Control device and method for controlling an internal combustion engine

Abstract

To provide a control device for an internal combustion engine and a control method for the internal combustion engine capable of highly accurately learning information on fuel concentration of a purge gas or a blow-by gas by using a simple configuration.SOLUTION: This invention relates to a control device for an internal combustion engine and a control method for the internal combustion engine. In the internal combustion engine including an evaporation fuel treatment device for introducing a purge gas containing evaporation fuel recovered from a fuel tank to an intake passage of the internal combustion engine via an electronic control type purge control valve and a blow-by gas recirculation device for recirculating a blow-by gas via a check valve to the intake passage, execution and prohibition of processing for learning information on fuel concentration of the purge gas or blow-by gas on the basis of information related to an exhaust air-fuel ratio of the internal combustion engine are switched on the basis of an opening / closing detection signal output by an opening / closing detector for detecting opening / closing of the check valve.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a control device for an internal combustion engine and a control method for an internal combustion engine. [Background technology]

[0002] The control device for an internal combustion engine in Patent Document 1 learns a value related to the concentration of fuel contained in purge gas based on a value related to an air-fuel ratio feedback correction amount when an instruction signal to open the purge control valve of an evaporated fuel treatment device to a predetermined opening degree is sent to the purge control valve. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-303857 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an internal combustion engine that is equipped with a blow-by gas recirculation device that recirculates blow-by gas to the intake passage of the internal combustion engine via a check valve, together with an evaporated fuel treatment device, when purge gas is supplied to the intake passage and information regarding the fuel concentration of the purge gas is being learned, if the check valve opens and the blow-by gas is recirculated, the learning accuracy decreases. Here, by replacing the check valve of the blow-by gas recirculation device with an electronically controlled valve, the supply states of purge gas and blow-by gas can be controlled so that they do not overlap, and information regarding the fuel concentration of the purge gas or blow-by gas can be learned with high accuracy.

[0005] However, the check valve of the blow-by gas recirculation device is a mechanical valve that opens based on the pressure difference between the inside of the crank chamber and the intake passage. For this reason, when a check valve is replaced with an electronically controlled valve, the cost of the valve used increases, a sensor for detecting pressure (or pressure difference) needs to be added, and the processing required to obtain the sensor signal and generate a control signal for the electronically controlled valve increases, resulting in an increased computational load on the microcomputer.

[0006] The present invention has been made in consideration of the conventional situation, and its purpose is to provide an internal combustion engine control device and an internal combustion engine control method that are capable of learning information regarding the fuel concentration of purge gas or blow-by gas with a simple configuration and with high accuracy. [Means for solving the problem]

[0007] Therefore, as one aspect of the present invention, the implementation or prohibition of a process for learning information regarding the fuel concentration of purge gas or blow-by gas based on information regarding the exhaust air-fuel ratio of the internal combustion engine is switched based on an opening / closing detection signal output by an opening / closing detector that detects the opening and closing of a check valve of the blow-by gas recirculation device. Effect of the Invention

[0008] According to the above invention, the information relating to the fuel concentration of purge gas or blow-by gas can be learned with a simple configuration and with high accuracy. [Brief description of the drawings]

[0009] [Figure 1] 1 is a system configuration diagram showing one embodiment of an internal combustion engine. [Diagram 2] 6 is a flowchart showing a learning process of information about the fuel concentration of purge gas. [Diagram 3] 5 is a flowchart showing a learning process of information regarding the fuel concentration of blow-by gas. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of the present invention will be described below. FIG. 1 is a system configuration diagram showing one embodiment of an internal combustion engine. The internal combustion engine 101 in FIG. 1 is a spark-ignition gasoline engine mounted on a vehicle.

[0011] The internal combustion engine 101 includes an ignition device 200 , a fuel injection device 300 , an electronically controlled throttle 108 , and an exhaust purification catalyst 112 . The ignition device 200 has an ignition plug 201 and an ignition coil 202 incorporating a power transistor, and ignites and burns the air-fuel mixture in the combustion chamber 110 by spark ignition.

