Control device for internal combustion engine

Abstract

To provide an internal combustion engine in which an exhaust valve and an intake valve are simultaneously opened at the time of transition from an exhaust stroke to an intake stroke, and deterioration of emission due to a blow-by phenomenon can be suppressed satisfactorily.SOLUTION: A control device for an internal combustion engine includes a port injection valve that injects a fuel into an intake port, and a supercharger, and is applied to an internal combustion engine in which an exhaust valve and an intake valve can be opened simultaneously at the time of transition from an exhaust stroke to an intake stroke. The control device sets a threshold based on the atmospheric pressure to be small when the temperature of the internal combustion engine is low as compared with that when the temperature is high, and starts a fuel injection from the port injection valve after the exhaust valve is closed, when the intake pressure of the internal combustion engine is the threshold or higher and the opening periods of the exhaust valve and the intake valve overlap.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a control device for an internal combustion engine including a port injection valve and a turbocharger. [Background technology]

[0002] Conventionally, there is known a control device for an engine including a port injection valve and a turbocharger that sets a valve overlap period during which the open state of the intake valve overlaps the open state of the exhaust valve when the exhaust stroke transitions to the intake stroke in order to improve the scavenging efficiency of the combustion gas and the volumetric efficiency of the intake air (see, for example, Patent Document 1). This control device makes the entire period from the start to the end of fuel injection fall within the first half of the intake stroke period when the temperature of the engine is below a predetermined threshold temperature (for example, 60°C) and the intake pressure is equal to or higher than a predetermined threshold intake pressure (for example, 130 kPa). This makes it possible to suppress the occurrence of a blow-by phenomenon in which the mixture flowing in from the intake port passes directly through to the exhaust port, thereby suppressing the deterioration of emissions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-119470 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above engine, even if the engine temperature is below the threshold temperature, when the intake pressure is below a certain threshold intake pressure, fuel may be injected from the port injection valve during the exhaust stroke, which may result in the occurrence of the blow-by phenomenon not being effectively suppressed, resulting in a deterioration of emissions.

[0005] Therefore, a primary object of the present disclosure is to effectively suppress deterioration of emissions due to the blow-by phenomenon in an internal combustion engine in which the exhaust valve and the intake valve can be opened simultaneously during the transition from the exhaust stroke to the intake stroke. [Means for solving the problem]

[0006] The control device for an internal combustion engine disclosed herein includes a port injection valve that injects fuel into an intake port and a turbocharger, and is capable of simultaneously opening the exhaust valve and the intake valve when transitioning from the exhaust stroke to the intake stroke. The control device sets a threshold value based on atmospheric pressure so that it is smaller when the temperature of the internal combustion engine is low compared to when the temperature is high, and when the intake pressure of the internal combustion engine is equal to or greater than the threshold value and the opening periods of the exhaust valve and the intake valve overlap, fuel injection from the port injection valve is started after the exhaust valve is closed.

[0007] The control device for an internal combustion engine disclosed herein sets a threshold value based on atmospheric pressure so that it is smaller when the temperature of the internal combustion engine is low than when the temperature of the internal combustion engine is high. Then, when the intake pressure of the internal combustion engine is equal to or higher than the threshold value and the open periods of the exhaust valve and the intake valve overlap, fuel injection from the port injection valve is started after the exhaust valve is closed. In this way, by setting the threshold value to be compared with the intake pressure based on atmospheric pressure, when the exhaust valve and the intake valve are simultaneously opened during the operation of the supercharger, or when the supercharger is operated from a stage where the engine load is relatively low at a high altitude where the atmospheric pressure is low, fuel is injected from the port injection valve after the exhaust valve is closed, and it is possible to effectively suppress the blow-by of the mixture when the open periods of the exhaust valve and the intake valve overlap. Furthermore, by setting the threshold value to be smaller when the temperature of the internal combustion engine is low than when the temperature is high, it is possible to suppress the occurrence of the blow-by phenomenon at low temperatures, in which the fuel injection amount may be increased, while allowing fuel injection from the port injection valve and suppressing a decrease in the output of the internal combustion engine. As a result, in an internal combustion engine in which the exhaust valve and the intake valve can be opened simultaneously when transitioning from the exhaust stroke to the intake stroke, it is possible to effectively suppress the deterioration of emissions due to the blow-by phenomenon.

