JP2016223438A - Control device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of an engine which can suppress the deterioration of a combustion characteristic of an air-fuel mixture in a cylinder resulting from the deviation of a property of fuel which is injected from a first injection valve, and a property of fuel which is injected from a second injection valve.SOLUTION: An engine 11 comprises a first injection valve 17 which injects fuel into an intake passage 13, and a second injection valve 18 which injects fuel into a cylinder 12. A fuel supply system 20 having a first supply route 23 for the first injection valve 17, and a second supply route 24 for the second injection valve 18 is arranged at the engine 11. The control device 100 of the engine 11 performs single-side injection processing for injecting the fuel from one injection valve out of the first injection valve 17 and the second injection valve 18, and prohibiting the injection of the fuel from the other injection valve when it is determined that a property of the fuel in the first supply route 23 and a property of the fuel in the second supply route 24 deviate from each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an engine control device applied to an engine provided with a plurality of injection valves capable of supplying fuel to one cylinder.

  Patent Document 1 describes an example of an engine in which a first injection valve that injects fuel into an intake passage and a second injection valve that directly injects fuel into a combustion chamber are provided for each cylinder. Yes. The engine fuel supply system includes a common path connected to the fuel tank, a first supply path connected to a downstream end of the common path and supplying fuel to the first injection valve, and a downstream of the common path. And a second supply path that is connected to the end and supplies fuel to the second injection valve. Then, when the fuel injection amount from the first injection valve is divided by the sum of the fuel injection amount from the first injection valve and the fuel injection amount from the second injection valve as the injection ratio, The engine control device controls each injection valve by setting the injection ratio to a value according to the operating state of the engine.

  The engine described in Patent Document 1 is an engine that can be operated using a fuel containing alcohol, and the injection ratio is changed according to the alcohol concentration of the fuel.

JP 2006-214415 A

  By the way, even if new fuel, which is new fuel, is supplied to the fuel tank, old fuel, which is fuel from before the refueling, remains in both the first supply path and the second supply path. . For this reason, even after refueling, either the first injection valve or the second injection valve is driven for a while, and the old fuel is injected from the injection valve. When the old fuel is injected from the injection valve in this way, the old fuel remaining in the supply path gradually decreases, and the supply path is eventually filled with the new fuel. When the supply path is filled with new fuel in this way, new fuel is injected from the injection valve.

  Here, since the volume of the first supply path and the volume of the second supply path are generally different from each other, the time when the first supply path is filled with the new fuel is the second supply path. It is unlikely to coincide with the time when the inside is filled with new fuel. That is, although the old fuel still remains in one of the first supply path and the second supply path, the other supply path is filled with the new fuel. Cheap. Then, for example, in a situation where old fuel still remains in the second supply path even if the first supply path is filled with new fuel, the new fuel is injected from the first injection valve. Thus, the old fuel is injected from the second injection valve. On the contrary, in the situation where the old fuel still remains in the first supply path even if the second supply path is filled with the new fuel, the new fuel is injected from the second injection valve. The old fuel is injected from the first injection valve.

  At this time, if the properties of the old fuel and the new fuel are greatly deviated, the properties of the fuel injected from the first injector and the properties of the fuel injected from the second injector are greatly deviated. Will be doing. Note that the injection ratio is set on the assumption that the properties of the fuel injected from the first injection valve and the properties of the fuel injected from the second injection valve are the same. Therefore, when the engine is operated in a state where fuels having different properties are supplied from separate injection valves, the combustion characteristics in the cylinder of the air-fuel mixture containing fuel and air may be deteriorated.

  An object of the present invention is to provide a combustion characteristic of an air-fuel mixture in a cylinder caused by a difference between the properties of fuel injected from the first injector and the properties of fuel injected from the second injector. An object of the present invention is to provide an engine control device that can suppress the deterioration of the engine.

  An engine control apparatus for solving the above problems is a control apparatus applied to an engine capable of supplying fuel from both a first injection valve and a second injection valve to one cylinder. is there. The fuel supply system of the engine provided with the control device includes a first supply path for supplying the fuel in the fuel tank to the first injection valve, and a second supply for supplying the fuel in the fuel tank to the second injection valve. It has a supply path. The engine control device is premised on a device that controls fuel injection from the first injection valve and fuel injection from the second injection valve according to the operating state of the engine. The engine control device includes a property determination unit that determines whether or not the property of the fuel in the first supply path is deviated from the property of the fuel in the second supply path, and a property determination unit that When it is determined that the property of the fuel in the first supply path is deviated from the property of the fuel in the second supply path, one of the first injection valve and the second injection valve is injected. An injection control unit that performs a one-side injection process of injecting fuel from the valve and prohibiting fuel injection from the other injection valve.

  According to the above configuration, when it is determined that the property of the fuel in the first supply path is different from the property of the fuel in the second supply path, the one-side injection process is performed. During the one-way injection process, fuel is injected from one of the first and second injectors, but no fuel is injected from the other injector. Therefore, an event in which fuels having different properties are supplied from separate injection valves in one cylinder does not occur. Therefore, deterioration of the combustion characteristics of the air-fuel mixture in the cylinder due to the difference between the properties of the fuel injected from the first injector and the properties of the fuel injected from the second injector is suppressed. Will be able to.

  Note that when the engine speed is low, such as when the engine is idling, the combustion characteristics of the air-fuel mixture in the cylinder deteriorates, causing engine stall due to a decrease in engine speed due to the deterioration of the combustion characteristics. The engine's operating condition tends to become unstable, such as becoming easier. Therefore, in the engine control apparatus, the property determination unit causes the property of the fuel in the first supply path and the property of the fuel in the second supply route to be different from each other when the engine is idling. It is preferable that the one-side injection process is performed by the injection control unit when it is determined that the injection is being performed. According to this configuration, during the idling operation of the engine, the deterioration of the combustion characteristics of the air-fuel mixture in the cylinder is suppressed by performing the one-side injection process, so that the operation state of the engine becomes unstable. Occurrence can be suppressed.

  In addition, when the vehicle is running, noise such as road noise is transmitted to the passengers in the passenger compartment, and vehicle vibrations that occur during driving are also transmitted to the passengers. Even if noise or vibration due to the deterioration of characteristics occurs in the engine, the passenger is less likely to feel uncomfortable. On the other hand, when the vehicle is stopped, the combustion characteristics of the air-fuel mixture in the cylinder deteriorate and the deterioration is caused by the absence of noise such as road noise and body vibration that occurs during traveling, unlike when the vehicle is traveling. When noise and vibration are generated in the engine, passengers tend to feel uncomfortable. Thus, when the vehicle is stopped, the property determination unit determines that the property of the fuel in the first supply path is different from the property of the fuel in the second supply path. Further, it is preferable that the one-side injection process is performed by the injection control unit. According to this configuration, the combustion characteristics of the air-fuel mixture can be deteriorated by carrying out the one-side injection process particularly when the vehicle is in a state where the passenger is likely to feel uncomfortable with noise and vibration due to the deterioration of the air-fuel mixture combustion characteristics. Can be suppressed. For this reason, it is possible to make it difficult for passengers to feel discomfort while the vehicle is stopped.

  By the way, when the properties of the fuel in the fuel tank change due to refueling or the like, and the properties of the fuel in the fuel tank and the properties of the fuel stored in the fuel supply system become different, In this case, fuel having different properties from the fuel previously stored in the fuel supply system (that is, fuel in the fuel tank) is supplied. In this case, there may be a discrepancy between the properties of the fuel in the first supply path and the properties of the fuel in the second supply path.

  Here, when the property of the fuel in the fuel tank changes and the property of the fuel in the fuel tank deviates from the property of the fuel stored in the fuel supply system, It is assumed that the fuel that has been stored in the fuel supply system before the change in fuel properties is the old fuel, and the fuel in the fuel tank is the new fuel. In addition, the supply path in which the old fuel remains in the first supply path and the second supply path is set as the specific supply path, and the specific supply path is included in the first injection valve and the second injection valve. It is assumed that an injection valve that injects the fuel is a specific injection valve.

  In this case, in the one-way injection processing, fuel is injected from a specific injection valve, and fuel injection from other injection valves other than the specific injection valve among the first injection valve and the second injection valve is prohibited. Is preferred. According to this configuration, it is possible to quickly create a situation where the old fuel is eliminated from the specific supply path and the specific supply path is filled with the new fuel. That is, it becomes possible to end the one-side injection process at an early stage. As a result, fuel injection control using both the first injection valve and the second injection valve can be performed early.