[0012] The fuel injection device 300 has a fuel injection valve 301 arranged in the intake port 102 upstream of the intake valve 119, a fuel tank 302 that stores the fuel (gasoline) to be injected from the fuel injection valve 301, and a fuel pipe 304 that supplies the fuel in the fuel tank 302 to the fuel injection valve 301. When the fuel injection valve 301 opens, fuel is injected into the intake port 102 , and the fuel injected from the fuel injection valve 301 is mixed with air to form an air-fuel mixture in the combustion chamber 110 . The fuel injection device 300 may be of a direct injection type in which the fuel injection valve 301 directly injects fuel into the combustion chamber 110 .

[0013] The electronically controlled throttle 108 has a throttle valve 108a which is a butterfly valve, a throttle motor 108b, and a throttle opening sensor 108c which detects the opening of the throttle valve 108a, and is a device which opens and closes the throttle valve 108a by the throttle motor 108b. The air that has passed through the air cleaner 107 has its flow rate adjusted by a throttle valve 108a. The exhaust purification catalyst 112 is disposed in the exhaust pipe 103 of the internal combustion engine 101, and purifies the exhaust gas from the internal combustion engine 101 by a catalyst such as a three-way catalyst.

[0014] Furthermore, the internal combustion engine 101 is equipped with various sensors for detecting the operating state of the internal combustion engine 101 . The air flow sensor 109 is disposed in the intake duct 104 upstream of the electronically controlled throttle 108 to detect the intake air flow rate of the internal combustion engine 101 . The crank angle sensor 106 is a sensor for measuring the rotation angle of the crankshaft 117, and detects the protrusion of the ring gear 114 and outputs a pulse signal that rises every time the crankshaft 117 rotates by a predetermined angle.

[0015] The air-fuel ratio sensor 111 is disposed in the exhaust pipe 103 upstream of the exhaust purification catalyst 112, and detects the exhaust air-fuel ratio based on the oxygen concentration in the exhaust. The oxygen sensor 116 is disposed in the exhaust pipe 103 downstream of the exhaust purification catalyst 112 , and detects whether the exhaust air-fuel ratio is rich or lean based on the oxygen concentration in the exhaust pipe 103 downstream of the exhaust purification catalyst 112 . The water temperature sensor 118 is disposed in the cooling water jacket 105 of the internal combustion engine 101 and detects the temperature of the cooling water in the cooling water jacket 105 .

[0016] The internal combustion engine 101 also includes a blow-by gas recirculation device 400 . The blow-by gas recirculation device 400 is a device that recirculates the blow-by gas that has flowed out from the combustion chamber 110 into the crank chamber 151 to the intake collector 152 (in other words, the intake passage) downstream of the electronically controlled throttle .

[0017] The blow-by gas recirculation device 400 has a recirculation pipe 401 that connects the crank chamber 151 and the intake collector 152, a check valve 402 arranged in the recirculation pipe 401, and a position detection switch 403 as an opening / closing detector that detects the opening and closing of the check valve 402. Blow-by gas is composed of unburned fuel, combustion gas, and oil mist components.

[0018] Check valve 402 is a mechanical valve that has valve element 402A and compression spring 402B, which is an elastic member that biases valve element 402A in the valve closing direction, and opens and closes in response to the pressure difference between before and after the valve. Here, the check valve 402 is configured to open when the pressure in the crank chamber 151 becomes higher than the pressure in the intake collector 152 by a predetermined value or more.

[0019] The position detection switch 403 is a limit switch that performs a mechanical operation in response to the movement of the valve body 402A, and switches an output signal between on (high level) and off (low level) depending on whether the check valve 402 is open or closed. In other words, the output signal of the position detection switch 403 is an open / close detection signal that indicates whether the check valve 402 is in an open state or a closed state by being on or off.

[0020] The internal combustion engine 101 also includes an evaporated fuel treatment device 500 . The evaporated fuel processing device 500 is a device that introduces evaporated fuel (gasoline vapor) recovered from the fuel tank 302 into the intake collector 152 (in other words, the intake passage) downstream of the electronically controlled throttle 108.

