JP2772757B2 - Exhaust particulate processing equipment for internal combustion engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust particulate processing apparatus for collecting particulates contained in exhaust gas of an internal combustion engine and treating the collected particulates, and more particularly, to a change in exhaust noise unexpected by a driver. The present invention relates to an exhaust particulate processing apparatus that does not recognize the exhaust gas.

[0002]

2. Description of the Related Art Conventionally, from the viewpoint of environmental protection, in order to prevent fine particles contained in the exhaust gas of an internal combustion engine from being discharged into the atmosphere, the fine particles are collected by a filter provided in an exhaust system. Exhaust particulate collection devices have been proposed. The exhaust particulate collecting device will be described, for example, as disclosed in Japanese Patent Application Laid-Open No. 5-54032. That is, the operating state of the internal combustion engine is detected, the amount of exhaust particulates discharged from the engine is calculated based on the detected engine operating state, the accumulated amount of exhaust particulates on each filter is obtained, and a predetermined When the exhaust particulates accumulate, the exhaust flow switching valve provided in the exhaust system is switched, and the exhaust flow switching valve is closed so that the exhaust does not flow into the exhaust system in which the filter is interposed, and the filter is regenerated. That is, when the deposition amount of the exhaust particulates reaches a predetermined amount, the exhaust flow switching valve is switched to energize a heater provided in the filter through which the exhaust gas has been flowing, and the filter is heated to thereby heat the filter. Exhaust particulates trapped in the combustion are removed.

[0003]

When the above-mentioned exhaust particulate processing apparatus is mounted in the middle of the exhaust system, the exhaust flow path switching valve is closed at the time of filter regeneration, so that the apparatus is located upstream of the closed switching valve. Exhaust noise is affected by the capacity, shape, and configuration of an exhaust system such as a filter case. That is, the resonator effect (resonance effect) of the exhaust system is exhibited, and the exhaust sound when the exhaust flow switching valve is closed on only one side is compared with the exhaust noise when the exhaust flow switching valve is open on both sides. Become smaller. However, depending on the operating state of the engine, the exhaust noise may be greatly reduced, causing a sudden change in the exhaust noise, causing the driver to erroneously recognize that an abnormality has occurred in the vehicle.

[0004] Further, the sudden change of the exhaust sound due to the decrease of the exhaust sound becomes particularly remarkable in the operating state where the engine speed is low, so that the engine speed is less than the predetermined operating speed. In particular, there is a possibility that the driver may be erroneously recognized as having an abnormality in the vehicle. The present invention has been made in view of such conventional circumstances, and has a similar tendency to change in sound generated by the engine itself and change in exhaust sound generated by opening / closing of the exhaust passage switching valve. Accordingly, an object of the present invention is to provide an exhaust particulate processing device for an internal combustion engine in which the driver does not feel uncomfortable even when the exhaust sound changes.

Further, according to the present invention, in an operating region where the change in exhaust sound generated by the switching of the exhaust passage switching valve is small, the opening and closing of the exhaust passage switching valve is performed.
It is an object of the present invention to provide an exhaust particulate treatment device for an internal combustion engine in which a driver does not feel uncomfortable.

[0006]

According to the first aspect of the present invention, there is provided a device for treating particulate matter of an internal combustion engine, wherein the exhaust passage of the internal combustion engine is branched into a plurality of passages, each of which is provided in the middle of each of the branched exhaust passages. A plurality of exhaust particulate collecting means provided with a filter for trapping particulates in the exhaust, and a plurality of heating means for regenerating the filter by heating, burning and removing the exhaust particulates collected by each of the filters. And a plurality of exhaust passage switching means interposed in each of the branched exhaust passages and capable of opening and closing the exhaust passages. Operating state detecting means for detecting an operating state including at least the engine rotational speed; and when the filter is regenerated, the engine rotational speed detected by the operating state detecting means is set to a predetermined value for a predetermined time. When the engine speed is increased, the exhaust passage in which the filter to be regenerated is interposed is closed to start the regeneration, and when the engine rotation speed increases by a predetermined value or more during a predetermined time during the regeneration, the exhaust passage is opened to terminate the regeneration. And a reproduction control means.

Further, in the exhaust particulate processing apparatus for an internal combustion engine according to the present invention, when the engine speed detected by the operating state detecting means is equal to or lower than the first predetermined rotational speed, the regeneration control means may control the regeneration control means. The start / end of the reproduction is controlled. Also, in the exhaust particulate processing apparatus for an internal combustion engine according to the invention of claim 3, the regeneration control means causes the total deposition amount of the exhaust particulate collected by each filter to exceed a maximum deposition amount that the filter can deposit. In such a case, the filter regeneration is started in preference to the regeneration start / end control according to the change in the engine speed.

According to a fourth aspect of the present invention, there is provided an apparatus for treating particulate matter of an internal combustion engine, wherein the exhaust passage of the internal combustion engine is branched into a plurality of parts, and each of the branched exhaust paths is interposed midway. A plurality of exhaust particulate collecting means including a filter for collecting particulates, a plurality of heating means for regenerating the filter by heating and burning and removing exhaust particulates collected by each of the filters; and A plurality of exhaust passage switching means interposed in each exhaust passage and capable of opening and closing the exhaust passage, wherein the plurality of exhaust particulate collecting means collects exhaust particulates during non-regeneration. An operating state detecting means for detecting an operating state including the rotational speed; and a filter for starting the regeneration of the filter when the engine rotational speed detected by the operating state detecting means is equal to or lower than a second predetermined rotational speed. Should do the filter has a playback start time closing prohibiting means is not performed the closing operation of the exhaust passage switching means interposed in the exhaust passage interposed, the arrangement comprising a.

According to a fifth aspect of the present invention, there is provided an apparatus for treating particulate matter of an internal combustion engine, wherein the exhaust passage of the internal combustion engine is branched into a plurality of parts, and each of the branched exhaust paths is interposed in the middle of each of the branched exhaust paths. A plurality of exhaust particulate collecting means including a filter for collecting particulates, a plurality of heating means for regenerating the filter by heating and burning and removing exhaust particulates collected by each of the filters; and A plurality of exhaust passage switching means interposed in each exhaust passage and capable of opening and closing the exhaust passage, wherein the plurality of exhaust particulate collecting means collects exhaust particulates during non-regeneration. An operating state detecting means for detecting an operating state including a rotational speed; and, when the engine rotational speed detected by the operating state detecting means is equal to or lower than a second predetermined rotational speed at the end of regeneration of the filter, Filter is a reproduction end time of closing inhibiting means does not perform the opening operation of the exhaust passage switching means interposed in the exhaust passage interposed, the arrangement comprising a being.

In the exhaust particulate processing apparatus for an internal combustion engine according to the invention of claim 6, the regeneration control means includes a filter to be regenerated by the regeneration start / stop prohibition means or the regeneration end / open prohibition means. Even when the opening / closing operation of the exhaust passage opening / closing means interposed in the exhaust passage is prohibited, the total amount of exhaust particulates collected by each filter exceeds the maximum amount that the filter can accumulate. In such a case, the regeneration of the filter is started immediately.

[0011]

According to the first aspect of the present invention, when the filter is not regenerated, the exhaust particulates are collected by the plurality of exhaust particulate collecting means. If the engine rotation speed detected by the above does not decrease by a predetermined value or more within a predetermined time, the exhaust passage in which the filter to be regenerated is interposed remains open and regeneration is not started. Then, when the engine rotation speed decreases by a predetermined value or more within a predetermined time, the exhaust passage is closed and regeneration is started.

