side, whereby the Regeneration effect of the filter element 104 is improved.
• b) The connection hole 107 at the top is located on an upstream side (near the front end) of the filter housing 102 , while the top connection hole 108 is located near the exhaust gas outlet 102 b (near the rear end) of the filter housing 102 . Accordingly, air for regeneration can be supplied evenly through the entire filter element 104 , whereby the filter element 104 is effectively regenerated.

While the only underside and oberseiti gene connection holes 107 , 108 have been shown and described in Fig. 3, it is obvious that a plurality of connection holes or passages 107 , 107 A on the underside and / or a plurality of connection holes or passages 108 , 108 A the top can be used, for example as shown in FIG . In such a case, the natural convection of air can be further activated, whereby a large amount of air is evenly supplied through the whole filter element 104 , whereby it is regenerated effectively.

Fig. 5 shows a modified example of the exhaust particle treatment device P of Fig. 3. This example has a structure similar to that of Fig. 4, except that the communication holes 107 , 108 are omitted so that the communication hole 107 A is close to that rear end of the Filterge häuses is located 102, while the connecting hole is located near the front end 108 A of the filter housing 102nd It is understood that the same effects as those in the example of Fig. 3 can be obtained while making it possible to change a position at which high temperature burned gas is discharged from the inside of the filter case.

FIG. 6 shows a third example of the first embodiment of the exhaust particle treatment device P, which is similar to the first example of FIG. 1, except for the provision of a hollow cylindrical heat collecting sleeve 110 . More specifically, the collecting sleeve 110 is arranged coaxially around the filter element 104 such that the inner peripheral surface of the sleeve 110 has a predetermined distance from the outer peripheral surface of the filter element 104 . The heat collecting sleeve 110 is fixedly attached at its front end to the exhaust gas introduction part 105 c. Through holes 112 , 113 are formed in the heat collecting sleeve 110 , each of which coincides with the connection holes 107 , 108 of the filter housing 102 in the vertical direction. By virtue of the heat collecting sleeve 110 , heat generated during the regeneration of the filter element 105 is prevented from radiating to the outside and is therefore used effectively for the regeneration of the filter element 105 . In addition, natural convection can be effectively promoted, which further improves the regeneration of the filter element 104 .

While the through holes 112 , 113 have been shown and described in the heat-receiving sleeve 110 , it is understood that they can be omitted, in which case the effect of natural convection of air can be obtained to some extent. In addition, it is understood that the through holes 112 , 113 do not necessarily coincide with the connection holes 107 , 108 of the filter housing 102 in the vertical direction, in which case the positions of the through holes 112 , 113 are appropriately set, the result of regeneration experiments is taken into account.

It is evident that the heat collecting sleeve 110 can be used in the exhaust gas particle treatment device P of FIGS . 1 and 2, in which a regeneration-improving effect due to the radiant heat can be expected in addition to the effect due to natural convection of air. For example, in the case where the heat collecting sleeve 110 is applied in the example of FIG. 2, the exhaust particle treatment device P is configured as shown in FIG. 7, in which the through hole 112 is expanded while the through hole 113 is omitted. It is understood that even in the case where the heat collecting sleeve 110 is applied to the example of FIG. 1, a configuration similar to that of FIG. 7 is obtained by arranging the filter housing 102 with the filter element 104 generally horizontally, so that the connection hole 107 is positioned on the underside of the filter housing 102 .

Although the respective examples of the exhaust gas particle treatment device discussed above have been shown and described so that they are provided with the lower-side connection holes 107 , 107 A and the upper-side connection holes 108 , 108 a and the like, which are formed by forming through holes in the filter housing 102 are formed, it makes sense that a connecting pipe 114 for establishing a connection between the exhaust gas outflow space S2 and the ambient air can be used instead of the underside connecting hole 107 , 107 A, in which case a connecting pipe 115 indicated by a broken line instead of the top connection hole 108 , 108 A can be used. Such an arrangement of FIG. 8 certainly prevents rain water from entering the filter housing 102 , thereby preventing, for example, electrical discharge from occurring during the regeneration of the filter element 104 . In addition, the upper side connecting pipe 115 is generally L-shaped, and therefore the discharge direction of the burned gas from the inside of the filter housing 102 is suitably adjustable so that the discharge of the burned gas is not directed to a fuel tank (not shown) or the like.

