JP2008265588A - Exhaust emission control device of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device of an engine with an automatic transmission capable of effectively regenerating a filter even when the vehicle becomes a decelerating state during regeneration processing of the filter. <P>SOLUTION: The exhaust emission control device of an engine with an automatic transmission includes a filter for collecting particulates, an oxidation catalyst part, a parameter value detection means, a regeneration control means for regenerating the filter, a lock-up clutch, a lock-up control means for controlling a fastening state of the lock-up clutch, and, a speed reduction detecting means. The regeneration control means stops a main injection when a deceleration state is detected during regeneration of the filter, and continuously carries out additional injections during the predetermined period. The lock-up control means puts the lock-up clutch into a fastening state or a slipping state during the predetermined period when decelerating state is detected during the filter regeneration. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an engine exhaust gas purification apparatus that purifies exhaust gas discharged from an engine.

  Conventionally, in order to purify exhaust gas discharged from a diesel engine, a filter for collecting particulates (particulates) in the exhaust gas is provided in an exhaust system. Since the filter is clogged if it continues to collect fine particles, when the amount of collected fine particles exceeds a predetermined amount, regeneration of the filter that raises the exhaust temperature and burns the fine particles is performed.

In order to raise the exhaust gas temperature in this way, when the filter reaches the regeneration timing, the automatic transmission is set so that the engine moves to an operating point where the particulate matter collected by the filter has an exhaust gas temperature at which self-ignition is possible. Although the control which changes the gear ratio of this is also performed (for example, refer patent document 1), the regeneration control which performs additional injection after main injection is generally performed. As a result, the unburned HC in the additionally injected fuel and the oxidation catalyst of the oxidation catalyst portion provided upstream of the filter in the exhaust system undergo an oxidation reaction, and the exhaust gas is heated by the reaction heat.
Japanese Patent Application Laid-Open No. 2004-211638

  By the way, when the vehicle is decelerated (throttle fully closed) during the operation of the vehicle, the main injection is normally stopped so that no torque is generated. Further, when the main injection is stopped, control is performed so that the normal additional injection is also stopped. Therefore, if the deceleration is performed during the regeneration of the filter, the main injection and the additional injection are stopped, so that the regeneration of the filter is not continued.

  On the other hand, in order for the additionally injected fuel and the oxidation catalyst to react, it is necessary that the oxidation catalyst portion has a certain high temperature (activation temperature or higher). If deceleration is performed during filter regeneration, the oxidation catalyst section temperature is high for a while after the start of deceleration, and the additional injection is stopped even though the filter can be regenerated. The temperature decreases. For this reason, in order to regenerate the filter again, it is necessary to raise the temperature of the oxidation catalyst section. However, if deceleration is performed while the oxidation catalyst portion temperature is rising, the oxidation catalyst portion temperature is lowered again. Therefore, if deceleration is repeatedly performed during traveling, the regeneration of the filter does not proceed and the clogging of the filter becomes serious.

  In order to avoid such a situation, when the deceleration state of the vehicle is detected during the regeneration of the filter, a regeneration control in which the main injection is stopped and the additional injection is continuously performed can be considered. As described above, even if the deceleration state is detected, the additional injection is continuously executed, so that the additionally injected fuel and the oxidation catalyst can react with each other in the oxidation catalyst portion that is in a high temperature state for a while from the start of the deceleration. it can. Thereby, since exhaust temperature rises, a filter can be maintained at high temperature. Therefore, even when a deceleration state is detected during filter regeneration, the filter regeneration can be continued.

  However, in an engine with an automatic transmission provided in an automatic vehicle or the like, the engine speed decreases immediately after the main injection is stopped. For this reason, there is a problem that if the vehicle is decelerated during regeneration of the filter, additional injection cannot be executed effectively.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an exhaust purification device for an engine with an automatic transmission that purifies exhaust gas discharged from the engine, while the filter is being regenerated. An object of the present invention is to provide a technique capable of effectively regenerating a filter even in a deceleration state.

  According to a first aspect of the present invention, there is provided a filter provided in an exhaust system of an engine having an automatic transmission having a torque converter for collecting particulates in exhaust gas discharged from the engine, and the filter in the exhaust system of the engine. An oxidation catalyst provided on the upstream side, parameter value detection means for detecting a parameter value related to the amount of fine particles collected by the filter, and parameter values detected by the parameter value detection means are predetermined. The engine exhaust purification device includes a regeneration control means for regenerating the filter by performing main injection near the top dead center of the compression stroke and performing additional injection after the main injection when the value exceeds the value. A lockup clutch capable of engaging the input side and the output side of the torque converter, and controlling the engagement state of the lockup clutch Lockup control means, and deceleration detection means for detecting the deceleration state of the vehicle, wherein the regeneration control means detects the main injection when the deceleration detection means detects the deceleration state during regeneration of the filter. The additional injection is continuously executed for a predetermined period from when the deceleration state is detected by the deceleration detection means until a predetermined time elapses, and the lockup control means The lockup clutch is configured to be in an engaged state or a slip state for a period of time.