[0021] The evaporated fuel treatment device 500 has a canister 501 filled with activated carbon for adsorbing evaporated fuel, an evaporated fuel piping 502 connecting the canister 501 with a fuel tank 302, a purge piping 503 connecting the canister 501 with an intake collector 152 (in other words, an intake passage) of the internal combustion engine 101, and an electronically controlled purge control valve 504 arranged in the purge piping 503. When evaporated fuel generated in the fuel tank 302 flows into the canister 501 through the evaporated fuel pipe 502, the canister 501 adsorbs and collects the evaporated fuel on the activated charcoal inside.

[0022] When the purge control valve 504 is controlled to be open and the pressure inside the purge piping 503 becomes negative due to the intake negative pressure of the internal combustion engine 101, outside air (atmosphere) is sucked into the canister 501 through the outside air introduction hole 501a, passes through the inside of the canister 501, and flows into the purge piping 503. At this time, the evaporated fuel adsorbed on the activated carbon in the canister 501 is desorbed, and the desorbed evaporated fuel is guided to the purge pipe 503 together with the outside air, merges with the intake air of the internal combustion engine 101 in the intake collector 152, and flows into the combustion chamber 110, where it is combusted. The purge control valve 504 is, for example, an electromagnetic valve.

[0023] The control device 600 is an electronic control device that includes an MPU (Microprocessor Unit) 601 and controls the operation of the internal combustion engine 101. The MCU 601 can be referred to as a microcomputer, a processor, a processing device, an arithmetic device, or the like.

[0024] The control device 600 acquires signals output by the various sensors described above, i.e., information regarding the operating state of the internal combustion engine 101, and calculates and outputs control commands (in other words, operating amounts) for each controlled object based on the acquired information. Specifically, the control device 600 outputs control commands to the ignition coil 202 (ignition device 200), the fuel injection valve 301 (fuel injection device 300), the throttle motor 108b (electronically controlled throttle 108), and the purge control valve 504 (evaporative fuel processing device 500).

[0025] In controlling the fuel injection amount by the fuel injection valve 301, the control device 600 sets an air-fuel ratio feedback correction coefficient for correcting the fuel injection amount so that the exhaust air-fuel ratio detected by the air-fuel ratio sensor 111 approaches the target air-fuel ratio. Hereinafter, the control for correcting the fuel injection amount so that the detected value of the air-fuel ratio approaches the target air-fuel ratio will be referred to as air-fuel ratio feedback control. The above air-fuel ratio feedback correction coefficient is information indicating the deviation between the actual air-fuel ratio and the target air-fuel ratio (in other words, the air-fuel ratio fluctuation) when air-fuel ratio feedback control is not performed, and is information regarding the exhaust air-fuel ratio.

[0026] Furthermore, the control device 600 performs a purge in the evaporated fuel treatment device 500, that is, performs an opening control of the purge control valve 504 while the above-mentioned air-fuel ratio feedback control is being performed. In purge control, the control device 600 determines a target purge rate from the load and rotation speed of the internal combustion engine 101, and furthermore, an air-fuel ratio feedback correction coefficient, and determines the control duty of the purge control valve 504 required to achieve the target purge rate. The control device 600 controls the opening degree of the purge control valve 504 by PWM control that controls the on / off of the purge control valve 504 in accordance with the control duty.

[0027] In addition, in order to prevent a decrease in the control accuracy of the air-fuel ratio due to the supply of purge gas by the evaporated fuel treatment device 500, the control device 600 performs feedforward control to correct the fuel injection amount based on the learned results of information related to the fuel concentration of the purge gas. Here, as a learning process of information related to the fuel concentration of the purge gas, the control device 600 updates the purge gas concentration learning value used for correcting and controlling the fuel injection amount based on the change in the air-fuel ratio feedback correction coefficient when the purge gas is supplied to the internal combustion engine 101 by the evaporative fuel treatment device 500, and stores the updated value in the built-in memory. That is, the control device 600 learns the purge gas concentration learning value, which is information related to the fuel concentration of the purge gas, based on the air-fuel ratio feedback correction coefficient, which is information related to the exhaust air-fuel ratio.