  The fuel supply system includes a fuel tank for storing fuel and a common path connected to the fuel tank, and the first supply path and the second supply path are provided at the downstream end of the common path. The structure which connected both the upstream ends may be sufficient. And when the detection sensor which detects the property of a fuel is provided in the common path | route, the property determination part will be provided on condition that the property of the fuel detected by the detection sensor has changed. It is preferable to determine whether or not the fuel property and the fuel property in the second supply path are different.

  According to the said structure, the property of the fuel in a common path | route can be acquired. Therefore, when the new fuel in the fuel tank flows into the common path by the fuel injection from the injection valve, the property of the new fuel can be acquired. When the property of the new fuel can be acquired in this way, it is determined whether or not the property of the fuel in the first supply path is different from the property of the fuel in the second supply path. Become. When it is determined that the fuel property in the first supply path is different from the fuel property in the second supply path, the one-side injection process is started. As a result, the deterioration of the combustion characteristics of the air-fuel mixture in the cylinder due to the difference between the properties of the fuel injected from the first injector and the properties of the fuel injected from the second injector. It becomes possible to suppress.

  The volume of the first supply path and the volume of the second supply path are values that can be grasped in advance. Further, the fuel injection amount from the first injection valve and the fuel injection amount from the second injection valve are values that can be estimated based on the energization time to the injection valve and the number of injections. Therefore, the engine control apparatus may estimate the remaining amount of the old fuel in the first supply path based on the volume of the first supply path and the fuel injection amount from the first injection valve, or , Based on a first calculation unit that calculates an estimated value of the amount of new fuel flowing into the first supply path, a volume of the second supply path, and a fuel injection amount from the second injection valve. A second calculating unit that calculates an estimated value of the remaining amount of old fuel in the second supply path or an estimated value of the amount of new fuel flowing into the second supply path. It may be. In this case, the property determination unit determines the property of the fuel in the first supply path and the property of the fuel in the second supply path based on the calculation result by the first calculation unit and the calculation result by the second calculation unit. It is preferable to determine whether or not is deviated.

  According to the above configuration, for example, the estimated value of the remaining amount of old fuel in the first supply path is “0 (zero)”, while the estimated value of the remaining amount of old fuel in the second supply path. When is larger than “0 (zero)”, it can be determined that the property of the fuel in the first supply path is different from the property of the fuel in the second supply path. The estimated value of the remaining amount of old fuel in the second supply path is “0 (zero)”, while the estimated value of the remaining amount of old fuel in the first supply path is “0 (zero)”. Also, when it is larger than “,” it can be determined that the property of the fuel in the first supply path is different from the property of the fuel in the second supply path.

  For example, the estimated value of the amount of new fuel flowing into the first supply path is equal to the value corresponding to the volume of the first supply path, while the new fuel flows into the second supply path. When the estimated value of the amount is smaller than the value corresponding to the volume of the second supply path, the property of the fuel in the first supply path is different from the property of the fuel in the second supply path. Can be determined. In addition, the estimated value of the amount of new fuel flowing into the second supply path is equal to the value corresponding to the volume of the second supply path, while the amount of new fuel flowing into the first supply path is Even when the estimated value is smaller than the value corresponding to the volume of the first supply path, the property of the fuel in the first supply path is different from the property of the fuel in the second supply path. Can be determined.

  By the way, when the amount of fuel stored in the fuel tank increases, it can be determined that fueling has been performed. And the property of the fuel supplied in the fuel tank by refueling may be different from the property of the fuel stored in the fuel tank or the fuel supply system before refueling. In this case, the property of the fuel stored in the fuel supply system before refueling and the property of the fuel supplied from the fuel tank to the fuel supply system after refueling are different.

  Therefore, when the amount of fuel stored in the fuel tank increases, the fuel that has been stored in the fuel supply system before the amount of fuel stored in the fuel tank increases is used as the old fuel. When the fuel is a new fuel, the injection control unit injects fuel from the specific injection valve in the one-side injection processing, and other than the specific injection valve among the first injection valve and the second injection valve. It is also possible to prohibit fuel injection from the injection valve.

  According to this configuration, the property of the old fuel that is fuel stored in the fuel supply system before refueling and the property of the new fuel that is fuel newly supplied from the fuel tank to the fuel supply system after refueling. Is actually deviated, the execution of the one-side injection process prevents the occurrence of an event in which fuel with different properties is supplied from separate injection valves in one cylinder, and within a specific supply path. Therefore, it is possible to quickly create a situation in which the old fuel is removed from the fuel and the specific supply path is filled with the new fuel. Then, by terminating the one-way injection process early in this way, it becomes possible to perform fuel injection control using both the first injection valve and the second injection valve at an early stage.

  Further, in such an engine control device, the property determination unit is configured on the condition that the amount of fuel stored in the fuel tank has increased, and the property of the fuel in the first supply path and the property in the second supply path. It can also be determined whether or not the fuel property deviates.

  According to the above configuration, when the amount of fuel stored in the fuel tank increases, the property of the new fuel in the fuel tank may be different from the property of the old fuel in the fuel supply system. It is determined whether or not the property of the fuel in the supply path is different from the property of the fuel in the second supply path. Therefore, the one-side injection process is performed when there is a possibility that the property of the fuel in the first supply path and the property of the fuel in the second supply path are deviated. As a result, the deterioration of the combustion characteristics of the air-fuel mixture in the cylinder due to the difference between the properties of the fuel injected from the first injector and the properties of the fuel injected from the second injector. It becomes possible to suppress.

  Such an engine control apparatus is configured to estimate the remaining amount of old fuel in the first supply path based on the volume of the first supply path and the fuel injection amount from the first injection valve. Alternatively, a first calculation unit that calculates an estimated value of the amount of new fuel flowing into the first supply path, a volume of the second supply path, and a fuel injection amount from the second injection valve An estimated value of the remaining amount of old fuel in the second supply path, or a second calculation unit that calculates an estimated value of the amount of new fuel flowing into the second supply path, You may make it prepare. In this case, the property determination unit determines the property of the fuel in the first supply path and the property of the fuel in the second supply path based on the calculation result by the first calculation unit and the calculation result by the second calculation unit. It is preferable to determine whether or not is deviated.

  The engine is provided with an air-fuel ratio sensor for detecting the oxygen concentration of the exhaust gas flowing through the exhaust passage, and the air-fuel ratio of the exhaust gas flowing through the exhaust passage is estimated based on the oxygen concentration detected by the air-fuel ratio sensor. can do. When the property of the fuel injected from the first injector and the property of the fuel injected from the second injector are different, if the injection ratio changes, the detection result by the air-fuel ratio sensor is displayed. The estimated air-fuel ratio of the exhaust gas changes. The injection ratio is a value obtained by dividing the fuel injection amount from the first injection valve by the sum of the fuel injection amount from the first injection valve and the fuel injection amount from the second injection valve. It is.

  Therefore, the property determination unit changes the properties of the fuel in the first supply path and the fuel in the second supply path when the air-fuel ratio of the exhaust flowing through the exhaust path of the engine changes due to the change in the injection ratio. You may make it determine with the property of no. According to this configuration, it is possible to determine the start timing of the one-side injection processing without newly providing a sensor or the like for detecting the property of the fuel.

  Incidentally, when the fuel is a fuel containing alcohol, the property of the fuel is the alcohol concentration of the fuel. In this case, the property determination unit preferably determines whether or not the alcohol concentration of the fuel in the first supply path is different from the alcohol concentration of the fuel in the second supply path. According to this configuration, when it is determined that the alcohol concentration of the fuel in the first supply path is different from the alcohol concentration of the fuel in the second supply path, the one-side injection process is performed. Will be able to.

  Note that the engine control device can be applied to an engine having both a first injection valve that injects fuel into the intake passage and a second injection valve that injects fuel into the cylinder.