FIGS. 9 through 15 show fourth examples of the first from the guide shape of the exhaust particulate treatment device P wel che the examples discussed above are similar except that the exhaust gas exhaust pipe is omitted 103, so that the exhaust gas from the filter housing 102. term by the untersei Connection hole 107 , 107 A and the top connec tion hole 108 , 108 a instead of the exhaust pipe 103 is pushed out. Such an arrangement of these examples leaves the exhaust pipe 103 downstream of the filter housing 102 and can improve the regeneration effect of the filter element 104 during regeneration.

The arrangements of FIGS. 9, 10 and 11 each correspond to the examples of FIGS. 4, 5 and 6 discussed above, where the exhaust pipe 103 is omitted.

The arrangement of FIG. 12 is similar to that of FIG. 11, except that through holes 112 , 113 are enlarged in their opening area compared to those in FIG. 11. This arrangement is intended to increase the amount of air that the space between the heat collecting sleeve 110th and is to be supplied to the filter element 104 , whereby the regeneration effect is improved and the exhaust gas back pressure is reduced in an exhaust gas system that contains the treatment device P. In other words, the arrangement of Fig. 11 preferably achieves efficient use of radiant heat, while the arrangement of Fig. 12 preferably achieves efficient supply of air for combustion and a reduction in exhaust gas back pressure, so that these arrangements are appropriately selected for use according to requirements can.

The arrangements of Figures 13 through 15 are such that each filter housing 102 is generally vertical. The arrangement of FIG. 13 is similar to that of FIG. 10 except that the connection holes 107 , 108 are formed on the same side of the filter housing 102 . The arrangement of FIG. 14 is similar to that of FIG. 13 except that the communication holes 107 , 108 are located on opposite sides of the axis of the filter housing 102 . The arrangement of Fig. 15 is similar to that the filter housing is disposed generally verti cal 102 of Fig. 12 with the exception.

Although the bottom and top communication holes 107 , 107 A, 108 , 108 A and the through holes 112 , 113 have been shown and described as being arranged such that in the respective examples discussed above, an imaginary vertical plane passes through the communication holes and the through holes , It is understood that the connec tion holes and the through holes may be arranged at a distance from the ge vertical plane according to the requirements in connection with a structure (layout) or the like.

Although the generally cylindrical heating element 105 has been shown and described to be disposed along the inner circumferential surface of the filter element 104 , it will be appreciated that the structure and arrangement of the heating element 105 are not limited to those used in the examples discussed above are sufficient that the heating element 105 functions to heat the filter element 104 and ignite the exhaust gas particles accumulated on and in the filter element 104 because the convection of air due to the heat of combustion occurs after the combustion of exhaust gas particles has been initiated , thereby providing the same advantageous effects as those in the above-mentioned examples of the exhaust particle treatment device P. Accordingly, the heating element 105 of the above-mentioned examples can be replaced by a burner or the like, and can be provided on the outer peripheral portion or on the End section of the filter element 104 may be arranged.

In addition, since the above-discussed examples of the exhaust particle treatment device P are designed so that the regeneration process of the filter element 104 is carried out after the engine operation is stopped, it is understood that the heating element 105 can be omitted, in which case a device ( not limited to an electric heating element) which heats and burns exhaust gas particles accumulated on the filter element during regeneration of the filter element 104 from the outside is inserted into the filter housing 102 , whereby the exhaust gas particles collected on the filter element 104 are burned and removed .

Next, with reference to FIGS. 16 and 23 from second guide of the exhaust particulate treatment device P accelerator as the invention discussed.

Figs. 16 and 17 show a first example of the second embodiment of the exhaust particulate treatment device P, which is similar to the one embodiment of FIG.. In this example, filter housing 102 is arranged to extend generally horizontally and have a generally oval cross-section, as shown in FIG. 17. The filter housing 102 has front and rear end walls E1, E2, through which the respective exhaust gas inlet 102 a and exhaust gas outlet 102 b are formed. A vertical wall 104 is fixed in the filter housing 102 and provided with two cylindrical sections 204 a, 204 b, which protrude laterally, defined by corresponding openings (not designated), which are arranged vertically. The vertical wall 104 defines the exhaust gas inflow space S1, which is in communication with the exhaust gas inlet 102 a, and the exhaust gas outflow space S2, which is in communication with the exhaust gas outlet 102 .