That is, the regeneration is not started unconditionally even when the filter reaches the regeneration time, and the regeneration is started when the engine rotational speed drops by a predetermined value or more within a predetermined time. So,
When the change in the engine speed is greatly reduced and the noise generated by the engine itself is also changing in the decreasing direction, regeneration of the filter is started, and the resonator effect is exhibited and the exhaust noise suddenly changes Even if the change in the decreasing direction occurs, the noise generated by the engine itself also changes in the decreasing direction, so that the driver does not erroneously recognize that an abnormality has occurred in the vehicle.

In order to regenerate the filter, the closed exhaust passage is kept closed until the engine speed increases by a predetermined value or more within a predetermined time. Then, when the engine speed increases by a predetermined value or more within a predetermined time, the state is shifted to the open state, and the regeneration of the filter is terminated. That is, even if the filter finishes the predetermined regeneration condition, the passage is unconditionally opened and the regeneration is not terminated, and the regeneration is terminated when the engine speed increases by a predetermined value or more within a predetermined time.
As a result, when the engine speed change greatly increases and the noise generated by the engine itself is also changing in the increasing direction, the passage is opened, and the resonator effect is not exhibited and the exhaust noise suddenly decreases. Even if a change in the increasing direction occurs, the noise generated by the engine itself also changes in the increasing direction, so that the driver does not feel uncomfortable.

Here, when the engine rotation speed is equal to or lower than the first predetermined rotation speed, a sharp change in the exhaust sound due to the decrease in the exhaust sound appears particularly remarkably. Therefore, according to the second aspect of the invention, in the operating state where the engine speed detected by the operating state detecting means is equal to or higher than the first predetermined rotational speed, the start / end control of the regeneration by the regeneration control means is performed. The regeneration control means performs start / end control of the regeneration in an operating state in which the engine speed detected by the operating state detecting means is equal to or lower than the first predetermined rotational speed. Therefore, in the operating condition in which the rapid change of the exhaust sound is particularly remarkable, the regeneration control is performed in consideration of the decrease / increase of the engine speed per a predetermined time, so that the driver may feel uncomfortable. There is no feeling.

According to the third aspect of the present invention, the regeneration control means may be configured to determine whether or not the total amount of exhaust particulate collected by each filter exceeds the maximum amount that the filter can deposit. Since the regeneration of the filter is started in preference to the regeneration start / end control according to the change in the engine rotation speed, the accumulation of exhaust particulates exceeding the maximum processing capacity on the exhaust particulate collecting means is prevented. In addition, an excessive load is prevented from being applied to the exhaust particulate processing device.

According to the fourth aspect of the present invention, when the filter is not regenerated, the exhaust particulates are collected by the plurality of exhaust particulate collecting means. When the engine rotation speed detected by the detection unit is equal to or lower than the second predetermined rotation speed, the closing operation of the exhaust passage opening / closing unit provided in the exhaust passage provided with the filter to be regenerated is not performed. Then, for example, only when the engine speed is higher than the second predetermined speed, the closing operation of the exhaust passage is performed, and the regeneration is started.

Here, when the exhaust passage is closed, a resonator effect is exerted, and the exhaust noise suddenly changes in a decreasing direction. The rate of the change becomes remarkable when the engine rotation speed is lower than a predetermined rotation speed. . Therefore, even if the filter is in the regeneration start timing, if the engine speed is equal to or lower than the second predetermined rotation speed, the regeneration is not immediately started and the exhaust passage is not closed, so that the resonator effect is not generated. Is not exhibited and the exhaust noise is not suddenly reduced, and the driver is not erroneously recognized as having an abnormality in the vehicle.

At the time when the filter starts regeneration,
When the engine speed is higher than the second predetermined speed,
The regeneration operation is started by performing the closing operation of the exhaust passage and operating the heating means. Here, even when the engine rotation speed is higher than the second predetermined rotation speed, the resonator effect is exhibited by closing the exhaust passage, but the engine rotation speed is higher than the second predetermined rotation speed. In this case, even when the resonator effect is exerted, the exhaust sound does not sharply decrease because the resonator effect does not greatly affect the resonator effect. Therefore, when the engine speed is higher than the second predetermined speed, even if the exhaust passage is closed and the resonator effect is exerted to cause a change in the exhaust sound in a decreasing direction, the change is small, and the engine is not operated. It is possible to prevent the driver from erroneously recognizing that the vehicle has failed due to the noise generated by the engine itself.

The operation of the invention according to claim 5 is characterized in that, even when the regeneration of the filter is completed, if the engine speed detected by the operating state detecting means is equal to or lower than the second predetermined rotation speed, The opening operation of the exhaust passage opening / closing means provided in the exhaust passage provided with the filter to be regenerated is not performed. Then, for example, after the engine rotation speed becomes higher than the second predetermined rotation speed, the opening operation of the exhaust passage is performed to flow exhaust gas.

Here, by opening the exhaust passage,
The resonator effect that was playing until then is no longer played,
Although the exhaust noise changes abruptly in the increasing direction, the rate of the change becomes remarkable when the engine rotation speed is lower than the predetermined rotation speed. Thus, even after the regeneration of the filter that has been performed with the exhaust passage opening / closing means interposed in the exhaust passage in which the filter to be regenerated is interposed is completed, the engine rotation speed remains at the second predetermined rotation speed. If the speed is less than or equal to, even if the reproduction is terminated by stopping the heating means being played,
If the opening operation of the exhaust passage in the closed state is performed unconditionally, the exhaust sound that has been reduced due to the resonator effect will increase sharply, causing the driver to experience abnormalities in the car. Will be mistakenly recognized. Thus, even if the regeneration is terminated by stopping the heating means from being activated, the closed exhaust passage is kept closed.

When the regeneration is terminated by stopping the heating means from being performed and the engine speed becomes higher than the second predetermined speed, the resonator effect is exerted until then and the engine speed is reduced. However, if the engine rotation speed is higher than the second predetermined rotation speed, even if the resonator effect is not suddenly exhibited, the loss of the resonator effect does not significantly affect the exhaust sound. So, as the exhaust noise does not increase suddenly,
The exhaust passage is opened. Therefore, even if the exhaust passage is opened, the change in the exhaust noise is small due to the loss of the resonator effect, so that the driver mistakenly recognizes that the vehicle is abnormal due to the noise generated by the engine itself generated by the engine. I won't let you.

According to a sixth aspect of the present invention, the regeneration control means includes an exhaust passage provided with a filter to be regenerated by the regeneration start / stop prohibiting means or the regeneration end / open / close prohibition means. Even if the opening and closing of the exhaust passage opening / closing means provided is prohibited, if the total amount of exhaust particulates collected by each filter exceeds the maximum amount that can be accumulated by the filter, prompt However, this configuration prevents the exhaust particulates from being deposited on the exhaust particulate collecting means and prevents an excessive burden from being applied to the exhaust particulate processing device. I have.

[0023]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a system configuration of an embodiment of the present invention. An exhaust passage 101 connected to an exhaust manifold of an internal combustion engine 100 is branched into two branches (the branch point is designated as 101a) and merges again. A first branch passage 120 and a second branch passage 130 are provided. In the first branch passage 120, a first filter in which a filter 102 for trapping exhaust particulates is interposed is provided. Case 11
Similarly, a second filter case 115 in which the filter 103 is interposed is interposed in the second branch passage 130.

Here, the filter case 114 and the filter 102, the second filter case 115 and the filter 103
These constitute the exhaust particulate collecting means according to the present invention.
The first branch passage 120 is provided with the first filter downstream of the first filter case 114 and upstream of the junction 101b between the first branch passage 120 and the second branch passage 130. A first opening / closing valve 104 provided to control the flow rate of exhaust gas flowing into the case 114 is interposed. Similarly, a second on-off valve 105 for controlling the flow rate of exhaust gas flowing into the second filter case 115 is interposed in the second branch passage 130.