  Thus, in the first invention, when the deceleration state is detected during the regeneration of the filter, the additional injection is continuously executed during the predetermined period, and the lockup clutch is brought into the engagement state or the slip state. The additional injection can be effectively executed while maintaining the engine speed at a high level. For this reason, it is possible to cause the additionally injected fuel and the oxidation catalyst to react in the oxidation catalyst portion that is in a high temperature state until a predetermined time has elapsed from the start of deceleration. Thereby, since the effectiveness of the oxidation reaction by the additional injection in the deceleration state can be enhanced, the state where the temperature of the filter is high can be maintained. Accordingly, it is possible to effectively regenerate the filter in the deceleration state.

  According to a second aspect, in the first aspect, the lock-up control means is configured to expand the slip region to the low vehicle speed side for the predetermined period.

  As described above, in the second aspect of the present invention, since the slip region is expanded to the low vehicle speed side during the predetermined period, the period during which the lockup clutch is in the slip state can be lengthened. Thereby, during a predetermined period, the state where the engine speed is high can be maintained for a longer time, so that the additionally injected fuel and the oxidation catalyst can be sufficiently reacted. Therefore, the state where the temperature of the filter is high can be reliably maintained.

  According to a third aspect of the present invention, the first or second aspect of the present invention further comprises temperature detection means for detecting the temperature of the oxidation catalyst section, and the lockup control means is configured to end the predetermined period or to perform the predetermined period. The lockup clutch is configured to be released when the temperature of the oxidation catalyst portion detected by the temperature detecting means falls below a predetermined temperature.

  As described above, in the third aspect of the invention, when the predetermined period ends or when the oxidation catalyst section temperature falls below the predetermined temperature during the predetermined period, the lockup clutch is released, so the engine speed is reduced. It can be quickly reduced. Thereby, it can suppress that the low temperature air which does not accompany the combustion by main injection is sent to a filter via an exhaust pipe. Therefore, it is possible to suppress a rapid decrease in the temperature of the filter.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the engine further includes engine speed detecting means for detecting the engine speed, and the regeneration control means has the engine speed for the predetermined period. The higher the engine speed detected by the detecting means, the higher the injection timing of the additional injection is corrected to the retard side, and the lock-up control means has the injection timing of the additional injection for the predetermined period. The lock-up clutch is configured to be in a slip state so as not to be retarded from a predetermined limit time.

  Thus, in the fourth aspect of the invention, even when the injection timing of the additional injection is corrected to the retard side as the engine speed is higher, the injection timing of the additional injection is not retarded from the predetermined limit timing. Put the lock-up clutch in the slip state. Thus, by setting the slip ratio in accordance with the engine speed and setting the lockup clutch in the slip state, it is possible to suppress the engine speed from becoming excessively high. Therefore, since it is possible to suppress the injection timing of the additional injection from being retarded from the predetermined limit timing, it is possible to suppress the occurrence of oil dilution.

  According to the present invention, when the deceleration state is detected during the regeneration of the filter, the additional injection is continuously performed for a predetermined period and the lockup clutch is brought into the engaged state or the slip state. It is possible to effectively execute the additional injection while maintaining the engine speed at a high level. Thereby, since the effectiveness of the oxidation reaction by the additional injection can be enhanced, the filter can be effectively regenerated in the deceleration state. Therefore, the chances of the filter regeneration process are dramatically increased, so that filter clogging can be reliably suppressed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1, an exhaust emission control device 50 for an engine according to an embodiment of the present invention includes a diesel engine (hereinafter referred to as an engine) 10, an intake pipe 11 through which air sucked from outside flows, and an engine 10. The exhaust pipe 21 through which the exhaust gas to be discharged circulates, the turbocharger 15 configured by coaxially connecting the compressor 15a and the turbine 15b, and each vehicle device (including the engine 10) are controlled. An engine control unit (ECU) 60 (see FIG. 3), which will be described later, and an automatic transmission 70, which will be described later, provided with a torque converter 90 (see FIG. 2) in which a lockup mechanism is provided.

  The engine 10 supplies fuel to a cylinder head 2 having an intake port 5 and an exhaust port 6 formed therein, a cylinder block 1, a cylinder liner 1a, a piston 3, and a combustion chamber 4 described later at an appropriate time of the cycle. It has an injector (fuel injector) 9 for injecting, an intake valve 7 for sucking air into the engine 10, and an exhaust valve 8 for discharging combustion gas.

  A space surrounded by the cylinder head 2, the cylinder liner 1 a, and the piston 3 constitutes a combustion chamber 4 that vaporizes and burns an air-fuel mixture. The injector 9 is connected to the common rail 32 via the fuel supply pipe 33. The fuel from the fuel tank 31 is supplied to the injector 9 through the fuel supply pipe 33 and the common rail 32. Further, the engine 10 includes an engine water temperature sensor 36 that detects the temperature of cooling water circulating inside the engine 10 (hereinafter referred to as water temperature), a crank angle sensor 35 that detects the rotation angle of the crankshaft, and the engine speed. And an engine speed sensor 34 for detecting. The engine speed detection means referred to in the present invention corresponds to the engine speed sensor 34 and the engine control device 60 (see FIG. 3).

