JPH05222922A - Exhaust emission control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent the damage of a particulate filter, in an exhaust emission control device for an internal combustion engine in which a plurality of particulate filters are provided so as to be parallel to respective exhaust passages, by evening the particulate collecting rates of respective filters for preventing the overheating of the respective filters at the time of burning. CONSTITUTION:An exhaust emission control device for an internal combustion engine equipped with a plurality of particulate filters that have been arranged in parallel in the respective exhaust passages is provided with a collection rate detecting means by which the collection rates of the respective filters are separately detected, a maximum collection filter detecting means by which the filter of the maximum collection rate is detected, and a control-valve position regulating means by which the collection rate of the other filter is regulated by a control valve that has been priovided to the branched part of the exhaust passage so as to agree with the collection rate of the maximum collection filter. The device is also provided with a regeneration starting means by which the regeneration of the filters is started when the collection rates of the respective filters have been nearly evened up to reach a predetermined regeneration reference value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying apparatus for an internal combustion engine, and more particularly to a device for collecting and removing particulates contained in the exhaust gas of a diesel engine by a plurality of filters when regenerating the particulates. The present invention relates to an exhaust gas purification device for an internal combustion engine, which can prevent melting damage of a filter due to combustion.

[0002]

2. Description of the Related Art Exhaust gas from internal combustion engines such as automobiles, especially diesel engines, contains exhaust particulates (particulates) containing carbon as a main component, which is a cause of exhaust black smoke. From the viewpoint of environmental pollution, it is desirable to remove this particulate, and in recent years, it has been proposed to dispose a diesel filter with a ceramic filter in the exhaust passage of the diesel engine.

FIG. 8 is provided with two branch passages 83 and 84 which are joined together after branching in the middle of the exhaust passage 82.
8 shows a schematic configuration of a conventional exhaust gas purification apparatus 80 for an internal combustion engine, which includes particulate collection filters A and B (hereinafter, simply referred to as particulate filters or filters) 84. In such an exhaust emission control device 80 for an internal combustion engine, the exhaust gas is divided into two, and the particulate filters A and B collect the particulates in the exhaust gas. When the particulates are collected in a predetermined amount, The particulate filters A and B are separated from the exhaust path, the electric heaters HA and HB are energized to ignite the collected particulates, and a regeneration gas such as secondary air is flown from an electric air pump (not shown) to particulates. A regeneration process for burning the is performed. This regeneration process is generally performed individually for each of the filters when the pressure loss before and after the filter is detected by using the pressure sensors SU and SD, and when the detected pressure loss exceeds a predetermined value.

However, such a regeneration process has no problem when the engine is normally operated during regeneration, but when the engine is stopped during regeneration of the filter, melting of the filter occurs. The problem occurs. This will be described with reference to FIG. FIG. 9 (a) shows the particulate collection state of the particulate filter A of FIG. 8, and FIG. 9 (b) shows the particulate collection state of the particulate filter B of FIG. is there. The amount of collected particulates increases as the exhaust gas flows in both filters A and B. Then, at the regeneration time, regeneration is started from one of the filters, for example, filter A. When the engine is stopped while the filter A is being regenerated, unburned particulates are left in the filter A. In this state, when the pressure detection values of the pressure sensors SU and SD are smaller than the regeneration timing determination value, the regeneration process is not performed and the collection is restarted. Then, after this, since the collection of the particulates is continued until the pressure detection values of the pressure sensors SU and SD reach the regeneration timing determination value for both the filters A and B, the particulates on the filter B side that have not been regenerated are collected. If the trapped amount becomes excessively large and regeneration is performed in this state, the combustion temperature on the filter B side rises too much, which may cause melting damage or cracks.

In order to correct the difference in the trapped amount of particulates in such a particulate filter, in the exhaust gas purifying apparatus using the dual particulate filter, the pressure on the upstream side of the two particulate filters is minimized. To control the valve opening amount of the valve provided at the upstream branch of the exhaust pipe so that
63-235614).

[0006]

SUMMARY OF THE INVENTION
In the device disclosed in Japanese Patent No. 63-235614, the valve opening amount of the branch valve is only controlled so that the pressure on the upstream side of the particulate filter is minimized. If the collection amount of the two filters fluctuates during regeneration, there is a risk of filter melting damage and cracks due to excessive rise in the combustion temperature of the filter with the larger collection amount. was there.