Here, the first on-off valve 104 is connected to the first branch passage 12.
0 is a butterfly valve having a valve body which is rotated by approximately 90 ° by a valve driving device 106 controlled by a control unit 150 with one point above as a fulcrum.
Reference numeral 5 denotes a butterfly valve having a valve element which is rotated by approximately 90 ° by a valve driving device 107 controlled by the control unit 150, with a point on the second branch passage 130 as a fulcrum.
Further, the first opening / closing valve 104 and the second opening / closing valve 105 have the same specifications (the same airflow resistance at the time of opening / closing the valve), and one of them is open and the other is closed. The exhaust gas is set so that approximately 1% to 3% of the total exhaust gas flows through the exhaust passage in the closed state.

Here, the first on-off valve 104 and the second
The on-off valve 105, the valve driving device 106, and the valve driving device 107 constitute an exhaust passage switching means according to the present invention. Each of the filters 102 and 103 is formed by winding a ceramic fiber in a hollow cylindrical shape. A ceramic foam or a metal foam formed in a hollow cylindrical shape may be used. It may be a honeycomb-shaped monolith filter in which the elongated holes whose other ends are closed are arranged in parallel with the flow of exhaust gas, and the openings and the closed portions are alternately arranged.

Each of the filter cases 114 and 115 receives the exhaust gas discharged from the internal combustion engine,
Each of the filters 102 and 103 is configured so that the exhaust gas passes from the inner peripheral side to the outer peripheral side so as not to flow out of the first filter case 114 and the second filter case 115 without being filtered. ing. However, the exhaust is
The filters 102 and 103 may be configured to pass from the outer peripheral side to the inner peripheral side. In the case of a honeycomb-shaped monolithic filter, it goes without saying that the exhaust gas may be passed from the front end to the rear end.

With such a configuration, the exhaust gas discharged from the internal combustion engine passes through the exhaust passage 101 when the first and second on-off valves 104 and 105 are both in the open state, and passes through the branch point 101a.
, And flow into the first filter case 114 and the second filter case 115. The uniformly distributed exhaust gas is filtered from the inner peripheral wall to the outer peripheral wall of each of the filters 102 and 103 provided in each of the first filter case 114 and the second filter case 115 while filtering the exhaust particles. After passing outside, they are merged at the junction 101b, and the exhaust gas containing no exhaust particulates is discharged to the atmosphere.

As shown in FIG. 1, a heater 108 is provided on the upstream side of the filter 102 in the first filter case 114, and the filter 108 in the second filter case 115 is similarly provided.
A heater 109 is provided upstream of the heater 103. And
The heater 108 and the heater 109 are connected to a control unit 150.
The heater is driven by a heater drive circuit 110 controlled by the heater.

The heaters 108 and 109 are connected to the filter 102 provided in the first filter case 114.
Alternatively, when exhaust particulates are collected by the filter 103 of the second filter case 115 and the first opening / closing valve 104 or the second opening / closing valve 105 is closed, a power supply (not shown) is provided by the heater drive circuit 110. After that, the exhaust fine particles which have been heated and energized for a predetermined time are ignited and reburned.

Here, the heater 108, the heater 109 and the heater driving circuit 110 constitute a heating means according to the present invention. Further, the internal combustion engine 100 has an engine rotation speed N
, A control lever sensor 142 for detecting the engine load Q from the control lever opening of the fuel injection pump, and a water temperature sensor 143 for detecting the engine water temperature.

Here, the rotational speed sensor 141, the control lever sensor 142, and the water temperature sensor 143 constitute an operating state detecting means according to the present invention. Signals from the sensors are input to the control unit 150. Based on the signals input from the sensors constituting the engine operating state detecting means, the control unit 150 receives signals from the engine as shown in a flowchart described later. Calculation of the amount of exhaust particulates discharged, the amount of exhaust particulates deposited on each filter, etc., is performed, the regeneration timing of each filter is determined, and the regeneration end timing is determined. Perform control.

Accordingly, the control unit 150 has a function of an exhaust gas amount detecting means for detecting the amount of exhaust fine particles discharged from the engine and a function of detecting the amount of exhaust fine particles deposited on each filter. Are provided in software as shown in a flowchart described later. Next, the operation of the exhaust particulate processing apparatus of the first embodiment according to the first and third aspects of the present invention will be described with reference to the flowcharts shown in FIGS.

FIGS. 2 and 3 are basic flowcharts for controlling the operation of the filter of the present embodiment for collecting fine particles and regenerating the filter. Here, since the filter regeneration operation is performed alternately, the heater 108, the filter 102, and the first on-off valve 104 on the first branch passage 120 side are respectively connected to the first heater, the first filter, and the first control unit for convenience. Called the valve, the second
The heater 109, the filter 103, and the second on-off valve 105 on the branch passage 130 side will be referred to as a second heater, a second filter, and a second control valve, respectively.

First, in step 1 (indicated by S1 in the figure, the same applies hereinafter), the engine speed N and the engine load Q are read from the rotation speed sensor 141 and the control lever sensor 142. In step 2, based on the engine speed N and the engine load Q read in step 1, the exhaust particulate emission amount ΔPM per unit time is calculated from the map of FIG.

In step 3, it is determined whether or not the reproduction flag 2 is ON. When the reproduction flag 2 is ON, the second
It is determined that the filter is being regenerated, and the exhaust particulates are collected only by the first filter. In step 17, a value obtained by multiplying the exhaust particulate amount ΔPM calculated in step 2 by a preset filter collection efficiency is used. is added to the current amount of the deposition of the first filter performs a total deposition amount beta ₁ of the detection of the first filter.

If the determination in step 3 is NO (regeneration flag 2 is OFF), the process proceeds to step 4 and reproduction flag 1 is
N is determined. When the reproduction flag 1 is ON, the first
It is determined that the filter is being regenerated, and the total deposition amount β ₂ of the second filter is detected in step 8 in the same manner as in step 17.
If it is determined in step 4 that the regeneration flag 1 is not ON, it is determined in step 5 that both the first and second filters are not being regenerated and the accumulated amount of exhaust particulate PM
Is distributed to the first and second filters and added, and the total deposition amounts β ₁ and β ₂ of both filters are detected.

Next, in Steps 6 and 7, it is determined whether or not the total deposition amount β ₁ , β _{2 of} each filter has reached a predetermined amount βRe determined to be a regeneration timing. And
When β ₁ ≧ βRe, that is, when it is determined that the first filter side is at the regeneration time, the process proceeds to step 51. In step 51, a first filter regeneration start determination routine to be described later is executed.

When the regeneration is determined by the first filter regeneration start determination routine, the process proceeds to step 9 and the following steps.
In steps 9, 10, and 11, the reproduction flag 1 is turned on, and the first
The opening is adjusted so that the control valve is closed, the first heater is turned on (energized), and the regeneration of the first filter is started. When β ₂ ≧ βRe, that is, when it is determined that the second filter is to be regenerated, the routine proceeds to step 52, where a second filter regeneration start determination routine to be described later is executed.

When the regeneration judgment is made by the second filter regeneration start judging routine, in steps 18, 19 and 20,
The regeneration flag 2 is turned on, the opening is adjusted so that the second control valve is closed, and the second heater is turned on (energized).
The regeneration of the second filter is started. Then, from the time when the heater is turned on in step 11, the measurement of the heater energization time is started until the determination in step 12 becomes YES, that is,
The In the first heater side, performing energization to the heater energization time Th ₁ filter side being played reaches a predetermined time Tre. When it is determined in step 12 that the heater energization time has reached the predetermined time, it is determined that it is time to end the regeneration, and in step 13 the first heater is turned off.

