JP2007270646A - Exhaust emission control device of vehicular internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device of a vehicular internal combustion engine, which performs a rich spike in the optimal timing in response to a driving operation pattern of a driver, when purging NOx of a storage type NOx catalyst. <P>SOLUTION: When purging the NOx of the storage type NOx catalyst 42, the driving operation pattern (an inter-shift operation time and a maximum engine speed of an engine with every shift stage) of the driver of a vehicle is detected and learnt (10b). The rich spike is performed by setting the timing of the rich spike on the basis of the driving operation pattern of the driver (10a). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an exhaust emission control device for an internal combustion engine for a vehicle, and more particularly to a NOx purge technique for a storage type NOx catalyst provided in an exhaust passage of the internal combustion engine.

An exhaust purification catalyst is generally provided as an exhaust aftertreatment device in an exhaust passage of an internal combustion engine (engine) mounted on a vehicle, and harmful substances (CO, HC, NOx, etc.) in the exhaust are exhausted by the exhaust purification catalyst. It is removed by oxidation or reduction.
In particular, when the engine is an engine that easily discharges NOx, such as a diesel engine, as an exhaust purification catalyst, the NOx is stored in an oxidizing atmosphere (under a lean air-fuel ratio), while the NOx is stored in a reducing atmosphere (under a rich air-fuel ratio). Storage NOx catalysts capable of purifying NOx by releasing the stored NOx and reducing and removing (NOx purge) are widely used.

In such a storage-type NOx catalyst, a rich air-fuel ratio gas (rich gas, for example, HC gas) is periodically supplied to the storage-type NOx catalyst in a spike manner, thereby forming a reducing atmosphere. NOx purge is performed (this is called rich spike).
By the way, the rich spike is often performed by increasing the fuel of the engine, but in such a case, it may be inappropriate to perform the rich spike depending on the operating state of the engine.

  For example, when the engine is in a low speed and low load operation state, the exhaust gas temperature is low, so the storage NOx catalyst is also low temperature, and even if rich spike is performed, the rich gas may slip (HC slip). When in the load operation state, if the rich spike is performed, the storage-type NOx catalyst may overheat. Further, depending on the operating state of the engine, if rich spike is performed, torque fluctuation may occur and torque shock may occur.

Therefore, when performing the rich spike, it is generally determined whether or not the rich spike execution condition is satisfied according to the operating state of the engine.
Also, if the transmission is changed during the rich spike, the torque fluctuation due to the rich spike overlaps with the torque fluctuation due to the shift, resulting in a large torque shock. A technique for performing rich spike so as not to overlap with the shift timing has been developed (Patent Document 1).
JP-A-9-184438

By the way, in the above patent document, the shift is predicted according to the vehicle speed and the throttle opening, and the shift is not predicted in consideration of the driving operation pattern of the driver. (For example, an acceleration operation pattern in an automatic transmission) There is still a problem that a shift and a rich spike may overlap each other.
In other words, a certain period of time is required to execute a single rich spike, but the time between shift operations from the previous shift to the next shift is normal depending on the driver's shift operation pattern based on the driver's preference, for example. In such a case, there is a problem that the rich spike is not completed if the rich spike is performed during the short time between the shifting operations. In this case, in order to prevent the torque shock from increasing as described above, the rich spike must be interrupted in an incomplete state, and it is necessary to execute the rich spike again, which is not preferable because it leads to deterioration of fuel consumption. .

  When such incomplete rich spikes are repeated intermittently, light oil as a reducing agent is intermittently supplied, and as a result, light oil is burned intermittently without reducing NOx. As a result, a large amount of heat of reaction continues to be generated. Further, in the state of excessive temperature rise, the stored NOx is easily released, and the released NOx cannot be reduced because the exhaust gas is in an oxidized state, and the NOx is discharged as it is, Since it is difficult for the catalyst to occlude NOx when the temperature is excessively high, there is a problem that NOx in the exhaust gas is discharged as it is.

Further, the storage type NOx catalyst has an exhaust flow rate, catalyst temperature, and the like that are appropriate for performing a rich spike, and a driver based on the driver's preference regarding the timing of the appropriate exhaust flow rate, catalyst temperature, etc. There is a problem that it is greatly influenced by the acceleration operation pattern.
The present invention has been made to solve such problems, and the object of the present invention is to perform rich NOx purging of the storage type NOx catalyst at an optimal time according to the driving operation pattern of the driver. An object of the present invention is to provide an exhaust emission control device for an internal combustion engine for a vehicle that can implement a spike.