The top filter element 104 A is at its one end section coaxially and tightly connected to the cylindrical portion 204 a of the vertical wall such that it extends along the axis of the filter housing 102 ent. The under-side filter element 104 B is coaxially and tightly connected at one end portion to the cylindrical portion 204 b of the vertical wall such that it extends along the axis of the filter housing 102 . It is understood that the filter elements 104 A, 104 B are similar to the filter element 104 in FIG. 1.

The top-side heat collecting sleeve 110 A is arranged around the top-side filter element 104 A and is attached at one end to the vertical wall 204 . The heat collecting sleeve 110 A is similar to the heat collecting sleeve 110 in FIG. 6. The heat collecting sleeve 110 is provided with through holes 112 A, 113 A, which are similar to the corresponding through holes 112 , 113 in FIG. 6. The underside heat collecting sleeve 110 B is arranged around the underside filter element 104 B and fixed at one end to the vertical wall 204 . The lower-side heat receiving sleeve 110 B is similar to the sleeve 110 in Fig. 6. The heat receiving sleeve 110 B is provided with the through holes 112 B, 113 B, which are similar to the corresponding holes 112, 113 in Fig. 6. In this embodiment, each of the through holes 112 A, 113 A, 112 B, 113 B is considerably wider in cross-sectional area than each of the connection holes 107 , 108 of the filter housing 102 .

The wire-like top heating element 105 A is arranged in the filter element 104 A and in contact therewith and is similar to the filter element 105 in FIG. 1. The wire mesh-like underside heating element 105 B is arranged in the filter element 104 B and in contact therewith and is similar to the filter element 105 in FIG. 1. In this example, each filter element 104 A, 104 B is formed by winding ceramic fiber around the corresponding heating element 105 A, 105 B. The heating elements 105 A, 105 B are electrically connected to the electrodes 105 a, 105 a through the respective end parts 105 b, 105 b. The electrodes 105 a, 105 a are electrically connected to the battery BT via the regeneration timer and relay or control circuit 106 a. In this example, the circuit 106 a is arranged so that it allows that electric current at a first time setting flows first to the lower-side heating element 105 B and then to the upper-side heating element 105 A at a second time setting, which by a predetermined Time t1 is later than the first time setting.

In the arrangement of FIG. 16, exhaust gas flowing through the exhaust passage 101 is introduced through the exhaust gas inlet 102 a into the exhaust gas inflow space S1. The exhaust gas flows into the inside of the respective top and bottom Fil terelemente 104 A, 104 B and then passes through the respective filter elements 104 A, 104 B, in which exhaust gas particles are filtered or captured, so that the particles on and in each filter element 104 A, 104 B can be accumulated. The exhaust gas passed through the filter elements 104 A, 104 B flows through the through holes 112 A, 113 A, 112 B, 113 B of the heat collecting sleeves 110 A, 110 B and is then expelled through the exhaust gas outlet 102 b and the exhaust gas exhaust pipe 103 .

When the time to regenerate the filter elements 104 A, 104 B has come, electrical current from the battery BT can flow through the regeneration timer and relay circuit 106 a to the electrodes 105 a, 105 a, so that the heating elements 105 A , 105 B electric current is supplied, which is required to carry out a regeneration of the filter elements 104 A, 104 B after stopping the engine operation. Since the filter elements 104 A, 104 B are arranged above and below, the supply of electric current at the first time setting is first made to the lower-side heating element 105 B and then to the upper-side heating element 105 A at the second time setting, which was corrected for the above Time t1 is later than the first time setting.

The type of electrical power supply to the top and bottom heating elements 105 A, 105 B will be discussed in more detail with reference to a timing chart in FIG. 18.

First, the electrical power supply to the lower-side heating element 105 B is initiated in a step S1. At a step S2, the circuit 106 A judges whether a time T during which the electric current is supplied to the lower-side heating element 105 B has a value t1 (for which the combustion of particles in the lower-side filter element 104 b is almost completed) or more. When the value is reached or at the end of the time t1, the processing goes to a step S3, in which the electrical power supply to the top heating element 105 A is initiated.