  The intake pipe 11 is connected to the intake port 5 via an intake manifold (not shown). An air cleaner 13 is provided near the inlet of the intake pipe 11. An intake air amount sensor 14, a compressor 15 a, an intercooler 16, an intake throttle valve 17, an intake air temperature sensor 18, and an intake air pressure sensor 19 are arranged in this order from the upstream side in a portion downstream of the air cleaner 13 in the intake pipe 11. ing. The intake air amount sensor 14 detects the amount of inhaled air. The intake throttle valve 17 adjusts the amount of air flowing through the intake pipe. The intake air temperature sensor 18 detects the temperature of the intake air (hereinafter referred to as intake air temperature). The intake pressure sensor 19 detects the pressure of the intake air.

The exhaust pipe 21 is connected to the exhaust port 6 through an exhaust manifold (not shown). The exhaust pipe 21 includes a turbine 15b, an oxidation catalyst unit 22, a first exhaust pressure sensor 23, a diesel particulate filter (DPF, hereinafter referred to as filter) 24, a second exhaust pressure sensor 25, and an exhaust temperature sensor 26 in order from the upstream side. , And an oxygen concentration sensor 27 is provided. The oxidation catalyst unit 22 carries an oxidation catalyst 22a made of platinum or platinum added with palladium, and at least functions to oxidize CO and HC in the exhaust gas and convert them into CO ₂ and H ₂ O, respectively. It is what you have.

  The first exhaust pressure sensor 23 detects the pressure of the exhaust gas immediately before flowing into the filter 24. The filter 24 collects particulates (PM: harmful substances such as particulates and black smoke) in the exhaust gas. The second exhaust pressure sensor 25 detects the pressure of the exhaust gas immediately after flowing out of the filter 24. The exhaust gas temperature sensor 26 detects the temperature of the oxidation catalyst unit 22 and the filter 24. The oxygen concentration sensor 27 detects the oxygen concentration in the exhaust gas immediately after flowing out of the filter 24. The temperature detecting means referred to in the present invention corresponds to the exhaust temperature sensor 26 and the engine control device 60 (see FIG. 3).

  A portion of the intake pipe 11 downstream of the intake pressure sensor 19 and a portion of the exhaust pipe 21 upstream of the turbine 15 b are connected via an exhaust gas recirculation pipe (hereinafter referred to as an EGR pipe) 41. The EGR pipe 41 is provided with a cooling device 42 and a control valve 43 in order from the upstream side. The cooling device 42 cools the recirculated exhaust gas flowing in the EGR pipe 41 by introducing cooling water therein.

  The engine control device 60 includes an input / output device, a storage device (ROM, RAM, etc.), a central processing unit (CPU), and a timer counter. As shown in FIG. 3, on the input side of the engine control device 60, an engine water temperature sensor 36, a crank angle sensor 35, an engine speed sensor 34, an exhaust temperature sensor 26, and first and second exhaust pressure sensors. 23, 25 and a throttle opening sensor 45 are connected. Then, detection information is input to the engine control device 60 from these sensors 22.

  On the other hand, at least the driver of the injector 9, the driver of the intake throttle valve 17, the driver of the control valve 43, and the like are connected to the output side of the engine control device 60. The engine control device 60 outputs optimum values such as the fuel injection amount and the injection timing calculated based on the detection information from the sensors 22 to the driver of the injector 9, while the intake throttle valve 17 Are output based on the detection information from the sensors 22,... And the optimum values of the opening amounts of the intake throttle valve 17 and the control valve 43 are output. The regeneration control means referred to in the present invention corresponds to the engine control device 60. Further, the deceleration detection means referred to in the present invention corresponds to the engine control device 60 and the throttle opening sensor 45.

  Further, when the pressure difference between the exhaust gas pressure detected by the first exhaust pressure sensor 23 and the exhaust gas pressure detected by the second exhaust pressure sensor 25 becomes a predetermined value or more, the engine control device 60. Determines that regeneration of the filter 24 is necessary. The parameter value detection means referred to in the present invention corresponds to the first and second exhaust pressure sensors 23 and 25 and the engine control device 60.

  As shown in FIG. 2, the hydraulic control device 70a of the automatic transmission 70 includes a torque converter 90 that transmits the torque of the engine 10 to the transmission mechanism via hydraulic oil, a hydraulic control circuit 80, and a duty solenoid valve to be described later. An automatic transmission control device 100 (see FIG. 3) for controlling various solenoids such as 84 is provided. The lockup control means in the present invention corresponds to the automatic transmission control device 100. Further, in the present invention, the automatic transmission 70 including the torque converter 90 is referred to.

  The torque converter 90 includes a cover 91 connected to the engine output shaft 98, a pump impeller 92 connected to the cover 91, and a turbine connected to the transmission input shaft 97 so as to face the pump impeller 92. A runner 93, a stator 95 provided between the pump impeller 92 and the turbine runner 93, and a lockup clutch 96 provided between the cover 91 and the turbine runner 93 are included. In the present invention, the input side of the torque converter 90 corresponds to the engine output shaft 98, and the output side of the torque converter 90 corresponds to the transmission input shaft 97.