Therefore, the present invention solves the problem of the conventional exhaust gas purifying apparatus for an internal combustion engine, and individually determines the particulate collection state of each filter when collecting the particulate filter, and always collects the collected amount. By correcting so that the filter amount with the larger number of filters is matched with the trap amount of the smaller filter, the amount of particulate collection of each filter is controlled uniformly, and the excessive collection of particulates to a specific filter is prevented. Another object of the present invention is to provide an exhaust gas purification device that can prevent overheating of the particulate filter during regeneration and prevent damage to the particulate filter during regeneration.

[0008]

FIG. 1 shows the configuration of an exhaust gas purifying apparatus for an internal combustion engine according to the present invention which achieves the above object.
As shown in FIG. 1, according to the present invention, a plurality of branch passages that join after branching are provided in a part of an exhaust passage of an internal combustion engine, and a filter for collecting particulates is built in each branch passage. The amount of collected particulates is detected and all the filters are regenerated at almost the same time. During regeneration, the filters to be regenerated are separated from the exhaust path, and the heating means heats the filters and regenerates them by supplying regeneration gas. In an exhaust gas purification apparatus for an internal combustion engine, a collection amount detection means for individually detecting the collection amount of each filter, a most collection filter detection means for detecting a filter having the largest collection amount, and this most collection filter. The amount of exhaust gas flowing into the maximum collection filter is reduced so that the amount of collection of other filters is made equal to the amount of collection of An exhaust gas control means to increase, when the collection amount of each filter has reached approximately equal become the reproduction reference value set in advance, and by providing a reproduction operation starting means for starting the regeneration operation of the filter.

[0009]

According to the exhaust gas purifying apparatus for an internal combustion engine of the present invention, the collected amount of each filter is individually detected, and the filter with the largest collected amount is detected. Then, the collection amount of the other filters is adjusted by adjusting the control valve provided in the branch portion of the exhaust passage so as to match the collection amount of the maximum collection filter. In this way, the regeneration operation of the filters is started when the trapped amounts of the respective filters become substantially equal to each other and reach the predetermined regeneration reference value. As a result, the temperature of the particulate filter does not rise excessively during regeneration, and damage to the filter is prevented.

[0010]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 2 shows a schematic configuration of an embodiment of an exhaust purification apparatus of the reverse flow alternate regeneration dual filter type according to the present invention. In the exhaust gas purifying apparatus for an internal combustion engine of this embodiment, an exhaust pipe 1 for guiding exhaust gas from an engine (not shown) is branched into branch pipes 4 and 5 at a branch portion a, and then merged at a merge portion b to form a muffler 6 Connected to. In the middle of the branch pipes 4 and 5, a first filter 2 and a second filter 3 are provided to collect particulates in the exhaust gas. This first filter 2
A honeycomb filter having a large number of filter cells is used as the second filter 3, and the exhaust upstream end and the downstream end of each filter cell are alternately plugged with plugs. Therefore, the first filter 2 and the second filter 3
The particulates in the exhaust gas that have flowed into the exhaust gas are collected by the filter cell when the exhaust gas passes through the wall surface of the filter cell.

Pressure sensors SP1 to SP4 are provided on the upstream and downstream sides of the first and second filters 2 and 3 in the branch pipes 4 and 5, respectively. Then, the upstream and downstream pressures of the first filter 2 are input to the differential pressure sensor 25 by the pressure sensors SP1 and SP2, and the differential pressure of the first filter 2 is obtained. Similarly, the upstream and downstream pressures of the second filter 3 are input to the differential pressure sensor 26 by the pressure sensors SP3 and SP4, and the differential pressure of the second filter 3 is obtained. The outputs of these differential pressure sensors 25 and 26 are input to the control circuit 12, and the control circuit 12 determines the regeneration timing of the first and second filters 2 and 3 based on this differential pressure.

On the other hand, the plug members (not shown) near the downstream end faces of the first and second filters 2 and 3 or at the downstream end portions are heated during filter regeneration to ignite particulates. Electric heaters 15 and 16 are provided, one end of each of the electric heaters 15 and 16 is grounded, and the other ends thereof are switches SW1 and SW2 controlled by the control circuit 12.
It is connected to the battery 8 via.

