JP2019210850A - Control device for vehicular internal combustion engine - Google Patents

Abstract

To improve a shift feeling at shift-up during performing of thermal insulation control.SOLUTION: A vehicle comprises a clutch CL connecting and disconnecting power to/from an internal combustion engine 1. The internal combustion engine comprises an injector 7 injecting fuel, an EGR valve 33 adjusting a flow rate of EGR gas, and post-treatment members 22, 23, 24 and 26 removing harmful components in an exhaust gas. A control device comprises: a control unit 100 controlling the injector and the EGR valve; and a detector 48 detecting the connection and disconnection of the clutch. When the disconnection of the clutch is detected by the detector, and a prescribed high-load condition is established during a stop of fuel injection by the injector, the control unit performs thermal insulation cease control for controlling the EGR valve to a valve-closing side by ceasing the thermal insulation control for insulating the post-treatment members.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a control device for an internal combustion engine for a vehicle.

  In a vehicle internal combustion engine, a fuel cut is executed to stop fuel injection by an injector when the vehicle is decelerated. When this fuel cut is executed, fresh air sucked into the combustion chamber is directly discharged from the combustion chamber to the exhaust passage and supplied to a post-processing member such as a catalyst provided in the exhaust passage. Then, the temperature of a post-processing member falls and the activity is lost.

  Therefore, in order to maintain the activity of the post-processing member, the EGR valve is opened during the fuel cut. Then, fresh air discharged from the combustion chamber is circulated to the intake passage via the EGR valve, and a fresh air circulation flow occurs between the combustion chamber and the EGR valve. Then, new intake and discharge of fresh air are suppressed, and a decrease in temperature of the post-processing member due to the supply of fresh air can be suppressed.

  Since this control is a control for keeping the post-processing member warm, it is called warm keeping control.

JP2013-24154A

  However, during the heat retention control, new intake and discharge of new air are suppressed, so that the pumping loss is reduced and the decrease in engine rotation tends to be delayed.

  On the other hand, when shifting up the transmission while the vehicle is running, if the clutch is disengaged at the same time as the accelerator pedal is returned, fuel cut is also executed at this time.

  If the upshift is executed during the heat retention control, the engine rotation is difficult to decrease after the clutch is disengaged, so there is a problem that the upshift is delayed and the shift feeling is deteriorated.

  Accordingly, the present disclosure has been made in view of such circumstances, and an object of the present disclosure is to provide a control device for a vehicle internal combustion engine that can improve a shift feeling when an upshift is performed during the execution of heat retention control. is there.

According to one aspect of the present disclosure,
A control device for an internal combustion engine for a vehicle,
The vehicle includes a clutch that connects and disconnects power from the internal combustion engine,
The internal combustion engine includes an injector that injects fuel, an EGR valve that adjusts the flow rate of EGR gas, and a post-processing member that removes harmful components in the exhaust gas,
The control device includes a control unit configured to control the injector and the EGR valve, and a detector that detects connection and disconnection of the clutch.
The control unit cancels the heat retention control for keeping the post-processing member warm when the detector detects the clutch disengagement while the fuel injection by the injector is stopped and a predetermined high load condition is satisfied. Then, the control apparatus for the vehicle internal combustion engine is provided, which performs the heat retention stop control for controlling the EGR valve to the valve closing side.

  Preferably, the control unit executes the heat retaining control when the high load condition is not satisfied even if the disengagement of the clutch is detected by the detector while the fuel injection by the injector is stopped.

  Preferably, the high load condition is satisfied when an operating state of the internal combustion engine is in a predetermined high load region between a first detection time of the clutch disengagement and a predetermined time before.

  Preferably, the control unit controls the EGR valve to be fully closed during execution of the heat retention stop control.

  Preferably, the control unit executes the heat retention stop control when a predetermined stop cancellation condition is not satisfied.

Preferably, the internal combustion engine includes a variable displacement turbocharger having a variable vane,
The control unit controls the variable vane to the valve closing side during execution of the heat retention stop control.

  According to the present disclosure, it is possible to improve the shift feeling when the upshift is executed during the heat retention control.