  The interior of the torque converter 90 is divided into an apply chamber (fluid transmission oil chamber, rear chamber) 96b and a release chamber (lockup oil chamber, front chamber) 96a by a piston 96p of the lockup clutch 96. The apply chamber 96b is partitioned by a cover 91 and a piston 96p, and is formed on the vehicle rear side of the piston 96p. In the apply chamber 96b, a pump impeller 92, a turbine runner 93, a stator 95, and the like are disposed. The release chamber 96a is defined by a cover 91 and a piston 96p, and is formed on the vehicle front side of the piston 96p.

  The pump impeller 92 is rotationally driven by the engine output shaft 98 through the cover 91. The turbine runner 93 is rotationally driven by the pump impeller 92 via the hydraulic oil when the lockup clutch 96 is in the released state. Further, the turbine runner 93 is directly connected to the pump impeller 92 when the lockup clutch 96 is in the engaged state.

  The stator 95 is attached to the transmission case 99 via a one-way clutch 94, and the hydraulic oil discharged from the turbine runner 93 is circulated to the pump impeller 92 to increase the torque of the pump impeller 92 and to the turbine runner 93. introduce. The lock-up clutch 96 is controlled to be able to be engaged by a differential pressure between the hydraulic pressure in the apply chamber 96b and the hydraulic pressure in the release chamber 96a. The lockup clutch 96 directly connects the engine output shaft 98 and the transmission input shaft 97 in the engaged state.

  The hydraulic control circuit 80 includes a lockup control valve (hereinafter referred to as a control valve) 81 that controls the differential pressure between the hydraulic pressure in the apply chamber 96b and the hydraulic pressure in the release chamber 96a, and a duty solenoid valve 84 that controls the control valve 81. The control hydraulic pressure supply oil passage 83 to which the control hydraulic pressure generated by the duty solenoid valve 84 is supplied and the apply pressure (lockup rear pressure, lockup fastening pressure) for supplying the control chamber 81 to the apply chamber 96b. Apply pressure supply oil passage 86, release pressure supply oil passage 85 for supplying release pressure (lock-up front pressure, lock-up release pressure) from the control valve 81 to the release chamber 96a, and line pressure for the control valve 81. Lock-up signal pressure supply to supply to And use oil passage 87, and a source pressure supply oil passage 82 for supplying the original pressure pressure regulated to a constant pressure to the control valve 81. The line pressure refers to a hydraulic pressure supplied to a friction transmission element such as a clutch or a brake.

  The duty solenoid valve 84 does not supply line pressure to the control valve 81 when the automatic transmission control device 100 is instructed to release the lockup clutch 96. At this time, the spool 81a of the control valve 81 is positioned on the right side in FIG. 2 by the urging force of the spring 81b, and the source pressure supply oil passage 82 and the release pressure supply oil passage 85 communicate with each other. And is supplied to the release chamber 96a. As a result, the lock-up clutch 96 is released.

  On the other hand, when the automatic transmission control device 100 instructs the duty solenoid valve 84 to put the lockup clutch 96 into the engaged state, the duty solenoid valve 84 sends the line pressure to the control valve 81 via the lockup signal pressure supply oil passage 87. Supply. At this time, the spool 81a of the control valve 81 is positioned on the left side as shown in FIG. 2 against the urging force of the spring 81b, and the original pressure supply oil passage 82 and the apply pressure supply oil passage 86 communicate with each other. The original pressure becomes the apply pressure and is supplied to the apply chamber 96b. Thereby, the lockup clutch 96 will be in a fastening state.

  At the same time, the control hydraulic pressure supply oil passage 83 and the release pressure supply oil passage 85 communicate with each other, and the control hydraulic pressure is supplied to the release chamber 96a as the release hydraulic pressure Pr. As a result, a slip state in which the engagement force of the lockup clutch 96 can be controlled according to the duty ratio (slip ratio) with respect to the duty solenoid valve 84 is obtained.

  As shown in FIG. 3, the automatic transmission control device 100 includes a vehicle speed sensor 101 for detecting the vehicle speed, the throttle opening sensor 45, and a turbine for detecting the turbine speed (output speed of the torque converter 90). A rotation speed sensor 102, an oil temperature sensor 104 for detecting the temperature of the hydraulic oil, and a brake switch 105 for detecting depression of a brake pedal (not shown) are connected. Detection information is input to the automatic transmission control device 100 from these sensors. On the other hand, on the output side of the automatic transmission control device 100, there are an operating state changing means 111 for friction engagement elements such as a clutch and a brake, and an operating state changing means (duty solenoid valve 84, etc.) 112 for the lockup clutch 96. It is connected. The automatic transmission control device 100 controls various solenoids such as the duty solenoid valve 84 based on detection signals from the respective sensors.