  In order to achieve the above object, an exhaust emission control device for an internal combustion engine for a vehicle according to claim 1 is provided in an exhaust passage of an internal combustion engine mounted on a vehicle, and stores NOx when in an oxidizing atmosphere while being in a reducing atmosphere. An occlusion type NOx catalyst for releasing and reducing the occluded NOx, a reducing agent supplying means for supplying a reducing agent to the occlusion type NOx catalyst to make the occlusion type NOx catalyst into a reducing atmosphere, a vehicle driver Driving operation pattern detection means for detecting a driving operation pattern, learning means for learning a driving operation pattern of the driver detected by the driving operation pattern detection means, and driving operation patterns of the driver learned by the learning means Based on the reducing agent supply timing setting means for setting the supply timing of the reducing agent by the reducing agent supply means, and the supply timing set by the reducing agent supply timing setting means. Characterized in that a control means for supplying a serial reducing agent.

An exhaust emission control device for an internal combustion engine for a vehicle according to claim 2 is characterized in that, in claim 1, the vehicle is provided with a transmission coupled to the internal combustion engine, and further includes a shift operation means for performing a shift operation of the transmission, The driving operation pattern detecting means detects a speed change operation pattern of the speed change operating means, and the learning means learns the detected speed change operation pattern.
According to a third aspect of the present invention, there is provided an exhaust purification apparatus for an internal combustion engine for a vehicle according to the second aspect, wherein the parameter defining the shift operation pattern is a time between shift operations from the previous shift stage to the next shift stage, and the learning means. Learns the time between the shift operations, and the reducing agent supply timing setting means determines that the time until the next shift stage is larger than the supply period of the reducing agent based on the time between the shift operations. The supply timing of the reducing agent is set at the shift speed.

An exhaust emission control device for an internal combustion engine for a vehicle according to claim 4 further comprises acceleration operation means for accelerating the internal combustion engine according to claim 2 or 3, wherein the driving operation pattern detection means further includes an acceleration operation pattern of the acceleration operation means. The learning means further learns the detected acceleration operation pattern for each gear stage of the transmission.
According to a fifth aspect of the present invention, there is provided an exhaust purification apparatus for an internal combustion engine for a vehicle according to any one of the second to fourth aspects, further comprising a rotational speed detecting means for detecting the rotational speed of the internal combustion engine, wherein the parameter defining the acceleration operation pattern The learning means learns the maximum rotational speed of the internal combustion engine for each shift speed.

  According to the exhaust purification system for an internal combustion engine for a vehicle of claim 1, when performing NOx purging of the storage type NOx catalyst, the driving operation pattern of the driver of the vehicle is detected and learned, and the driving operation pattern of the driver is obtained. Since the rich spike is executed based on the above, the rich spike can be executed at an optimal time in consideration of the driver's favorite driving operation pattern. As a result, it is possible to stabilize the rich spike and to optimize the NOx purge.

  According to the exhaust emission control device for an internal combustion engine for a vehicle according to claim 2, the shift operation pattern of the shift operation means by the driver is detected and learned, and the rich spike is performed based on the shift operation pattern of the driver. Therefore, the rich spike can be performed at an optimum time so as not to overlap with the gear shift timing in consideration of the driver's favorite gear shift operation pattern. As a result, the torque shock can be prevented from increasing, and the rich spike can be prevented from being interrupted in an incomplete state by shifting, thereby preventing deterioration of fuel consumption. It is possible to prevent excessive temperature rise and NOx emission associated therewith.

  According to the exhaust purification system for an internal combustion engine for a vehicle according to claim 3, the parameter defining the shift operation pattern is the time between shift operations from the previous shift stage to the next shift stage, and the reduction is performed based on the shift operation time. When the time until the next gear stage is longer than the agent supply period, the reducing agent is supplied at the previous gear stage. Therefore, it can be carried out at a gear position that does not overlap with the gear shift timing.