In a step S4, by the circuit 106a judges whether the time T during which electric current is supplied to the heating element unterseiti gen fed 105 B, the value has reached t2 or more. When the value is reached or when the time t2 has elapsed, the processing proceeds to a step S5, in which the electrical power supply to the lower-side heating element 105B is ended. Subsequently, at a step S6 through the circuit 106 a judged whether the time T, while the electric current to the top-side heater is supplied 105 A, the value has reached t2 or more. When the value is reached, or when the time t2 has elapsed, the processing goes to a step S7, in which the electrical power supply to the upper-side heating element 105 A is ended.

Effects of the above example of FIGS. 16 to 18 are explained in comparison with a conventional case in which two heating elements for upper and lower side filter elements are supplied with electric current at the same time, regarding an exhaust gas particle treatment device in which two filter elements 105 A, 105 B are arranged at the top and bottom, taking into account a restriction in the layout of the exhaust system.

In the conventional case, the two heating elements for the top and bottom filter elements are supplied with electric power at the same time as conventional. A temperature characteristic of the filter elements during regeneration is shown in Fig. 19, which shows the temperature changes of the top and bottom filter elements with respect to the heating element power supply time T, while the electric current is supplied to the top or bottom heating element which is for the top or bottom Filter element is used. In Fig. 19, a curve a 'shows the temperature characteristic of the upper filter element, while a curve b' shows the temperature characteristic of the lower filter element. A vertical broken line t2 in FIG. 19 indicates a time at which the supply of electric power to the heating elements has ended. The diagram of Fig. 19 demonstrates the fact that the temperature on the top filter element is lower than that on the bottom filter element, and therefore a sufficient regeneration process cannot be achieved in the top filter element. This is caused for the following reasons: the top filter element is exposed to regeneration gas (low in oxygen concentration) emitted by the bottom filter element and accordingly surrounded by air with low oxygen concentration. Accordingly, it is difficult to burn the exhaust gas particles even when heated by the heating element. Consequently, the burning of the particles is difficult to propagate through the entire top filter element, making it difficult to sufficiently burn the particles accumulated on the top filter element. Thus, the heat of combustion of the particles is hardly generated by the top filter element, and therefore the temperature on the top filter element is lower than that on the bottom filter element.

A natural consequence is that adequate regeneration possible for the top and bottom filter element Lich when the time during which electrical current is added leads for the top and bottom filter element that is extended well beyond t2; but this can be the Increase consumption of electrical energy, causing the Possibility of a battery voltage drop occurs.

In contrast, a temperature characteristic curve (corresponding to the example of FIGS. 16 to 18) of the top and bottom filter elements during regeneration is shown in FIG. 20, which shows the temperature changes of the top and bottom filter elements 104 A, 104 B as a function of represents the heating element power supply time during which the upper and lower heating elements 105 A, 105 B are supplied with electric current, which serve for the respective filter elements 104 A, 104 B. In Fig. 20, curve a indicates the temperature characteristic of the upper-side filter element 104 A, while a curve b shows the temperature characteristic of the lower-side filter element 104 B.

As can be seen in Fig. 20, after the time t1 from the start of the electric power supply to the bottom heating element 105 B for the bottom filter element 104 B (the burning of particles in the bottom filter element is almost completed by the time t1) that Electric power supply to the top heating element 105 A triggered for the top filter element 104 A, so that a sufficient temperature rise even in the top filter element 104 A is obtained. In Fig. 20, the electric power supply to the lower-side heating element 105 B is stopped at the time t2, while the electric power supply to the upper-side heating element 105 A is stopped at the time t3.

The temperature characteristic shown in Fig. 20 is obtained for the following reasons: At about a time when the combustion of particles collected in the upper-side filter element 104 A is started, natural convection of air occurs due to residual heat on the lower side Filter element 104 B, the regeneration of which has almost been completed, and therefore the environment of the upper-side filter element 104 A is in a state which has a high oxygen concentration. As a result, particles accumulated in the top filter element 104 A can be sufficiently burned. In addition, by using the remaining heat of the lower-side heating element 105 B, it is possible to shorten the time during which the upper-side heating element 105 A is supplied with electric current.

As discussed above, by delaying electrical power to the top heater 105 A relative to electrical power to the bottom heater 105 B, the regeneration efficiency of the top filter element 104 A can be improved without increasing all of the electrical energy required for regeneration the effect of natural air convection is needed.