[0008] The threshold value may be set by adding an offset value to the atmospheric pressure, and the offset value may be set to zero when the temperature of the internal combustion engine is equal to or higher than a predetermined temperature, and may be set to a negative value that decreases as the temperature of the internal combustion engine decreases when the temperature of the internal combustion engine is lower than the predetermined temperature. This makes it possible to effectively suppress the occurrence of the blow-by phenomenon at low temperatures.

[0009] Furthermore, the internal combustion engine may include, in addition to the port injection valve, an in-cylinder injection valve that directly injects the fuel into the combustion chamber, and in a supercharging region in which the supercharger is operated, the fuel may be injected from both the port injection valve and the in-cylinder injection valve. This makes it possible to reduce the burden on a fuel pump that pressurizes and supplies fuel to the in-cylinder injection valve, thereby suppressing an increase in costs. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram illustrating an internal combustion engine controlled by an internal combustion engine control device according to the present disclosure; [Diagram 2] 1 is a block diagram showing a control device for an internal combustion engine according to the present disclosure; [Diagram 3] 2 is an explanatory diagram for explaining a control procedure of an internal combustion engine by an internal combustion engine control device according to the present disclosure; FIG. [Figure 4] 3 is a flowchart showing a control procedure for an internal combustion engine by the internal combustion engine control device of the present disclosure. [Diagram 5] FIG. 4 is an explanatory diagram illustrating an offset value setting map; [Figure 6] 5 is a time chart illustrating the operating states of an exhaust valve, an intake valve, and a port injection valve when the routine of FIG. 4 is executed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Next, an embodiment of the present disclosure will be described with reference to the drawings.

[0012] 1 is a schematic diagram illustrating an engine 10, which is an internal combustion engine controlled by an engine electronic control unit (hereinafter referred to as "engine ECU") 100 as a control device of the present disclosure. The engine 10 shown in the figure is, for example, an in-line gasoline engine that converts the reciprocating motion of pistons 13, which accompanies the combustion of a mixture of hydrocarbon fuel and air in a plurality of combustion chambers 12 formed in an engine block 11, into the rotational motion of a crankshaft (output shaft) 14, and is mounted on a vehicle. As shown in FIG. 1, engine 10 includes, in addition to engine block 11, multiple combustion chambers 12, pistons 13, and crankshaft 14, an air cleaner 15, an intake pipe 16, an electronically controlled throttle valve 17, a surge tank 18, multiple intake valves 19i that open and close corresponding intake ports, exhaust valves 19e that open and close corresponding exhaust ports, a variable valve mechanism (variable valve timing mechanism) 190 that changes the opening timing and lift amount of intake valves 19i and exhaust valves 19e, multiple port injection valves 20p and in-cylinder injection valves 20d, multiple spark plugs 21, and an exhaust pipe 22 that forms an exhaust passage.

[0013] The engine 10 also includes an upstream purification device 23 and a downstream purification device 24, each of which is incorporated in the exhaust pipe 22, as exhaust gas purification devices. The upstream purification device 23 includes a NOx storage type exhaust gas purification catalyst (three-way catalyst) 230 that purifies harmful components such as CO (carbon monoxide), HC, and NOx in the exhaust gas from each combustion chamber 12 of the engine 10. The downstream purification device 24 includes a particulate filter (GPF) 240 that collects particulate matter (fine particles) in the exhaust gas, and is disposed downstream of the upstream purification device 23. In this embodiment, the particulate filter 240 is a porous filter carrying a NOx storage type exhaust gas purification catalyst (three-way catalyst). That is, the downstream purification device 24 is configured as a four-way catalyst having the purification function of a three-way catalyst and the collection function of particulate matter.

[0014] Furthermore, the engine 10 includes a coolant circulation passage 25 for cooling the engine block 11 etc., an electric pump 26, and a radiator 27. The electric pump 26 circulates coolant (LLC) through the coolant circulation passage 25. The radiator 27 cools the coolant that has absorbed heat from the engine block 11 etc. by heat exchange with air from traveling wind or an electric fan (not shown). A water temperature sensor 25t is also provided in the coolant circulation passage 25. The water temperature sensor 25t detects the water temperature Tw of the coolant that has absorbed heat from (flowed out of) the engine block 11.