It is a schematic diagram showing composition of an embodiment of this indication. It is a flowchart of the routine which calculates the basic target opening of a variable vane and an EGR valve. It is a figure which shows various maps. It is a flowchart of the routine which controls the opening degree of a variable vane and an EGR valve.

  Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the following embodiments.

  FIG. 1 is a schematic diagram illustrating a configuration of an embodiment of the present disclosure. An internal combustion engine (also called an engine) 1 is a vehicular multi-cylinder engine mounted on a vehicle (not shown). In the present embodiment, the vehicle is a large vehicle such as a truck, and is a manual (MT) vehicle including a manual friction clutch CL and a transmission TM. The engine 1 as a vehicle power source is an in-line four-cylinder diesel engine. However, there are no particular limitations on the types, types, applications, and the like of the vehicle and the internal combustion engine. For example, the vehicle may be a small vehicle such as a passenger car, and the engine 1 may be a gasoline engine.

  The engine 1 includes an engine body 2, an intake passage 3 and an exhaust passage 4 connected to the engine body 2, a turbocharger 14, and a fuel injection device 5. The engine body 2 includes structural parts such as a cylinder head, a cylinder block, and a crankcase, and movable parts such as a piston, a crankshaft, and a valve housed therein.

  The fuel injection device 5 includes a common rail fuel injection device, and includes a fuel injection valve, that is, an injector 7 provided in each cylinder, and a common rail 8 connected to the injector 7. The injector 7 directly injects fuel into the cylinder 9, that is, into the combustion chamber. The common rail 8 stores the fuel injected from the injector 7 in a high pressure state.

  The intake passage 3 is mainly defined by an intake manifold 10 connected to the engine body 2 (particularly a cylinder head) and an intake pipe 11 connected to the upstream end of the intake manifold 10. The intake manifold 10 distributes and supplies the intake air sent from the intake pipe 11 to the intake ports of each cylinder. The intake pipe 11 is provided with an air cleaner 12, an air flow meter 13, a compressor 14 </ b> C of the turbocharger 14, an intercooler 15, and an electronically controlled intake throttle valve 16 in order from the upstream side. The air flow meter 13 is a sensor for detecting an intake air amount per unit time of the engine 1, that is, an intake flow rate, and is also referred to as a MAF sensor or the like.

  The exhaust passage 4 is mainly defined by an exhaust manifold 20 connected to the engine body 2 (particularly a cylinder head) and an exhaust pipe 21 disposed on the downstream side of the exhaust manifold 20. The exhaust manifold 20 collects exhaust gas sent from the exhaust port of each cylinder. A turbine 14 </ b> T of the turbocharger 14 is provided between the exhaust pipe 21 or between the exhaust manifold 20 and the exhaust pipe 21. In the exhaust pipe 21 downstream of the turbine 14T, an oxidation catalyst 22, a particulate filter (DPF) 23, a selective reduction type NOx catalyst (SCR) 24, and an ammonia oxidation catalyst 26 are provided in this order from the upstream side. An addition valve 25 for adding urea water is provided on the upstream side of the NOx catalyst 24, particularly in the exhaust passage 4 near the inlet.

  The turbocharger 14 is a variable capacity turbocharger. The turbocharger 14 includes a plurality of variable vanes 28 for making the opening degrees of the nozzles at the turbine inlet variable, and a turbo actuator 29 that simultaneously changes the opening degrees of these variable vanes.

The oxidation catalyst 22, the DPF 23, the SCR 24, and the ammonia oxidation catalyst 26 are post-treatment members that remove harmful components in the exhaust gas. The oxidation catalyst 22 oxidizes and purifies unburned components (hydrocarbon HC and carbon monoxide CO) in the exhaust gas, heats the exhaust gas with the reaction heat at this time, raises the temperature of the exhaust gas, and removes NO in the exhaust gas. It is oxidized to NO _2. The DPF 23 is a so-called continuous regeneration type DPF with a catalyst, which collects particulate matter (PM) contained in the exhaust gas and continuously burns and removes the collected PM. The SCR 24 reduces NOx in the exhaust using ammonia resulting from the urea water added from the addition valve 25 as a reducing agent. The ammonia oxidation catalyst 26 oxidizes excess ammonia discharged from the SCR 24 and purifies it.