[0028] Here, when the control device 600 is performing the learning process of the purge gas concentration learning value, specifically, when sampling the air-fuel ratio feedback correction coefficient while purge gas is being supplied, if the check valve 402 of the blow-by gas recirculation device 400 opens, the control device 600 will erroneously learn the purge gas concentration learning value. When the check valve 402 of the blow-by gas recirculation device 400 opens while purge gas is being supplied, the fuel components contained in the purge gas and the fuel components contained in the blow-by gas flow into the combustion chamber 110 and are burned, and the air-fuel ratio feedback correction coefficient is controlled to a value corresponding to the change in the air-fuel ratio due to both fuel components.

[0029] Therefore, when the control device 600 learns the purge gas concentration learning value with the check valve 402 open, the learning value of the purge gas concentration will include the influence of the fuel components contained in the blow-by gas, and the accuracy of the feedforward control based on the purge gas concentration learning value will decrease. Therefore, the control device 600 acquires an open / close detection signal output by the position detection switch 403, and switches between execution and prohibition of a process of learning the purge gas concentration learning value based on an air-fuel ratio feedback correction coefficient (in other words, information related to the exhaust air-fuel ratio) based on the open / close detection signal of the position detection switch 403.

[0030] Specifically, when the control device 600 determines that the open / close detection signal of the position detection switch 403 indicates that the check valve 402 is open and that the fuel contained in the purge gas and the fuel contained in the blow-by gas are flowing into the combustion chamber 110, the control device 600 prohibits learning of the purge gas concentration learning value, thereby preventing erroneous learning of the purge gas concentration learning value. On the other hand, when the open / close detection signal of the position detection switch 403 indicates that the check valve 402 is closed and the evaporated fuel processing device 500 is in a purging state, the control device 600 learns the purge gas concentration learning value.

[0031] In the above-mentioned configuration, the opening and closing of the return pipe 401 of the blow-by gas return device 400 is performed by the check valve 402, which is a mechanical valve, so that the return of the blow-by gas can be started and stopped with a simple configuration. On the other hand, the control device 600 switches between executing and prohibiting the process of learning the purge gas concentration learning value based on the open / close detection signal of the position detection switch 403, thereby suppressing the influence of blow-by gas recirculation and enabling the purge gas concentration learning value to be learned with high accuracy.

[0032] The flowchart in FIG. 2 shows one embodiment of a process for switching between execution and inhibition of the learning process of the purge gas concentration learning value based on an open / closed detection signal of the position detection switch 403. The control device 600 (more specifically, the MCU 601) acquires an open / closed detection signal of the position detection switch 403 in step S701.

[0033] Next, in step S702, the control device 600 determines whether the open / close detection signal of the position detection switch 403 is on or off, to detect whether the check valve 402 is in an open state or a closed state. When the open / close detection signal of the position detection switch 403 indicates that the check valve 402 is open, the control device 600 performs a setting to prohibit learning of the purge gas concentration learning value (information on the fuel concentration of the purge gas) in step S703.

[0034] This makes it possible for the control device 600 to prevent erroneous learning of the purge gas concentration learning value in a state in which the fuel components contained in the purge gas and the fuel components contained in the blow-by gas flow into the combustion chamber 110. Therefore, it is possible to prevent a deterioration in the exhaust gas properties due to a decrease in the control accuracy of the air-fuel ratio when purging is performed caused by an erroneous learning of the purge gas concentration learning value.

[0035] In addition, when the open / close detection signal of the position detection switch 403 indicates that the check valve 402 is open, in step S704, the control device 600 sets the air-fuel ratio related learning processes other than the learning process of the purge gas concentration learning value to be prohibited if they are affected by the supply of blow-by gas. The learning processes that are prohibited in step S704 include, for example, learning processes of an air-fuel ratio learning value for compensating for a steady deviation between a target air-fuel ratio and an actual air-fuel ratio detected by the air-fuel ratio sensor 111.