Figs. 21 and 22 show a second example of the second embodiment of the exhaust particulate treatment device P, which is similar to the first example of FIG. 1,. In this example, the filter housing 102 is arranged so that it extends generally horizontally and has a generally cylindrical cross section, as shown in FIG. 21. The filter housing 102 has front and rear end walls E1, E2, through which the exhaust gas inlet 102 a and the exhaust gas from passage 102 b are formed. The vertical wall 204 is fixedly arranged in the filter housing 102 and is provided with a cylindrical section 204 c which projects laterally and defines an opening (not designated). The vertical wall 204 defines the exhaust gas inflow space S1, which communicates with the exhaust gas inlet 102 , and the exhaust gas outflow space S2, which communicates with the exhaust gas outlet 102 b. The filter element 104 is arranged coaxially and is connected at its one end portion to the cylindrical portion 204 of the vertical wall in such a way that it extends along the axis of the filter housing 102 .

The heat collecting sleeve 110 is arranged around the filter element 104 and fixedly attached at one end to the vertical wall 204 . The heat collecting sleeve 110 is similar to that in FIG. 6. The heat collecting sleeve 110 is provided with the through holes 112 , 113 which are similar to the holes 112 , 113 in FIG. 6. In this embodiment, each of the through holes 112 , 113 is considerably larger in cross-sectional area than each of the connecting holes 107 , 108 of the filter housing 102 .

A pair of wire mesh-like upper and lower heating elements 105 U, 105 L are arranged inside and along the inner peripheral surface of the filter element 104 . The heating elements 105 U and 105 L are generally semi-cylindrical and arranged symmetrically to each other so that they are to be shaped into a generally cylindrical shape, and at a short distance from one another. Each of the heating elements 105 U, 105 L is formed from the same material as each of the heating elements 105 of FIG. 1. In this example, the filter element 104 is formed from ceramic fiber and formed by winding the ceramic fiber around the heating element 105 U, 105 L, which are generally cylindrical in shape.

The heating elements 105 U, 105 L are connected via the regeneration time transmitter and control circuit 106 a to the battery BT. In this example, the circuit 106 a is set up so that it allows electric current to flow to the lower heating element 150 L at a first time setting and then to the upper heating element 105 U at a second time setting, which by the predetermined time period t1 is later than the first time setting.

With the arrangement of FIGS. 21 and 22 is introduced through the exhaust passage 101 exhaust gas flowing into the exhaust-Einströmungsraum S1 through the exhaust gas inlet 102 a. The exhaust gas flows into the inside of the filter element 104 and then passes through the respective filter element 104 , in which exhaust gas parts are filtered or trapped, so that the particles are accumulated on and in the filter element 104 . The exhaust gas passed through the filter element 104 flows through the through holes 112 , 113 of the heat collecting sleeves 110 A, 110 B and is then ejected through the exhaust gas outlet 102 b and the exhaust gas exhaust pipe 103 .

When the time has come when a regeneration of the filter element 104 is required, electrical current is allowed to flow from the battery BT through the regeneration timer and control circuit 106 a to the heating elements 105 U, 105 L in order to regenerate the filter element 104 after stopping engine operation. Since the heating elements 105 U, 105 L are separated from one another and are arranged above and below, here the elec trical power supply at the first time setting is made first to the lower heating element 105 L and then to the upper heating element 105 U at the second time setting, which is later than the first time setting by the predetermined time period t1.

The type of electric power supply to the upper and lower heating elements 105 U, 105 L will be discussed in more detail with reference to a timing chart in FIG. 23.

First, in step S11, the electric power supply to the lower heating element 105 L is started. At a step S12, the circuit 106a judges whether the time. T, while the electric current is supplied to the lower heating element 105 L, has reached a value t1 (for which the combustion of particles in the lower part of the filter element 104 has almost ended) or more. When the value is reached, or when the time t1 has elapsed, the processing proceeds to a step S13, in which the electric current supply to the upper heating element 105 U is started.

In a step S14, the circuit 106 a judges whether the time T during which the electric current is supplied to the lower heating element 105 L has reached t2 or more. When the value is reached, or when the time t2 has elapsed, the processing goes to a step S5 in which the electric power supply to the lower heating element 105L is stopped.