The lineblock diagram showing the outline of the engine provided with the control device of the engine of a 1st embodiment. The map which shows the control aspect of the injection valve according to the engine speed and engine load in the same engine. The schematic diagram which shows a mode that the common path | route, the 1st supply path | route, and the 2nd supply path | route are satisfy | filled with the old fuel in the fuel supply system of the same engine. The schematic diagram which shows a mode that the old fuel runs out from a common path | route in the fuel supply system, and the common path | route is satisfy | filled with the new fuel. The schematic diagram which shows a mode that the new fuel is flowing in in the 1st supply path | route in the fuel supply system. The schematic diagram which shows a mode that the old fuel was lost from the 1st supply path | route, and the inside of the 1st supply path | route was satisfy | filled with the new fuel in the fuel supply system. The schematic diagram which shows a mode that the new fuel is flowing in into the 2nd supply path | route in the fuel supply system. The schematic diagram which shows a mode that the old fuel runs out from the 2nd supply path | route in the fuel supply system, and the 2nd supply path | route is satisfy | filled with the new fuel. The block diagram which shows the function structure of the control apparatus of the engine. The flowchart which shows the process routine performed in order to determine whether the new fuel reached the downstream end in a common path | route in the control apparatus of the engine. The flowchart which shows the process routine performed in order to estimate the residual amount of the old fuel in the 1st supply path | route in the control apparatus of the engine. The flowchart which shows the process routine performed in order to estimate the residual amount of the old fuel in the 2nd supply path | route in the control apparatus of the engine. In the control device of the engine, a processing routine executed to determine whether or not the alcohol concentration of the fuel in the first supply path and the alcohol concentration of the fuel in the second supply path are deviated. The flowchart shown. The flowchart which shows the process routine performed when controlling the fuel injection of a 1st injection valve, and the fuel injection of a 2nd injection valve in the control apparatus of the engine. The flowchart which shows the process routine performed when execution of the one-way injection process is requested | required in the control apparatus of the engine. In an engine provided with the engine control device of a 2nd embodiment, a lineblock diagram showing an outline of a part of fuel supply system and its peripheral member, and a part of functional composition of a control device. The flowchart which shows the process routine performed in order to determine whether the old fuel remains in a common path | route in the control apparatus of the engine. In the engine control apparatus according to another embodiment, it is determined from the air-fuel ratio whether or not the alcohol concentration of the fuel in the first supply path is different from the alcohol concentration of the fuel in the second supply path. FIG. In an engine control apparatus according to another embodiment, for determining from the air-fuel ratio whether or not the alcohol concentration of the fuel in the first supply path is deviated from the alcohol concentration of the fuel in the second supply path. 7 is a flowchart showing a processing routine executed in the step. The block diagram which shows the outline of an engine provided with the control apparatus of the engine of other another embodiment.

(First embodiment)
Hereinafter, a first embodiment of an engine control device will be described with reference to FIGS.
FIG. 1 illustrates an engine 11 including a control device 100 as the engine control device of the present embodiment. The engine 11 is an engine capable of using, as fuel, alcohol mixed fuel obtained by mixing gasoline and alcohol in addition to gasoline.

  As shown in FIG. 1, the engine 11 includes a plurality of cylinders 12, an intake passage 13 that communicates with the inside of each cylinder 12, and an exhaust passage 14 that communicates with each cylinder 12. A throttle valve 15 that adjusts the amount of intake air into each cylinder 12 is provided in the intake passage 13. In such an intake passage 13, it is branched for each cylinder downstream of the throttle valve 15. The exhaust passage 14 is provided with an exhaust purification device 16 for purifying exhaust flowing in the exhaust passage 14.

  Further, the engine 11 includes a first injection valve 17 that injects fuel downstream of the throttle valve 15 in the intake passage 13 and a second injection valve 18 that directly injects fuel into the cylinder 12. . In the engine 11, both the first injection valve 17 and the second injection valve 18 are provided for each cylinder 12. That is, a plurality of injection valves capable of supplying fuel are provided in one cylinder 12. An air-fuel mixture containing fuel injected from at least one of the first injection valve 17 and the second injection valve 18 and air introduced into the cylinder 12 through the intake passage 13 is generated in the cylinder 12. As a result, the crankshaft of the engine 11 is rotated.

  As shown in FIG. 1, the engine 11 is provided with a fuel supply system 20 for supplying the fuel stored in the fuel tank 21 to both the first injection valve 17 and the second injection valve 18. Yes. The fuel supply system 20 includes a common path 22 whose upstream end, which is the lower end in the figure, is connected to the fuel tank 21, and a first supply path that is connected to the downstream end 22A, which is the upper end of the common path 22, in the figure. 23 and a second supply path 24 connected to the downstream end 22 </ b> A of the common path 22. A feed pump 221 for pumping the fuel in the fuel tank 21 into the common path 22 is provided at the upstream end of the common path 22.

The first supply path 23 is configured to include a first delivery pipe 231 in which fuel supplied to the first injection valve 17 is temporarily stored.
The second supply path 24 is configured to include a second delivery pipe 241 in which fuel supplied to the second injection valve 18 is temporarily stored. The second supply path 24 is provided with a high-pressure fuel pump 242 that further pressurizes the fuel pumped from the fuel tank 21 by the feed pump 221. Therefore, the pressure in the second delivery pipe 241 is higher than the pressure in the first delivery pipe 231.

  As shown in FIG. 1, a vehicle speed sensor 111, a crank angle sensor 112, an air-fuel ratio sensor 113, and a property detection sensor 114 are electrically connected to the control device 100 of the engine 11. The vehicle speed sensor 111 is a sensor that detects a vehicle speed VS that is the speed of a vehicle on which the engine 11 is mounted, and the crank angle sensor 112 is a sensor that detects an engine rotation speed NE that is the rotation speed of the crankshaft of the engine 11. The air-fuel ratio sensor 113 is a sensor that detects the oxygen concentration of the exhaust gas flowing in the exhaust passage 14 upstream of the exhaust gas purification device 16. Based on the oxygen concentration of the exhaust gas detected by the air-fuel ratio sensor 113, the cylinder 12 can estimate the air-fuel ratio of the air-fuel mixture burned in (i.e., the exhaust gas). The property detection sensor 114 is an example of a detection sensor that detects the property of the fuel, and is disposed at a position where the property of the fuel in the downstream end 22A of the common path 22 can be detected. As described above, the engine 11 is an engine that can use an alcohol-mixed fuel. Therefore, the property detection sensor 114 detects the alcohol concentration of the fuel in the downstream end 22 </ b> A of the common path 22.

  And the control apparatus 100 controls the throttle valve 15, each 1st injection valve 17, and each 2nd injection valve 18 based on the information detected by detection systems, such as each sensor 111-114. Yes. That is, the fuel supply system includes a fuel supply system 20, a property detection sensor 114, and a control device 100.

  In the engine 11, the fuel injection from the first injection valve 17 and the fuel injection from the second injection valve 18 are controlled in accordance with the injection ratio determined by the operating region of the engine 11. The injection ratio is a value obtained by dividing the fuel injection amount from the first injection valve 17 by the sum of the fuel injection amount from the first injection valve 17 and the fuel injection amount from the second injection valve 18. It is. When the injection ratio is “1”, fuel is injected from the first injection valve 17, while fuel is not injected from the second injection valve 18. When the injection ratio is “0 (zero)”, the fuel is injected from the second injection valve 18, while the fuel is not injected from the first injection valve 17. Further, when the injection ratio is larger than “0 (zero)” and smaller than “1”, the fuel is injected from both the first injection valve 17 and the second injection valve 18. It has become.

  Here, the relationship between the operating range of the engine 11 and the fuel injection control will be described with reference to the map shown in FIG. “Port injection” refers to fuel injection from the first injection valve 17, and “in-cylinder injection” refers to fuel injection from the second injection valve 18.

  As shown in FIG. 2, in the operation region where both the engine speed NE and the engine load are small, the injection ratio is “1”, only the port injection is performed, and the in-cylinder injection is not performed. The operation region includes idle operation of the engine 11.

  In addition, when the engine 11 is idling, the in-cylinder injection is basically not performed, but the in-cylinder injection may be performed exceptionally. That is, when the engine operation in which the in-cylinder injection is not performed is continued, the temperature of the second injection valve 18 is increased by the heat generated in the cylinder 12 or the like. When the temperature of the second injection valve 18 rises in this way, the temperature of the fuel staying in the second injection valve 18 rises excessively, and the fuel may vaporize in the second injection valve 18. When the fuel is vaporized in this way, the controllability of fuel injection from the second injection valve 18 is degraded. For this reason, even when the engine is idling without originally performing in-cylinder injection, if it is determined that there is a risk of vaporization in the second injection valve 18, the fuel is injected from the second injection valve 18. Sometimes.