[0036] In the above-described process of learning the air-fuel ratio learning value, the control device 600 divides the operating state of the internal combustion engine 101 into a plurality of regions based on, for example, the rotation speed and load of the internal combustion engine 101, and learns, for each region, an air-fuel ratio learning value for compensating for a steady-state deviation between a target air-fuel ratio and an actual air-fuel ratio based on an air-fuel ratio feedback correction coefficient. If the control device 600 performs the above-mentioned learning process of the air-fuel ratio learning value in a state in which blow-by gas is being recirculated, the learning will be performed in a state in which the air-fuel ratio has fluctuated due to the recirculation of blow-by gas, and the steady air-fuel ratio deviation will not be learned, resulting in a decrease in the accuracy of control of the air-fuel ratio using the air-fuel ratio learning value.

[0037] Therefore, when the open / close detection signal of the position detection switch 403 indicates that the check valve 402 is open, the control device 600 prohibits the learning process of the air-fuel ratio learning value as well as the learning process of the purge gas concentration learning value. The control device 600 can include in the learning processes prohibited in step S704 a learning process for correcting the control center in the air-fuel ratio control based on the actual air-fuel ratio detected by the air-fuel ratio sensor 111, based on the output of the oxygen sensor 116.

[0038] On the other hand, if the control device 600 determines in step S702 that the open / close detection signal of the position detection switch 403 indicates that the check valve 402 is closed, the control device 600 proceeds to step S705, where it determines whether or not purging is being performed in the evaporated fuel treatment device 500 by controlling the purge control valve 504 to open. If purging is being performed, the control device 600 proceeds to step S706, and if a predetermined learning condition is established, the control device 600 executes a learning process for a purge gas concentration learning value.

[0039] At this time, the check valve 402 is in a closed state and the fuel components contained in the blow-by gas do not flow into the combustion chamber 110, so that the control device 600 can learn the purge gas concentration learning value with high accuracy. The conditions for learning the purge gas concentration learning value include that the warm-up of the internal combustion engine 101 is completed, that the air-fuel ratio feedback control is performed, and that the air-fuel ratio learning value is converged.

[0040] As described above, the control device 600 can detect the opening and closing of the check valve 402 from the opening and closing detection signal of the position detection switch 403, and also controls the start and stop of purging in the evaporated fuel processing device 500. Therefore, the control device 600 can identify a state in which purging is stopped and blow-by gas is being recirculated, and learn information regarding the fuel concentration of the recirculated blow-by gas based on the air-fuel ratio feedback correction coefficient, which is a signal related to the exhaust air-fuel ratio.

[0041] Furthermore, when the blow-by gas is recirculated, the control device 600 can perform feedforward control to correct the fuel injection amount based on the learning results of information regarding the fuel concentration of the blow-by gas (hereinafter referred to as the blow-by gas concentration learning value). In other words, the control device 600 acquires the open / close detection signal output by the position detection switch 403, and can switch between implementing and prohibiting the process of learning the blow-by gas concentration learning value based on the air-fuel ratio feedback correction coefficient (in other words, information related to the exhaust air-fuel ratio) based on the open / close detection signal of the position detection switch 403.

[0042] The flowchart of FIG. 3 shows one embodiment of a learning process for the blow-by gas concentration learning value. The control device 600 acquires an open / closed detection signal of the position detection switch 403 in step S801. Next, in step S802, the control device 600 determines whether the open / close detection signal of the position detection switch 403 is on or off, to detect whether the check valve 402 is in an open state or a closed state.

[0043] When the open / close detection signal of the position detection switch 403 indicates that the check valve 402 is closed, the control device 600 performs a setting to prohibit learning of the blow-by gas concentration learning value in step S803. In other words, when the recirculation of blow-by gas is stopped, the control device 600 cannot learn the blow-by gas concentration learning value based on a signal related to the exhaust air-fuel ratio, and therefore does not learn the blow-by gas concentration learning value if the check valve 402 is closed.

[0044] On the other hand, if the open / close detection signal of the position detection switch 403 indicates that the check valve 402 is open and the recirculation of blow-by gas is being performed, the control device 600 proceeds to step S804. In step S804, control device 600 determines whether or not there is a disturbance factor that causes the exhaust air-fuel ratio to fluctuate other than the recirculation of blow-by gas. The disturbance factors include the execution of purging in the evaporated fuel processing device 500, a fuel cut that stops fuel injection by the fuel injection valve 301 during deceleration, and an increase correction of the fuel injection amount during acceleration.