  The engine 1 also includes an EGR device 30. The EGR device 30 includes an EGR passage 31 for returning a part of exhaust gas (referred to as “EGR gas”) in the exhaust passage 4 (particularly in the exhaust manifold 20) to the intake passage 3 (particularly in the intake manifold 10). The EGR cooler 32 that cools the EGR gas flowing through the EGR passage 31 and the EGR valve 33 for adjusting the flow rate of the EGR gas are provided.

  In addition, the control device according to the present embodiment includes an electronic control unit (ECU) 100 serving as a control unit, a circuit element, or a controller. ECU 100 includes a CPU, a ROM, a RAM, an input / output port, a storage device, and the like. The ECU 100 is configured and programmed to control the injector 7, the intake throttle valve 16, the addition valve 25, the EGR valve 33, and the turbo actuator 29.

  In addition to the air flow meter 13 described above, the control device according to the present embodiment includes a rotational speed sensor 40 for detecting the rotational speed of the engine (specifically, the rotational speed per minute (rpm)). And an accelerator opening sensor 41 for detecting the accelerator opening. The control device also includes exhaust temperature sensors 42, 43, 44, 46 for detecting exhaust temperatures (inlet gas temperatures) upstream or near the inlet of each of the oxidation catalyst 22, DPF 23, SCR 24, and ammonia oxidation catalyst 26. . The control device also includes a differential pressure sensor 45 for detecting the differential pressure between the exhaust pressures at the inlet and outlet (front and rear) of the DPF 23.

  Further, the control device detects a boost pressure sensor 47 for detecting a boost pressure or a boost pressure, a clutch switch (clutch SW) 48 for detecting connection / disconnection of the clutch CL, and a neutral of the transmission TM. The neutral switch (neutral SW) 49 and a brake switch (brake SW) 50 for detecting the operation of the brake are provided.

  The boost pressure sensor 47 is installed on the downstream side of the intake throttle valve 16 and is installed in the intake pipe 11 immediately before the intake manifold 10 in this embodiment, but the installation position is arbitrary, for example, installed in the intake manifold 10. May be. The clutch switch 48 is a switch that is turned off when the clutch is engaged and turned on when the clutch is disengaged. The neutral switch 49 is a switch that is turned on when the transmission TM is neutral and turned off otherwise. The brake switch 50 is a switch that is turned on when the brake is operated (on) and turned off when the brake is not operated (off).

  The clutch switch 48 constitutes a detector referred to in the claims.

  Next, the control of this embodiment will be described. First, a method for calculating the basic target openings Svt and Set of the variable vane 28 and the EGR valve 33 will be described with reference to FIG. The illustrated routine is repeatedly executed by the ECU 100 at every predetermined calculation cycle τ (for example, 10 msec). Normally, the openings of the variable vane 28 and the EGR valve 33 are controlled so as to coincide with the basic target openings Svt and Set, respectively.

  In step S101, the ECU 100 compares the engine speed Ne, the accelerator opening Ac, the boost pressure Pb, and the intake air amount Ga detected by the rotation speed sensor 40, the accelerator opening sensor 41, the boost pressure sensor 47, and the air flow meter 13, respectively. Get the value.

  In step S102, the ECU 100 determines the fuel injection amount, specifically, the command injection amount to the injector 7 according to a predetermined map as shown in FIG. 3A based on the engine speed Ne and the accelerator opening degree Ac. A target fuel injection amount Q is calculated.

  The engine speed Ne, the accelerator opening degree Ac, and the target fuel injection amount Q are all engine parameters that represent the operating state of the engine. Further, the accelerator opening degree Ac and the target fuel injection amount Q are both engine parameters corresponding to the engine load.

  Next, the ECU 100 calculates the basic target opening degree Svt of the variable vane 28 and the basic target opening degree Set of the EGR valve 33 by executing steps S103 to S106. These basic target openings Svt and Set are obtained by adding feed-forward (F / F) terms Svff and Seff and feedback (F / B) terms Svfb and Sefb.

  The basic target opening degrees Svt and Set are calculated in the same way, and here, the basic target opening degree Svt of the variable vane 28 will be described in detail first.