Subsequently, in a step S16, the circuit 106a judges whether the time T during which the electric current is supplied to the upper heating element 105 U has reached the value t2 or more. When the value is reached or when the time t2 has elapsed, the processing goes to a step S17, in which the electric power supply to the upper heating element 105 U is ended.

The effects of the above example of Figs. 21 to 23 will be explained.

Assume that the supply of electric current to the upper and lower heating elements 105 U, 105 L is released simultaneously. In this case, the upper-side portion of the Filter lementes 104 the regeneration gas (low concentration in the Sauer) exposed, which is generated by the lower side part of the filter element 104 when the Burn NEN accumulated in the filter element 104 exhaust particulates progresses, and therefore the upper part of the filter element 104 inevitably surrounded by air, which contains a low oxygen concentration under the action of natural convection of air. As a result, it is difficult to cause the combustion of particles to spread through the entire filter element 104 .

The above problems can, however, according to the arrangement and Be operating example of the example of Figure 21 are overcome to 23 by the following fact. Approximately at a time when the burning of the 104 A is initiated of collected particles in the upper-side filter element occurs natural convection tion of air due to the remaining heat in the lower part of the filter element 104 , the regeneration of which is almost complete (or remaining heat of the lower heating element 105 L), and therefore the environment of the upper part of the filter element 104 is in a state that has a high oxygen concentration. Consequently, particles accumulated on the upper part of the filter element 104 can be sufficiently burned. In addition, due to the use of the remaining heat of the lower-side heating element 105 B, it is possible to shorten the time during which electric current is supplied to the upper-side heating element 105 A.

Figs. 24 to 26 illustrate a third embodiment of the exhaust particulate treatment device P according to the invention which is similar to the example of FIG. 2. In this embodiment, the filter housing 102 is vertically angeord net, so that the exhaust gas inlet 102 a is positioned lower than the exhaust gas outlet 102 b. Hollow and cylindrical filter elements 104 M, 104 N on the inside and on the outside are arranged coaxially in the filter housing 102 . An annular space A is defined between the outer peripheral surface of the inner filter element 104 M and the inner circumferential surface of the outer filter element 104 N. The annular space A is closed at its upper end (on the side of the exhaust gas outlet 102 b) with a closure plate part 306 , so that the annular space A forms part of the exhaust gas inflow space S1. An annular space B is defined between the outer peripheral surface of the outer Fil terelementses 104 N and the inner peripheral surface of the Filterge housing 102nd The annular space B is closed at its lower end (on the side of the exhaust gas inlet 102 a) with a closure plate part 107 , so that the annular space B forms part of the exhaust gas outflow space S2. An axially elongated space C is defined within the inner Filterele mentes 104 M. The space G is closed at its lower end (on the side of the exhaust gas inlet 102 a) with a closure plate part 308 , so that the space C forms part of the exhaust gas outflow space S2.

A connecting pipe or duct 310 is provided to supply air (ambient air) to room C. The connecting pipe 310 is arranged in the filter housing 102 and has an upstream end section which projects into the ambient air and a downstream end section which projects into the space C. Air required for regeneration of the filter elements 104 M, 104 N is introduced into the filter housing 102 through the connection pipe 310 in addition to the connection hole or passage 107 formed in the filter housing.

A wire mesh-like and cylindrical inner heating element 105 M is arranged in and in contact with the inner peripheral surface of the inner filter element 104 M so as to heat the inner heating element 105 M. A wire mesh-like and cylindrical outer heating element 105 N is arranged in and in contact with the inner peripheral surface of the outer heating element 104 N. Each heating element 105 M, 105 N is made of the same material as the heating element 105 in FIG. 1. In this embodiment, each of the filter elements 104 M, 104 N is formed by winding ceramic fiber around the corresponding heating element 105 M, 105 N. The heating elements 105 M, 105 N are electrically connected to the electrode 105 a, which in turn is electrically connected to the battery BT via the regeneration timer and relay circuit (or heating control unit) 106 a. The circuit 106 a is arranged to control the electrical power supply from the battery BT to the heating elements 105 M, 105 N.