  According to the exhaust gas purification apparatus for an internal combustion engine for a vehicle according to the fourth aspect, the acceleration operation pattern of the acceleration operation means is further detected and learned for each gear stage of the transmission, and the rich spike is performed based on the acceleration operation pattern. As a result, the rich spike can be performed at an optimum time in consideration of the driver's favorite acceleration operation pattern. Thereby, incomplete rich spikes can be prevented from being repeated, and the NOx purification rate can be improved while suppressing wasteful consumption of reducing agent.

  According to the exhaust gas purification apparatus for an internal combustion engine for a vehicle according to claim 5, since the parameter that defines the acceleration operation pattern is the maximum rotation speed of the internal combustion engine for each shift stage, the rich spike is based on the driver's favorite acceleration operation. In consideration of the maximum rotational speed of the internal combustion engine for each shift stage, it can be carried out at the time when the optimal rotational speed and thus the exhaust flow rate, catalyst temperature, etc., which are optimal for the rich spike. As a result, since the rich spike can be performed with the exhaust gas temperature suitable for the catalyst as much as possible, the reducing agent reacts sufficiently, and it is possible to improve the NOx purification rate while preventing HC slip. it can.

Hereinafter, an embodiment of an exhaust emission control device for an internal combustion engine for a vehicle according to the present invention will be described with reference to the drawings.
FIG. 1 is a system configuration diagram of an exhaust purification device for an internal combustion engine for a vehicle according to the present invention. In FIG. 1, reference numeral 1 indicates a common rail diesel engine, for example, and reference numeral 10 indicates a main part of the engine control device. An electronic control unit (hereinafter referred to as ECU) is shown.

  Although not shown in detail, a common rail diesel engine (hereinafter simply referred to as an engine) 1 includes a needle valve and a fuel injector having a fuel chamber and a control chamber provided on the distal end side and the proximal end side of the needle valve. Provided for each cylinder, the fuel chamber and the control chamber are connected to a pressure accumulating chamber via a fuel passage, and the control chamber is connected to a fuel tank via a fuel return passage. Under the control of the ECU 10, when the solenoid valve provided in the fuel injector is opened, the high-pressure fuel supplied from the pressure accumulating chamber is injected into the combustion chamber of the engine 1 through the fuel injector, and when the solenoid valve is closed, the fuel injection is finished. Thus, the fuel injection start / end timing (fuel injection amount) is adjusted by controlling the opening / closing timing of the solenoid valve.

  The engine 1 has an intake pipe 12 connected to an intake manifold 11 and an exhaust pipe (exhaust passage) 14 connected to an exhaust manifold 13. In the middle of the intake pipe 12, a compressor 21, an intercooler 31, and an intake throttle valve 32 of the supercharger 20 are arranged. On the other hand, a turbine 22 of the supercharger 20, an exhaust brake 15, a light oil addition injector 50, an aftertreatment device 40 and a muffler (not shown) are provided in the middle of the exhaust pipe 14.

In FIG. 1, reference numeral 36 denotes an EGR passage extending from the exhaust manifold 13 to the intake pipe 12. In the middle of the EGR passage 36, an EGR cooler 37 that cools EGR gas and supply of EGR gas to the engine 1 and supply interruption An EGR valve 38 is provided.
A manual transmission 18 is connected to the engine 1 via a clutch (not shown), and the manual transmission 18 is selected in accordance with a shift operation of a shift lever (not shown, shift operation means). It is configured to be. Here, the manual transmission 18 includes, for example, four forward speeds (1st, 2nd, 3rd and 4th) and one reverse speed.

  The post-processing device 40 includes a diesel particulate filter (DPF) 41 that collects particulate matter (PM) and burns and removes the particulate matter (PM), and NOx in exhaust gas in an oxidizing atmosphere (lean air-fuel ratio) that is positioned in front of the DPF 41. NOx occlusion catalyst (occlusion type NOx catalyst) 42 that occludes NOx occluded in a reducing atmosphere (rich air-fuel ratio) and releases and removes (NOx purge), and excess HC and CO located in the subsequent stage of the DPF 41 And a rear-stage catalyst 43 that oxidizes and removes the catalyst. A light oil addition injector 50 is provided in the front stage of the aftertreatment device 40.