[0015] In addition, the engine 10 includes a turbocharger 30 that compresses intake air by utilizing the energy of exhaust gas, and a liquid-cooled intercooler 39 that cools the air compressed by the turbocharger 30. As shown in FIG. 1, the turbocharger 30 is a turbocharger that includes a turbine wheel 31, a compressor wheel 32, a turbine shaft 33 that integrally connects the turbine wheel 31 and the compressor wheel 32, a wastegate valve 34, and a blow-off valve 35. The turbine wheel 31 is rotatably disposed in a turbine housing 220 formed in the exhaust pipe 22 so as to be located upstream of the upstream purification device 23. The compressor wheel 32 is rotatably disposed in a compressor housing 160 formed in the intake pipe 16 so as to be located between the air cleaner 15 and the throttle valve 17.

[0016] The turbine shaft 33 is rotatably disposed in a bearing housing 300 fixed between the turbine housing 220 and the compressor housing 160. The bearing housing 300 holds a bearing (not shown) and rotatably supports the turbine shaft 33 via the bearing. In addition, an oil passage for circulating a lubricating oil for lubricating and cooling the turbine shaft 33 and the bearings, and a refrigerant passage for cooling the inside of the bearing housing 300 are formed in the bearing housing 300 (both are not shown). Hydraulic oil as a lubricating oil is supplied to the oil passage in the bearing housing 300 from a hydraulic control device (not shown) that adjusts the pressure of hydraulic oil from a mechanical oil pump (not shown) driven by the engine 10. In addition, cooling water is supplied to the refrigerant passage in the bearing housing 300 from a cooling system (not shown) that circulates cooling water to an intercooler 39.

[0017] The wastegate valve 34 of the turbocharger 30 is a flow control valve, and is installed in a bypass pipe 225 connected to the exhaust pipe 22 so as to bypass the turbine housing 220 (turbine wheel 31) as shown in FIG. 1. By adjusting the opening of the wastegate valve 34, it is possible to change the ratio between the amount of exhaust gas flowing through the bypass pipe 165 and the amount of exhaust gas rotating the turbine wheel 31 and the compressor wheel 32. That is, in the turbocharger 30, it is possible to adjust the intake pressure Pin of the engine 10 by adjusting the opening of the wastegate valve 34. In addition, by fully opening the wastegate valve 34, it is possible to substantially stop the compression of the intake air by the turbocharger 30 (compressor wheel 32).

[0018] 1, the blow-off valve 35 of the turbocharger 30 is installed in a bypass pipe 165 connected to the intake pipe 16 so as to bypass the compressor housing 160 (compressor wheel 32). By opening the blow-off valve 35, it is possible to release the pressure (excess pressure) between the compressor wheel 32 of the intake pipe 16 and the throttle valve 17. This makes it possible to suppress deterioration of the responsiveness of the throttle valve 17 and the occurrence of surging. The blow-off valve 35 may be a check valve that opens when the pressure on the downstream side of the compressor wheel 32 becomes higher than the pressure on the upstream side by a predetermined value or more.

[0019] The engine ECU 100 that controls the engine 10 includes a microcomputer having a CPU, ROM, RAM, input / output interfaces, etc. (not shown), various drive circuits, various logic ICs, etc. As shown in Fig. 2, the engine ECU 100 obtains detection values ​​of the crank angle sensor 14a, the air flow meter 16a, the pressure sensor 16p, the boost pressure sensor 16c, the temperature sensor 16t, the throttle opening sensor 17o, the intake pressure sensor 18p, the temperature sensor 18t, the upstream air-fuel ratio sensor 22f, the downstream air-fuel ratio sensor 22r, the exhaust gas temperature sensor 22t, the water temperature sensor 25t, the outside air temperature sensor 28, the atmospheric pressure sensor 29, etc., via an input port (not shown).

[0020] The crank angle sensor 14a detects the rotational position (crank position) of the crankshaft 14. The air flow meter 16a detects the intake air amount Qa upstream of the compressor wheel 32 of the intake pipe 16. The pressure sensor 16p detects the air pressure Pp upstream of the compressor wheel 32 of the intake pipe 16. The temperature sensor 16t detects the air temperature Tp upstream of the compressor wheel 32 of the intake pipe 16. The boost pressure sensor 16c detects the boost pressure Pc, which is the pressure of air compressed by the compressor wheel 32 between the compressor housing 160 of the intake pipe 16 and the intercooler 39. The throttle opening sensor 17o detects the opening TH of the throttle valve 17. The intake pressure sensor 18p detects the intake pressure Pin, which is the pressure of the air in the surge tank 18 to be drawn into each combustion chamber 12, and the temperature sensor 18t detects the intake temperature Tin, which is the temperature of the air in the surge tank 18 to be drawn into each combustion chamber 12. The upstream air-fuel ratio sensor 22f detects the upstream air-fuel ratio AFf, which is the air-fuel ratio of exhaust gas flowing into the upstream purification device 23 on the upstream side of the upstream purification device 23, and the downstream air-fuel ratio sensor 22r detects the downstream air-fuel ratio AFr, which is the air-fuel ratio of exhaust gas flowing into the downstream purification device 24 on the downstream side of the upstream purification device 23. The exhaust gas temperature sensor 22t detects the temperature Teg of exhaust gas flowing through a portion of the exhaust pipe 22 between the upstream purification device 23 and the downstream purification device 24.