  Further, the engine 11 performs various diagnostic processes. Among such diagnostic processes, there is also a diagnostic process that requires both port injection and in-cylinder injection. Examples of such diagnosis processing include imbalance diagnosis that detects the degree of variation in the amount of fuel supplied into the cylinder 12 between the cylinders. When such a diagnosis process is performed during idle operation that does not perform in-cylinder injection, in-cylinder injection may be performed in addition to port injection, or in-cylinder injection may be performed instead of port injection. .

  Further, as shown in FIG. 2, in the operation region where the engine load is not so large and the engine speed NE is large, the injection ratio becomes “0 (zero)”, only in-cylinder injection is performed, and port injection is performed. Is not implemented. Further, in the operation region where the engine speed NE is not so large and the engine load is large, the injection ratio is larger than “0 (zero)” and less than “1”, and the port injection and the in-cylinder injection are performed. Both are implemented.

  Further, in the engine 11 that is operated using a fuel containing alcohol, the injection ratio is larger than “0 (zero)” and “1” in an operation region where both the engine speed NE and the engine load are large. The value is less than "", and both port injection and in-cylinder injection are performed. When a fuel containing alcohol is used, the air-fuel mixture is less likely to burn than when a fuel not containing alcohol is used. Therefore, when a fuel containing alcohol is used, the fuel injection amount in one cycle is increased. Therefore, in the high rotation and high load operation region, there is a possibility that a sufficient amount of fuel necessary for combustion cannot be supplied into the cylinder 12 by in-cylinder injection alone, so that not only in-cylinder injection but also port injection is performed. Thereby, the favorable combustion characteristic of air-fuel | gaseous mixture can be ensured.

  By the way, the fuel supply system 20 may be supplied with a plurality of types of fuel having different properties, that is, alcohol concentrations. The combustion of the air-fuel mixture in the cylinder 12 is performed when the fuel having the first alcohol concentration is used and when the fuel having the second alcohol concentration different from the first alcohol concentration is used. The characteristics are different. Therefore, during the operation of the engine 11 using the fuel having the first alcohol concentration, fuel injection control for the fuel is performed. On the other hand, during the operation of the engine 11 using the fuel having the second alcohol concentration, fuel injection control for the fuel is performed.

  The injection ratio is set on the assumption that the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18 are not different. . Therefore, when the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18 are different, the injection ratio cannot be set appropriately, The combustion characteristics of the air-fuel mixture in each cylinder 12 may be deteriorated. In such an event, the injection ratio is greater than “0 (zero)” and smaller than “1”, and fuel is injected from both the first injection valve 17 and the second injection valve 18. Appears when the Therefore, it is necessary to monitor whether or not the alcohol concentration of the fuel in the first supply path 23 is different from the alcohol concentration of the fuel in the second supply path 24. The state where the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 deviate is, for example, the alcohol of the fuel stored in the fuel supply system 20 This occurs when a fuel having an alcohol concentration different from the concentration is supplied into the fuel tank 21.

  Here, with reference to FIGS. 3 to 8, a method for determining whether or not a fuel having an alcohol concentration different from the fuel stored in the fuel supply system 20 has reached the downstream end 22 </ b> A in the common path 22; An example of the method for estimating the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 will be described.

  When refueling is performed, the fuel stored in the fuel tank 21 and the newly supplied fuel are mixed in the fuel tank 21 before refueling. Therefore, when the alcohol concentration of the fuel stored in the fuel tank 21 before refueling and the alcohol concentration of the fuel newly supplied into the fuel tank 21 are different, the fuel supply system 20 (that is, The alcohol concentration of the fuel in the common path 22, the first supply path 23 and the second common path 24) and the alcohol concentration of the fuel in the fuel tank 21 are different.

  Therefore, in the present embodiment, the alcohol concentration of the fuel in the fuel tank 21 changes so that the alcohol concentration of the fuel in the fuel tank 21 and the alcohol concentration of the fuel stored in the fuel supply system 20 are different. In this case, the fuel stored in the fuel supply system 20 before the alcohol concentration of the fuel in the fuel tank 21 changes is called “old fuel”, and the fuel in the fuel tank 21 is called “new fuel”. Shall. In FIGS. 3 to 8, a region where a large number of dots are given is a region where old fuel is accumulated, and a region where a large number of diagonal lines are given is a region where new fuel is accumulated. is there.

  FIG. 3 shows a state immediately after the alcohol concentration of the fuel in the fuel tank 21 changes due to refueling or the like. As shown in FIG. 3, immediately after the alcohol concentration of the fuel in the fuel tank 21 changes, the new fuel stays only in the fuel tank 21, and in the common path 22 and the first supply path 23. The inner and second supply paths 24 are filled with old fuel. When the engine 11 is operated in this state and old fuel is injected from the injection valves 17 and 18, new fuel flows from the fuel tank 21 into the common path 22. Thus, when the old fuel still remains in the common path 22, whether the old fuel is injected from the first injection valve 17 or the old fuel is injected from the second injection valve 18, the injection valve An amount of new fuel commensurate with the amount of fuel injected from 17 and 18 flows into the common path 22.

  If the injection of the old fuel by the injectors 17 and 18 is continued in this way, the common path 22 is filled with the new fuel and no old fuel remains in the common path 22 as shown in FIG. It becomes a state. As described above, the control device 100 of the present embodiment can detect the alcohol concentration of the fuel staying at the downstream end 22 </ b> A of the common path 22 based on the detection result by the property detection sensor 114.

  That is, in the control device 100 of the present embodiment, when the new fuel reaches the downstream end 22A in the common path 22, the alcohol concentration detected by the property detection sensor 114 changes, so that the new fuel flows downstream in the common path 22. It can be determined that the end 22A has been reached.

  Even if refueling is performed, the alcohol concentration of the fuel in the fuel tank 21 may not change. In this case, in the control device 100 that performs the above determination using the detection result of the property detection sensor 114, the fuel supplied from the fuel tank 21 into the fuel supply system 20 after refueling, and the fuel supply system 20 from before the refueling. It cannot be distinguished from the stored fuel.

  After it is determined that the new fuel has reached the downstream end 22A in the common path 22 based on the change in the detection result by the property detection sensor 114, the alcohol concentration of the fuel in the first supply path 23 is estimated. The estimation of the alcohol concentration of the fuel in the second supply path 24 is performed. That is, the volume of the first supply path 23 and the volume of the second supply path 24 are values that can be grasped in advance. The total amount of old fuel injected by each first injection valve 17 after determining that the new fuel has reached the downstream end 22A in the common path 22 is the total energization time of each first injection valve 17. Or the number of injections of each first injection valve 17 can be estimated. Similarly, the total amount of old fuel injected by the second injectors 18 after determining that the new fuel has reached the downstream end 22A in the common path 22 is the energization time of each second injector 18 and the second energization time. It can be estimated based on the number of injections of the two injection valves 18.

  FIGS. 5 and 6 schematically show a state in which the remaining amount of the old fuel in the first supply path 23 gradually decreases due to the injection of the old fuel by the first injection valve 17. When it is determined that the new fuel has reached the downstream end 22A in the common path 22, the first supply path 23 is filled with the old fuel. The remaining amount of old fuel at this time is referred to as a “first old fuel full tank value”. The first old fuel full value is a value that correlates with the volume of the first supply path 23 and can be grasped in advance. When the old fuel is injected from the first injection valve 17, the remaining amount of the old fuel in the first supply path 23 gradually decreases, while the new fuel in the first supply path 23 is reduced. The amount of inflow gradually increases.

  That is, the total amount of old fuel injected by each first injection valve 17 after determining that the new fuel has reached the downstream end 22 </ b> A in the common path 22 is the inflow of the new fuel into the first supply path 23. The difference obtained by subtracting the total amount of old fuel injected by each first injection valve 17 from the first old fuel full tank value corresponds to the remaining amount of old fuel in the first supply path 23. . Therefore, based on the volume of the first supply path 23 and the total injection amount of fuel from each first injection valve 17 after it is determined that the new fuel has reached the downstream end 22A in the common path 22. The estimated value of the remaining amount of the old fuel in one supply path 23 can be calculated. That is, the estimated value of the remaining amount of the old fuel in the first supply path 23 is obtained by determining that the new fuel has reached the downstream end 22 </ b> A in the common path 22 and the old fuel by each first injection valve 17. The smaller the total injection amount, the smaller.