The light oil addition injector 50 mainly uses light oil (fuel, HC) in the exhaust gas to raise the temperature of the NOx storage catalyst 42 and raise the temperature of the DPF 41 at the time of forced regeneration of the DPF 41 that mainly burns and removes PM collected by the DPF 41. And is driven and controlled by the ECU 10.
The ECU 10 includes a clutch sensor 60 that detects whether or not the clutch is operated by detecting the clutch engagement / disengagement state, a shift position sensor 61 that detects a shift position selection position (shift position) of the shift lever, an accelerator pedal ( Various sensors such as an accelerator opening sensor 62 that detects an accelerator opening (not shown) and a crank angle sensor 63 that detects a crank angle are connected. The crank angle sensor 63 can detect the engine rotational speed Ne based on the crank angle (rotational speed detecting means).

Thus, the ECU 10 determines the operating region of the engine 1 based on the accelerator opening detected by the accelerator opening sensor 62 and the engine rotational speed Ne detected by the crank angle sensor 63, and according to the engine operating region. The fuel injection timing and the fuel injection amount can be controlled by turning on and off the solenoid valve of each fuel injector of the engine 1.
Further, the ECU 10 is provided with a NOx purge control unit (reducing agent supply timing setting means, control means) 10a for performing NOx purge of the NOx storage catalyst 42. In addition to the above, the NOx purge control unit 10a is configured to be able to control the solenoid valves of the fuel injectors so as to perform NOx purge. Specifically, the NOx purge control unit 10a increases a predetermined amount of light oil (fuel, reducing agent, HC) from each of the fuel injectors over a predetermined period (reducing agent supply period) in response to a request to perform NOx purging. Thus, the rich air-fuel ratio gas (rich gas) is discharged to the exhaust pipe 14 and supplied to the NOx storage catalyst 42, and so-called rich spike is performed (reducing agent supply means). As a result, the NOx storage catalyst 42 can be in a reducing atmosphere, and NOx stored in the NOx storage catalyst 42 can be released and reduced and removed.

Further, as described above, depending on the operating state of the engine 1 and the like, when the rich spike is performed, torque fluctuation occurs and torque shock is caused. Therefore, the NOx purge control unit 10a has such problems. In this way, the NOx purge can be performed at an appropriate time regardless of the operating state of the engine 1 or the like.
Further, the ECU 10 is provided with a driving operation pattern learning unit (driving operation pattern detecting means, learning means) 10b. Since the driving operation pattern learning unit 10b has a different preference for driving the vehicle for each driver (such as a crisp driving, a comfortable driving, etc.) and this influence also appears in the rich spike period, it is optimal to eliminate such an influence. The driving operation pattern for each driver can be learned so that a rich spike can be performed at an appropriate time.

The operation and effect of the exhaust emission control device for an internal combustion engine for a vehicle according to the present invention configured as described above will be described below.
First, the learning content in the driving operation pattern learning unit 10b will be described.
Although there are various driving operation patterns, here, learning of a shift operation pattern when operating the shift lever having a large influence on the rich spike timing and an acceleration operation pattern when operating the accelerator pedal will be described.

[Learning gear shifting pattern]
FIGS. 2 and 3 show the time between the shift operation from the previous shift stage to the next shift stage at the time of the shift up, for example, based on information from the clutch sensor 60 until the clutch is operated once. 2 is shown for each switching operation of each gear stage, FIG. 2 shows a shifting operation pattern of driver A who prefers a leisurely driving, and FIG. 3 shows a shifting operation pattern of driver B who prefers a crisp driving. .

  According to FIG. 2, in the case of driver A who likes slow driving at the time of upshifting, the vehicle accelerates moderately at 1st (dashed line), then shifts from 2nd to 3rd immediately (solid line), and greatly accelerates at 3rd (dashed line) On the other hand, according to FIG. 3, in the case of driver B who prefers the crisp operation, the gear shifts from 1st to 2nd (dash-dotted line) and then greatly accelerates (solid line) at 2nd. It turns out that it tends to accelerate moderately (broken line) at 3rd.

Thus, in learning of the shift operation pattern, based on information from the clutch sensor 60 or information from the shift position sensor 61, the time between shift operations for each switching operation of each shift stage is detected for each driver (driving operation). Pattern detection means), learns this, and stores the learned value in the memory of the ECU 10. Note that learning of this shift operation pattern is constantly updated.
[Learning acceleration operation patterns]
For example, in the case of driver B who prefers to drive crisply, the acceleration operation of the accelerator pedal is also relatively steep, and the engine rotational speed Ne at each shift stage is considered to be relatively large, while he prefers to drive slowly. In the case of the driver A, the acceleration operation of the accelerator pedal is also relatively slow, and the engine rotational speed Ne at each shift stage is considered to increase relatively slowly.

