JP2010106750A - Exhaust emission control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent generation of deceleration shock in a shift change process upon shift-changing during filter regeneration in an exhaust emission control device automatically regenerating a filter 14b collecting PM in exhaust gas of a vehicle having a manual transmission 2 connected to an internal combustion engine 1 through a clutch 3. <P>SOLUTION: The exhaust emission control device includes a filter 14b disposed in an exhaust gas passage (42) of the internal combustion engine 1 and collecting particulate matter in exhaust gas, an exhaust throttle valve 15 disposed at a downstream side of the filter 14b in the exhaust gas passage (42), and a control device 4 executing filter regeneration in which temperature of the filter 14b is raised to a filter regeneration temperature as the occasion demands. The control device 4 executes exhaust throttle control after completion of shift change upon shift-changing during regeneration of the filter 14b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exhaust emission control device for a vehicle such as an automobile in which a manual transmission is connected to an internal combustion engine (also referred to as an engine) via a clutch, and more specifically, on the assumption that an exhaust throttle valve is provided in an exhaust passage. It is said.

  In a diesel engine or the like mounted on a vehicle or the like, exhausted exhaust gas contains particulate matter (PM) containing carbon as a main component, and it is not preferable to discharge it to the atmosphere. Therefore, conventionally, a catalyst device is provided in the exhaust passage of the diesel engine.

  The catalyst device is included in an oxidation catalyst for oxidizing and purifying hydrocarbon (HC) and carbon monoxide (CO) contained in exhaust gas passing through the exhaust passage, and in exhaust gas passing through the exhaust passage. It includes a filter that collects PM and reduces the amount of emissions released into the atmosphere.

  The filter is generally called a DPF (Diesel Particulate Filter) or a DPR (Diesel Particulate active Reduction system). The DPF has a configuration in which a porous member is provided, and the DPR has a configuration in which an oxidation catalyst is supported on the porous member.

  In such a filter, clogging occurs when the amount of collected PM increases, and in such a case, the PM trapping function decreases and the pressure loss of the exhaust gas passing through the filter increases. The accompanying increase in engine exhaust back pressure leads to a decrease in engine output and fuel consumption.

  In order to eliminate such problems, conventionally, when the PM collection amount (deposition amount) of the filter reaches a predetermined limit amount, so-called regeneration is performed to recover the PM collection function by cleaning the filter. It is considered to do. In this filter regeneration, it is effective to raise the temperature of the exhaust gas entering the filter and to burn and remove the PM collected by the filter.

  With regard to this form of filter regeneration, for example, at the time of filter regeneration, the exhaust throttle valve provided downstream of the filter is throttled in the exhaust passage of the internal combustion engine, thereby raising the exhaust temperature and burning and removing PM collected by the filter. (For example, refer patent document 1).

  In addition, for example, Patent Documents 2 and 3 disclose that filter regeneration is performed by a combination of exhaust throttle control and post injection control.

Post-injection control refers to, for example, a small amount of fuel that is injected into the combustion chamber by the fuel injection valve before the exhaust valve (not shown) is closed after the main fuel is injected into the combustion chamber of the internal combustion engine by the fuel injection valve. It is control to inject.
JP 2005-282534 A JP 2008-133738 A JP 2008-144726 A

  When the exhaust throttle valve is throttled during filter regeneration as in the conventional examples according to Patent Documents 1 to 3, it can be said that the temperature of the filter can be increased quickly by raising the exhaust temperature. In such a case, it is necessary to devise the timing at which the exhaust throttle valve is throttled.

  That is, for example, in the case where the power train of the vehicle has a configuration in which a manual transmission is connected to the internal combustion engine via a clutch, if the clutch is disconnected for a shift change, the exhaust throttle control for filter regeneration is performed. If this is done, there is a concern that a deceleration shock due to the exhaust throttle will occur during the shift change process, causing the driver to feel uncomfortable.

  Therefore, when the exhaust purification device is applied to, for example, a vehicle having a configuration in which a manual transmission is connected to an internal combustion engine via a clutch, the execution start timing of exhaust throttle control for performing filter regeneration should be devised. Is required.

  Incidentally, for example, Japanese Utility Model Laid-Open No. 5-9240 discloses that the exhaust throttle valve is closed to keep the catalyst at the activation temperature during idling stop. In this prior art, there is no description that the exhaust throttling is performed for filter regeneration.