  When the estimated value of the remaining amount of the old fuel becomes “0 (zero)” or less, the old fuel does not already remain in the first supply path 23 and the fuel in the first supply path 23 It can be determined that the alcohol concentration of the fuel becomes equal to the alcohol concentration of the new fuel.

  On the other hand, FIGS. 7 and 8 schematically show that the remaining amount of the old fuel in the second supply path 24 is gradually decreased by the injection of the old fuel by the second injection valve 18. Yes. When it is determined that the new fuel has reached the downstream end 22 </ b> A in the common path 22, the second supply path 24 is filled with the old fuel. The remaining amount of the old fuel at this time is referred to as a “second old fuel full tank value”. The second old fuel full tank value correlates with the volume of the second supply path 24 and is a value that can be grasped in advance. When the old fuel is injected from the second injection valve 18, the remaining amount of the old fuel in the second supply path 24 gradually decreases, while the new fuel in the second supply path 24 is reduced. The amount of inflow gradually increases.

  That is, the total amount of old fuel injected by each second injector 18 after determining that the new fuel has reached the downstream end 22 </ b> A in the common path 22 is the inflow of new fuel into the second supply path 24. The difference obtained by subtracting the total amount of old fuel injected by the second injector 18 from the second old fuel full tank value corresponds to the remaining amount of old fuel in the second supply path 24. Therefore, based on the volume of the second supply path 24 and the total injection amount of fuel from each second injection valve 18 after it is determined that the new fuel has reached the downstream end 22A in the common path 22. The estimated value of the remaining amount of the old fuel in the two supply paths 24 can be calculated. In other words, the estimated value of the remaining amount of the old fuel in the second supply path 24 is obtained by determining the amount of old fuel by the second injection valve 18 after determining that the new fuel has reached the downstream end 22A in the common path 22. The smaller the total injection amount, the smaller.

  When the estimated value of the remaining amount of the old fuel becomes “0 (zero)” or less, the old fuel does not already remain in the second supply path 24 and the fuel in the second supply path 24 It can be determined that the alcohol concentration of the fuel becomes equal to the alcohol concentration of the new fuel.

  In the control device 100 of the present embodiment, after it is determined that the new fuel has reached the downstream end 22 </ b> A in the common path 22, one of the first supply path 23 and the second supply path 24 is supplied. When the old fuel does not remain in the path and the old fuel still remains in the other supply path, the alcohol concentration of the fuel in the first supply path 23 and the second supply path 24 It is determined that the alcohol concentration of the fuel deviates. When the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are deviated, of the first injection valve 17 and the second injection valve 18 One-way injection processing is performed in which fuel is injected from one injection valve and fuel injection from the other injection valve is prohibited. By performing this one-way injection process, it is possible to suppress the deterioration of the fuel characteristics of the air-fuel mixture caused by the fuel having different alcohol concentrations being injected from separate injection valves.

  When the engine speed NE is low, such as when the engine 11 is idling, if the combustion characteristics of the air-fuel mixture in the cylinder 12 deteriorate, the engine speed NE decreases due to the deterioration of the combustion characteristics. The operating state of the engine 11 is likely to become unstable, such as an engine stall is likely to occur. On the other hand, when the engine rotational speed NE is relatively high, the operating state of the engine 11 is unstable even if the fuel characteristics of the air-fuel mixture deteriorate due to the fuel having different alcohol concentrations being injected from separate injection valves. It is hard to become.

  Further, when the vehicle is traveling, noise such as road noise is transmitted to the passengers in the passenger compartment, and the vehicle body vibration generated during the traveling is transmitted to the passengers. Even if noise or vibration due to deterioration of combustion characteristics occurs in the engine 11, the occupant is less likely to feel uncomfortable. On the other hand, when the vehicle is stopped, the combustion characteristics of the air-fuel mixture in the cylinder 12 are deteriorated as much as noise such as road noise and body vibration that occurs when the vehicle travels do not occur unlike when the vehicle travels. When noise or vibration due to the deterioration occurs in the engine 11, the occupant tends to feel uncomfortable.

  Therefore, in the control device 100 of the present embodiment, the execution conditions of the one-side injection processing include both that the engine 11 is idling and that the vehicle is stopped. That is, even when the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are different from each other, fuels having different alcohol concentrations are separated from different injection valves. One-way injection processing is not performed when the operating state of the engine 11 is not likely to become unstable even when the fuel characteristics of the air-fuel mixture due to the injection deteriorate, and when the occupant is less likely to feel uncomfortable. Therefore, the injection control of the first injection valve 17 and the injection control of the second injection valve 18 can be performed based on the injection distribution ratio according to the operating state of the engine 11 at that time.

  Note that there are learning processes and diagnostic processes that cannot be performed under a situation where the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve are different. Therefore, in order to start the execution of such processing at an early stage, the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18 are different. The condition needs to be resolved early.

  Therefore, the first supply path 23 and the second supply path 24 are defined as the supply path in which the old fuel remains, and the first injection valve 17 and the second injection valve 18 are specified. It is assumed that an injection valve that injects fuel in the supply path is a specific injection valve. In this case, in the control device 100 of the present embodiment, in the one-side injection processing, fuel is injected from a specific injection valve, and the specific injection valve of the first injection valve 17 and the second injection valve 18 is the same. Fuel injection from other injection valves is prohibited. As a result, the old fuel is quickly removed from the specific supply path, and a situation in which the specific supply path is filled with the new fuel is created early. That is, the state in which the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18 deviate from each other by the one-way injection processing is eliminated early. The

Next, the functional configuration of the control device 100 of the present embodiment will be described with reference to FIG.
As illustrated in FIG. 9, the control device 100 includes an injection control unit 201, a new fuel inflow determination unit 202, a first calculation unit 203, and a second function unit configured as at least one of software and hardware. A calculation unit 204 and a property determination unit 205 are included.

  The injection control unit 201 controls the first injection valve 17 and the second injection valve 18 on the basis of the above-described injection distribution ratio according to the operating state of the engine 11. In addition, the injection control unit 201 performs the alcohol operation of the fuel in the first supply path 23 and the fuel in the second supply path 24 under the situation where the engine 11 is idling and the vehicle is stopped. When the fact that the alcohol concentration is deviated from the property determination unit 205 described later is input, the one-side injection process is performed.

  The new fuel inflow determination unit 202 monitors the alcohol concentration of the fuel detected by the property detection sensor 114. Since the property detection sensor 114 detects the alcohol concentration of the fuel at the downstream end 22 </ b> A in the common path 22, the new fuel inflow determination unit 202 determines when the alcohol concentration of the fuel detected by the property detection sensor 114 has changed. Then, it is determined that the new fuel has reached the downstream end 22 </ b> A in the common path 22. When the new fuel inflow determination unit 202 determines that the new fuel has reached the downstream end 22 </ b> A in the common path 22, the new fuel inflow determination unit 202 outputs that fact to both the first calculation unit 203 and the second calculation unit 204. .

  When the fact that new fuel has reached the downstream end 22 </ b> A in the common path 22 is input from the new fuel inflow determination unit 202, the first calculation unit 203 determines the remaining amount of old fuel in the first supply path 23. Estimated value Y1 is calculated. Then, the first calculation unit 203 outputs the calculated estimated value Y1 of the old fuel remaining amount in the first supply path 23 to the property determination unit 205.

  When the fact that new fuel has reached the downstream end 22 </ b> A in the common path 22 is input from the new fuel inflow determination unit 202, the second calculation unit 204 determines the remaining amount of old fuel in the second supply path 24. Estimated value Y2 is calculated. Then, the second calculation unit 204 outputs the calculated estimated value Y2 of the old fuel remaining amount in the second supply path 24 to the property determination unit 205.

  The property determination unit 205 uses the information input from the first calculation unit 203 and the information input from the second calculation unit 204, and uses the alcohol concentration of the fuel in the first supply path 23 and the second supply path. It is determined whether or not the alcohol concentration of the fuel within 24 deviates. When the property determination unit 205 determines that the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are different from each other, injection control is performed to that effect. Output to the unit 201. Note that when the fact that there is such a divergence is output to the injection control unit 201, the property determination unit 205 also outputs to the injection control unit 201 information relating to a supply path in which old fuel still remains, that is, a specific supply path. To do.