Thus, in the learning of the acceleration operation pattern, the maximum engine speed Nem that can be reached at each gear position is detected for each driver based on the information from the crank angle sensor 63 (driving operation pattern detection means). Learning is performed, and the learning value is stored in the memory of the ECU 10. The learning of the acceleration operation pattern is constantly updated.
Next, the content of NOx purge control in the NOx purge control unit 10a will be described.

FIG. 4 is a flowchart showing a control routine for NOx purge control according to the present invention, which will be described below.
In step S10, it is determined whether or not a NOx purge request has been made. If the determination result is false (No), the routine is exited. On the other hand, if the determination result is true (Yes) and it is determined that a NOx purge request has been made, the process proceeds to step S12.

In step S12, it is determined whether or not the current gear position is 1st. If the determination result is true (Yes) and the current gear position is 1st, the process proceeds to step S14.
In step S14, it is determined whether or not there is no shift operation to the 2nd before the completion of the rich spike based on the learned time between the 1st and 2nd shift operations. In other words, the rich spike requires a predetermined period as described above, but based on the learned time between 1st and 2nd shift operations, the predetermined period for the rich spike is predicted to be a shift operation from the current time to 2nd. It is discriminated whether or not it is within the time until the specified time.

If the determination result in step S14 is true (Yes) and it is determined that there is no 2nd shift operation before the completion of the rich spike, the process proceeds to step S30.
In step S30, whether or not the optimal rich spike point is obtained from the learning, that is, the optimal rich spike point corresponding to the maximum engine speed Nem that can be reached in 1st based on the learning of the acceleration operation pattern. It is determined whether or not there is. Specifically, for example, the optimum rich spike point is determined when the engine speed is close to the maximum engine speed Nem.

  Thus, generally, the higher the engine speed Ne, the higher the exhaust flow rate and the higher the exhaust temperature. Therefore, it is suitable for the rich spike. For example, in the case of the driver B who prefers the crisp operation, the maximum engine speed Nem is high. The rich spike can be executed at the highest engine speed Ne as much as possible. On the other hand, in the case of the driver A who prefers a leisurely driving, the maximum engine speed Nem is relatively low, without waiting for the engine speed Ne to increase. Rich spikes can be implemented.

In step S32, rich spike is performed at the first rich spike point.
If the determination result in step S14 is false (No) and it is determined that there is a shift operation to 2nd before the rich spike is completed, the process proceeds to step S16.
In step S16, it is determined based on the learned time between 2nd to 3rd speed change operations whether rich spike is possible in 2nd. That is, it is determined whether or not the predetermined period for the rich spike falls within the learned 2nd to 3rd shift operation time. If the determination result is true (Yes) and it is determined that rich spike is possible at 2nd, or if the determination result in step S12 is false (No), the process proceeds to step S18.

In step S18, it is determined whether or not the current gear position is 2nd. If the determination result is true (Yes) and the current gear position is 2nd, the process proceeds to step S20.
In step S20, based on the learned time between shift operations from 2nd to 3rd, as in the case of step S14, it is determined whether or not there is no shift operation to 3rd before completion of rich spike. If the determination result is true (Yes) and it is determined that there is no shift operation to 3rd before the rich spike is completed, the process proceeds to step S30 and the optimal rich spike corresponding to the maximum engine speed Nem that can be reached in 2nd. It is determined whether or not it is a point.

If the determination result of step S30 is true (Yes) and it is determined that the optimal rich spike point is reached, the process proceeds to step S32, and rich spike is performed at the second rich and optimal rich spike point.
For example, according to FIGS. 2 and 3, in the case of driver A who prefers leisurely driving, there is a high possibility that rich spike cannot be completed in 2nd because the time between shifting operations from 2nd to 3rd is short. In the case of driver B who prefers, the rich spike can be completed at 2nd because the time between shifting operations from 1st to 2nd is short while the time between shifting operations from 2nd to 3rd is long.