  Also, for example, in Japanese Patent Application Laid-Open No. 2005-155534, when it is necessary to raise the exhaust gas temperature with an exhaust throttle for filter regeneration, the engine idling speed is increased to a higher target speed than usual. Thus, it is disclosed that exhaust throttling is performed and the exhaust throttling is released at the end of the temperature rise control. This prior art is not intended for a vehicle having a configuration in which a manual transmission is connected to an internal combustion engine via a clutch.

  In any of the prior arts, there is no technical idea of performing filter regeneration with an optimum exhaust throttle in consideration of the relationship between the exhaust throttle for performing filter regeneration and the presence or absence of a shift change of the manual transmission. Therefore, these prior arts are only presented as reference examples.

  In addition, Japanese Utility Model Publication No. 62-148754 discloses a vehicle having a configuration in which a manual transmission is connected to an internal combustion engine via a clutch, and an exhaust brake shutter (corresponding to an exhaust throttle valve) is provided in an exhaust passage. It is described that when the exhaust brake is operated, first, the fuel supply to the internal combustion engine is shut off, and then the exhaust shutter is closed after a predetermined time has elapsed. This prior art does not have the technical idea of closing the exhaust shutter for filter regeneration, but merely describes that the closing operation of the exhaust shutter as an exhaust brake is delayed. Therefore, this prior art is only presented as a reference example.

  In view of such circumstances, the present invention provides a filter regeneration in an exhaust purification device that automatically regenerates a filter that collects PM in exhaust of a vehicle in which a manual transmission is connected to an internal combustion engine via a clutch. The purpose is to perform exhaust throttling control after waiting for the shift change to end when the shift change is made, and to prevent the occurrence of a deceleration shock in the shift change process.

  The present invention relates to an exhaust emission control device for a vehicle in which a manual transmission is connected to an internal combustion engine via a clutch, a filter provided in an exhaust passage of the internal combustion engine for collecting particulate matter in the exhaust, and an exhaust An exhaust throttle valve provided on the downstream side of the filter in the passage, and a control device for performing filter regeneration for raising the temperature of the filter to a filter regeneration temperature as necessary. Detection means for detecting that the operation area has transitioned from the execution prohibition area of the exhaust throttle control to the execution permission area, and when the detection means detects the transition, the cause of the transition is disengagement of the clutch for the shift change. If the determination means determines whether or not, and the determination means makes an affirmative determination, the exhaust throttle control is executed with a time delay required to complete the shift change. And a first address means is characterized by.

  The filter regeneration is to restore the function of the filter by burning and removing particulate matter accumulated on the filter. The filter regeneration temperature is a temperature at which particulate matter deposited on the filter can be combusted. Further, when exhaust throttle control is performed, exhaust heat is retained upstream of the exhaust throttle valve in the exhaust passage, so that the temperature of the filter is raised relatively early. On the other hand, since the exhaust resistance increases, a deceleration shock is likely to occur in the vehicle.

  In short, in the above configuration, when a shift change is made during filter regeneration, the temperature of the filter is raised by exhaust throttle control after waiting for the end of the shift change.

  In other words, since the exhaust throttle valve is not operated to the closing side during the shift change process, it becomes possible to prevent the occurrence of deceleration shock caused by the throttle of the exhaust throttle valve during the shift change process, improving drivability. To do.

  In addition, the filter regeneration by the exhaust throttle control is not stopped, but the exhaust throttle valve is controlled to close immediately after the shift change is completed, so that the filter regeneration can be performed promptly and reliably. Is possible.

  Preferably, when the determination means makes a negative determination, it further includes a second coping means that executes exhaust throttle control with a delay for a specified time proportional to the current vehicle speed.

  In this case, for example, the delay time can be lengthened as the vehicle speed is fast, the delay time can be shortened as the vehicle speed is slow, and the delay time can be zero when the vehicle speed is zero. Therefore, if the execution of the exhaust throttle control is delayed for the specified time, vehicle deceleration proceeds for this delay amount, so that the feeling of deceleration (deceleration shock) that occurs with the exhaust throttle is reduced. It becomes possible to reduce the deceleration shock in each speed range.

  Preferably, the detection means also detects that the engine operation area is maintained in the execution permission area without changing from the execution restriction area of the exhaust throttle control to the execution prohibition area during the filter regeneration. The apparatus further includes third coping means for quickly executing exhaust throttle control when the detection means detects that the execution permission area is maintained.