[0045] If the above-mentioned disturbance factor is present, the control device 600 proceeds to step S803 and performs a setting to prohibit learning of the blow-by gas concentration learning value. In other words, even if the recirculation of blow-by gas is being performed, if there is a disturbance factor such as purging, the control device 600 cannot learn the blow-by gas concentration learning value with high accuracy, and therefore prohibits learning of the blow-by gas concentration learning value.

[0046] On the other hand, when the control device 600 determines that there is no disturbance factor other than the recirculation of blow-by gas, the process proceeds to step S805, and if the predetermined learning condition is established, the control device 600 performs a learning process for the blow-by gas concentration learning value. The learning conditions for the blow-by gas concentration learning value include that the warm-up of the internal combustion engine 101 is completed, that the air-fuel ratio feedback control is performed, and that the air-fuel ratio learning value has converged.

[0047] In the learning process of the blow-by gas concentration learning value, the control device 600 updates the blow-by gas concentration learning value based on the change in the air-fuel ratio feedback correction coefficient when the blow-by gas is returned to the intake passage of the internal combustion engine 101 via the check valve 402 and the intake air amount of the internal combustion engine 101, and stores the updated blow-by gas concentration learning value in the built-in memory. Here, if the change in the air-fuel ratio feedback correction coefficient (in other words, the rich change in the exhaust air-fuel ratio) is the same, the control device 600 estimates that the smaller the intake air amount at that time, the higher the fuel concentration of the blow-by gas, and updates the blow-by gas concentration learning value. In the next step S806, the control device 600 sets that the next time it detects from the signal of the position detection switch 403 that the check valve 402 has opened, it will perform feedforward control to correct the fuel injection amount based on the blow-by gas concentration learning value.

[0048] In this manner, the control device 600 can determine the recirculation or stop of the blow-by gas from the open / close detection signal of the position detection switch 403, and learn the blow-by gas concentration learning value. The control device 600 then performs feedforward control to correct the amount of fuel injection when the blow-by gas is recirculated based on the blow-by gas concentration learning value, thereby suppressing fluctuations in the air-fuel ratio when the blow-by gas is recirculated and improving the exhaust properties.

[0049] If the time between when check valve 402 switches from open to closed and when check valve 402 is opened again is long, new unburned fuel may leak into crank chamber 151 during that time, causing an error in the blow-by gas concentration learning value. Therefore, when the check valve 402 is opened again within a predetermined time after it was closed, the control device 600 can correct the fuel injection amount based on the blow-by gas concentration learned value learned when the check valve 402 was in the previous open state. Then, when the check valve 402 is opened after the predetermined time has elapsed, the control device 600 can stop correcting the fuel injection amount based on the blow-by gas concentration learning value learned in the previous open state, and reset the blow-by gas concentration learning value.

[0050] In addition, the control device 600 can update the blow-by gas concentration learning value based on the operating state of the internal combustion engine 101 that correlates with the amount of unburned fuel leaking into the crank chamber 151 while the check valve 402 is closed. The operating state of the internal combustion engine 101 that correlates with the amount of unburned fuel leaking into the crank chamber 151 is, for example, the temperature of the internal combustion engine 101 when the internal combustion engine 101 is started, the number of cold starts, and the like. The control device 600 then estimates that the lower the temperature at startup, the greater the leakage of unburned fuel into the crank chamber 151, and that the greater the number of cold starts during which the check valve 402 remains closed, the greater the amount of unburned fuel leaking into the crank chamber 151, and updates the blow-by gas concentration learning value.

[0051] The technical ideas described in the above embodiments can be used in any suitable combination as long as no contradiction occurs. Furthermore, although the contents of the present invention have been specifically described with reference to preferred embodiments, it is obvious that a person skilled in the art can adopt various modified embodiments based on the basic technical concept and teachings of the present invention.