  In addition, data is exchanged between the engine control device 60 and the automatic transmission control device 100. For example, the engine control device 60 can use a signal from the oil temperature sensor 104 input to the automatic transmission control device 100, a signal from the brake switch 105, or the like. Furthermore, the automatic transmission control device 100 can use information such as the engine speed input to the engine control device 60 and the fuel injection amount and injection timing output from the engine control device 60. A single integrated control unit that combines the functions of the engine control device 60 and the automatic transmission control device 100 may be used.

-Process of filter regeneration-
The filter regeneration process will be described below.

  When the trapped amount of the particulates collected by the filter 24 becomes a predetermined amount α or more (the exhaust gas differential pressure detected by the first exhaust pressure sensor 23 and the second exhaust pressure sensor 25 is a predetermined value or more), the regeneration flag. When F is turned on (F = 1), regeneration control by the engine control device 60 is started. The engine control device 60 performs the main injection for injecting fuel into the combustion chamber 4 near the top dead center of the compression stroke, and performs the additional injection for injecting fuel into the combustion chamber 4 in the expansion stroke after the main injection. 9 drivers are controlled.

  FIG. 4 is a diagram for explaining a mode of additional injection in normal regeneration (a state that is not deceleration regeneration described later). As shown in FIG. 4, the additional injection is divided into three injections (additional injections 1 to 3) in the expansion stroke after the main injection. As a result, in the oxidation catalyst unit 22, oxidation reaction heat is generated by oxidizing unburned HC in the additionally injected fuel. The exhaust gas is heated by the generated oxidation reaction heat. The heated exhaust gas flows into the filter 24 and heats the filter 24. As a result, the fine particles burn (the ignition temperature of the fine particles is, for example, 600 ° C.), and the filter 24 is regenerated.

  The injection amount in the additional injection can be controlled by, for example, open loop control based on the throttle opening and the engine speed, or feedback control so that the oxygen concentration detected by the oxygen concentration sensor becomes the target oxygen concentration. it can. This forced regeneration control is performed until the trapped amount of fine particles becomes less than a predetermined amount β smaller than the predetermined amount α.

  On the other hand, when the deceleration detection unit 45 detects the deceleration state of the engine 24 during the regeneration of the filter 24, the engine control device 60 stops the main injection and the deceleration detection unit 45 detects the deceleration state. The driver of the injector 9 is controlled so as to continue the additional injection for a predetermined period until the predetermined time elapses. That is, the engine exhaust gas purification apparatus according to this embodiment, when a deceleration state (throttle fully closed) is detected during the regeneration of the filter 24, regenerates the filter 24 by continuing the additional injection for a predetermined period (hereinafter referred to as “reduction”). "Decelerated playback").

  Here, the predetermined period is a period from the time when the deceleration state is detected until the time when the oxidation catalyst unit 22 is in a high temperature state (for example, 200 to 250 ° C.) sufficiently reacting with the additionally injected fuel. A predetermined period set in advance based on experimental data or the like can be set. The set predetermined period can be managed by the timer counter or the central processing unit provided in the engine control device 60.

  In addition, in the present embodiment, the condition that the oxidation catalyst portion temperature detected by the exhaust temperature sensor 26 exceeds the predetermined temperature γ is set as a condition for executing the additional injection during the deceleration regeneration. For this reason, when the temperature detected by the exhaust temperature sensor 26 is equal to or lower than the predetermined temperature γ, the additional injection is not executed even during the predetermined period. Here, the predetermined temperature is a temperature (200 ° C., 250 ° C., etc.) at which the unburned HC in the additionally injected fuel sufficiently reacts with the oxidation catalyst 22a in the oxidation catalyst unit 22.

  In the present embodiment, the open loop control for setting a predetermined period and the feedback control in which the oxidation catalyst part temperature exceeds the predetermined temperature for each loop as the execution condition of the additional injection are combined. Control by either one is also possible.

  FIG. 5 is a diagram for explaining a mode of additional injection in the deceleration regeneration. As shown in FIG. 5, the additional injection at the time of the slow regeneration is divided and injected in three times similarly to the normal regeneration. Further, in each of the additional injections 1 to 3, the injection timing is corrected to the retard side as the engine speed increases.

  When a deceleration state is detected during regeneration of the filter 24, the automatic transmission control device 100 performs lock-up control so that the lock-up clutch 96 is engaged or slipped during the predetermined period. When the lockup clutch 96 is engaged, the engine output shaft 98 of the torque converter 90 and the transmission input shaft 97 are directly connected, and the driving force of the driving wheels is transmitted to the engine 10. Thereby, although the main injection is stopped, a high engine speed state is maintained for a long time. As a result, during the predetermined period, the oxidation reaction between the additionally injected fuel and the oxidation catalyst 22a is effectively performed.

  In addition, the automatic transmission control apparatus 100 controls the duty solenoid valve 84 and the like so as to change a region for performing the deceleration slip control (deceleration slip region). Here, the deceleration slip control in the automatic transmission 70 having the four-speed transmission mechanism from the first forward speed to the fourth forward speed will be described. As shown in FIG. 6, in the deceleration travel region where the throttle opening is zero (fully closed), the high rotation side where the engine speed is relatively high is set as the 4-speed deceleration slip region, and the medium rotation side is 3 It is set in the fast deceleration slip region (the belt-shaped hatched portion in FIG. 6). When the driving state of the vehicle is in these deceleration slip regions, the slip ratio (lock-up slip ratio) with respect to the duty solenoid valve 84 is controlled to a medium value to reduce the lock-up clutch 96 to the slip state (half-connected state). Slip control (lock-up slip control) is performed.