  In this case, since the exhaust throttle valve is quickly throttled to the closed side when the engine operation area is maintained in the execution permission area due to a cause other than a shift change during filter regeneration, the temperature of the filter is quickly raised. It becomes possible.

  Preferably, the exhaust purification device further includes an oxidation catalyst provided upstream of the filter in the exhaust passage of the internal combustion engine, and the control device supplies the fuel to the exhaust passage as needed during filter regeneration. Fuel supply control is performed to raise the temperature of the filter by oxidizing the oxidation catalyst.

  In this case, the filter regeneration can be performed using both the exhaust throttle control and the fuel supply control, so that the time required for the filter regeneration can be shortened.

  In the exhaust emission control device for a vehicle according to the present invention, it is possible to prevent the occurrence of deceleration shock during the shift change process by changing the execution form of the exhaust throttle according to the presence or absence of the shift change during filter regeneration. This is advantageous in improving drivability, for example. In addition, after the shift change, filter regeneration is performed by exhaust throttle control, so that filter regeneration can be performed promptly and reliably.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.

  1 to 5 show an embodiment of the present invention. First, referring to FIG. 1, a schematic configuration of a power train of a vehicle that is an object of use of an exhaust purification apparatus according to the present invention will be described.

  The power train shown in FIG. 1 is of a type mounted on a front engine / rear drive (FR) type vehicle. In FIG. 1, 1 is an internal combustion engine, 2 is a manual transmission, 3 is a clutch, 4 is a control device, 5 is a propeller shaft, 6 is a differential, and 7 is a rear wheel serving as a drive wheel.

  In this power train, the rotational power generated in the internal combustion engine 1 is input to the manual transmission 2 via the clutch 3, and is shifted to an appropriate gear ratio by the manual transmission 2, via the propeller shaft 5 and the differential 6. Are transmitted to the left and right rear wheels 7,7.

  The control device 4 controls the operation of the internal combustion engine 1. For example, the control device 4 recognizes the operation amount of the accelerator pedal 8 based on the detection output from the accelerator opening sensor 80, and the internal combustion engine 1 according to the recognition result. The fuel injection amount and engine speed are controlled.

  Note that the clutch switch 82 in FIG. 1 is a normally open (off) type, and outputs an ON signal in response to a depression operation of the clutch pedal 9 over a certain stroke by the driver (completely disengaging operation of the clutch 3). Then, an off signal is output in response to a pulling-off operation from the depressed position of the clutch pedal 9 (engagement operation of the clutch 3).

  The clutch switch 82 is conventionally used to prohibit the start of the internal combustion engine 1 when it is off when the internal combustion engine 1 is started. The control device 4 recognizes the start and completion of the shift change of the manual transmission 2 based on the output signal from the clutch switch 82.

  Next, a schematic configuration of the internal combustion engine 1 will be described with reference to FIG. An internal combustion engine 1 shown in FIG. 2 is, for example, an in-cylinder direct injection type in-line four-cylinder diesel engine. Basically, air supplied from an intake system and fuel supplied from a fuel supply system are appropriately used. After the air-fuel mixture mixed at the air-fuel ratio is injected into the combustion chamber 1a and burned, the exhaust gas in the combustion chamber 1a is released into the atmosphere from the exhaust system.

  The intake system has a configuration in which an air cleaner 23 and a throttle valve 24 are sequentially arranged from the upstream side in the air flow direction in an intake passage formed by connecting an intake pipe 22 to an intake manifold 21 connected to an intake port 1b of a cylinder head. is there.

  The fuel supply system has a structure in which a fuel tank 32, a supply pump 33, a common rail 34, a plurality of fuel injection valves 35,... The supply pump 33 is driven by a crankshaft (not shown) of the internal combustion engine 1 and pumps fuel from the fuel tank 32 and supplies the pumped fuel to the common rail 34 via the fuel supply path 31. The common rail 34 has a function as a pressure accumulation chamber that holds (accumulates) the high-pressure fuel supplied from the supply pump 33 at a predetermined pressure, and distributes the accumulated fuel to each fuel injection valve 35. The fuel injection valve 35 is an electromagnetically driven on-off valve that opens when a predetermined voltage is applied and injects fuel into the combustion chamber 1a.

  The exhaust system includes an exhaust passage configured by connecting a muffler 42 to an exhaust manifold 41 connected to the exhaust port 1c of the cylinder head.