  Next, a processing routine executed by the new fuel inflow determination unit 202 of the control device 100 in order to determine that new fuel has reached the downstream end 22A in the common path 22 will be described with reference to the flowchart shown in FIG.

  As shown in FIG. 10, the new fuel inflow determination unit 202 acquires the alcohol concentration X of the fuel detected by the property detection sensor 114 (step S11). Subsequently, the new fuel inflow determination unit 202 calculates the difference between the acquired alcohol concentration X of the current fuel and the alcohol concentration reference value XTH, and determines whether or not the difference is larger than the determination value ΔX (step). S12). The alcohol concentration reference value XTH is set to a value substantially equal to the alcohol concentration of the fuel stored in the fuel supply system 20 before the alcohol concentration of the fuel in the fuel tank 21 changes. Therefore, when the difference (= | X−XTH |) is larger than the determination value ΔX, it can be determined that the new fuel has reached the downstream end 22 </ b> A in the common path 22.

  Therefore, when the difference (= | X−XTH |) is equal to or smaller than the determination value ΔX (step S12: NO), the new fuel inflow determination unit 202 once ends this processing routine. On the other hand, when the difference is larger than the determination value ΔX (step S12: YES), the new fuel inflow determination unit 202 determines that the new fuel has reached the downstream end 22A in the common path 22 (step S13). Then, the new fuel inflow determination unit 202 substitutes the alcohol concentration X of the current fuel acquired in step S11 for the alcohol concentration reference value XTH (step S14), and ends this processing routine.

  Next, referring to the flowchart shown in FIG. 11, a processing routine executed by the first calculation unit 203 of the control device 100 when calculating the estimated value Y1 of the remaining amount of old fuel in the first supply path 23. explain.

  As shown in FIG. 11, the first calculation unit 203 determines the total amount Z1 of fuel injection from each first injection valve 17 after it is determined that the new fuel has reached the downstream end 22A in the common path 22. Is calculated (step S21). Then, the first calculation unit 203 subtracts the total fuel injection amount Z1 from each first injection valve 17 from the first old fuel full value Y1MAX correlated with the volume of the first supply path 23. The difference (= Y1MAX−Z1) is set to the estimated value Y1 of the old fuel in the first supply path 23 (step S22), and this processing routine is ended.

  Next, referring to the flowchart shown in FIG. 12, the processing routine executed by the second calculation unit 204 of the control device 100 when calculating the estimated value Y2 of the remaining amount of old fuel in the second supply path 24. explain.

  As shown in FIG. 12, the second calculation unit 204 determines the total amount of fuel injection Z2 from each second injection valve 18 after it is determined that the new fuel has reached the downstream end 22A in the common path 22. Is calculated (step S31). Then, the second calculation unit 204 subtracts the total fuel injection amount Z2 from each second injection valve 18 from the second old fuel full tank value Y2MAX correlated with the volume of the second supply path 24. The difference (= Y2MAX−Z2) is set as the estimated value Y2 of the old fuel in the second supply path 24 (step S32), and this processing routine is ended.

  Next, referring to the flowchart shown in FIG. 13, in order to determine whether or not the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are different. A processing routine executed by the property determination unit 205 of the control device 100 will be described.

  As illustrated in FIG. 13, the property determination unit 205 has an estimated value Y1 of the remaining amount of old fuel in the first supply path 23 calculated by the first calculation unit 203 equal to or less than “0 (zero)”. Is determined (step S41). When the estimated value Y1 of the remaining amount is equal to or less than “0 (zero)”, it is determined that no old fuel remains in the first supply path 23, and the estimated value Y1 of the remaining amount is greater than “0 (zero)”. When it is larger, it can be determined that the old fuel remains in the first supply path 23. Therefore, when the estimated value Y1 of the remaining amount is “0 (zero)” or less (step S41: YES), the property determination unit 205 determines that no old fuel remains in the first supply path 23 ( In step S42), the process proceeds to the next step S43. On the other hand, when the estimated value Y1 of the remaining amount is larger than “0 (zero)” (step S41: NO), the property determination unit 205 moves the process to the next step S43 without executing the process of step S42. Transition.

  In step S43, the property determination unit 205 determines whether the estimated value Y2 of the remaining amount of the old fuel in the second supply path 24 calculated by the second calculation unit 204 is “0 (zero)” or less. Determine. When the estimated value Y2 of the remaining amount is equal to or less than “0 (zero)”, it is determined that no old fuel remains in the second supply path 24, and the estimated value Y2 of the remaining amount is greater than “0 (zero)”. When it is larger, it can be determined that the old fuel remains in the second supply path 24. Therefore, when the estimated value Y2 of the remaining amount is equal to or less than “0 (zero)” (step S43: YES), the property determination unit 205 determines that no old fuel remains in the second supply path 24 ( In step S44), the process proceeds to the next step S45. On the other hand, when the estimated value Y2 of the remaining amount is larger than “0 (zero)” (step S43: NO), the property determination unit 205 moves the process to the next step S45 without executing the process of step S44. Transition.

  In step S <b> 45, the property determination unit 205 determines whether the old fuel remains only in one of the first supply path 23 and the second supply path 24. That is, the old fuel remains in the first supply path 23, the old fuel does not remain in the second supply path 24, and the old fuel remains in the second supply path 24. If no old fuel remains in the first supply path 23, the determination in step S45 is affirmative. On the other hand, when old fuel remains in both the first supply path 23 and the second supply path 24, and no old fuel remains in both the first supply path 23 and the second supply path 24. In this case, the determination in step S45 is a negative determination.

  If the determination in step S45 is affirmative (YES), the property determination unit 205 determines that the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are different. (Step S46) and this processing routine is terminated. On the other hand, when the determination in step S45 is negative (NO), the property determination unit 205 causes the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 to differ. It is determined that it has not been performed (step S47), and this processing routine is terminated.

  Next, referring to the flowchart shown in FIG. 14, a processing routine executed by the injection control unit 201 of the control device 100 when controlling the fuel injection of the first injection valve 17 and the fuel injection of the second injection valve 18. explain.

  As shown in FIG. 14, in this processing routine, the injection control unit 201 indicates that the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are different. It is determined whether or not the determination result is input from the property determination unit 205 (step S51). When the property determination unit 205 inputs a determination result indicating that the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are different (step) (S51: YES), the injection control unit 201 proceeds to step S54, which will be described later.

  On the other hand, when the determination result indicating that the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are different is not input from the property determination unit 205, the injection A determination result that the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are not deviated from the property determination section 205 is input to the control unit 201. Yes. Therefore, when the determination result that the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are different is not input from the property determination unit 205 (step (S51: NO), the injection control unit 201 proceeds to the next step S53.

  In step S53, the injection control unit 201 requests execution of normal injection processing. Thereafter, the injection control unit 201 ends this processing routine. In this case, the injection control unit 201 controls the first injection valve 17 and the second injection valve 18 based on the injection distribution ratio according to the operation state of the engine 11 at that time.

  In step S54, the injection control unit 201 determines whether or not both the engine 11 is idling and the vehicle is stopped. Specifically, whether or not the vehicle is stopped is determined by whether or not the vehicle speed VS detected by the vehicle speed sensor 111 is equal to or less than a stop determination threshold value. If at least one of the engine 11 is in idle operation and the vehicle is not stopped (step S54: NO), the injection control unit 201 proceeds to step S53 described above. Transition. That is, even when the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are different from each other, the engine 11 is not in idle operation or the vehicle When is not stopped, the normal injection process is performed without performing the one-side injection process.

  On the other hand, if both the engine 11 is idling and the vehicle is stopped (step S54: YES), the control device 100 requests execution of the one-way injection process (step S54). (S55) This processing routine is temporarily terminated.

  Next, a processing routine executed by the injection control unit 201 of the control device 100 when the execution of the one-side injection processing is requested in the processing routine shown in FIG. 14 will be described with reference to the flowchart shown in FIG.

  As shown in FIG. 15, in this processing routine, the injection control unit 201 determines whether or not old fuel remains in the first supply path 23 (step S81). When old fuel does not remain in the first supply path 23, it can be determined that old fuel remains in the second supply path 24. If the old fuel remains in the first supply path (step S81: YES), the injection control unit 201 prohibits fuel injection from the second injection valve 18 (step S82), Fuel is injected from the injection valve 17 (step S83), and then this processing routine ends.