[0021] The engine ECU 100 calculates the rotation speed Ne of the engine 10 (crankshaft 14) based on the crank position from the crank angle sensor 14a, and calculates a load factor KL based on the intake air amount Qa from the air flow meter 16a and the rotation speed Ne of the engine 10. The load factor KL is a ratio of the volume of air actually taken in during one cycle to the stroke volume per cycle of the engine 10. The engine ECU 100 also calculates a required load factor KL*, which is a required value of the load factor KL, based on the accelerator opening Acc and the rotation speed Ne, and sets a target opening TH* of the throttle valve 17 based on the required load factor KL*. The engine ECU 100 controls the throttle valve 17, the variable valve mechanism 190, the multiple port injection valves 20p and the in-cylinder injection valves 20d, the multiple ignition plugs 21, etc., based on the rotation speed Ne, the required load factor KL*, the target opening TH*, etc. Furthermore, the engine ECU 100 controls the wastegate valve 34 and blow-off valve 35 of the turbocharger 30, the electric pump 26, an electric pump (not shown) included in the cooling system of the turbocharger 30, etc., based on the load rate KL, the required load rate KL*, etc.

[0022] Further, as shown in Fig. 3, when the load rate KL is equal to or lower than a relatively small predetermined value, the engine ECU 100 injects fuel directly into each combustion chamber 12 only from the in-cylinder injection valve 20d, and when the load rate KL is higher than the predetermined value, the engine ECU 100 injects fuel into each combustion chamber 12 from the in-cylinder injection valve 20d and also injects fuel into the intake port from the port injection valve 20p. In this embodiment, when injecting fuel from both the in-cylinder injection valve 20d and the port injection valve 20p, the engine ECU 100 controls the in-cylinder injection valve 20d and the port injection valve 20p so that the fuel injection amount (in-cylinder injection amount) of the in-cylinder injection valve 20d is larger than the fuel injection amount of the port injection valve 20p (for example, in-cylinder injection amount:port injection amount = 8:2). Therefore, as shown in Fig. 3, in the supercharging region in which the supercharger 30 is operated, fuel is injected from both the in-cylinder injection valve 20d and the port injection valve 20p. In this way, when the load rate KL exceeds a predetermined value, fuel is injected from both the in-cylinder injection valve 20d and the port injection valve 20p, thereby reducing the burden on the fuel pump (not shown) that pressurizes and supplies fuel to the in-cylinder injection valve 20d. This makes it possible to suppress cost increases by reducing the system size of the fuel pump, for example.

[0023] Furthermore, when the rotation speed Ne and the load factor KL are included in the scavenging region (see the shaded area in the figure) shown in Fig. 3, the engine ECU 100 controls the variable valve mechanism 190 to simultaneously open the exhaust valve 19e and the intake valve 19i at the transition from the exhaust stroke to the intake stroke, so that their opening periods overlap. This makes it possible to scavenge residual gas remaining in the combustion chamber 12 into the exhaust pipe 22 by scavenging using the pressure difference generated between the intake side and exhaust side of the engine 10, thereby improving the charging efficiency of the intake air and suppressing the occurrence of turbo lag in the supercharger 30 when the rotation speed Ne of the engine 10 is low.