If the determination result in step S20 is false (No) and it is determined that there is a shift operation to 3rd before the rich spike is completed, the process proceeds to step S22.
In step S22, it is determined whether or not rich spike is possible at 3rd based on the learned time between 3rd and 4th gear shifting operations. That is, it is determined whether or not the predetermined period for the rich spike falls within the learned 3rd to 4th shift operation time. If the determination result is true (Yes) and it is determined that rich spike is possible at 3rd, or if the determination result in step S18 is false (No), the process proceeds to step S24.

In step S24, it is determined whether or not the current gear position is 3rd. If the determination result is true (Yes) and the current gear position is 3rd, the process proceeds to step S26.
In step S26, based on the learned inter-shift time from 3rd to 4th, as in the case of steps S14 and S20, it is determined whether or not there is no shift operation to 4th before the completion of the rich spike. If the determination result is true (Yes) and it is determined that there is no gear shift operation to 4th before the completion of the rich spike, the process proceeds to step S30 and the optimal rich spike corresponding to the maximum engine speed Nem that can be reached in 3rd. It is determined whether or not it is a point.

If the determination result of step S30 is true (Yes) and it is determined that the optimum rich spike point is reached, the process proceeds to step S32, and the rich spike is executed at 3rd and at the optimal rich spike point.
For example, according to FIGS. 2 and 3, in the case of driver B who prefers the crisp operation, the time between 3rd to 4th gear shifting operations is relatively short, so there is a high possibility that the rich spike cannot be completed in 3rd. In the case of driver A who prefers a comfortable driving, the time between the shifting operations from 1st to 2nd and 2nd to 3rd is short, while the time between shifting operations from 3rd to 4th is long, so that the rich spike can be completed at 3rd.

If the determination result in step S26 is false (No) and it is determined that there is a shift operation to 4th before the rich spike is completed, or if the determination result in step S24 is false (No), the process proceeds to step S28. .
In step S28, it is determined whether or not the current shift speed is 4th of the highest speed shift speed. If the determination result is true (Yes) and the current gear position is 4th, the process proceeds to step S30 to determine whether or not the optimal rich spike point corresponding to the maximum engine speed Nem that can be reached at 4th. To do.

If the determination result in step S30 is true (Yes) and it is determined that the point is an optimal rich spike point, the process proceeds to step S32, and rich spike is performed at 4th and at the optimal rich spike point.
That is, if the execution condition of the rich spike is not satisfied in the first, second, or third, the rich spike is finally executed at the 4th regardless of the shift operation pattern.

  As described above, in the exhaust gas purification apparatus for an internal combustion engine for a vehicle according to the present invention, the shift operation pattern is learned for each driver using the time between shift operations for each shift stage switching operation as a parameter. Acceleration operation patterns are learned for each driver using the maximum engine speed Nem that can be reached as a parameter, and based on these learning values, rich spikes can be implemented, and optimal rich spike points for each gear stage are set. Like to do.

  Therefore, the rich spike can be executed at a gear position that does not overlap with the gear shift timing in consideration of the driver's favorite gear shift operation pattern, and the torque spike can be prevented from increasing, and the rich spike is imperfect due to the gear shift. Thus, the fuel consumption can be prevented from being deteriorated by not being interrupted in an unfavorable state, and the excessive temperature rise of the NOx occlusion catalyst 42 and the accompanying release of NOx due to incomplete rich spikes can be prevented.

In addition, the rich spike can be executed at the time when the optimum rotation speed and the exhaust flow rate, the catalyst temperature, etc. are optimal for the rich spike in consideration of the driver's favorite acceleration operation pattern, and NOx while preventing HC slip. The purification rate can be improved.
As described above, according to the exhaust emission control device for an internal combustion engine for a vehicle according to the present invention, it is possible to stabilize the rich spike and to optimize the NOx purge.

This is the end of the description of the embodiment of the exhaust emission control device for an internal combustion engine for a vehicle according to the present invention, but the embodiment of the present invention is not limited to the above.
For example, in the above embodiment, the driving operation pattern has been described as, for example, a shift operation pattern and an acceleration operation pattern. However, the present invention is not limited to this, and other driving operation pattern information may be used as long as it affects a rich spike. It is also possible to learn by taking in and reflect the learning result in the NOx purge control.