On the other hand, the low rotation side where the engine speed is relatively low in the deceleration traveling region is set to the converter region (the region where the lockup clutch 96 is released). That is, when the vehicle speed falls below the lower limit vehicle speed V _{40 in} the 4-speed deceleration slip region (the lower limit vehicle speed V _{30 in} the case of the 3-speed deceleration slip region), the deceleration slip control ends and the lockup clutch 96 is released. As described above, during the deceleration traveling, the slip-up slip control is performed to improve the fuel consumption by increasing the engine speed and extending the period during which the main injection is stopped by setting the lock-up clutch 96 to the slip state.

When the deceleration state is detected during regeneration of the filter 24, the automatic transmission control apparatus 100 according to the present embodiment expands the deceleration slip region to the low vehicle speed side during the predetermined period. That is, the automatic transmission control device 100, the lower limit vehicle speed _{V 40} of the fourth speed deceleration slip region '(the lower limit vehicle speed _{V 30} in the case of 3-speed deceleration slip region _{V 30} up' to) _{V 40} in FIG. 6 lowers it (The strip-shaped white portion in FIG. 6) is controlled so that the period during which the lock-up clutch 96 is in the slip state during the slow-down regeneration is lengthened. As a result, the high engine speed state is maintained for a longer period than when the deceleration slip region is not expanded to the low vehicle speed side.

  Further, the automatic transmission control device 100 activates the lockup clutch 96 when the predetermined period ends or when the oxidation catalyst portion temperature detected by the exhaust temperature sensor 26 during the predetermined period falls below the predetermined temperature. Put it in a released state. Such control is performed for the following reason.

  In the engine exhaust gas purification apparatus according to the present embodiment, during the slow regeneration, additional injection is performed and the lockup clutch 96 is engaged to increase the engine speed. At this time, since the main injection is stopped, low-temperature air not accompanied by the combustion by the main injection flows into the exhaust pipe 21. And this low temperature air is supplied to the exhaust pipe 21 early, so that an engine speed is high. For this reason, if the engine speed becomes excessively high by engaging the lock-up clutch 96, the temperature of the oxidation catalyst section decreases earlier than the end of the predetermined period. As a result, the additionally injected fuel is less likely to react with the oxidation catalyst 22a even during the predetermined period. Furthermore, the temperature of the filter 24 rapidly decreases due to the low-temperature air sent to the filter via the exhaust pipe 21.

  In order to suppress such a decrease in the temperature of the filter 24, even if the oxidation catalyst portion temperature is lowered below a predetermined temperature even during a predetermined period, the locked lockup clutch 96 is released. . Thereby, the operation of increasing the engine speed is stopped, and low temperature air is suppressed from being sent to the filter via the exhaust pipe 21. As a result, a rapid decrease in the temperature of the filter 24 can be suppressed.

-Control device operation-
Hereinafter, the operations of the engine control device 60 and the automatic transmission control device 100 will be described with reference to the flowchart shown in FIG.

  First, in step S1, information such as the engine speed, the catalyst temperature, the exhaust pressure, and the throttle opening detected by the sensors 22,. Next, in step 2, the main injection amount is determined based on the engine speed, throttle opening, and the like.

  In subsequent step S3, the differential pressure of the exhaust gas detected by the first exhaust pressure sensor 23 and the second exhaust pressure sensor 25 is less than a predetermined value, that is, the particulate amount of the filter 24 is less than the predetermined amount β. It is determined whether or not there is. If the particulate amount of the filter 24 is equal to or larger than the predetermined amount β (the determination result in step S3 is NO), the process proceeds to step S4, where it is determined whether or not the particulate amount is equal to or larger than the predetermined amount α.

  If the particulate amount of the filter 24 is equal to or greater than the predetermined amount α (the determination result in step S4 is YES), the regeneration of the filter 24 is to be executed, so that the process proceeds to step S5 and the regeneration flag F is turned on. (F = 1). In a succeeding step S8, it is determined whether or not the vehicle is decelerated (throttle fully closed).

  If the determination result in step S8 is NO, that is, if it is determined that the vehicle is not in a decelerating state, the process proceeds to steps S9 and S14 in order to regenerate the filter 24. Specifically, the main injection is performed based on the main injection amount determined in step 2 (step S9), and the additional injection is performed in the expansion stroke after the main injection (step S14). Further, since it is determined in step S8 that the vehicle is not in a decelerating state, the subsequent step S16 returns to the start without performing lockup control of the lockup clutch 96.