[0052] The control device 600 can stop purging in the evaporated fuel processing device 500 when it determines from the open / close detection signal of the position detection switch 403 that the check valve 402 is open and the recirculation of the blow-by gas is being performed. When the check valve 402 is closed, the control device 600 can carry out purging in the evaporated fuel processing device 500 and can also carry out learning of the purge gas concentration learning value.

[0053] Moreover, the internal combustion engine 101 may be provided with a displacement sensor (stroke sensor) instead of the position detection switch 403 as an opening / closing detector for detecting whether the check valve 402 of the blow-by gas recirculation device 400 is open or closed. In addition, the control device 600 updates the blow-by gas concentration learning value based on the change in the air-fuel ratio feedback correction coefficient during the open period, on condition that the check valve 402 has been open for a predetermined time or more, and can prohibit updating of the blow-by gas concentration learning value when the open period of the check valve 402 falls short of the predetermined time. [Explanation of symbols]

[0054] 101... internal combustion engine, 152... intake collector (intake passage), 302... fuel tank, 400... blow-by gas recirculation device, 401... recirculation pipe, 402... check valve, 403... position detection switch (opening / closing detector), 500... evaporated fuel treatment device, 503... purge pipe, 504... purge control valve, 600... control device

Claims

1. an evaporated fuel treatment device that introduces purge gas containing evaporated fuel recovered from a fuel tank into an intake passage of an internal combustion engine via an electronically controlled purge control valve; a blow-by gas recirculation device for recirculating blow-by gas to the intake passage through a check valve; A control device for an internal combustion engine, which is applied to the internal combustion engine comprising: Acquire an open / close detection signal output by an open / close detector that detects the open / close of the check valve; switching between execution and inhibition of a process of learning information about the fuel concentration of the purge gas or the blow-by gas based on information about an exhaust air-fuel ratio of the internal combustion engine based on the open / close detection signal; outputting a control command to a fuel injection device that injects fuel into the internal combustion engine based on a learning result of the information about the fuel concentration; A control device for an internal combustion engine.

2. 2. The control device for an internal combustion engine according to claim 1, when the open / close detection signal indicates that the check valve is open, learning of information regarding the fuel concentration of the purge gas is prohibited. A control device for an internal combustion engine.

3. 2. The control device for an internal combustion engine according to claim 1, learning information about the fuel concentration of the blow-by gas when the open / close detection signal indicates an open state of the check valve and purging in the evaporated fuel treatment device is stopped; A control device for an internal combustion engine.

4. The control device for an internal combustion engine according to claim 3, learning information about a fuel concentration of the blow-by gas based on information about an exhaust air-fuel ratio of the internal combustion engine and information about an intake air amount of the internal combustion engine; A control device for an internal combustion engine.

5. 2. The control device for an internal combustion engine according to claim 1, learning information about a fuel concentration of the purge gas when the open / close detection signal indicates a closed state of the check valve and a purge is being performed in the evaporated fuel treatment device; learning information about the fuel concentration of the blow-by gas when the open / close detection signal indicates an open state of the check valve and purging in the evaporated fuel treatment device is stopped; A control device for an internal combustion engine.

6. 2. The control device for an internal combustion engine according to claim 1, The open / close detector is a position detection switch that switches between on and off depending on whether the check valve is open or closed. A control device for an internal combustion engine.

7. an evaporated fuel treatment device that introduces purge gas containing evaporated fuel recovered from a fuel tank into an intake passage of an internal combustion engine via an electronically controlled purge control valve; a blow-by gas recirculation device for recirculating blow-by gas to the intake passage through a check valve; A control method for an internal combustion engine, which is applied to the internal combustion engine comprising: Acquire an open / close detection signal output by an open / close detector that detects the open / close of the check valve; switching between execution and inhibition of a process of learning information regarding the fuel concentration of the purge gas or the blow-by gas based on a signal regarding an exhaust air-fuel ratio of the internal combustion engine based on the open / close detection signal; outputting a control command to a fuel injection device that injects fuel into the internal combustion engine based on a learning result of the information about the fuel concentration; A method for controlling an internal combustion engine.

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