In step 53, a first filter regeneration end determination routine to be described later is executed. When the end of regeneration is determined by the first filter regeneration end determination routine, in steps 14, 15, and 16, the first control valve is fully opened, the regeneration flag 1 is turned off, and the total accumulated amount of exhaust particulates β ₁ Is cleared to 0, and the reproduction operation ends. On the other hand, on the second heater side, measurement of the heater energization time is started from the time when the heater is turned on in step 20, and until the determination in step 21 becomes YES, that is, the heater energization time Th on the filter side during regeneration. Energization is performed until ₂ reaches a predetermined time Tre.
When it is determined in step 21 that the heater energization time has reached the predetermined time, it is determined that it is time to end the regeneration, and in step 22, the second heater is turned off.

In step 54, a second filter regeneration end determination routine to be described later is executed. When the end of the regeneration is determined by the second filter regeneration end determination routine, in steps 14, 15, and 16, the second control valve is fully opened, the regeneration flag 2 is turned off, and the total accumulated amount of exhaust particulates β ₂ Is cleared to 0, and the reproduction operation ends. FIG. 4 is a flowchart showing a first filter regeneration start determination routine in the control basic flowchart of the first embodiment.
It has the functions according to claims 1 and 3 of the present invention.

In step 26, the rotational speed sensor 141
It is determined whether the amount of decrease ΔN _DE per unit time of the engine speed N detected by the above is larger than a predetermined value N ₂ or not. When ΔN _DE ≧ N ₂ , that is, when it is determined that the engine rotation speed N is greatly reduced to a predetermined value N ₂ or more per unit time, for example, the driver turns off the accelerator and the vehicle It can be determined that the vehicle is decelerating, the engine rotational speed is decreasing, and the noise generated by the engine itself is also decreasing.

Accordingly, by proceeding to step 9 and subsequent steps, by closing the first control valve and starting regeneration of the first filter, even if the resonator effect is exhibited and the exhaust sound suddenly changes in the decreasing direction, Since the noise generated by the engine itself also changes in the decreasing direction, it is possible to prevent the driver from erroneously recognizing that the vehicle has failed.

Therefore, when ΔN _DE ≧ N ₂ , the routine proceeds to the above-mentioned step 9 and subsequent steps. That is, the determination in step 26 has a function as a reproduction control unit according to the first aspect. On the other hand, in step 26, when ΔN _DE <N ₂ , that is, when the engine rotation speed N has not decreased by the predetermined value N ₂ per unit time, the engine rotation speed has not decreased. There is no change in the sound generated by the engine itself. Therefore, in order to start the regeneration of the first filter, the process proceeds to step 9 and thereafter, and
If the control valve is closed and the exhaust sound changes suddenly in a decreasing direction, the driver may mistakenly recognize that the vehicle has an abnormality. The process proceeds to step 27 without starting regeneration of one filter.

In step 27, the engine speed N is detected from the speed sensor 141 and the control lever sensor 142.
And the engine load Q. In step 28, the engine speed N and the engine load Q read in step 27
Is calculated based on the map shown in FIG. 8 from the map shown in FIG.

In step 29, since neither the first nor the second filter is being regenerated, the accumulation amount ΔPM of the exhaust particulates is calculated as
The signals are distributed to the first and second filters and added, and the total deposition amounts β ₁ and β ₂ of both filters are detected. In step 30, it determines the total deposition amount beta ₁ of the first filter, whether reached the maximum deposition beta _MAX which the first filter may be deposited, respectively. Then, when the β ₁ ≧ β _{MA X,} that is, the first filter side, as it is impossible to collect any more exhaust particulate, the process proceeds to the following step 9 described above, forcing the first
Start regeneration of the filter to protect the device.

That is, the judgment in step 30 has the function according to claim 3. Next, what is shown in FIG.
5 is a flowchart showing a second filter regeneration start determination routine in the control basic flowchart of the first embodiment, and has a function according to claims 1 and 3 of the present invention. Steps having the same functions as those in the flowchart shown in FIG. 4 are denoted by the same step numbers, and description thereof is omitted.

At step 31, the rotational speed sensor 141
It is determined whether the amount of decrease ΔN _DE per unit time of the engine speed N detected by the above is larger than a predetermined value N ₂ or not. When ΔN _DE ≧ N ₂ , that is, when it is determined that the engine rotation speed N is greatly reduced to a predetermined value N ₂ or more per unit time, for example, the driver turns off the accelerator and the vehicle It can be determined that the vehicle is decelerating, the engine rotational speed is decreasing, and the noise generated by the engine itself is also decreasing.

Accordingly, by proceeding to step 18 and subsequent steps, by closing the second control valve and starting regeneration of the second filter, even if the resonator effect is exhibited and the exhaust noise suddenly changes in the decreasing direction, Since the noise generated by the engine itself is also sufficiently low, it is possible to prevent the driver from erroneously recognizing that an abnormality has occurred in the vehicle.

That is, the judgment in the step 31 has a function as a reproduction control means according to the first aspect. On the other hand, when ΔN _DE <N ₂ in step 31, the process proceeds to step 27 without first starting regeneration of the first filter. In step 35, the total deposition amount β of the second filter
₂ is the maximum deposition β _MAX that the second filter can deposit
Is determined individually. And β ₂ ≧ β
When _{MA X,} that is, the second filter side, as it is impossible to collect any more exhaust particulate, the process proceeds to the following step 18 described above, forced to start playback of the second filter, Protect equipment.

That is, the judgment in step 35 has the function according to claim 3. FIG. 6 is a flowchart showing a first filter regeneration end determination routine in the control basic flowchart of the first embodiment, and has a function according to claims 1 and 3 of the present invention. Steps
In 36, increment .DELTA.N _IN per unit time of the engine rotational speed N detected by the rotational speed sensor 141 to determine whether greater than a predetermined value N _3. And ΔN _IN
When ≧ N ₃ , that is, when it is determined that the engine rotation speed N is greatly increased to a predetermined value N ₃ or more per unit time, for example, the driver turns on the accelerator and the vehicle is accelerating. Thus, it can be determined that the engine rotational speed is increasing, and the noise generated by the engine itself is also changing in the increasing direction.

Here, when the first control valve is opened to terminate the regeneration of the first filter, the resonator effect is not exhibited and the exhaust noise is increased, but the noise generated by the engine itself is also increased. Since the direction changes, the increase in the exhaust noise and the increase in the noise generated by the engine itself are mixed, and the driver is not erroneously recognized as having an abnormality in the vehicle.

Therefore, when ΔN _IN ≧ N ₃ , the process proceeds to the above-mentioned step 14 and subsequent steps. That is, the judgment in the step 36 has a function as a reproduction control means according to the first aspect. On the other hand, in step 36, when ΔN _IN <N ₃ , that is, when the engine speed N does not increase as much as the predetermined value N ₃ per unit time, the engine speed does not increase. There is no change in the sound generated by the engine itself. Therefore, if the exhaust sound changes suddenly in the increasing direction by ending the regeneration of the first filter, the driver may be erroneously recognized as having an abnormality in the vehicle. The process proceeds to step 37 without ending the regeneration of the first filter.

At step 37, the engine speed N is detected from the speed sensor 141 and the control lever sensor 142.
And the engine load Q. In step 38, the engine speed N and the engine load Q read in step 37
Is calculated based on the map shown in FIG. 8 from the map shown in FIG.