  On the other hand, if the determination result in step S8 is YES, that is, if it is determined that the vehicle is in a decelerating state, the process proceeds to step S10 and main injection is stopped. Next, in step S12, it is determined whether or not a predetermined period from when the deceleration state is detected until a predetermined time elapses. Note that the detection of the deceleration state, which is the start of the predetermined period, does not mean the determination of the deceleration state for each loop (step 8), but the detection of the first deceleration state after the start of deceleration.

  If the decision result in the step S12 is YES, that is, if it is decided that it is during a predetermined period, it is determined in a succeeding step S13 whether or not the oxidation catalyst part temperature exceeds a predetermined temperature γ. When it is determined that the oxidation catalyst portion temperature exceeds the predetermined temperature γ, the process proceeds to step S15 and the additional injection is continuously executed. At this time, the injection timing of the additional injection is corrected to the retard side as the engine speed increases.

  Further, in step S17, the slip region is expanded to the low vehicle speed side. That is, the lower limit vehicle speed in the slip region is set lower than that during normal operation so that the period during which the lockup clutch 96 is in the slip state becomes longer during the deceleration regeneration. In the subsequent step S20, the lockup control is performed so that the lockup clutch 96 is engaged or slipped, and the process returns to the start.

  On the other hand, even if it is determined in step S8 that the vehicle is in the deceleration state, if the determination result in step S12 or step S13 is NO, the process proceeds to step S18 to return the lockup control to the normal control state. Specifically, the slip region expanded to the low vehicle speed side is returned to the region during normal operation, and the engaged lock-up clutch 96 is released. In subsequent step S21, the additional injection is stopped and the process returns to the start.

  The regeneration of the filter 24 is continued until the determination result in step S3 is YES, that is, until the particulate amount of the filter 24 becomes less than the predetermined amount β. Even when the particulate amount of the filter 24 becomes less than the predetermined amount α in step S4, the regeneration is continued if the regeneration flag F is on (F = 1) in step S6. When the determination result of step S3 is YES, or when the determination result of step S6 is NO, the process proceeds to step S7 and the regeneration flag F is turned off (F = 0).

  In the state where the regeneration flag F is OFF, it is not necessary to regenerate the filter 24, so the main injection is performed in step S11, but the lockup control (step S19) and the additional injection (step S21) are not performed, and the process returns to the start.

-Effect-
As described above, according to the present embodiment, when the deceleration state is detected during the regeneration of the filter 24, the additional injection is continuously executed during the predetermined period, and the lockup clutch 96 is brought into the engaged state or the slip state. Therefore, the additional injection can be executed effectively while maintaining the engine speed at a high level. For this reason, it is possible to cause the additionally injected fuel to react with the oxidation catalyst 22a in the oxidation catalyst unit 22 that is in a high temperature state until a predetermined time has elapsed from the start of deceleration. Thereby, since the effectiveness of the oxidation reaction by the additional injection during the deceleration regeneration can be improved, the state where the temperature of the filter 24 is high can be maintained. Therefore, the regeneration of the filter 24 in the deceleration state can be performed effectively.

  Further, since the slip region is expanded to the low vehicle speed side during the predetermined period, it is possible to lengthen the period during which the lockup clutch 96 is in the slip state. As a result, during a predetermined period, the state of high engine speed can be maintained for a longer time, so that the additionally injected fuel and the oxidation catalyst 22a can be sufficiently reacted. Therefore, the state where the temperature of the filter 24 is high can be reliably maintained.

  Further, when the predetermined period ends, or when the oxidation catalyst portion temperature falls below the predetermined temperature during the predetermined period, the lockup clutch 96 is released, so that the engine speed can be quickly reduced. . Thereby, it is possible to suppress low-temperature air that is not accompanied by combustion due to main injection from being sent to the filter 24 via the exhaust pipe 21. Therefore, it is possible to suppress the temperature of the filter 24 from rapidly decreasing.

(Embodiment 2)
In the present embodiment, the engine control device 60 corrects the injection timing of the additional injection to the retard side as the engine speed detected by the engine speed sensor 34 increases, and the automatic transmission control device 100 performs the additional injection. The lockup clutch 96 is brought into a slip state so that the injection timing is not retarded from the predetermined limit timing, and the other points are substantially the same as in the first embodiment.

  Normally, the injection timing of the additional injection is corrected to the retard side as the engine speed increases in order to temporarily supply a large amount of HC to the oxidation catalyst unit 22. However, if the injection timing of the additional injection is delayed too much, the fuel may mix with the oil adhering to the cylinder wall surface and cause oil dilution. When the injected fuel mixes with the oil on the cylinder wall surface and the oil is diluted, the lubricating action of the cylinder wall surface by the oil is impaired.

  In this embodiment, a predetermined limit time is set at which oil dilution does not occur even if the injection timing of the additional injection is delayed, and the engine speed is set so that the injection timing of the additional injection is not retarded from the predetermined limit time. maintain. Specifically, the engine speed is suppressed from becoming excessively high by setting the slip ratio according to the engine speed and setting the lock-up clutch 96 to the slip state.

-Control device operation-
Hereinafter, the operations of the engine control device 60 and the automatic transmission control device 100 will be described with reference to the flowchart shown in FIG. Note that step S22 in FIG. 8 corresponds to step S17 and step S20 in FIG. 7, and the other steps are the same as those in the flowchart shown in FIG.