  The internal combustion engine 1 exemplified in this embodiment is equipped with a turbocharger (supercharger) 11, an intercooler 12, an EGR device 13 as an exhaust gas recirculation device, a catalyst device 14, and an exhaust throttle valve 15. This will be described below.

  As is generally known, the turbocharger 11 boosts and supercharges intake air using exhaust gas, and mainly includes a compressor impeller 11a and a turbine wheel 11b. The compressor impeller 11 a is disposed in the intake pipe 22, and the turbine wheel 11 b is disposed between the aggregate portion of the exhaust manifold 41 and the muffler 42.

  The intercooler 12 forcibly cools the intake air boosted and supercharged by the turbocharger 11, and is disposed between the compressor impeller 11 a of the turbocharger 11 and the throttle valve 24. The throttle valve 24 is an electronically controlled on-off valve whose opening degree can be adjusted steplessly, and the flow area of the intake air is reduced under a predetermined condition, and the supply amount of the intake air is adjusted (reduced). ) Function.

  The EGR device 13 lowers the combustion temperature by returning a part of the exhaust gas (EGR gas) to the intake system and supplying the exhaust gas again to the combustion chamber 1a, thereby reducing the amount of NOx generated, and in the EGR passage 13a. The EGR cooler 13b and the EGR valve 13c are arranged from the upstream side.

  The EGR passage 13a includes a bypass passage that bypasses the combustion chamber 1a from the exhaust system to the intake system. The EGR cooler 13b includes a heat exchanger that lowers the temperature of the exhaust gas by exchanging heat between the exhaust gas passing through the EGR passage 13a and the coolant of the internal combustion engine 1, for example. The EGR valve 13c controls the recirculation amount of the exhaust gas recirculated from the exhaust system side to the intake system side in the EGR passage 13a.

  The catalyst device 14 is interposed between an exhaust manifold 41 and a muffler 42 that constitute an exhaust passage, and includes an oxidation catalyst 14a and a particulate filter 14b. The oxidation catalyst 14a is provided upstream of the particulate filter 14b in the exhaust passage.

  The particulate filter 14b is generally called, for example, a known DPF (Diesel Particulate Filter) or DPR (Diesel Particulate active Reduction system).

  In addition, DPF is set as the structure which provided the porous member. The DPR has a structure in which, for example, a honeycomb structure made of a porous ceramic is supported with an oxidation catalyst (for example, a precious metal such as platinum as a main component), and in principle, harmful substances in exhaust gas are removed. It is oxidized with an oxidation catalyst, converted into carbon dioxide and water vapor, and further PM is collected in the fine pores of the porous ceramic substrate of the honeycomb structure.

  The exhaust throttle valve 15 is provided on the downstream side of the catalyst device 14 in the exhaust passage, and adjusts the exhaust gas flow rate. The opening degree of the exhaust throttle valve 15 is controlled by the control device 4.

  Various operations of the internal combustion engine 1 are controlled by the control device 4. The control device 4 is generally a known ECU (Electronic Control Unit), and includes, for example, a CPU 101, a ROM 102, a RAM 103, a backup RAM 104, and the like as shown in FIG. This control device 4 corresponds to the control means described in the claims.

  The ROM 102 stores various control programs, maps that are referred to when the various control programs are executed, and the like. The CPU 101 executes various arithmetic processes based on various control programs and maps stored in the ROM 102. The RAM 103 is a memory that temporarily stores calculation results of the CPU 101, data input from each sensor, and the like. The backup RAM 104 is a nonvolatile memory that stores data to be saved when the internal combustion engine 1 is stopped, for example. Sex memory. The ROM 102, CPU 101, RAM 103, and backup RAM 104 are connected to each other via a bidirectional bus 107 and are connected to an input interface 105 and an output interface 106.

As shown in FIG. 3, the input interface 105 includes a water temperature sensor 71, an air flow meter 72, an intake air temperature sensor 73, an intake air pressure sensor 74, an A / F (air / fuel ratio) sensor 75, an O ₂ (oxygen) sensor 76, a temperature. A sensor 77, a rail pressure sensor 78, a throttle opening sensor 79, an accelerator opening sensor 80, a crank position sensor 81, a clutch switch 82, and the like are connected.