  In step S103, the ECU 100 calculates the F / F term Svff according to a predetermined map as shown in FIG. 3B based on the engine speed Ne and the target fuel injection amount Q.

  In step S104, the ECU 100 calculates the target boost pressure Pbt according to a predetermined map as shown in FIG. 3C based on the engine speed Ne and the target fuel injection amount Q.

  In step S105, the ECU 100 calculates the F / B term Svfb based on the difference between the target boost pressure Pbt and the actual boost pressure Pb acquired in step S101. Specifically, ECU 100 calculates a difference ΔPb = Pbt−Pb between target boost pressure Pbt and actual boost pressure Pb. Based on the difference ΔPb, the F / B term Svfb is calculated according to a predetermined map (not shown). When the difference ΔPb is positive, that is, when the actual boost pressure Pb is smaller than the target boost pressure Pbt, the negative F / B term Svfb on the boost pressure increasing side is calculated. Conversely, when the difference ΔPb is negative, that is, when the actual boost pressure Pb is larger than the target boost pressure Pbt, the positive F / B term Svfb on the boost pressure decrease side is calculated. In calculating the F / B term Svfb, it is preferable to set the total value of the P term, the I term, and the D term corresponding to the difference ΔPb as the F / B term Svfb in accordance with the PID control method.

  In step S106, the ECU 100 calculates the variable vane basic target opening degree Svt (= Svff + Svfb) by adding the calculated F / F term Svff and F / B term Svfb.

  Thus, the opening degree control of the variable vane 28 is basically performed by a combination of the F / F control by the F / F term Svff and the F / B control by the F / B term Svfb. The F / F term Svff is a value serving as a base for the variable vane basic target opening degree Svt, and is a value that can generally achieve the target boost pressure Pbt in the current engine operating state. On the other hand, the target boost pressure Pbt cannot always be realized only by the F / F term Svff, for example, because the actual engine operating state constantly changes. Therefore, the feedback term Svsb is added, and the variable vane opening is precisely controlled so that the target boost pressure Pbt can be stably realized.

  Next, a method for calculating the EGR valve basic target opening degree Set will be described.

  In step S103, the ECU 100 calculates the F / F term Seff based on the engine speed Ne and the target fuel injection amount Q according to a predetermined map as shown in FIG.

  In step S104, the ECU 100 calculates a target intake air amount Gat based on the engine speed Ne and the target fuel injection amount Q according to a predetermined map as shown in FIG.

  In step S105, the ECU 100 calculates the F / B term Sefb based on the difference between the target intake air amount Gat and the actual intake air amount Ga acquired in step S101. Specifically, the ECU 100 calculates a difference ΔGa = Gat−Ga between the target intake air amount Gat and the actual intake air amount Ga. Based on the difference ΔGa, the F / B term Sefb is calculated according to a predetermined map (not shown). When the difference ΔGa is positive, that is, when the actual intake air amount Ga is smaller than the target intake air amount Gat, the negative F / B term Sefb on the intake air amount increase side, that is, the EGR gas amount decrease side is calculated. Conversely, when the difference ΔGa is negative, that is, when the actual intake air amount Ga is larger than the target intake air amount Gat, the positive F / B term Sefb on the intake air amount decrease side, that is, the EGR gas amount increase side is calculated. . In calculating the F / B term Sefb, it is preferable to set the total value of the P term, the I term, and the D term according to the difference ΔGa as the F / B term Sefb in accordance with the PID control method.

  In step S106, the ECU 100 calculates the EGR valve basic target opening degree Set (= Seff + Sefb) by adding the calculated F / F term Seff and the F / B term Sefb.

  Thus, the opening degree control of the EGR valve 33 is also basically performed by a combination of the F / F control by the F / F term Seff and the F / B control by the F / B term Sefb. The F / F term Seff is a value that serves as a base for the EGR valve basic target opening degree Set, and is a value that can generally achieve the target EGR rate in the current engine operating state. On the other hand, the target EGR rate cannot always be realized only by the F / F term Seff, for example, because the actual engine operating state constantly changes. Therefore, the feedback term Sesb is added, and the EGR valve opening is precisely controlled so that the target EGR rate can be stably realized.