  When the deceleration state is detected during the regeneration of the filter, it is determined that it is during a predetermined period, and when it is determined that the oxidation catalyst part temperature exceeds the predetermined temperature γ, the process proceeds to step S15 and additional injection is performed. Continue to execute. At this time, the engine control device 60 corrects the injection timing of the additional injection to the retard side as the engine speed increases.

  Further, in step S22, the slip ratio is set according to the engine speed so that the injection timing of the additional injection is not retarded from the predetermined limit timing, and the lock-up clutch 96 is slipped to return to the start.

-Effect-
As described above, according to the present embodiment, even when the injection timing of the additional injection is corrected to the retard side as the engine speed is higher, the injection timing of the additional injection is not retarded from the predetermined limit timing. The lockup clutch 96 is brought into a slip state. Thus, by setting the slip ratio according to the engine speed and setting the lock-up clutch 96 to the slip state, it is possible to suppress the engine speed from becoming excessively high. Therefore, since it is possible to suppress the injection timing of the additional injection from being retarded from the predetermined limit timing, it is possible to suppress the occurrence of oil dilution.

  The present invention is not limited to the embodiments, and can be implemented in various other forms without departing from the spirit or main features thereof.

  As described above, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is defined by the claims, and is not limited by the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  As described above, the present invention is useful for an engine exhaust gas purification device that purifies exhaust gas exhausted from an engine.

1 is a schematic configuration diagram of an engine exhaust gas purification apparatus according to an embodiment of the present invention. It is a schematic block diagram of the hydraulic control apparatus of an automatic transmission. It is a schematic block diagram of an engine control apparatus and an automatic transmission control apparatus. It is a figure explaining the aspect of the additional injection in normal reproduction | regeneration. It is a figure explaining the aspect of the additional injection in deceleration reproduction | regeneration. It is a figure explaining the automatic transmission transmission characteristic provided with the four-stage transmission mechanism, and the control characteristic of a lockup clutch. It is a flowchart which shows operation | movement of an engine control apparatus and an automatic transmission control apparatus. It is a flowchart which shows operation | movement of an engine control apparatus and an automatic transmission control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Diesel engine 21 Exhaust pipe 22 Oxidation catalyst part 23 1st exhaust pressure sensor (parameter value detection means)
24 Diesel particulate filter 25 Second exhaust pressure sensor (parameter value detection means)
26 Exhaust temperature sensor (temperature detection means)
34 Engine speed sensor (engine speed detection means)
45 Throttle opening sensor (deceleration detection means)
50 Exhaust purification device 60 Engine control device (regeneration control means)
70 Automatic transmission 90 Torque converter 96 Lock-up clutch 97 Transmission input shaft (output side of torque converter)
98 Engine output shaft (torque converter input side)
100 automatic transmission control device (lock-up control means)

Claims (4)

A filter that is provided in an exhaust system of an engine with an automatic transmission including a torque converter and that collects particulates in exhaust gas discharged from the engine;
An oxidation catalyst portion provided upstream of the filter in the exhaust system of the engine;
Parameter value detecting means for detecting a parameter value related to the amount of fine particles collected in the filter;
When the parameter value detected by the parameter value detection means exceeds a predetermined value, main injection is performed near the top dead center of the compression stroke, and additional injection is performed after the main injection, thereby regenerating the filter. An exhaust purification device for an engine comprising a regeneration control means for performing,
A lockup clutch capable of fastening the input side and the output side of the torque converter;
Lockup control means for controlling the engagement state of the lockup clutch;
A deceleration detecting means for detecting a deceleration state of the vehicle,
The regeneration control means stops the main injection when a deceleration state is detected by the deceleration detection means during regeneration of the filter, and until a predetermined time elapses after the deceleration state is detected by the deceleration detection means. It is configured to continuously execute the additional injection for a predetermined period,
The engine exhaust gas purification apparatus, wherein the lockup control means is configured to put the lockup clutch in an engaged state or a slip state for the predetermined period. The exhaust emission control device for an engine according to claim 1,
The engine exhaust gas purification apparatus, wherein the lock-up control means is configured to expand the slip region to the low vehicle speed side during the predetermined period. The engine exhaust gas purification apparatus according to claim 1 or 2,
A temperature detecting means for detecting the temperature of the oxidation catalyst section;
The lockup control means releases the lockup clutch when the predetermined period ends or when the temperature of the oxidation catalyst portion detected by the temperature detection means falls below a predetermined temperature during the predetermined period. An exhaust emission control device for an engine characterized by comprising: The engine exhaust gas purification apparatus according to any one of claims 1 to 3,
An engine speed detecting means for detecting the engine speed;
The regeneration control means is configured to correct the injection timing of the additional injection to the retard side as the engine speed detected by the engine speed detection means is higher during the predetermined period.
The lock-up control means is configured to place the lock-up clutch in a slip state so that the injection timing of the additional injection does not become retarded from a predetermined limit timing for the predetermined period. Exhaust gas purification device for the engine.

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