  The water temperature sensor 71 outputs a detection signal corresponding to the cooling water temperature of the internal combustion engine 1. The air flow meter 72 outputs a detection signal corresponding to the flow rate (intake air amount) of intake air upstream from the throttle valve 24 of the intake system. The intake air temperature sensor 73 is disposed in the intake manifold 21 and outputs a detection signal corresponding to the intake air temperature. The intake pressure sensor 74 is disposed in the intake manifold 21 and outputs a detection signal corresponding to the intake air pressure. The A / F sensor 75 outputs a detection signal that continuously changes according to the oxygen concentration in the exhaust gas downstream of the catalyst device 14 of the exhaust system 7.

  The temperature sensor 77 is provided between the oxidation catalyst 14a and the particulate filter 14b in the catalyst device 14, and similarly, the outlet temperature (exhaust temperature) of the oxidation catalyst 14a or the inlet temperature (exhaust temperature) of the particulate filter 14b. A corresponding detection signal is output. The rail pressure sensor 78 outputs a detection signal corresponding to the fuel pressure stored in the common rail 34. The throttle opening sensor 79 detects the opening of the throttle valve 24. The accelerator opening sensor 80 outputs a detection signal corresponding to the depression amount of the accelerator pedal. The crank position sensor 81 outputs a detection signal (pulse) every time a crankshaft (not shown) of the internal combustion engine 1 rotates by a certain angle.

  On the other hand, the output interface 106 is connected to the throttle valve 24, the fuel injection valve 35, the EGR valve 13c, the exhaust throttle valve 15, and the like.

  The control device 4 controls various operations of the internal combustion engine 1 based on signals from various sensors (operation parameters: signals according to the running state of the vehicle and the operating state of the internal combustion engine). Then, only control (for example, filter regeneration) related to the feature of the present invention will be described, and description of control unrelated to the feature of the present invention will be omitted.

  The filter regeneration refers to recovering the PM collecting function of the particulate filter 14b by raising the temperature of the particulate filter 14b to burn and remove the PM collected by the particulate filter 14b.

  The exhaust purification device in this embodiment mainly includes a fuel injection valve 35, a catalyst device 14, an exhaust throttle valve 15, and a control device 4, and filter regeneration is performed between exhaust throttle control and post injection control. Either one or a combination of both is performed.

  In the exhaust throttle control, the exhaust filter 15b is throttled to the closed side, and the exhaust heat is retained upstream of the exhaust throttle valve 15 in the exhaust passage (exhaust manifold 41, muffler 42), whereby the particulate filter 14b. Is to raise the temperature. For reference, in the exhaust throttle control, for example, the exhaust temperature entering the particulate filter 14b is detected based on the detection output of the temperature sensor 77, and the detected exhaust temperature and the filter regeneration temperature (for example, 600) serving as the temperature increase control target. The degree of opening of the exhaust throttle valve 15 is controlled based on the degree of deviation from the temperature (° C.).

  However, in the exhaust throttle control at the time of filter regeneration, the opening is set so as to allow passage of a predetermined amount of exhaust gas and avoid exhaust clogging without fully closing the exhaust throttle valve 15. Such a state is referred to as a closed state. When the exhaust throttle control is terminated, the opening degree of the exhaust throttle valve 15 is returned to a predetermined opening degree.

  The post-injection control is well known. For example, after the main fuel is injected into the combustion chamber 1a of the internal combustion engine 1 by the fuel injection valve 35, the fuel injection valve (not shown) is closed. This is a control for injecting a small amount of fuel into the combustion chamber 1a by 35.

  In this embodiment, during the filter regeneration, the exhaust throttling execution start timing is made different depending on whether or not there is a shift change.

  Specifically, the control operation of filter regeneration by the control device 4 will be described in detail with reference to the flowchart shown in FIG.

  The control device 4 estimates the PM accumulation amount of the particulate filter 14b during the operation of the internal combustion engine 1. As a method for estimating the PM accumulation amount, for example, the PM adhesion amount according to the operating conditions (for example, exhaust temperature, fuel injection amount, engine speed, etc.) of the internal combustion engine 1 is examined in advance through experiments and mapped. In addition, the PM deposition amount obtained from this map is integrated to obtain the PM deposition amount, the PM deposition amount is estimated according to the vehicle travel distance or travel time, or the inlet (upstream) of the particulate filter 14b. And a method of estimating a PM accumulation amount collected by the particulate filter 14b based on the sensor output.

  The control device 4 determines that the recovery of the function of the particulate filter 14b, that is, regeneration is necessary when the estimated value of the PM accumulation amount exceeds a predetermined upper limit value (limit accumulation amount), and sets the filter regeneration flag. Turn on.