With this arrangement of FIGS. 24 and 25, exhaust gas from the engine through the exhaust gas inlet 102 a of the filter housing 102, a passed into the annular space A between the inner and outer filter element 105 M, 105 N. Then, a part of the exhaust gas by the outer filter element 104 N and flows to the exhaust gas outlet 102 b through the annular space B between the outer filter element 104 N and the filter housing 102 , while the remaining part of the exhaust gas passes through the inner filter element 104 M and to the exhaust gas outlet 102 b through the Space C in the inner filter element 104 M flows. Here, during the passage of the exhaust gas through the inner and outer filter elements 104 M, 104 N exhaust gas particles are filtered or trapped by them. Although a part of the exhaust gas from the filter housing 102 through the communication hole 107 and the connection pipe is discharged 310 during operation of the engine, lies in the fact not a problem since the communication hole and pipe 107, 310 to the exhaust Ausströmungsraum S2 are open, the on the downstream side of the filter element 104 M, 104 N is defined. The regeneration is achieved by passing electrical current through the heating elements 105 M, 105 N after stopping the engine operation when the time has come when regeneration of the filter elements 104 M, 104 N is required.

More specifically, the program of a flowchart of Fig. 26 is executed when the time comes.

First, the supply of electric current to the heating elements 105 M, 105 N is triggered in a step S31. Then, in step S32, it is judged by the heating control unit 106 a whether the time during which the electric current is supplied to the heating elements 105 M, 105 N is a time t0 (for which the regeneration of the filter elements 104 M, 104 N has almost ended) or more. When the time t0, the Bear's processing to a step S33 at which the supply is terminated by electrical schem current to the heating elements 105 M, 105 N.

When the regeneration of the filter elements 104 M, 104 N is achieved by the heating elements 105 M, 105 N, an upward ge air flow is generated in the housing 102 under the effect of natural convection of air, in which burned gas through the upper exhaust outlet 102 b is discharged while the air (ambient air) is introduced through the connection hole 107 and the connection pipe 310 , as indicated by dashed arrows in FIG. 24. In other words, air required for regeneration can not only be introduced into the space B in the filter housing 102 through the connection hole 107 , but also into the space C in the filter housing 102 through the connection tube 310 .

Thus, the inner and the outer filter element 104 M, 104 N are provided with a sufficient amount of air, which promotes the combustion of exhaust gas particles accumulated in the filter elements 104 M, 104 N, thus improving their regeneration efficiency.

Claims (15)