[0024] In the engine 10 of this embodiment, as shown in Fig. 3, when the turbocharger 30 is operated with the rotation speed Ne being relatively low, the exhaust valve 19e and the intake valve 19i are simultaneously opened during the transition from the exhaust stroke to the intake stroke, and fuel is injected not only from the in-cylinder injection valve 20d but also from the port injection valve 20p. Therefore, unless any measures are taken, when the turbocharger 30 is operated with the rotation speed Ne being relatively low, a blow-by phenomenon occurs in which the mixture flows directly from the intake port into the exhaust pipe 22, and the emissions of the engine 10 may deteriorate. In addition, when a vehicle equipped with the engine 10 runs at a high altitude where the atmospheric pressure is low, the output torque decreases due to a decrease in the actual intake air amount of the engine 10. For this reason, if the turbocharger 30 is operated at a stage where the load rate KL* required for the engine 10 is relatively low compared to when traveling on flat ground, and fuel is injected from the port injection valve 20p in a state where the exhaust valve 19e and the intake valve 19i are simultaneously opened, the blow-by phenomenon may occur. In light of this, the engine ECU 100 repeatedly executes the routine shown in Fig. 4 at predetermined time intervals while the engine 10 is operating in order to suppress the blow-by phenomenon from occurring in the scavenging region.

[0025] 4, the engine ECU 100 acquires the intake pressure Pin detected by the intake pressure sensor 18p, the atmospheric pressure Pa detected by the atmospheric pressure sensor 29, and the coolant temperature Tw detected by the water temperature sensor 25t (step S100). Note that the intake pressure Pin is not limited to that detected by the intake pressure sensor 18p, and may be estimated based on, for example, the rotation speed Ne of the engine 10, the load factor KL, the intake temperature Tin, etc.

[0026] Next, the engine ECU 100 sets the offset value α (step S110). In this embodiment, as shown in Fig. 5, an offset value setting map that defines the relationship between the water temperature Tw indicating the temperature of the engine 10 and the offset value α is prepared in advance, and in step S110, the engine ECU 100 derives a value corresponding to the water temperature Tw acquired in step S100 from the offset value setting map and sets it as the offset value α. As shown in Fig. 5, the offset value setting map is created so that the offset value α is set to zero when the water temperature Tw is equal to or higher than a predetermined temperature (for example, 80°C in this embodiment), and is set to a negative value that decreases in proportion to the decrease in the water temperature Tw when the water temperature Tw is lower than the predetermined temperature.

[0027] After the process of step S110, the engine ECU 100 adds the offset value α to the atmospheric pressure Pa acquired in step S100 to set the threshold value Pref (step S120), and determines whether the intake pressure Pin acquired in step S100 is equal to or greater than the threshold value Pref (step S130). If the engine ECU 100 determines that the intake pressure Pin is less than the threshold value Pref (step S130: NO), the engine ECU 100 does not execute the subsequent processes and temporarily ends the routine of FIG.

[0028] On the other hand, when it is determined that the intake pressure Pin is equal to or greater than the threshold Pref (step S130: YES), the engine ECU 100 calculates the valve overlap amount (overlap angle) θ between the exhaust valve 19e and the intake valve 19i based on the rotational position (crank angle) of the crankshaft 14 and the like (step S140), and determines whether the calculated valve overlap amount θ is equal to or greater than zero (°) (step S150). When it is determined that the valve overlap amount θ is equal to or greater than zero (step S150: YES), the engine ECU 100 sets an advance guard value (advance limit) of the injection timing of each port injection valve 20p so that fuel injection from the corresponding port injection valve 20p starts after each exhaust valve 19e is closed (step S160), and temporarily ends the routine of FIG. On the other hand, when it is determined that the valve overlap amount θ is less than zero (step S150: NO), engine ECU 100 temporarily ends the routine of FIG. 4 without executing the process of step S160.

[0029] As described above, the engine ECU 100 that controls the engine 10 sets the threshold value Pref based on the atmospheric pressure Pa detected by the atmospheric pressure sensor 29 so that the threshold value Pref is smaller when the water temperature Tw, which indicates the temperature of the engine 10, is low than when the water temperature Tw is high (steps S110-S120). Furthermore, when the intake pressure Pin of the engine 10 is equal to or higher than the threshold value Pref (step S130: YES) and the opening periods of the exhaust valve 19e and the intake valve 19i overlap (step S150: YES), the advance guard value is set (step S160) to start fuel injection from the port injection valve 20p after the exhaust valve 19e is closed, as shown in FIG.