  Now, when the vehicle is decelerated, a fuel cut that stops fuel injection by the injector 7 is executed to improve fuel efficiency. When this fuel cut is executed, fresh air sucked into the combustion chamber is directly discharged from the combustion chamber to the exhaust passage 4 and supplied to a post-processing member such as the SCR 24 provided in the exhaust passage 4. Then, the temperature of a post-processing member falls and the activity is lost.

  Therefore, in order to maintain the activity of the post-processing member, the EGR valve 33 is controlled to the valve opening side during the fuel cut. That is, the opening degree of the EGR valve 33 is controlled to be fully opened (or an opening degree in the vicinity thereof). Then, fresh air discharged from the combustion chamber is circulated to the intake passage 3 via the EGR valve 33, and a fresh air circulation flow occurs between the combustion chamber and the EGR valve 33. Then, new intake and discharge of fresh air are suppressed, and a decrease in temperature of the post-processing member due to the supply of fresh air can be suppressed.

  Since this control is a control for keeping the post-processing member warm, it is called warm keeping control.

  However, during the heat retention control, new intake and discharge of new air are suppressed, so that the pumping loss is reduced and the decrease in engine rotation tends to be delayed.

  On the other hand, when shifting up the transmission TM while the vehicle is running, the clutch CL is disengaged at the same time as the accelerator pedal is returned, and the fuel cut is also executed at this time.

  When the heat retention control is executed by the fuel cut and the EGR valve 33 is fully opened, the engine rotation is difficult to decrease after the clutch is disconnected, and there is a problem that the shift up is delayed and the shift feeling is deteriorated.

  The heat insulation control is effective during a coasting operation on a downhill where the fuel cut is relatively long. However, there is a drawback that the shift feeling is worsened at the time of such upshifting.

  Therefore, in this embodiment, when clutch disengagement is detected during fuel cut, it is regarded as a shift-up during execution of the heat retention control, and the heat retention stop control is executed to stop the heat retention control and control the EGR valve 33 to the valve closing side. . In the case of this embodiment, the opening degree of the EGR valve 33 is controlled to be fully closed (or an opening degree in the vicinity thereof).

  Then, since fresh air flows through the intake passage 3 and the exhaust passage 4 as a whole, the pumping loss can be increased and the decrease in engine rotation can be accelerated. As a result, the engine rotation after the clutch is disengaged can be accelerated, the shift up can be performed quickly, and the shift feeling can be improved.

  Further, since the heat retention control is stopped only within a very short time during the clutch disengagement at the time of upshifting, it is possible to minimize the decrease in the activity of the post-processing member due to the suspension of the heat retention control.

  By the way, even when the clutch disengagement is detected during the fuel cut, it is not preferable to uniformly stop the heat retention control and execute the heat retention stop control. This is because when the engine is operating at a low load, the exhaust gas temperature is low and the temperature of the post-processing member is also low. If the heat retention control is stopped at this time, the post-processing member is deactivated and exhaust emission deteriorates. There is a fear. For example, the temperature of the SCR 24 on the relatively downstream side is difficult to increase, but when the SCR 24 falls into an inactivated state, a large amount of NOx is discharged into the atmosphere.

  On the other hand, when the engine is operating at a high load, the exhaust gas temperature is high and the temperature of the post-processing member is also high. Therefore, even if the heat retention control is stopped at this time, the post-processing member is not easily deactivated, and the exhaust emission is not easily deteriorated.

  Therefore, in this embodiment, when the clutch disengagement is detected during the fuel cut, if the predetermined high load condition is satisfied, the heat retention control is stopped and the heat retention stop control is executed. Thus, the heat retention stop control can be executed only when there is little risk of exhaust emission deterioration, and both exhaust emission and shift feeling can be achieved.

  In this embodiment, when clutch disengagement is detected during fuel cut, if the high load condition is not satisfied, the heat retention stop control is not performed and the heat retention control is performed. Thereby, when there is much possibility of exhaust emission deterioration, heat insulation control can be performed as a principle, and deterioration of exhaust emission can be suppressed reliably.