  That is, the control device 4 monitors whether the filter regeneration flag is turned on at regular intervals during the operation of the internal combustion engine 1, and executes filter regeneration when determining that the filter regeneration flag is turned on. .

  Here, in the flowchart shown in FIG. 4, first, in step S1, it is determined whether or not the current operation region of the internal combustion engine 1 is located in an execution prohibition region (see B in FIG. 5) that does not permit execution of the exhaust throttle control. Determine. In short, in short, based on the map for determining whether or not exhaust throttle control can be executed as shown in FIG. 5, the current engine operation region is the exhaust prohibition control execution prohibition region (B) or the execution permission region ( Check if A).

  In this map, an execution permission area (A) and an execution prohibition area (B) are set based on an engine hardware limit that has been empirically examined in advance through experiments and calculations, and is stored in the ROM 102 of the control device 5. ing. The boundaries between the areas (A) and (B) in the figure serve as threshold values for area determination. The engine hardware limit means that the back pressure and the exhaust temperature are excessively increased and the exhaust manifold and the like are easily damaged when the exhaust throttle valve 15 is throttled to the fully closed side using the fuel injection amount and the engine speed as parameters. It is a critical value. The boundary is set by adding an appropriate margin to the strict critical value.

  If the determination in step S1 is affirmative, that is, if it is determined that the current engine operation region is the execution prohibition region (B), the exhaust throttle valve 15 is fully opened in step S2, and then this flowchart is exited. .

  On the other hand, if a negative determination is made in step S1, that is, if it is determined that the current engine operation region is the execution permission region (A), the flow proceeds to steps S3 to S7.

  In steps S3 to S7, when executing the exhaust throttle control, an appropriate execution start timing is sought in consideration of the operating conditions of the vehicle and the internal combustion engine 1.

  First, in step S3, it is determined whether or not the previous determination result in step S1 is the execution prohibited area (B). Based on the results of step S3 and step S1, the engine operating status is grasped.

  If a negative determination is made in step S3, that is, if the previous engine operation region is the execution permission region (A), the exhaust throttle control is immediately executed in step S4, and then this flowchart is exited.

  Thus, the situation that the previous engine operation region is the execution permission region (A) and the current engine operation region is also the execution permission region (A) is, in short, that the fuel injection amount and the engine speed are low and change. It means that there is no or a small change. Even if the exhaust throttle control is immediately executed in such a situation, no special malfunction occurs.

  On the other hand, if an affirmative determination is made in step S3, that is, if it is determined that the previous engine operation region is the execution prohibition region (B), it is determined in step S5 whether or not an ON signal is input from the clutch switch 82. .

  Thus, the situation that the previous engine operation area is the execution prohibition area (B) and the current engine operation area is the execution permission area (A) means that the fuel injection amount and the engine speed have decreased for some reason. is doing. Possible causes of such a decrease include when the clutch 3 is disengaged due to a shift change, when the accelerator pedal 8 is returned, or when the vehicle travels uphill. Therefore, in order to investigate the cause, the step S5 is executed.

  If an affirmative determination is made in step S5, that is, if the transition is made from the execution prohibited area (B) to the execution permitted area (A) due to the clutch 3 being disengaged due to a shift change, the shift is performed. Executing exhaust throttle control during a change is not desirable because a deceleration shock will occur, etc. In step S6, exhaust throttle control is delayed by a fixed time (experience set by the time required to complete the shift change). Then run.

  On the other hand, if a negative determination is made in step S5, that is, because the accelerator pedal 8 has been returned instead of a shift change or the vehicle has gone uphill, the execution prohibited area (B) is changed to the execution permitted area (A). When the transition is made, in step S7, the exhaust throttle control is executed with a time delay specified in proportion to the current vehicle speed. For reference, the relationship between the vehicle speed and the exhaust throttle control delay time is shown in Table 1 below.

この表１に示されているように、例えば車速がゼロ、つまり停車している場合には遅延時間をゼロとし、車速が速くなるに従い遅延時間を増やすように設定している。

As shown in Table 1, for example, when the vehicle speed is zero, that is, when the vehicle is stopped, the delay time is set to zero, and the delay time is set to increase as the vehicle speed increases.

  As described above, when exhaust throttle control is executed with a delay, the vehicle is decelerated for the delay time, so that the feeling of deceleration (or deceleration shock) accompanying the delay execution of exhaust throttle control is not delayed. Will be reduced compared to.