In step 39, since the first filter is being regenerated and the second filter is not being regenerated, the accumulated amount ΔPM of the exhaust particulates is added to the second filter to detect the total accumulated amount β ₂ of the second filter. Do. In step 40, it determines the total deposition amount of the second filter beta ₂ is whether reached the maximum deposition beta _MAX to which the second filter can be respectively deposited. Then, when the beta ₂ ≧ beta _{MA X,} i.e. the second filter side, as it is impossible to collect any more exhaust particulate, the process proceeds to the following step 14 described above, forcing the second filter Start playback to protect the device.

That is, the judgment in step 40 has the function according to claim 3. Next, what is shown in FIG.
4 is a flowchart showing a second filter regeneration end determination routine in the control basic flowchart of the first embodiment, and has a function according to claims 1 and 3 of the present invention. Steps having functions similar to those of the flowchart shown in FIG. 6 are denoted by the same step numbers, and description thereof is omitted.

Here, by opening the second control valve in order to end the regeneration of the second filter, the resonator effect is not exhibited and the exhaust noise increases, but ΔN _IN ≧
When N _3, since the engine is also changed to increasing direction generated sound of the engine itself occurs, a state in which increase and are mixed for increasing the engine itself generated sound of the exhaust aspirated,
This does not cause the driver to erroneously recognize that an abnormality has occurred in the vehicle.

Therefore, in step 41, ΔN _IN ≧ N ₃
When the determination is made, the process proceeds to step 23 and subsequent steps. That is, the determination in the step 41 has a function as a reproduction control unit according to the first aspect. Meanwhile, step 41
When ΔN _IN <N _3, the process proceeds to step 37 without first terminating the regeneration of the second filter.

In step 44, since the second filter is being regenerated and the first filter is not being regenerated, the accumulated amount ΔPM of the exhaust particulates is added to the first filter, and the detection of the total accumulated amount β ₁ of the first filter is performed. Do. In step 45, it determines the total deposition amount beta ₁ of the first filter, whether reached the maximum deposition beta _MAX which the first filter may be deposited, respectively. Then, when the β ₁ ≧ β _{MA X,} i.e. the first filter side, as it is impossible to collect any more exhaust particulate, the process proceeds to the following step 23 described above, forcing the first filter Start playback to protect the device.

That is, the judgment in the step 45 has the function according to claim 3. Therefore, as described above, according to the first embodiment, even if the first filter or the second filter reaches the regeneration timing, the engine rotation speed N
If the decrease amount ΔN _DE per unit time does not decrease to the predetermined value N ₂ or more, the exhaust passage in which the first filter or the second filter to be regenerated is interposed remains open, and the regeneration is performed. Without performing regeneration of the first filter or the second filter, adsorption by the filter on the other side is performed. Then, when the decrease amount ΔN _DE has decreased to the predetermined value N ₂ or more, the exhaust passage is closed and full-scale regeneration is started.

That is, while the engine speed N is decreasing, the noise generated by the engine itself also changes in a decreasing direction. At that time, the exhaust passage is closed and the regeneration of the filter is started in earnest. Will be started
Even when the resonator effect is exerted and the exhaust noise suddenly changes in the decreasing direction, the noise generated by the engine itself also changes in the decreasing direction, so the exhaust noise changes and the driver The vehicle is not erroneously recognized as having an abnormality in the vehicle (exhaust sound is reduced as indicated by a dotted line in FIG. 9).

The closed state of the exhaust passage for the regeneration is based on the increase ΔN per unit time of the engine rotational speed N.
_IN is continued until rises above a predetermined value N _3. Then, while the increase amount ΔN _IN is rising to the predetermined value N ₃ or more, the exhaust passage is shifted to the open state, and the regeneration is ended. That is, when the engine rotation speed N is increasing and the engine rotation speed is increasing due to an accelerator operation or the like, the noise generated by the engine itself also changes in the increasing direction. Even if the exhaust sound suddenly changes in the increasing direction due to the shift to the open state and the resonator effect is not exhibited, the noise generated by the engine itself also changes in the increasing direction. And the driver does not feel uncomfortable (exhaust sound increases as shown by the dotted line in FIG. 9).

In the first embodiment, step 30 in the first filter regeneration start determination routine and second
In step 45 the filter regeneration termination determination routine, if the total deposited amount beta ₁ of the first filter has reached the maximum deposition beta _{MA X} of the first filter may be deposited, the forced regeneration of the first filter To start, and in step 35 in the second filter regeneration start determination routine and step 40 in the first filter regeneration termination determination routine,
When the total deposition amount β ₂ of the second filter reaches the maximum deposition β _{MAX at} which the second filter can deposit, the regeneration of the second filter is forcibly started to protect the device. In addition, an excessive load is prevented from being applied to the exhaust particulate processing device.

Next, the operation of the exhaust particulate processing apparatus according to the second embodiment of the present invention will be described with reference to the flowchart shown in FIG. Here, since the operation according to the above-described first embodiment is the same except for the following functions,
Description is omitted. In the second embodiment, as shown in FIG. 10, after reading the engine speed N and the engine load Q from the rotation speed sensor 141 and the control lever sensor 142 in step 1, the process proceeds to step 61, where the engine speed N There determines first whether a predetermined rotational speed N ₁ or less.

Only when the engine speed N is equal to or lower than the _first predetermined engine speed N ₁ , the process proceeds to step 2 or lower.
Performs the same control as in the first embodiment described above, the engine rotational speed N is first case higher than the predetermined rotational speed N ₁ does not perform the control of the exhaust particulate processing device, the routine returns. In the second embodiment, the same operation and effect as those of the first embodiment are provided. However, as a special operation and effect according to the second embodiment, as is apparent from FIG. The exhaust sound is greatly reduced by this, and a sudden change occurs in the exhaust sound when the engine rotation speed N is equal to or less than the _first predetermined rotation speed N1. By performing the regeneration control in consideration of the above-mentioned decrease / increase of the engine speed per predetermined time,
In particular, it is possible to prevent the driver from feeling uncomfortable.

Next, a third embodiment according to claims 4 to 6 of the present invention will be described. Since the system configuration is the same as that of the first embodiment, reference is made to FIG. Description is omitted. Next, the operation of the exhaust particulate processing apparatus according to the fourth to sixth aspects of the present invention will be described.

The basic flow chart of the control of the particulate collection operation and the filter regeneration operation by the filter of the exhaust particulate processing apparatus according to the fourth to sixth aspects of the present invention is the same as that of the first embodiment except for steps 51, 52, 53 and 54. This is the same as the control basic flowchart of the operation of collecting the fine particles by the filter and the operation of regenerating the filter of the first embodiment shown in FIGS. Here, since the filter regeneration operation is performed alternately, the heater 108, the filter 102, and the first on-off valve 104 on the first branch passage 120 side are respectively connected to the first heater, the first filter, and the first control unit for convenience. The heater 109, the filter 103, and the second on-off valve 10 on the side of the second branch passage 130 are called a valve.
5 will be referred to as a second heater, a second filter, and a second control valve, respectively.

Accordingly, only the functions different from those of the above-described first embodiment will be described with reference to FIGS. 11 and 12, which are the basic control flowcharts of the particulate collection operation and the filter regeneration operation according to the third embodiment. . In Steps 6 and 7, it is determined whether or not the total deposition amounts β ₁ and β _{2 of} each filter have reached a predetermined amount βRe determined to be the regeneration time. When β ₁ ≧ βRe, that is, when it is determined that the first filter side is at the regeneration time, the process proceeds to step 71.

In step 71, a first control valve closing judgment routine described later is executed. If the determination is made by the first control valve closing determination routine, the process proceeds to step 9 and the following steps. In steps 9, 10, and 11, the regeneration flag 1 is turned on, and the opening is adjusted so that the first control valve is closed. Is performed, the first heater is turned on (energized), and the regeneration of the first filter is started.