  Here, if the heat retention stop control is not executed, there is a concern that the shift feeling will deteriorate. However, at this time, since the upshift is performed during the low load operation, the upshift is often not rushed. Therefore, even if the engine rotation is delayed, no particular problem occurs, and the shift feeling does not deteriorate.

  Here, the high load condition will be described. The ECU 100 stores a predetermined area map as shown in FIG. The area map is created in advance through an actual machine test or the like. In the region map, the entire engine operation region is defined by the engine speed Ne and the target fuel injection amount Q, and this entire operation region is divided into a high load region A and a low load region B by a boundary line a. .

  In the case of the present embodiment, the actual engine operating state (engine speed Ne and target fuel injection amount Q) is between the first detection time point of clutch disengagement and a predetermined time before (referred to as an operating state detection period). When in the high load region A, the high load condition is satisfied, and when not, the high load condition is not satisfied. When the high load condition is established, it is considered that the temperature of the post-processing member is sufficiently high so that there is no problem even if the heat retention control is stopped for a short time. For this reason, when the high load condition is established, the heat retention control is stopped, and the speed reduction of the engine rotation is preferentially performed.

  In the present embodiment, when the actual engine operation state is in the high load region A over the entire operation state detection period, the high load condition is satisfied, but instead, the actual engine operation state is the operation state. If it is in the high load region A even within the detection period, the high load condition may be satisfied. In addition, other conditions that can satisfy the high load condition can be modified. In short, the condition that the temperature of the post-processing member is high enough that there is no problem even if the heat retention control is temporarily stopped during the clutch disengagement for upshifting may be a high load condition. . From such a viewpoint, the position of the boundary line a and the size of the predetermined time are also appropriately determined.

  On the other hand, when the high load condition is not established, the actual engine operation state is at least temporarily in the low load region B within the operation state detection period, and the problem occurs when the heat retention control is stopped even for a short time. The temperature of the processing member may be lowered. For this reason, when the high load condition is not established, the heat retention control is executed to preferentially retain the heat of the post-processing member.

  The form of the boundary line a, the high load area A, and the low load area B shown in FIG. 3F is merely an example and can be modified. In the case of the illustrated example, the boundary line a becomes the low load side as it goes to the high rotation side.

  In the present embodiment, since the EGR valve 33 is controlled to be fully opened during the heat retention control, the flow rate of the circulating flow between the combustion chamber and the EGR valve 33 can be maximized to maximize the heat retaining effect of the post-processing member. it can. Further, since the EGR valve 33 is controlled to be fully closed during the execution of the heat retention stop control, the pumping loss can be increased to the maximum and the engine rotation can be lowered as quickly as possible.

  Further, in the present embodiment, the variable vane 28 is controlled to the valve opening side, in particular, fully open (or the opening degree in the vicinity thereof) during the heat retention control. If the opening degree of the variable vane 28 is decreased while the heat retention control is being executed, the boost pressure rises and fresh air is easily supplied to the post-processing member. In the present embodiment, since the variable vane 28 is controlled to the valve opening side during the heat retention control, the supply of fresh air to the post-processing member can be suppressed, and the post-processing member can be advantageously kept warm. In particular, since the variable vane 28 is controlled to be fully opened, the heat retaining effect of the post-processing member can be maximized.

  In the present embodiment, the variable vane 28 is controlled to the valve closing side during the heat retention stop control. If the opening degree of the variable vane 28 is increased during execution of the heat retention stop control, the boost pressure is reduced and the pumping loss is reduced, which may hinder the rapid reduction of the engine speed. In this embodiment, since the variable vane 28 is controlled to the valve closing side during the execution of the heat retention stop control, the boost pressure and the pumping loss can be increased, and the reduction in engine rotation can be advantageously accelerated.

  The opening degree of the variable vane 28 during execution of the heat retention stop control is preferably as small as possible from the viewpoint of speeding down the engine rotation, and is preferably fully closed or in the vicinity thereof. However, if there is a hardware lower limit that takes into account the turbine expansion ratio, etc., the lower limit may be used.

  In the same way, even if the intake throttle valve 16 is controlled to the valve opening side (for example, fully open) during the heat retention control, and the intake throttle valve 16 is controlled to the valve closing side (for example, fully closed) during the heat retention stop control. Good.