  By executing steps S4, S6, and S7 as described above, the particulate filter 14b is heated to the filter regeneration temperature. And although not described in FIG. 4, the control device 4 estimates the PM accumulation amount of the particulate filter 14b as described above, and confirms that this estimated value is equal to or less than a predetermined lower limit value. The filter regeneration is terminated after the filter regeneration flag is turned off.

  As is clear from the above description, the above steps executed by the control device 4 are function realizing means. For example, steps S1 and S3 correspond to detection means described in claims, and step S5 corresponds to determination means described in claims. Step S6 corresponds to the first coping means described in the claims, step S7 corresponds to the second coping means described in the claims, and step S4 corresponds to the third coping means described in the claims. Yes.

  As described above, in the embodiment to which the feature of the present invention is applied, the engine operation area is set to the exhaust restriction execution prohibition area (due to the clutch 3 being disconnected in association with the shift change during the filter regeneration. When the transition is made from B) to the execution permission region (A), the exhaust throttle valve 15 is controlled to be throttled after the shift change is completed. As a result, frequent opening / closing of the exhaust throttle valve 15 during the shift change process can be avoided, so that it is possible to prevent a deceleration shock accompanying the exhaust throttle during the shift change process. In addition, when the accelerator pedal 8 is returned instead of a shift change, or when the vehicle has started uphill driving, the engine operating region transitions from the exhaust throttling execution prohibition region (B) to the execution permission region (A). In this case, the throttle control of the exhaust throttle valve 15 is executed with a specified time delay proportional to the vehicle speed. Thereby, for example, it becomes possible to reduce the deceleration shock in each speed range.

  In this way, it is possible to perform filter regeneration promptly and reliably while ensuring drivability at the time of shift change in consideration of changes in engine operating conditions during filter regeneration.

  By the way, if the engine operating region changes from the exhaust prohibition control execution prohibition region (B) to the execution permission region (A) due to, for example, accelerator off or uphill traveling other than shift change, the exhaust throttle control is temporarily performed. If the execution is started with a delay of a certain time regardless of the vehicle speed, the exhaust temperature may be lowered. However, in such a case, if the post injection amount by the post injection control is increased in order to raise the exhaust temperature, oil dilution (post injection fuel is mixed into the oil of the internal combustion engine 1) is likely to occur. This is not preferable. The above embodiment is advantageous in suppressing the occurrence of such oil dilution as much as possible.

  In addition, this invention is not limited only to embodiment mentioned above, All the deformation | transformation and application included in the range equivalent to the claim and the said range are possible. Examples are given below.

  (1) Although the internal combustion engine 1 exemplified in the above embodiment is exemplified by the one equipped with the turbocharger 11 and the EGR device 13, even if one or both of them are eliminated, the present invention. Can be applied.

  (2) In the above embodiment, an example in which the post-injection control by the fuel injection valve 35 is used as the fuel supply control in the filter regeneration is described. However, the present invention is not limited to this and is not shown in the figure. It is possible to perform fuel addition control in which a fuel addition valve is provided in a passage (for example, the exhaust manifold 41) and fuel is injected into the exhaust passage by this fuel addition valve.

  This fuel addition valve is preferably installed so as to inject fuel (for example, diesel oil in a diesel engine) toward the assembly portion of the exhaust manifold 41. Further, the fuel addition valve can be installed in a region between the turbocharger 11 and the catalyst device 14 in the exhaust passage. This fuel addition valve may be connected to the supply pump 33 via the additive supply path.

  When fuel is injected into the exhaust passage (for example, the exhaust manifold 41) with such a fuel addition valve, the oxidation catalyst 14a oxidizes (combusts) to the added fuel, and the exhaust temperature entering the particulate filter 14b increases, The temperature of the particulate filter 14b is increased.

  Incidentally, in this case, the control device 4 obtains the required addition amount and the addition interval with reference to a map prepared in advance by experiments or calculations based on the engine speed Ne read from the output of the crank position sensor 81, for example. By appropriately controlling the opening degree of the fuel addition valve according to the result, appropriate fuel addition to the exhaust manifold 41 can be repeated intermittently.

  (3) In the above embodiment, an example is given in which the particulate filter 14b of the catalyst device 14 is DPF or DPR. However, this filter 14b can be a DPNR (Diesel Particulate-NOx Reduction system). .