[0030] In this way, by setting the threshold value Pref to be compared with the intake pressure Pin based on the atmospheric pressure Pa (steps S110-S120), when the turbocharger 30 is operated in a state where the rotation speed Ne is relatively low, even if fuel is injected from the port injection valve 20p in addition to the in-cylinder injection valve 20d and the exhaust valve 19e and the intake valve 19i are simultaneously opened during the transition from the exhaust stroke to the intake stroke, it is possible to effectively suppress the occurrence of the blow-by phenomenon. Also, even when the turbocharger 30 is operated from a stage where the load of the engine 10 (required load rate KL*) is relatively low at a high altitude or the like where the atmospheric pressure Pa is low, it is possible to inject fuel from the port injection valve 20p after the exhaust valve 19e is closed. This makes it possible to effectively suppress the blow-by of the mixture when the open periods of the exhaust valve 19e and the intake valve 19i overlap. Furthermore, by setting the threshold value Pref to be smaller when the temperature of the engine 10 is low than when the temperature is high (steps S110-S120, FIG. 5), it is possible to suppress the occurrence of the blow-by phenomenon at low temperatures when the fuel injection amount may be increased for warming up or the like, while permitting fuel injection from the port injection valve 20p and suppressing a decrease in the output of the engine 10. As a result, in the engine 10 in which the exhaust valve 19e and the intake valve 19i can be opened simultaneously when transitioning from the exhaust stroke to the intake stroke, it is possible to extremely effectively suppress the deterioration of emissions due to the blow-by phenomenon.

[0031] Furthermore, the engine ECU 100 sets the threshold Pref by adding an offset value to the atmospheric pressure Pa, sets the offset value α to zero when the temperature of the engine 10 is equal to or higher than a predetermined temperature, and sets the threshold Pref to a negative value that decreases as the water temperature Tw (the temperature of the engine 10) decreases when the water temperature Tw (the temperature of the engine 10) is lower than the predetermined temperature (steps S110-S120). This makes it possible to effectively suppress the occurrence of the blow-by phenomenon at low temperatures.

[0032] Furthermore, in the supercharging region where the supercharger 30 is operated, the engine ECU 100 injects fuel from both the in-cylinder injection valve 20d and the port injection valve 20p (see FIG. 5). This reduces the burden on the fuel pump that pressurizes and supplies fuel to the in-cylinder injection valve 20d, making it possible to suppress an increase in costs. However, it goes without saying that the invention of the present disclosure can be applied to an engine in which fuel is injected only from the in-cylinder injection valve 20d in the supercharging region.

[0033] The present disclosure is not limited to the above embodiment, and various modifications can be made within the scope of the present disclosure. Furthermore, the above embodiment is merely a specific form of the invention described in the Summary of the Invention, and does not limit the elements of the invention described in the Summary of the Invention. [Industrial Applicability]

[0034] The invention of the present disclosure can be used in the internal combustion engine manufacturing industry and the like. [Explanation of symbols]

[0035] 10 engine (internal combustion engine), 11 engine block, 12 combustion chamber, 13 piston, 14 crankshaft, 14a crank angle sensor, 15 air cleaner, 16 intake pipe, 16a air flow meter, 16c boost pressure sensor, 16p pressure sensor, 16t temperature sensor, 160 compressor housing, 165 bypass pipe, 17 throttle valve, 17o throttle opening sensor, 18 surge tank, 18p intake pressure sensor, 18t temperature sensor, 19e exhaust valve, 19i intake valve, 190 variable valve mechanism, 20d in-cylinder injection valve, 20p port injection valve, 21 spark plug, 22 exhaust pipe, 220 turbine housing, 225 bypass pipe, 240 particulate filter, 22f upstream air-fuel ratio sensor, 22r downstream air-fuel ratio sensor, 22t exhaust gas temperature sensor, 23 upstream purification device, 24 downstream purification device, 25 refrigerant circulation passage, 25t water temperature sensor, 26 electric pump, 27 radiator, 28 outside air temperature sensor, 29 atmospheric pressure sensor, 30 turbocharger, 31 turbine wheel, 32 compressor wheel, 33 turbine shaft, 34 wastegate valve, 35 blow-off valve, 39 intercooler, 300 bearing housing, 100 ECU (engine electronic control unit).

Claims

[Claim 1] A control device for an internal combustion engine including a port injection valve that injects fuel into an intake port and a turbocharger, the control device being capable of simultaneously opening an exhaust valve and an intake valve when transitioning from an exhaust stroke to an intake stroke, A control device for an internal combustion engine that sets a threshold value based on atmospheric pressure so that the threshold value is smaller when the temperature of the internal combustion engine is low compared to when the temperature is high, and when the intake pressure of the internal combustion engine is equal to or higher than the threshold value and the opening periods of the exhaust valve and the intake valve overlap, starts fuel injection from the port injection valve after the exhaust valve is closed.

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