  Next, a method for controlling the EGR valve 33 and the variable vane 28 will be described with reference to FIG. The ECU 100 performs control by repeatedly executing a routine shown in the figure every predetermined calculation cycle τ (for example, 10 msec).

  In step S201, the ECU 100 determines whether or not a fuel cut (F / C) is being executed. The fuel cut is executed by the ECU 100 when the fuel cut execution condition is satisfied. Therefore, here, it is substantially determined whether or not the fuel cut execution condition is satisfied.

  The fuel cut execution condition is that the actual engine rotational speed Ne detected by the rotational speed sensor 40 is higher than the predetermined return rotational speed Nfc, and the actual accelerator opening Ac detected by the accelerator opening sensor 41 is predetermined. It is established when it is less than or equal to the fully closed determination threshold Afc. The return rotational speed Nfc is a rotational speed for returning from fuel cut (restarting fuel injection), and is set to a value slightly higher than a predetermined idle rotational speed. The fully closed determination threshold is a threshold for detecting that the accelerator pedal is fully returned and the accelerator opening is fully closed (minimum), and is slightly smaller than the accelerator opening when fully closed. It is set to a large value.

  When the fuel cut is not being executed, the ECU 100 controls the EGR valve 33 and the variable vane 28 as usual. That is, it progresses to step S211 and sets the target opening degree Se of the EGR valve 33 to the basic target opening degree Set calculated according to the routine of FIG. Next, the routine proceeds to step S212, where the target opening degree Sv of the variable vane 28 is set to the basic target opening degree Svt calculated according to the routine of FIG.

  In step S207, the opening degree of the EGR valve 33 is controlled to the target opening degree Se. In step S208, the opening degree of the variable vane 28 is controlled to the target opening degree Sv, and the routine is finished.

  On the other hand, if the fuel cut is being executed in step S201, that is, if the fuel cut execution condition is satisfied, the ECU 100 proceeds to step S202 and determines whether or not the clutch switch 48 is on (ON). To do.

  When the clutch switch 48 is on, the clutch CL is disengaged. That is, the accelerator opening is fully closed and the clutch is disengaged. Therefore, at this time, it is regarded as a shift up.

  If the clutch switch 48 is on, the ECU 100 proceeds to step S203 and determines whether or not the above-described high load condition is satisfied. If it is determined that the condition is satisfied, the ECU 100 proceeds to step S204 to determine whether or not a predetermined cancellation cancellation condition is not satisfied.

  The cancellation cancellation condition is a condition for canceling or prohibiting the heat retention cancellation control. When the cancellation cancellation condition is satisfied, the thermal suspension cancellation control is canceled, and when the cancellation cancellation condition is not satisfied, the thermal cancellation control is not canceled (permitted). The cancellation cancellation condition includes one or more subconditions for which the heat retention cancellation control is to be canceled. When at least one of these subconditions is satisfied, the cancellation cancellation condition is established. The cancellation cancellation conditions of the present embodiment include the following four subconditions 1 to 4.

  Small condition 1: Brake switch 48 is on. This is because the brake is being operated in this case, and it can be regarded as not an upshifting operation.

  Small condition 2: Neutral switch 49 is kept on for a predetermined time or longer. This is because when the accelerator opening is fully closed and the clutch is disengaged and the transmission TM is neutral for a predetermined time or longer, it can be considered that the normal shift-up operation is not being performed and the engine speed is sufficiently reduced.

  Minor condition 3: A predetermined time or more has elapsed since the first time when the judgments in steps S201 and S202 both became yes. At this time, since a predetermined time or more has elapsed since the clutch disengagement, it can be considered that the engine speed has sufficiently decreased.

  Minor condition 4: The neutral switch does not turn on within a predetermined time from when the clutch switch 48 is first turned on. In this case, the clutch is simply disengaged, the gear shifting operation is not started, and it can be regarded as not an upshifting operation.

  When it is determined that the cancellation cancellation condition is not satisfied, the ECU 100 executes the heat retention cancellation control in steps S205 to S208. That is, the ECU 100 sets the target opening degree Se of the EGR valve 33 to the heat retention stop control target opening degree Sec (for example, fully closed) in step S205. Next, in step S206, the target opening degree Sv of the variable vane 28 is set to the target opening degree Svt for heat retention stop control (for example, fully closed).