  The DPNR is capable of removing nitrogen oxides (NOx) in addition to the function of the DPR. For example, an oxidation catalyst (for example, a main component of a noble metal such as platinum) is formed on a porous ceramic structure. A NOx occlusion reduction catalyst is supported. This DPNR is collected when PM in the exhaust gas passes through the porous wall, and when the air-fuel ratio of the exhaust gas is lean, NOx in the exhaust gas is occluded in the NOx occlusion reduction type catalyst, When the air-fuel ratio becomes rich, the stored NOx is reduced and released.

  In the case of such DPNR, in addition to performing the same process as the filter regeneration described above, it is necessary to perform a NOx reduction process for recovering from S poisoning of the NOx storage reduction catalyst. Also in this case, the control described in the above embodiment can be performed during the filter regeneration.

  (4) In the above embodiment, the catalyst device 14 is configured to include the oxidation catalyst 14a and the particulate filter 14b. However, in addition to these, an NSR catalyst may be added. is there.

In short, this NSR catalyst is a kind of what is called a NOx occlusion reduction type catalyst. For example, alumina (Al ₂ O ₃ ) is used as a carrier, and, for example, potassium (K), sodium (Na), lithium ( Li), alkali metals such as cesium (Cs), alkaline earths such as barium (Ba) and calcium (Ca), rare earths such as lanthanum (La) and yttrium (Y), and platinum (Pt) It is configured to carry a noble metal.

This NSR catalyst occludes NOx in a state where a large amount of oxygen is present in the exhaust gas, the exhaust gas has a low oxygen concentration, and a large amount of reducing components (for example, unburned components (HC) of the fuel) are present. In this state, NOx is reduced to NO ₂ or NO and released. NO NOx released as NO ₂ or NO, the N ₂ is further reduced due to quickly reacting with HC or CO in the exhaust gas. Further, HC and CO are oxidized to H ₂ O and CO ₂ by reducing NO ₂ and NO.

1 is a schematic configuration diagram illustrating an embodiment of a power train of a vehicle to which a vehicle exhaust gas purification apparatus according to the present invention is applied. It is a schematic block diagram of the internal combustion engine of FIG. It is a schematic block diagram of the control apparatus of FIG. 1 and FIG. 3 is a flowchart used to explain an operation during filter regeneration by the control device of FIGS. 1 and 2. 3 is a map for determining whether exhaust throttling control can be executed or not, stored in the control device of FIGS. 1 and 2;

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Manual transmission 3 Clutch 4 Control device 9 Clutch pedal 14 Catalytic device 14a Oxidation catalyst 14b Particulate filter 15 Exhaust throttle valve 41 Exhaust manifold (a part of exhaust passage)
42 Muffler (part of exhaust passage)
77 Temperature sensor 82 Clutch switch

Claims (4)

An exhaust emission control device for a vehicle in which a manual transmission is connected to an internal combustion engine via a clutch,
A filter provided in the exhaust passage of the internal combustion engine for collecting particulate matter in the exhaust, an exhaust throttle valve provided downstream of the filter in the exhaust passage, and, if necessary, the filter to a filter regeneration temperature Including a control device that performs filter regeneration for raising the temperature,
The control device detects a transition of the engine operation region from the execution prohibition region of the exhaust throttle control to the execution permission region during filter regeneration,
Determining means for determining whether or not the cause of the transition is disengagement of a clutch for shift change when the detecting means detects the transition;
An exhaust emission control device for a vehicle comprising: first coping means that executes exhaust throttle control with a time delay required for completion of a shift change when the determination means makes an affirmative determination. The exhaust emission control device for a vehicle according to claim 1,
An exhaust emission control device for a vehicle, further comprising second coping means that executes exhaust throttle control with a specified time delay proportional to the current vehicle speed when a negative determination is made by the determination means. The exhaust emission control device for a vehicle according to claim 1 or 2,
The detection means also detects that the engine operation region is maintained in the execution permission region without changing from the execution restriction region of the exhaust throttle control to the execution prohibition region during filter regeneration,
The control device further includes third coping means for quickly executing exhaust throttle control when the detection means detects the maintenance of the execution permission region. The exhaust emission control device for a vehicle according to any one of claims 1 to 3,
The exhaust purification device further includes an oxidation catalyst provided upstream of the filter in the exhaust passage of the internal combustion engine,
The control device executes fuel supply control for causing the oxidation catalyst to oxidize and supplying a fuel to an exhaust passage as needed during filter regeneration to raise the temperature of the filter. apparatus.

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