If β ₂ ≧ βRe, that is, if it is determined that the second filter is to be regenerated, the routine proceeds to step 72, where a second control valve closing determination routine described later is executed. If the determination is made by the second control valve closing determination routine, the regeneration flag 2 is turned on in steps 18, 19, and 20, and
The opening degree is adjusted so that the second control valve is closed, the second heater is turned on (energized), and the regeneration of the second filter is started.

When it is determined in step 12 that the heater energizing time has reached the predetermined time, it is determined that it is time to end the regeneration, and in step 13 the first heater is turned off. In step 73, a first control valve opening determination routine described later is executed. If the determination is made by the first control valve opening determination routine, in steps 14, 15, and 16,
Fully open the first control valve, the regeneration flag 1 and OFF, clears the value of the total deposition amount beta ₁ of exhaust particulate to 0, the reproduction operation is ended.

On the other hand, when it is determined in step 21 that the heater energizing time has reached the predetermined time, it is determined that it is time to end the regeneration, and in step 22, the second heater is turned off. In step 74, a second
A control valve opening determination routine is executed. If the judgment is made by the second control valve opening judgment routine, steps 14 and 1 are executed.
At 5 and 16, the second control valve is fully opened, and the regeneration flag 2 is turned off.
F, the value of the total accumulated amount β ₂ of exhaust particulates is cleared to 0, and the regeneration operation ends.

FIG. 13 is a flowchart showing a first control valve closing judgment routine in the control basic flowchart of the third embodiment, and has a function according to claims 4 and 6 of the present invention. In step 75, the engine speed N detected by the speed sensor 141 is set to a predetermined value N.
Determine if it is greater than _four . When N ≧ N ₄ , that is, when the filter is at the regeneration start time and the engine speed N is higher than the predetermined value N ₄ , the resonator effect is exhibited by closing the first passage 120. In this case, since the resonator effect is not significantly affected, the exhaust noise is not sharply reduced. It has been, when the engine rotational speed N is higher than the predetermined value N ₄ also changes in the decreasing direction in exhaust sound the first passage 120 is exerted resonator effect as closing is caused, since said change is small,
It can be determined that the driver does not mistakenly recognize that an abnormality has occurred in the vehicle due to the noise generated by the engine itself.

[0075] with, when N ≧ N ₄ proceeds to the following step 9 above. That is, the judgment in the step 75 has a function as the opening / closing prohibition means at the start of reproduction according to the fourth aspect. On the other hand, even if the filter becomes regeneration start timing, in step 75, when N <N _4, when the resonator effect by the first passage 120 and closing is exerted, said resonator effect is greatly affected Therefore, the exhaust noise is sharply reduced. If the first passage 120 is immediately closed and the regeneration is started immediately, there is a possibility that the driver may erroneously recognize that an abnormality has occurred in the vehicle.

When N <N ₄ , the process proceeds to step 9 and thereafter to start regeneration of the first filter.
If the control valve is closed and the exhaust sound changes suddenly in a decreasing direction, the driver may mistakenly recognize that the vehicle has an abnormality. The process proceeds to step 27 without starting regeneration of one filter. Further, it is determined in step 30, the total deposition amount beta ₁ of the first filter, whether reached the maximum deposition beta _MAX which the first filter may be deposited, respectively. Then, when β ₁ ≧ β _MAX , that is, on the first filter side, it is determined that it is impossible to collect exhaust particulates any more. To protect the device.

That is, the judgment in step 30 has the function according to claim 6. Next, what is shown in FIG.
It is a flowchart which shows the 2nd control valve closing determination routine in the control basic flowchart of this 3rd Example, and has the function which concerns on Claim 4 and Claim 6 of this invention. Steps having the same functions as those in the flowchart shown in FIG. 13 are denoted by the same step numbers, and description thereof is omitted.

In step 76, the rotational speed sensor 141
Engine rotational speed N detected by the determines whether greater than the predetermined value N _4. And when N ≧ N ₄ ,
That is, the filter becomes regeneration start timing, when the engine rotational speed N is higher than the predetermined value N ₄ is the second passage 130
Even when the resonator effect is exhibited by closing, the exhaust sound does not sharply decrease because the resonator effect is not greatly affected. It has been, when the engine rotational speed N is higher than the predetermined value N ₄ is the second passage 13
Even if 0 is closed and the resonator effect is exerted and the exhaust noise changes in a decreasing direction, the change is small, so the noise generated by the engine itself is influenced by the noise generated by the engine itself, and the driver has trouble with the car. It can be determined that there is no erroneous recognition that this has occurred.

[0079] with, when N ≧ N ₄ proceeds to the following step 18 described above. That is, the judgment in the step 76 has a function as the opening / closing prohibiting means at the start of reproduction according to the fourth aspect. On the other hand, even if the filter becomes regeneration start timing, in step 76, when N <N _4, when the resonator effect by the second passage 130 and closing is exerted, said resonator effect is greatly affected Therefore, the exhaust noise is sharply reduced. If the second passage 130 is immediately closed and the regeneration is started immediately, there is a possibility that the driver may erroneously recognize that an abnormality has occurred in the vehicle.

When N <N ₄ , the process proceeds to step 18 and thereafter to start regeneration of the second filter.
If the control valve is closed and the exhaust sound changes suddenly in a decreasing direction, the driver may mistakenly recognize that the vehicle has an abnormality. The process proceeds to step 27 without starting regeneration of the two filters. Further, it is determined in step 35, the total deposition amount of the second filter beta ₂ is whether reached the maximum deposition beta _MAX which the first filter may be deposited, respectively. Then, when β ₂ ≧ β _MAX , that is, on the second filter side, it is determined that it is impossible to collect the exhaust particulate any more, and the process proceeds to the above-mentioned step 18 and thereafter, and the regeneration of the second filter is forcibly performed. To protect the device.

That is, the judgment in step 35 has the function according to claim 6. FIG. 15 is a flowchart showing a first control valve closing determination routine in the control basic flowchart of the third embodiment, and has a function according to claims 5 and 6 of the present invention. In step 77, the engine rotational speed N detected by the rotational speed sensor 141 to determine whether greater than the predetermined value N _4. When N <N ₄ , that is, when the engine rotation speed N is smaller than the predetermined value N ₄ even when the regeneration of the filter is completed, the first passage through which the first filter to be regenerated is interposed. The opening / closing of the exhaust passage opening / closing means interposed in is not performed.

That is, when the first filter is regenerated, the regeneration is performed by closing the first control valve interposed in the first passage in which the regenerated first filter is interposed. even after the reproduction is completed, when the engine rotational speed N is a predetermined value N ₄ smaller than, be ended regenerated by the OFF of energization of the heater, the first control valve in a state where in the closed When the is opened, the exhaust sound that has been reduced by the resonator effect will increase sharply, and there is a risk that the driver may mistakenly recognize that there is an abnormality in the car, so dare The process proceeds to step 37 without terminating the regeneration of the first filter. That is, the power supply to the heater is turned off.
Thus, even if the regeneration is terminated, the closed exhaust passage is kept closed.

In step 40, it is determined whether or not the total deposition amount β ₂ of the second filter has reached the maximum deposition β _{MAX at} which the second filter can deposit. And
When β ₂ ≧ β _MAX , that is, on the side of the second filter, it is determined that it is impossible to collect the exhaust particulate any more. To protect the device.