  On the other hand, if no old fuel remains in the first supply path 23 in step S81 (step S81: NO), the injection control unit 201 prohibits fuel injection from the first injection valve 17 (step S84). ), Fuel is injected from the second injection valve 18 (step S85), and then this processing routine is terminated.

  Next, the operation of the engine 11 including the control device 100 of the present embodiment will be described. As a premise, it is assumed that the alcohol concentration of the fuel in the fuel tank 21 is changed by refueling.

  Immediately after the alcohol concentration of the fuel in the fuel tank 21 changes, the new fuel has not yet flowed into the first supply path 23 and the second supply path 24, so the first supply path 23 The old fuel still remains in both the inside and the second supply path 24 (step S51: NO). Therefore, the normal injection process is performed for a while immediately after the alcohol concentration of the fuel in the fuel tank 21 is changed. Thereby, regardless of which of the first injection valve 17 and the second injection valve 18 is driven, old fuel is injected from the injection valve (step S53). In this case, since the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18 are not different, the fuel characteristics of the air-fuel mixture in the cylinder 12 Does not get worse.

  When the new fuel reaches the downstream end 22A in the common path 22 after a while, the new fuel flows into the first supply path 23 and the second supply path 24 thereafter. If the old fuel in the first supply path 23 runs out before the old fuel in the second supply path 24 (step S51: YES), the old fuel in the second supply path 24 runs out. During this time, the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18 are different. On the other hand, even when the old fuel in the second supply path 24 disappears before the old fuel in the first supply path 23 (step S51: YES), the old fuel in the first supply path 23 is depleted. Until the fuel is consumed, the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18 are different from each other.

  Even under such circumstances, when the engine 11 is not idling or the vehicle is not stopped (step S54: NO), the normal injection process is performed instead of the one-side injection process. (Step S53). However, under such circumstances, when the vehicle stops and the engine 11 performs an idle operation (step S54: YES), a one-way injection process is performed (step S55).

  When old fuel still remains in the first supply path 23 (step S81: YES), the first supply path 23 corresponds to a specific supply path, and the first injection valve 17 becomes a specific injection valve. Applicable. Therefore, in the one-way injection process in such a case, fuel is injected from the first injection valve 17, while fuel is not injected from the second injection valve 18 (steps S82 and S83). On the other hand, when the old fuel still remains in the second supply path 24 (step S81: NO), the second supply path 24 corresponds to the specific supply path, and the second injection valve 18 Corresponds to the injection valve. Therefore, in such a one-side injection process, fuel is injected from the second injection valve 18 while fuel is not injected from the first injection valve 17 (steps S84 and S85). That is, even in the idling operation where only port injection is originally performed, only in-cylinder injection may be performed without performing port injection (see FIG. 2). It should be noted that during the period in which the one-way injection process is performed in this way, the diagnosis process and the learning process that involve both the port injection and the in-cylinder injection are not performed.

  Eventually, when the old fuel is exhausted from the specific supply path for supplying fuel to the injection valve (specific injection valve) that is injecting fuel by performing the one-side injection process, the fuel in the first supply path 23 is discharged. The alcohol concentration does not deviate from the alcohol concentration of the fuel in the second supply path 24 (step S51: NO). Therefore, the one-side injection process is finished and the normal injection process is executed (step S53). That is, the prohibition of fuel injection from the non-specific injection valve is canceled.

  In addition, when the operation of the engine 11 is not idle operation or the vehicle starts to travel during the one-way injection process (step S54: NO), the one-way injection process is finished and the normal injection is performed. Processing is performed (step S53).

As mentioned above, according to the said structure and effect | action, the effect shown below can be acquired.
(1) When the alcohol concentration of the fuel injected from the first injection valve 17 deviates from the alcohol concentration of the fuel injected from the second injection valve 18, the one-side injection processing is performed. During the one-way injection process, fuel is injected from one of the first injection valve 17 and the second injection valve 18 while fuel is injected from the other injection valve. Since the fuel is not injected, an event in which fuels having different alcohol concentrations are supplied from separate injection valves in one cylinder 12 does not occur. Therefore, the combustion of the air-fuel mixture in the cylinder 12 due to the difference between the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18. The deterioration of characteristics can be suppressed.

  (2) The execution condition of the one-way injection process includes that the engine 11 is idling. Therefore, during the idling operation of the engine 11, the deterioration of the combustion characteristics of the air-fuel mixture in the cylinder 12 is suppressed by performing the one-side injection process. Can be suppressed. On the other hand, when the engine 11 is not idling, the one-way injection process is not performed because the operating state of the engine 11 is not easily destabilized due to the deterioration of the combustion characteristics of the air-fuel mixture. Therefore, unnecessary implementation of the one-side injection process can be suppressed.

  (3) Moreover, the implementation conditions of the one-way injection process include that the vehicle is stopped. For this reason, the one-side injection process is performed when the vehicle is stopped, particularly when the occupant tends to feel uncomfortable with the noise and vibration generated in the engine 11 due to the deterioration of the combustion characteristics of the air-fuel mixture. Deterioration can be suppressed. By performing the one-way injection process while the vehicle is stopped in this manner, it is possible to make it difficult for the passenger to feel uncomfortable. On the other hand, the one-sided injection process is not performed when the vehicle 11 travels when it is difficult for the occupant to feel uncomfortable even if noise or vibration due to the deterioration of the combustion characteristics of the air-fuel mixture occurs in the engine 11. Therefore, unnecessary implementation of the one-side injection process can be suppressed.

  (4) Further, in the control device 100 of the present embodiment, on the condition that the new fuel has reached the downstream end 22A of the common path 22, the alcohol concentration of the fuel in the first supply path 23 and the second It is determined whether the alcohol concentration of the fuel in the supply path 24 is deviated. That is, fuel (new fuel) having a different alcohol concentration from the fuel (old fuel) that has been stored in the fuel supply system 20 from before flows into the common path 22 from the fuel tank 21, and the first supply path When there is a possibility that the alcohol concentration of the fuel in 23 and the alcohol concentration of the fuel in the second supply path 24 are different from each other, the one-side injection process can be performed. On the other hand, when it is not detected that a fuel (new fuel) having a different alcohol concentration from the fuel (old fuel) stored in the fuel supply system 20 from before has flowed into the common path 22, Since the alcohol concentration of the fuel injected from the first injection valve 17 does not deviate from the alcohol concentration of the fuel injected from the second injection valve 18, the one-side injection process is not performed. Therefore, unnecessary implementation of the one-side injection process can be suppressed.

  (5) In the one-way injection process, fuel is injected only from a specific injection valve that injects fuel in a specific supply path in which old fuel still remains. Therefore, the old fuel can be eliminated from the specific supply path, and a situation where the specific supply path is filled with the new fuel can be created early. That is, it becomes possible to end the one-side injection process at an early stage. As a result, fuel injection control using both the first injection valve 17 and the second injection valve 18 can be performed early. That is, the various learning processes and diagnosis processes described above can be performed at an early stage.

  (6) In the control device 100 of the present embodiment, even if refueling is performed, the alcohol concentration of fuel in the fuel tank 21 is the alcohol concentration of fuel stored in the fuel supply system 20 before refueling. When they are almost equal, the one-side injection process is not performed. Therefore, unnecessary implementation of the one-side injection process can be suppressed.

  (7) When the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are different from each other, the exhaust passage 14 is changed along with the change in the injection ratio. The air-fuel ratio of the flowing exhaust gas may change. Therefore, whether or not the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are deviated is determined by the exhaust gas when the injection ratio is changed. This can also be done by monitoring the air-fuel ratio. However, in this case, the mixing in the cylinder 12 is performed until it can be determined that the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are different. Qi combustion characteristics will deteriorate. On the other hand, in this embodiment, the amount of fuel in the first supply path 23 is determined based on the remaining amount of old fuel in the first supply path 23 and the remaining amount of old fuel in the second supply path 24. It is determined whether or not the alcohol concentration deviates from the alcohol concentration of the fuel in the second supply path 24. Therefore, without causing deterioration of the combustion characteristics of the air-fuel mixture in the cylinder 12 due to the difference between the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24, This determination can be performed.