During regeneration of the first and second filters 2 and 3, the electric heater 15 or 16 is energized, and regeneration gas is supplied from the downstream side of the first filter 2 or the second filter 3 on the energized side. It is necessary to flush and discharge the combustion gas from the upstream side. Therefore, in this embodiment, the regeneration gas supply port 22 is provided at the confluence portion b of the branch pipes 4 and 5, and the regeneration gas supply port 22 is provided with the check gas 21 in the middle thereof. Secondary air is supplied as a regeneration gas from the electric air pump 20 through the supply passage 7. The electric air pump 20 and the check valve 21 are both driven and controlled by the control circuit 12. Further, a regeneration gas discharge port 18 is provided at the branching portion a of the branch pipes 4 and 5. One end of the regeneration gas discharge port 18 is open to the atmosphere, and a check valve 19 is provided on the way. The regeneration gas discharge passage 17 is connected. The check valve 19 is also driven and controlled by the control circuit 12.

At the branch portion a where the regeneration gas discharge port 18 is opened, the connection between the exhaust pipe 1, the branch pipes 4 and 5, and the regeneration gas discharge port 18 upstream of the branch portion a is switched. At the confluence part b where the control valve 10 is provided and the regeneration gas supply port 22 is opened, the connection of the exhaust pipe 1, the branch pipes 4, 5 and the regeneration gas supply port 22 on the downstream side of the confluence part b is switched. Two control valves 11 are provided. Further, an opening / closing valve 9 is provided in the exhaust pipe 1 on the upstream side of the first control valve 10.

The first and second control valves 10 and 11 are both driven by a control circuit (ECU) 12 and diaphragm type actuators 13 and 14, for example, an actuator drive signal output from the control circuit 12. If the actuator 13 operates so as to pull the rod 13a connected to the first control valve 10, the first control valve 1
0 moves to the side of the broken line position a in FIG. 2, and if the actuator 13 operates so as to push the rod 13a, the first control valve 1
0 moves to the broken line position b side. This operation is the same when the diaphragm actuator 14 moves the rod 14a. In addition, the diaphragm type actuator 1 for operating the above-mentioned first control valve 10 and second control valve 11
Negative pressure is introduced into the valves 3 and 14 by the negative pressure switching valves 23 and 24 whose opening and closing are controlled by the control circuit 12.

3 and 4 show these first control valves 10
2 shows an example of the actual configuration of the second control valve 11. For the first control valve 10 and the second control valve 11, for example, butterfly valves are used, and the rotary shafts 10a and 11a provided near the openings of the regeneration gas discharge port 18 and the regeneration gas supply port 22 are mainly used. By rotating the valve body 10b11b, the regeneration gas discharge port 18 and the regeneration gas supply port 22 can be opened to either side of the branch pipes 4 and 5.

These first control valve 10 and second control valve 1
1 when collecting the particulates, the positions when the first and second filters 2 and 3 are regenerated, and these control valves 10 and 1
Check valves 19 and 21, heaters 15 and 1 associated with the operation 1
The normal operations of 6, the electric air pump 20, and the opening / closing valve 9 are as shown in the timing chart of FIG. This will be described for each case. (1) During particulate collection (before time t1) Both the first control valve 10 and the second control valve 11 operate so as to occupy the position of the solid line c, and the exhaust gas flowing through the exhaust pipe 1 is branched into two hands. The exhaust gases that have flowed through the branch pipes 4 and 5 at the same time and have passed through the first filter 2 and the second filter 3 merge again to flow to the muffler 6. At this time, the check valves 19 and 21 are closed. The heaters 15 and 16 are off, and the electric air pump 20 and the opening / closing valve 9 are also off. (2) During regeneration of the first filter 2 (time t1 to time t2) Both the first control valve 10 and the second control valve 11 operate so as to occupy the broken line position a, and the exhaust gas flowing through the exhaust pipe 1 is branched. Only the exhaust gas after flowing through the pipe 5 and passing through the second filter 3 is allowed to flow through the muffler 6. At this time, the check valves 19 and 21 are open, and the regeneration gas discharge port 18
Is opened in the branch pipe 4 at the branch portion a, and the regeneration gas supply port 22 is opened in the branch pipe 4 at the joining portion b. Therefore, the secondary air supplied from the electric pump 20 enters the branch pipe 4 through the regeneration gas supply port 22 and assists the combustion of the particulates of the first filter 2 which is ignited when the heater 15 is turned on for a predetermined time, and the combustion thereof is performed. The gas is discharged to the atmosphere through the regeneration gas discharge port 18 and the regeneration gas discharge passage 17. The on-off valve 9 is off. (3) At the time of regeneration of the second filter 3, both the first control valve 10 and the second control valve 11 operate so as to occupy the position B of the broken line, and the exhaust gas flowing through the exhaust pipe 1 flows into the branch pipe 4, Only the exhaust gas after passing through the filter 2 is allowed to flow to the muffler 6. At this time, the check valves 19 and 21 are open, and the regeneration gas discharge port 18
Is opened in the branch pipe 5 at the branch portion a, and the regeneration gas supply port 22 is opened in the branch pipe 5 at the joining portion b. Therefore, the secondary air supplied from the electric pump 20 enters the branch pipe 5 through the regeneration gas supply port 22, and the heater 15 is turned on for a predetermined time to assist the combustion of the particulates of the second filter 3 to generate the combustion gas. Regeneration gas outlet 1
8. It is discharged to the atmosphere through the regeneration gas discharge passage 17. The on-off valve 9 is off.