  In step S207, the opening degree of the EGR valve 33 is controlled to the target opening degree Se, and in step S208, the opening degree of the variable vane 28 is controlled to the target opening degree Sv, and the routine is finished.

  On the other hand, when the clutch switch is not on (ie, is off) in step S202, that is, when the clutch CL is engaged, the ECU 100 executes heat retention control in steps S209, S210, S207, and S208. That is, the ECU 100 sets the target opening degree Se of the EGR valve 33 to the heat retention control target opening degree Seo (for example, fully open) in step S209. Next, in step S207, the target opening degree Sv of the variable vane 28 is set to the target opening degree Svo for heat retention control (for example, fully open). Steps S207 and S208 are the same as described above.

  In addition, the ECU 100 executes the heat retention control in steps S209, S210, S207, and S208 both when the high load condition is not satisfied at step S203 and when the cancellation cancellation condition is satisfied at step S204.

  When the high load condition is not established, the heat retention control is executed instead of the heat retention stop control. Therefore, when there is a risk of exhaust emission deterioration, the heat insulation control is executed as a rule to reliably suppress the exhaust emission deterioration. it can.

  As mentioned above, although embodiment of this indication was described in detail, various embodiment of this indication can be considered variously.

  (1) For example, some of the four post-treatment members (the oxidation catalyst 22, DPF 23, SCR 24, and ammonia oxidation catalyst 26) may be omitted, or other post-treatment members may be added. .

  (2) The vehicle may be an automatic (AT) vehicle capable of automatic transmission, and in particular, an AT vehicle equipped with an AMT (Automated Manual Transmission) for controlling a friction clutch and a manual transmission with an actuator. Good.

  Embodiments of the present disclosure are not limited to the above-described embodiments, and all modifications, applications, and equivalents included in the concept of the present disclosure defined by the claims are included in the present disclosure. Accordingly, the present disclosure should not be construed as being limited, but can be applied to any other technique belonging to the scope of the idea of the present disclosure.

1 Internal combustion engine
7 Injector 14 Turbocharger 14T Turbine 22 Oxidation catalyst 23 Filter 24 NOx catalyst 26 Ammonia oxidation catalyst 28 Variable vane 33 EGR valve 48 Clutch switch 100 Electronic control unit (ECU)
CL clutch

Claims (6)

A control device for an internal combustion engine for a vehicle,
The vehicle includes a clutch for connecting / disconnecting power from the internal combustion engine,
The internal combustion engine includes an injector that injects fuel, an EGR valve that adjusts the flow rate of EGR gas, and a post-processing member that removes harmful components in the exhaust gas,
The control device includes a control unit configured to control the injector and the EGR valve, and a detector that detects connection and disconnection of the clutch.
The control unit cancels the heat retention control for keeping the post-processing member warm when the detector detects the clutch disengagement while the fuel injection by the injector is stopped and a predetermined high load condition is satisfied. Then, the control apparatus for the internal combustion engine for a vehicle is characterized by executing a heat retention stop control for controlling the EGR valve to the valve closing side. The said control unit performs the said heat retention control, when the said high load condition is not satisfied, even if the disconnection of the said clutch is detected by the said detector while the fuel injection by the said injector is stopped. Control device for internal combustion engine for vehicle. 3. The vehicle according to claim 1, wherein the high load condition is satisfied when an operating state of the internal combustion engine is in a predetermined high load region between a first detection time of the clutch disengagement and a predetermined time before. Control device for internal combustion engine. The control device for an internal combustion engine for a vehicle according to any one of claims 1 to 3, wherein the control unit controls the EGR valve to be fully closed during execution of the heat retention stop control. The control device for an internal combustion engine for a vehicle according to any one of claims 1 to 4, wherein the control unit executes the heat retention stop control when a predetermined stop cancellation condition is not satisfied. The internal combustion engine includes a variable displacement turbocharger having a variable vane,
The control device for an internal combustion engine for a vehicle according to any one of claims 1 to 5, wherein the control unit controls the variable vane to a valve closing side during execution of the heat retention stop control.

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