That is, the judgment in step 40 has the function according to claim 6. On the other hand, in step 77, when N ≧ N ₄ , that is, when the energization to the heater is turned off, the regeneration is terminated, and the engine speed N
If it becomes the higher than a predetermined rotational speed N _4, it until it becomes possible to exhaust sound resonator effect was reduced is exerted is increased again, the engine rotational speed N is a second predetermined rotational speed N ₄ If it is higher, even if the resonator effect is not suddenly exhibited, the absence of the resonator effect does not have a great effect, so that the exhaust noise does not increase rapidly. Therefore, even if the first control valve is opened and the exhaust passage is opened, the change in the exhaust noise is small due to the elimination of the resonator effect. Is not mistakenly recognized as having occurred.

[0085] with, in step 77, when N ≧ N ₄ directly proceeds to step 14 below. Next, FIG. 16 is a flowchart showing a second control valve opening determination routine in the control basic flowchart of the third embodiment, and has a function according to claims 4 and 6 of the present invention. .

Steps having the same functions as those in the flowchart shown in FIG. 15 are assigned the same step numbers, and descriptions thereof are omitted. In step 78, the rotational speed sensor
The engine rotation speed N detected by 141 is equal to a predetermined value N ₄
It is determined whether it is larger than the above. When N <N ₄ , that is, when the engine rotation speed N is smaller than the predetermined value N ₄ even when the regeneration of the filter is completed, the second passage in which the second filter to be regenerated is interposed. The opening / closing of the exhaust passage opening / closing means interposed in is not performed.

That is, when the second filter is regenerated, the regeneration is performed by closing the second control valve interposed in the second passage in which the regenerated second filter is interposed. even after the reproduction is completed, when the engine rotational speed N is a predetermined value N ₄ smaller than, be ended regenerated by the OFF the power supply to the heater, a second control valve in a state where in the closed When the is opened, the exhaust sound that has been reduced by the resonator effect will increase sharply, and there is a risk that the driver may mistakenly recognize that there is an abnormality in the car, so dare The process proceeds to step 37 without terminating the regeneration of the second filter. That is, the power supply to the heater is turned off.
Thus, even if the regeneration is terminated, the closed exhaust passage is kept closed.

[0088] In step 45, the total deposition amount beta ₁ of the first filter, respectively determines whether reached the maximum deposition beta _MAX which the first filter may be deposited. And
When β ₁ ≧ β _MAX , that is, on the first filter side, it is determined that it is impossible to collect any more exhaust particulates, so the process proceeds to step 23 and the following to forcibly start regeneration of the second filter. To protect the device.

That is, the judgment in step 45 has the function according to claim 6. On the other hand, in step 78, when N ≧ N ₄ , that is, when the energization to the heater is turned off, the regeneration is terminated, and the engine speed N becomes the second
If it becomes the higher than a predetermined rotational speed N _4, it until it becomes possible to exhaust sound resonator effect was reduced is exerted is increased again, the engine rotational speed N is a second predetermined rotational speed N ₄ If it is higher, even if the resonator effect is not suddenly exhibited, the absence of the resonator effect does not have a great effect, so that the exhaust noise does not increase rapidly. Therefore, even if the second control valve is opened and the exhaust passage is opened, the change in exhaust sound is small due to the elimination of the resonator effect. Is not mistakenly recognized as having occurred.

When N ≧ N ₄ in step 77, the process directly proceeds to step 23 and subsequent steps. Therefore, as described above, according to the third embodiment, even when the first filter or the second filter regeneration timing, when the engine rotational speed N is a predetermined value N ₄ smaller than, be the reproduction The regeneration of the first filter or the second filter to be performed is not performed, and the adsorption by the filter on the other side is performed. Then, the engine rotational speed N is in the case of more than the predetermined value N _4, starts a full-scale reproduction of the exhaust passage is closed (see FIG. 17).

[0091] That is, when the engine rotational speed N is equal to or higher than the predetermined value N ₄ is not as large resonator effect, with the exhaust passage at that time is closed, the will the filter regeneration is started in earnest, resonator Even if the effect is exhibited, the exhaust noise does not change suddenly in the decreasing direction, and the change in the exhaust noise is small, so that the driver does not mistakenly recognize that an abnormality has occurred in the car (see FIG. As shown by the dotted line in Fig. 17, the resonator effect is not large).

[0092] Also, the closed state of the exhaust passage according to the regeneration, the engine rotational speed N is continued until rises above a predetermined value N _4. And when the engine rotational speed N rises above a predetermined value N _4, the process proceeds to the exhaust passage in an open state to end the playback. That is, when the engine rotation speed N is smaller than the predetermined value N ₄ , the resonator effect is large. Therefore, when the exhaust passage is shifted from the closed state to the open state at that time, the resonator effect is not exhibited. In this case, the exhaust sound changes in a sharply increasing direction, which may make the driver feel uncomfortable (the exhaust sound is increasing as shown by the dotted line in FIG. 17).

Note that in the third embodiment described above,
Predetermined value N ₄ may be a first equivalent predetermined rotational speed N ₁ in the second embodiment described above. Further, in the third embodiment, step 30 in the first control valve closing determination routine and
In step 45 in the second control valve opens determination routine, if the total deposited amount beta ₁ of the first filter has reached the maximum deposition beta _MAX which the first filter may be deposited, forced regeneration of the first filter And in step 35 of the first control valve closing determination routine and step 40 of the first control valve opening determination routine, the total deposition amount β ₂ of the second filter is the maximum deposition amount that the second filter can deposit. β
_{When the maximum value} is reached, the regeneration of the second filter is forcibly started to protect the apparatus, thereby preventing an excessive load from being applied to the exhaust particulate processing apparatus.

[0094]

As described above, according to the first aspect of the present invention, the regeneration does not start unconditionally even when the filter reaches the regeneration time, and the engine rotational speed decreases by a predetermined value or more within a predetermined time. In this case, since the regeneration is started, the regeneration of the filter is started when the noise generated by the engine itself is also changing in the decreasing direction, and the resonator effect is exerted and the exhaust noise is sharply reduced. Even if there is a change in the decreasing direction, the noise generated by the engine itself also changes in the decreasing direction, so that the driver does not mistakenly recognize that the car has an abnormality and the filter Even if the predetermined regeneration condition is terminated, the passage is opened unconditionally and the regeneration is not terminated. When the engine rotational speed increases by a predetermined value or more within a predetermined time, the regeneration is terminated. The passage is opened when the sound generated by the engine itself also changes in the increasing direction, and even if the exhaust sound changes suddenly in the increasing direction, the sound generated by the engine itself also changes in the increasing direction. The effect is that the driver does not feel uncomfortable.

According to the second aspect of the present invention, when operating conditions in which a sharp change in exhaust sound due to a decrease in exhaust sound is particularly noticeable, that is, in an operating state in which the engine speed is equal to or lower than the first predetermined speed, Furthermore, since the regeneration control is performed in consideration of the above-mentioned decrease / increase of the engine speed per predetermined time, there is an effect that the driver does not particularly feel uncomfortable.

Further, according to the third aspect of the present invention, it is possible to prevent exhaust particulates exceeding the maximum processing capacity from being deposited on the exhaust particulate collecting means, thereby preventing an excessive load from being applied to the exhaust particulate processing apparatus. effective. According to the fourth aspect of the present invention, even if the filter reaches the regeneration start time, if the engine rotation speed is equal to or lower than the second predetermined rotation speed, the regeneration is not immediately started, and the exhaust passage closing operation is not performed. Is not performed, the exhaust noise is not suddenly reduced due to the effect of the resonator, and the driver is not erroneously recognized as having an abnormality in the vehicle. On the other hand, when the engine rotation speed is higher than the second predetermined rotation speed, the closing operation of the exhaust passage is performed, so that even if the resonator effect is exhibited and the exhaust noise changes in the decreasing direction,
Since the change is small, there is no possibility that the driver will mistakenly recognize that the vehicle has an abnormality because the noise is generated by the engine itself, and the filter is immediately regenerated. There is.