In the above embodiment, the driving operation pattern is learned to set the optimum time of the rich spike. However, information other than the driving operation pattern, such as road conditions (if it affects the rich spike, for example, It is also possible to learn by taking in a flat road or a slope, and reflect the learning result in the NOx purge control.
In the above embodiment, the case where the transmission is the manual transmission 18 has been described as an example. However, the transmission may be an automatic transmission. In this case, for example, an accelerator opening sensor is used as a shift operation pattern. The accelerator pedal acceleration operation pattern based on the information from 62 may be used.

In the above-described embodiment, a rich spike is performed by increasing a predetermined amount of fuel from each fuel injector and injecting it over a predetermined period. However, other methods such as light oil (fuel) The present invention can be satisfactorily applied even when rich spike is performed by adding a reducing agent, HC).
Further, in the above embodiment, the case where the post-treatment device 40 is configured by the DPF 41, the NOx storage catalyst 42, and the post-stage catalyst 43 has been described as an example. It may be a thing.

1 is a system configuration diagram of an exhaust emission control device for an internal combustion engine for a vehicle according to the present invention. FIG. 6 is a diagram showing a frequency distribution of the time between shift operations from the previous shift stage to the next shift stage at the time of upshifting, for each switching operation of each shift stage, and showing a shift operation pattern of driver A who prefers leisurely driving. It is. FIG. 7 is a diagram showing a frequency distribution of the time between shift operations from the previous shift stage to the next shift stage at the time of upshifting, for each switching operation of each shift stage, and showing a shift operation pattern of driver B who prefers a crisp operation. It is. 3 is a flowchart showing a control routine of NOx purge control according to the present invention.

Explanation of symbols

1 engine (diesel engine)
10 Electronic control unit (ECU)
10a NOx purge control unit (reducing agent supply timing setting means, control means)
10b Driving operation pattern learning unit (driving operation pattern detection means, learning means)
18 Manual transmission 40 Aftertreatment device 42 NOx storage catalyst (storage type NOx catalyst)
60 Clutch sensor 61 Shift position sensor 62 Accelerator opening sensor 63 Crank angle sensor (rotational speed detection means)

Claims (5)

An occlusion-type NOx catalyst that is provided in an exhaust passage of an internal combustion engine mounted on a vehicle and that occludes NOx when in an oxidizing atmosphere and releases and occludes the occluded NOx when in a reducing atmosphere;
Reducing agent supply means for supplying a reducing agent to the storage NOx catalyst so as to bring the storage NOx catalyst into a reducing atmosphere;
Driving operation pattern detection means for detecting the driving operation pattern of the driver of the vehicle;
Learning means for learning the driver's driving operation pattern detected by the driving operation pattern detecting means;
Reducing agent supply timing setting means for setting the supply timing of the reducing agent by the reducing agent supply means based on the driving operation pattern of the driver learned by the learning means;
Control means for supplying the reducing agent at the supply time set by the reducing agent supply time setting means;
An exhaust emission control device for an internal combustion engine for a vehicle, comprising: The vehicle is provided with a transmission coupled to an internal combustion engine, and includes a speed change operation means for performing a speed change operation of the transmission,
The driving operation pattern detection means detects a speed change operation pattern of the speed change operation means,
The exhaust purification device for an internal combustion engine for a vehicle according to claim 1, wherein the learning means learns the detected shift operation pattern. The parameter defining the shift operation pattern is a time between shift operations from the previous shift stage to the next shift stage, and the learning means learns the time between the shift operations,
The reducing agent supply timing setting means determines the supply timing of the reducing agent at the previous shift stage when the time until the next shift stage is larger than the supply period of the reducing agent based on the time between shift operations. The exhaust emission control device for an internal combustion engine for a vehicle according to claim 2, wherein: Accelerating operation means for accelerating the internal combustion engine,
The driving operation pattern detection means further detects an acceleration operation pattern of the acceleration operation means,
The exhaust purification device for an internal combustion engine for a vehicle according to claim 2 or 3, wherein the learning means further learns the detected acceleration operation pattern for each gear stage of the transmission. A rotation speed detecting means for detecting the rotation speed of the internal combustion engine;
3. The parameter that defines the acceleration operation pattern is a maximum rotational speed of the internal combustion engine for each shift stage, and the learning unit learns the maximum rotational speed of the internal combustion engine for each shift stage. 5. An exhaust emission control device for an internal combustion engine for a vehicle according to any one of claims 1 to 4.

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