Next, the control when either the first filter 2 or the second filter 3 stops the engine for trapping and collecting particulates will be described with reference to the flowchart of FIG. First, a case where the first filter 2 and the second filter 3 are normally regenerated after collecting a specified amount of particulates from a new state will be described. When the first filter 2 and the second filter 3 are used for the first time, it is assumed that engine stop flags ESF2 and ESF3, which will be described later, are "0".

Therefore, in this case, NO is obtained in step 601 and step 602, and the process proceeds to step 603.
Step 603 is to determine whether it is the regeneration time,
As described above, the control circuit 12 determines the regeneration timing of the first and second filters 2 and 3 based on the outputs from the differential pressure sensors 25 and 26. If it is not the regeneration time, this step is repeated until the regeneration time is reached.

When it is judged at step 603 that the regeneration time has come, the routine proceeds to step 604, where the regeneration processing of the filter 2 is performed. Then, in the following step 605, the filter 2
It is determined whether or not the regeneration of is completed, and if it is not completed, the routine proceeds to step 606, where it is determined whether or not the engine (engine) is stopped during the regeneration. If the engine is not stopped during playback, return to step 604 and filter 2
When the regeneration of the filter 2 is completed during this period, the engine stop flag ESF2 of the filter 2 is set to "0" at step 607 and the routine proceeds to step 608 where the regeneration process of the filter 3 is performed. Then, in the following step 609, it is determined whether or not the regeneration of the filter 3 is completed, and if it is not completed, the process proceeds to step 610 and it is determined whether or not the engine (engine) is stopped during the regeneration. .. If the engine is not stopped during regeneration, the process returns to step 608 to continue the regeneration process of the filter 3,
When the regeneration of the filter 3 is completed during this period, the engine stop flag ESF3 of the filter 3 is set to "0" in step 611.
Then, the process proceeds to step 612 to end this routine.

Next, the case where the engine is stopped during the regeneration of the first filter 2 and the second filter 3 will be described. For example, when the first filter 2 is in the reproduction state, the process proceeds to step 606 as in the normal case described above.
Then, several times Step 604 → Step 605 → Step 6
06 → The engine is stopped while repeating the loop of step 604, and it is determined in step 606 that the engine is stopped while the filter 2 is being regenerated. Then, the control proceeds from Step 606 to Step 613, the engine stop flag ESF2 of the filter 2 is set to "1", and Step 614 is performed.
To end this routine. Further, when the first filter 2 normally ends the reproduction and the second filter 3 is in the reproduction state, the process proceeds to step 608 as in the case of the normal condition described above. And several times Step 608 → Step 60
9 → Step 610 → While repeating the loop of Step 608, the engine is stopped, and it is determined in Step 610 that the engine was stopped during the regeneration of the filter 3. Then, the control proceeds from step 610 to step 615, the engine stop flag ESF3 of the filter 3 is set to "1", and the routine proceeds to step 616 to end this routine.