1. exhaust gas particle oxidation device (P) for an internal combustion engine, comprising:
a filter housing ( 102 ) for arrangement in an exhaust gas passage ( 101 ) of the internal combustion engine,
a filter element ( 104 ) which is arranged in the filter housing in order to filter out particles from the exhaust gas emitted by the internal combustion engine,
a switchable heating element ( 105 ) for heating and burning the particles filtered out for regeneration of the filter element,
wherein the filter housing ( 102 ) has an exhaust gas inflow space (S1) on the upstream side of the filter element in the exhaust gas flow direction and an exhaust gas outflow space (S2) on the downstream side of the filter element in the exhaust gas flow direction, characterized in that on the filter housing ( 102 ) an air introduction device is provided for the effective introduction of air into the filter housing ( 102 ) by natural convection, which is generated within the filter housing ( 102 ) during the combustion of the particles filtered out during the regeneration of the filter element ( 104 ). 2. exhaust gas particle oxidation device according to claim 1, characterized in that the air introduction device comprises a device which a plurality of in the filter housing ( 102 ) formed connecting passages ( 107 , 107 A, 108 , 108 A, 103 , 114 , 115 ) for fluid communication between the exhaust gas inflow space and the ambient air, the connecting passages comprising a first connecting passage ( 107 , 107 A, 114 ) which is close to a lower portion of the filter element ( 104 ), and during regeneration of the filter element under the effect of natural convection of air. Ambient air is introduced into the exhaust gas inflow space (S1) through the first connecting passage, 3. exhaust particle oxidation device according to claim 2, characterized in that the connecting passages comprise a second connecting passage ( 108 , 108 A, 103 , 115 ) which is positioned higher in the vertical direction than the first connecting passage, the first connecting passage upstream of the second Connection passage is positioned with respect to the flow direction of exhaust gas. 4. exhaust gas particle oxidation device according to claim 2, characterized in that the connecting passages comprise a second connecting passage ( 108 , 108 A, 103 , 115 ), which is positioned higher than the first connec tion passage in the vertical direction, the first connecting passage downstream of the second connection passage is positioned with respect to the flow direction of exhaust gas. 5. Exhaust particle oxidation device according to claim 3, characterized in that a heat collecting sleeve ( 110 ) around the filter element ( 104 ) is arranged around and between an outer peripheral surface of the filter element and an inner peripheral surface of the filter housing ( 102 ), the heat being catch sleeve is provided with at least one through hole ( 112 , 113 ) which is close to the first connecting passage. 6. exhaust particle oxidation device according to claim 5, characterized in that a first and a second through hole ( 112 , 113 ) are provided, which are spaced from each other in a generally vertical direction, wherein the first through hole ( 112 ) and the first Connection passage ( 107 ) at least partially coincides in a radial direction of the filter element ( 104 ), and wherein the second through hole ( 113 ) and the second connection passage ( 108 ) at least partially coincide with each other in the radial direction of the filter element ( 104 ). 7. exhaust particle oxidation device according to claim 2, characterized in that the filter element ( 104 ) comprises a plurality of filter elements, comprising first and second filter elements ( 104 A, 104 B), which are arranged above and below in a vertical direction, and that the heating means comprises first and second heating elements ( 105 A, 105 B) which are arranged so as to heat the respective first and second filter elements, and further characterized by a current supply control device for triggering the supply of electrical current to the second heating element ( 105 B) at a first time setting and then to the first heating element ( 105 A) at a second time setting which is a predetermined time period (t1) later than the first time setting. 8. exhaust gas particle oxidation device according to claim 7, characterized records that the predetermined period (t1) is adjustable so that the regeneration of the second filter element almost ended within the predetermined time period is. 9. exhaust particle oxidation device according to claim 2, characterized in that the heating device comprises first and second heating elements ( 105 U, 105 L), which are separated from one another and are arranged above and below in a vertical direction, the first and the second Heating element are arranged such that the filter element can be heated, and that the treatment device comprises a power supply control device for initiating the supply of electrical current to the second heating element ( 105 L) at a first time setting and then to the first heating element ( 105 U ) at a second time setting which is later than the first time setting by a predetermined time period (t1). 10. exhaust particle oxidation device according to claim 9, characterized records that the predetermined period (t1) is set so that the Regenera tion of the second filter element almost be within the predetermined period ends is. 11. Exhaust particle oxidation device according to claim 2, characterized in that the filter element comprises a first cylindrical filter element ( 104 M) and a second cylindrical filter element ( 104 N) which is arranged around the first filter element, wherein a first space (A ) is defined between the first and the second filter element, a second space (B) which is defined between the second filter element and the filter housing, a third space (C) which is defined in the first filter element, each space first and has second end sections, which are respectively located on the upstream and downstream sides in the flow direction of the exhaust gas, that the treatment device has a first closure device ( 306 ) for closing the second end section of the first space, a second closure device ( 307 ) for closing the first End portion of the second room, and a third closure device ( 308 ) for closing de s first end portion of the third space, and that the air introduction means comprises means defining a first communication passage ( 107 ) through which the second space communicates with ambient air and means defining a second communication passage ( 310 ) which the third room is in connection with the ambient air. 12. Exhaust particle oxidation device according to claim 11, characterized in that the filter housing ( 102 ) has an exhaust gas inlet and outlet ( 102 A, 102 B), each of which is formed upstream and downstream of the first and the second filter element the first communication passage ( 107 ) to the second room is opened at a lower position than the exhaust gas outlet in a vertical direction and the second communication passage ( 310 ) to the third room is opened at a lower position than the exhaust gas outlet in the vertical direction. 13. Exhaust particle oxidation device according to claim 12, characterized in that the filter housing ( 102 ) is located so that the exhaust gas inlet ( 102 a) is positioned lower in the vertical direction than the exhaust gas outlet ( 102 b). 14. Exhaust particle oxidation device according to claim 11, characterized in that the first connection passage is a connection hole ( 107 ) which is open to the second space at a position near the second closure device. 15. Exhaust particle oxidation device according to claim 11, characterized in that the second connecting passage is a connecting pipe ( 310 ) which is open to the third space at a position near the third closure device.