According to the fifth aspect of the present invention, even after the regeneration of the filter is completed, if the engine speed is equal to or lower than the second predetermined speed, the operation of the heating means is stopped. Even when the regeneration is finished, the closed exhaust passage is kept closed as it is, and if the engine speed is higher than the second predetermined rotation speed, even if the resonator effect is not suddenly exhibited, the Elimination of the resonator effect does not have a significant effect, so that the exhaust noise does not increase sharply. Therefore, even if the opening operation of the exhaust passage is performed, since the change in the exhaust noise is small due to the elimination of the resonator effect, the noise generated by the engine itself is influenced by the noise generated by the engine itself, and the driver has an abnormality in the vehicle. Since there is no erroneous recognition that the exhaust gas has occurred, there is an effect that the exhaust passage can be opened immediately and the collection of exhaust particulates can be started.

Further, according to the present invention, it is possible to prevent exhaust particles having a maximum processing capacity from being deposited on the exhaust particle collecting means, thereby preventing an excessive load from being applied to the exhaust particle processing apparatus. This has the effect of improving the reliability of the device.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of an exhaust particulate processing apparatus for an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a basic operation of controlling a particulate collection operation and a filter regeneration operation by the filter according to the first embodiment of the present invention.

FIG. 3 is a flowchart illustrating a basic operation of controlling a particulate collection operation and a filter regeneration operation by the filter according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing a first filter regeneration start determination routine according to the first embodiment;

FIG. 5 is a flowchart showing a second filter regeneration start determination routine according to the first embodiment;

FIG. 6 is a flowchart showing a first filter regeneration end determination routine according to the first embodiment;

FIG. 7 is a flowchart showing a second filter regeneration end determination routine according to the first embodiment;

FIG. 8 is a graph showing exhaust particulate emission characteristics depending on engine speed and engine load.

FIG. 9 is a graph showing exhaust sound characteristics depending on engine speed.

FIG. 10 is a flowchart illustrating a basic control operation of a particulate collection operation and a filter regeneration operation by the filter according to the second embodiment of the present invention.

FIG. 11 is a flowchart illustrating a basic operation of controlling a particulate collection operation and a filter regeneration operation by the filter according to the third embodiment of the present invention.

FIG. 12 is a flowchart illustrating a basic operation of controlling a particulate collection operation and a filter regeneration operation by the filter according to the third embodiment of the present invention.

FIG. 13 is a flowchart illustrating a first control valve closing determination routine according to the third embodiment.

FIG. 14 is a flowchart showing a second control valve closing determination routine according to the third embodiment.

FIG. 15 is a flowchart illustrating a first control valve opening determination routine according to the third embodiment.

FIG. 16 is a flowchart illustrating a second control valve opening determination routine according to the third embodiment.

FIG. 17 is a graph showing exhaust sound characteristics depending on engine speed.

[Explanation of symbols]

 100 Internal combustion engine 101 Exhaust passage 102 Filter 103 Filter 104 First on-off valve 105 Second on-off valve 108 Heater 109 Heater 120 First branch passage 130 Second branch passage 141 Rotation speed sensor 142 Control lever sensor 150 Control unit

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuhisa Kitahara 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Inside Nissan Motor Co., Ltd. (72) Motohiro Niizawa 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. In-company (56) References JP-A-5-163931 (JP, A) JP-A-5-321637 (JP, A) JP-A-5-288039 (JP, A) (58) Fields studied (Int. . ^6, DB name) F01N 3/02 321 F01N 3/02 331 F01N 3/02 341

Claims (6)

(57) [Claims] 1. A plurality of exhaust particulate collecting means, comprising: a plurality of exhaust passages for an internal combustion engine, each of which is provided with a filter that is interposed in each of the branched exhaust passages and that collects particulates in exhaust gas. A plurality of heating means for regenerating the filter by heating and burning and removing the exhaust fine particles collected by each of the filters; interposed in each of the branched exhaust passages to open and close the exhaust passages A plurality of exhaust passage switching means, wherein in an exhaust particulate processing apparatus for an internal combustion engine that collects exhaust particulates by the plurality of exhaust particulate collecting means during non-regeneration, an operation detecting at least an operating state including an engine rotation speed. The state detecting means and the filter to be regenerated when the engine rotation speed detected by the operating state detecting means decreases by a predetermined value or more for a predetermined time are interposed at the regeneration time of the filter. A regeneration control unit that starts regeneration by closing the air passage, and that terminates regeneration by opening the exhaust passage when the engine rotation speed increases by a predetermined value or more during a predetermined time during the regeneration. Exhaust particulate processing device for an internal combustion engine. 2. An engine according to claim 1, wherein the engine speed detected by the operating condition detecting means is equal to or lower than a first predetermined speed.
2. The exhaust particulate processing apparatus for an internal combustion engine according to claim 1, wherein said regeneration control means controls start / end of said regeneration. 3. The regeneration control means according to the change in the engine speed when the total amount of exhaust particulates collected by each filter exceeds the maximum amount that the filters can accumulate. 2. The exhaust particulate processing apparatus for an internal combustion engine according to claim 1, wherein the regeneration of the filter is started prior to the start / end control of the regeneration. 4. A plurality of exhaust particulate collecting means provided with a filter which branches an exhaust passage of an internal combustion engine into a plurality of parts, is provided in the middle of each of the branched exhaust paths, and collects particulates in the exhaust. A plurality of heating means for regenerating the filter by heating and burning and removing the exhaust fine particles collected by each of the filters; interposed in each of the branched exhaust passages to open and close the exhaust passages A plurality of exhaust passage switching means, wherein in an exhaust particulate processing apparatus for an internal combustion engine that collects exhaust particulates by the plurality of exhaust particulate collecting means during non-regeneration, an operation detecting at least an operating state including an engine rotation speed. A state detection means, and when the engine rotation speed detected by the operating state detection means is equal to or lower than a second predetermined rotation speed at the start of regeneration of the filter, a filter to be regenerated is interposed. Exhaust particulate processing device for an internal combustion engine, characterized by being configured and a playback start time closing prohibiting means is not performed the closing operation of the exhaust passage switching means interposed in the passage. 5. A plurality of exhaust particulate collecting means provided with a filter which branches an exhaust passage of an internal combustion engine into a plurality of parts, is provided in the middle of each of the branched exhaust paths, and collects particulates in the exhaust. A plurality of heating means for regenerating the filter by heating and burning and removing the exhaust fine particles collected by each of the filters; interposed in each of the branched exhaust passages to open and close the exhaust passages A plurality of exhaust passage switching means, wherein in an exhaust particulate processing apparatus for an internal combustion engine that collects exhaust particulates by the plurality of exhaust particulate collecting means during non-regeneration, an operation detecting at least an operating state including an engine rotation speed. A state detecting means, and, when the engine rotation speed detected by the operating state detection means is equal to or lower than a second predetermined rotation speed at the end of the regeneration of the filter, the exhaust filter provided with the regenerated filter is interposed. A reproduction end time of closing inhibiting means does not perform the opening operation, by being configured with an exhaust particulate processing device for an internal combustion engine characterized by the exhaust passage switching means interposed in the passage. 6. The regeneration control means controls the opening / closing operation of an exhaust passage opening / closing means provided in an exhaust passage provided with a filter to be regenerated by the regeneration start / stop prohibition means or the regeneration end opening / closing prohibition means. Even during prohibition, if the total accumulated amount of exhaust particulates collected by each filter exceeds the maximum accumulation amount that the filter can accumulate, restart the filter immediately. Claim 4
6. The exhaust particulate processing device for an internal combustion engine according to claim 5.