As described above, when the engine is restarted after the engine is stopped during the regeneration of the first filter 2 and the second filter 3, step 601 or step 602 is performed.
Is judged as YES. First, the case where the engine is stopped and restarted during the regeneration of the first filter 2 and the filter 2 is interrupted will be described. In this case, in step 601, YE
Become S and proceed to step 617. And step 617
Then, after the first control valve 10 is controlled to the position b, step
Continue to 603. This is because when the engine is stopped during regeneration of the first filter 2, the trapped amount of the first filter 2 becomes the second amount.
Since it is less than the collection amount of the filter 3, the first filter 2
This is to increase only the collection amount of 2 to match the collection amount of the second filter 3.

Next, the case where the engine is stopped and restarted during the regeneration of the second filter 3 and the filter 3 is interrupted will be described. In this case, step 601 is NO, step 602 is NO, and step 618 is executed. move on. At this time, the first filter 2 finishes the regeneration and collects the particulates. In this case, in step 618, the first control valve 10 is controlled to the position a and the exhaust gas is caused to flow through the second filter 3 whose regeneration has been interrupted, and the differential pressure ΔP3 of the second filter 3 is detected,
The detected value of the differential pressure ΔP3 is stored as the pressure value Pb.
The differential pressure Δ of the second filter 3 whose regeneration has been interrupted in this way
After P3 is detected, proceed to step 619, where the first
The control valve 10 is controlled to the position b, and the exhaust gas starts to flow again to the first filter 2. In this state, the first filter 2
The differential pressure ΔP2 is detected.

In step 620, the detected value of the differential pressure ΔP2 of the first filter 2 is stored as the pressure value Pa. In the following step 621, the differential pressure ΔP2 of the first filter 2 which is currently trapped is
It is determined whether or not the differential pressure ΔP3 of the second filter 3 for which the regeneration has been interrupted has become equal to or greater than the differential pressure, and the amount of trapped by the first filter 2 should be the same as the amount of trapped by the second filter 3 whose regeneration has been interrupted. It is what Then, the collection of particulates by the first filter 2 is continued until Pa ≧ Pb, and when Pa ≧ Pb, the routine proceeds to step 622 and the first
The control valve 10 is controlled to the position C to be in a neutral state, and the exhaust gas begins to flow again to the first filter 2 and the second filter 3 evenly. When step 622 ends, the routine proceeds to step 603, where it is judged whether or not the filter is the regeneration time, as described above.

According to the procedure described above, the first filter 2
First filter 2 when the engine is stopped during playback
The reproduction operation of the second filter 3 is shown in FIGS. 7 (a) and 7 (b). This figure shows the state change of the particulates inside the first and second filters 2 and 3 with the passage of time. Both filters 2 and 3 collect particulates at the same time, and when the regeneration time comes, the regeneration from the first filter 2 is started. When the engine is stopped while the first filter 2 is being regenerated, the regeneration of the first filter 2 is temporarily stopped, and the unburned particulates remain in the first filter 2. Then, at the time of restart, the second filter 3 is not collected, but only the first filter 2 is collected, and after the collected amount becomes about the same as the second filter 3, the first filter 2 is collected again. Will be played from. This is because the second filter 3 has reached the regeneration time once, and it is not necessary to collect it again.

Next, the regeneration operation of the first filter 2 and the second filter 3 when the engine is stopped while the second filter 3 is regenerating is shown in FIG. 7 (c). This figure also shows the state change of the particulates inside the first and second filters 2 and 3 with the passage of time. It is the same that both filters 2 and 3 collect particulates at the same time, and when the regeneration time comes, the regeneration is started from the first filter 2, and FIG. The state after reproduction is shown. When the regeneration of the first filter 2 is completed, the first filter 2 immediately shifts to the collecting operation, and the regeneration of the second filter 3 is started. If the engine is stopped while the second filter 3 is being regenerated, the regeneration of the second filter 3 is temporarily stopped, and the unburned particulates remain in the second filter 3. Then, at the time of restart, the second filter 3 does not collect only the differential pressure ΔP3, but collects only the first filter 2. The collection amount of the first filter 2 is periodically detected by the differential pressure ΔP2, and after the differential pressure ΔP2 becomes approximately the same as the differential pressure ΔP3 of the second filter 3, both filters 2 and 3 simultaneously collect. I do. Then, when the collection amount of both filters 2 and 3 reaches the regeneration time, regeneration is performed from the first filter 2.

As described above, in the exhaust gas purifying apparatus for an internal combustion engine according to the present invention, even if the engine is stopped during the regeneration of the filters, the amount of collected particulates in each filter is controlled to be the same. Since the playback operation is performed,
Particulates will not be trapped excessively on a specific filter. In the embodiment described above, the exhaust gas purification device for the internal combustion engine of the reverse flow alternate regeneration dual filter type has been described as an example, but the present invention is the exhaust gas purification device for the dual filter type internal combustion engine of the forward flow alternate regeneration, or the exhaust gas. Needless to say, the present invention can be applied to an exhaust gas purification device of a dual filter type internal combustion engine that includes a bypass passage and performs alternate regeneration. Further, it can be applied to the case where the exhaust passage is branched into three or more.

The present invention can be applied not only when the engine is stopped during regeneration, but also when unburned particulates are left in the filter during normal regeneration.
The next collection amount can be uniformly controlled by the differential pressure between the upstream and downstream of each filter.

[0029]

According to the present invention, in an exhaust gas purification apparatus having a plurality of particulate filters arranged in parallel in the exhaust path, even when the vehicle is stopped and the internal combustion engine is stopped during regeneration of the particulate filters. , The amount of particulates trapped in each filter can be controlled uniformly, preventing excessive collection of particulates in a specific filter to prevent overheating of the particulate filter during regeneration, and preventing damage to the particulate filter during regeneration. The effect is that it can be prevented.

[Brief description of drawings]

FIG. 1 is a principle diagram illustrating a configuration of an exhaust gas purification device for an internal combustion engine of the present invention.

FIG. 2 is a diagram showing a schematic configuration of an embodiment of an exhaust purification device of a reverse flow alternate regeneration dual filter type to which the present invention is applied.

FIG. 3 is an enlarged view showing a specific configuration example of the first control valve of FIG.

FIG. 4 is an enlarged view showing a specific configuration example of the second control valve of FIG.

5 is an operation time chart showing the operation of each part of the exhaust emission control device of FIG. 2 during normal operation.

FIG. 6 is a flowchart illustrating a filter regeneration operation when the engine is stopped during the filter regeneration of the exhaust emission control device of FIG.

FIG. 7 is an explanatory diagram showing a filter collecting and regenerating state based on the flowchart of FIG. 5 when the engine is stopped at the time of regenerating the filter of the exhaust emission control device of FIG. 2, where (a) is the first filter regeneration. Second when the engine is stopped during
The condition of the filter, (b) is the condition of the first filter when the engine is stopped during the regeneration of the first filter, and (c) is the first and the second when the engine is stopped during the regeneration of the second filter.
It is explanatory drawing which shows the collection condition of the particulates of a filter.

FIG. 8 is an explanatory diagram showing a schematic configuration of a conventional dual filter type exhaust gas purification apparatus for an internal combustion engine.

FIG. 9 is an explanatory diagram for explaining the regeneration operation of (a) the first filter and (b) the second filter when the engine is stopped during the regeneration of the filter of the exhaust emission control device of FIG. 8.

[Explanation of symbols]

 1 ... Exhaust pipe 2, 3 ... Filter 4,5, Branch pipe 7 ... Regeneration gas supply passage 9 ... Open / close valve 10 ... First control valve 11 ... Second control valve 12 ... Control circuit 15, 16 ... Electric heater 18 Regeneration gas discharge port 19, 21 Check valve 20 Electric air pump 22 Regeneration gas supply port a Branching part b Joining part

Claims (1)

[Claims] 1. An internal combustion engine is provided with a plurality of branch passages, which join together after branching, in a part of an exhaust passage, and each branch passage has a built-in filter for collecting particulates, and the amount of particulate collection of each filter. Exhaust gas purification device for an internal combustion engine that detects all the conditions and regenerates all of the filters at approximately the same time, disconnects the filter to be regenerated during regeneration from the exhaust path, heats the filter by heating means, and supplies regeneration gas for regeneration. In, the collection amount detection means for individually detecting the collection amount of each filter, the most collection filter detection means for detecting the filter having the largest collection amount, and the collection amount of this most collection filter The exhaust gas amount that flows into the largest collection filter is reduced and the exhaust gas amount that flows into other filters is relatively increased so that the collection amount of each filter becomes equal. The internal combustion engine is characterized in that: the filter control means and regeneration operation starting means for starting the regeneration operation of the filter when the trapping amounts of the respective filters become substantially equal and reach a predetermined regeneration reference value. Exhaust gas purification device for engines.