(Second Embodiment)
Next, a second embodiment of the engine control device will be described with reference to FIGS. In the control device of the present embodiment, the definition of the new fuel and the old fuel, and whether the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are different from each other. The conditions for making such a determination are different from those of the first embodiment. Therefore, in the following description, parts different from those of the first embodiment will be mainly described, and the same or corresponding member configurations as those of the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. Shall.

  As shown in FIG. 16, the engine 11 including the control device 100 of the present embodiment is provided with a storage amount detection sensor 115 that detects the fuel storage amount in the fuel tank 21. For this reason, the control device 100 monitors the fuel storage amount detected by the storage amount detection sensor 115, whereby the alcohol concentration of the fuel stored in the fuel supply system 20 and the alcohol concentration of the fuel in the fuel tank 21 are measured. Can be determined to be deviated. Therefore, in the present embodiment, when the amount of fuel stored in the fuel tank 21 increases, the fuel stored in the fuel supply system 20 before the amount of fuel stored in the fuel tank 21 increases becomes “old The fuel in the fuel tank 21 is referred to as “new fuel”.

  However, in this case, after an increase in the amount of fuel stored in the fuel tank 21 is detected, that is, the alcohol concentration of the fuel stored in the fuel supply system 20 and the alcohol concentration of the fuel in the fuel tank 21 are Even after it is determined that there is a possibility of a divergence, the first supply path until the old fuel disappears from the common path 22 and the common path 22 is filled with the new fuel. No new fuel is allowed to flow into the second supply path 24 or the second supply path 24. Therefore, in the control device 100 of the present embodiment, since it can be determined that refueling has been performed when an increase in the amount of fuel stored in the fuel tank 21 is detected, it is determined whether or not old fuel remains in the common path 22. Is done. When it is determined that no old fuel remains in the common path 22, the estimated value Y1 of the old fuel remaining amount in the first supply path 23 is calculated, and the old fuel in the second supply path 24 is calculated. The estimated value Y2 of the remaining amount of fuel is calculated.

  That is, as illustrated in FIG. 16, the control device 100 includes an injection control unit 201, a first calculation unit 203, a second calculation unit 204, and properties as functional units configured by at least one of software and hardware. In addition to the determination unit 205, an oil supply determination unit 207 and a common determination unit 206 are provided.

  The fuel supply determination unit 207 determines that the fuel supply is performed when the fuel storage amount in the fuel tank 21 increases based on the detection result by the storage amount detection sensor 115. Specifically, the fuel supply determination unit 207 has a difference between the fuel storage amount when the operation of the engine 11 is stopped and the fuel storage amount when the operation of the engine 11 is subsequently started larger than the determination difference. Sometimes, it is determined that refueling has been performed. If the fuel supply determination unit 207 determines that the fuel supply has been performed, the fuel supply determination unit 207 outputs the fact to the common determination unit 206.

  The common determination unit 206 is based on the volume of the common path 22 and the total amount of fuel injection from each of the injection valves 17 and 18 after the fact that the refueling is performed from the fuel supply determination unit 207 is input. It is determined whether or not old fuel remains in the interior. When the common determination unit 206 determines that no old fuel remains in the common path 22, the common determination unit 206 outputs the fact to the first calculation unit 203 and the second calculation unit 204.

  When the fact that no old fuel remains in the common path 22 is input from the common determination unit 206, the first calculation unit 203 calculates the estimated value Y1 of the remaining amount of old fuel in the first supply path 23. To start. In this case, the first calculation unit 203 acquires the total amount of fuel injection of the first injection valve 17 after the time when it is input that no old fuel remains in the common path 22. Then, the first calculation unit 203 subtracts the total amount of fuel injection of the first injection valve 17 from the first old fuel full tank value, and uses the difference as the remaining amount of old fuel in the first supply path 23. The estimated value Y1.

  When the fact that no old fuel remains in the common path 22 is input from the common determination unit 206, the second calculation unit 204 calculates an estimated value Y2 of the remaining amount of old fuel in the second supply path 24. To start. In this case, the second calculation unit 204 acquires the total amount of fuel injection of the second injection valve 18 after the time when it is input that no old fuel remains in the common path 22. Then, the second calculation unit 204 subtracts the total fuel injection amount of the second injection valve 18 from the second old fuel full tank value, and uses the difference as the remaining amount of old fuel in the second supply path 24. Is an estimated value Y2.

  Next, a processing routine executed by the common determination unit 206 of the control device 100 in order to determine that old fuel does not remain in the common path 22 will be described with reference to the flowchart shown in FIG.

  As shown in FIG. 17, the common determination unit 206 calculates the total amount Z3 of fuel injection from each of the injection valves 17 and 18 after it is determined that the fuel supply determination unit 207 has supplied fuel (step S61). The common determination unit 206 calculates an estimated value Y3 of the remaining amount of old fuel in the common path 22 (step S62). That is, the volume of the common path 22 is a value that can be grasped in advance. Therefore, when the common path 22 is filled with old fuel, the amount of old fuel in the common path 22 can also be grasped. If the remaining amount of the old fuel in the common path 22 when the common path 22 is filled with the old fuel is set to the “common old fuel full tank value Y3MAX”, the common determination unit 206 sets the common old fuel full level. The total amount Z3 calculated in step S61 is subtracted from the tongue value Y3MAX, and the difference is set as an estimated value Y3 of the remaining amount of old fuel in the common path 22.

  Subsequently, the common determination unit 206 determines whether or not the calculated estimated value Y3 of the remaining amount of old fuel is equal to or less than “0 (zero)” (step S63). When the estimated value Y3 of the remaining amount is “0 (zero)” or less, it can be determined that the old fuel does not remain in the common path 22. Therefore, when the estimated value Y3 of the remaining amount is “0 (zero)” or less (step S63: YES), the common determination unit 206 determines that no old fuel remains in the common path 22 (step S64). This processing routine ends. On the other hand, when the estimated value Y3 of the remaining amount is larger than “0 (zero)” (step S63: NO), the common determination unit 206 ends this processing routine without executing the process of step S64.

Next, the operation of the engine 11 including the control device 100 of the present embodiment will be described.
Even if the amount of fuel stored in the fuel tank 21 increases due to refueling, immediately after that, the old fuel is still in both the common path 22, the first supply path 23, and the second supply path 24. Remaining. Therefore, the normal injection process is performed for a while even after refueling. In this case, regardless of which one of the first injection valve 17 and the second injection valve 18 is driven, old fuel is injected from the injection valve. As described above, when old fuel is injected from at least one of the injection valves 17 and 18, new fuel flows from the fuel tank 21 into the common path 22.

  Thereafter, when the old fuel disappears from the common path 22 by the fuel injection of at least one of the injection valves 17 and 18 (step S64) and the common path 22 is filled with the new fuel, the fuel is injected from the first injection valve 17. As a result, the new fuel flows into the first supply path 23. In addition, fuel injection from the second injection valve 18 causes new fuel to flow into the second supply path 24.

  When the old fuel in the first supply path 23 runs out before the old fuel in the second supply path 24, the first fuel is used until the old fuel in the second supply path 24 runs out. There is a possibility that the alcohol concentration of the fuel injected from the injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18 are different. On the other hand, even if the old fuel in the second supply path 24 disappears before the old fuel in the first supply path 23, the first fuel in the first supply path 23 runs out until the old fuel is exhausted. There is a possibility that the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18 are different.

  Even under such circumstances, when the engine 11 is not idling or the vehicle is not stopped, the normal injection process is performed instead of the one-way injection process. However, the engine 11 is idle in a situation where the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18 may deviate. When both driving and the vehicle is stopped, one-side injection processing is performed. In the one-side injection processing that is performed when old fuel still remains in the first supply path 23, the first supply path 23 corresponds to a specific supply path, and the first injection valve 17 is a specific injection. Since it corresponds to a valve, fuel is injected from the first injection valve 17 while fuel injection from the second injection valve 18 is prohibited. On the other hand, in the one-way injection processing that is performed when old fuel still remains in the second supply path 24, the second supply path 24 corresponds to a specific supply path, and the second injection valve 18 is Since it corresponds to a specific injection valve, while the fuel is injected from the second injection valve 18, the fuel injection from the first injection valve 17 is prohibited.

  When the old fuel disappears from the specific supply path for supplying fuel to the injection valve (specific injection valve) that is injecting fuel by performing the one-side injection process, the alcohol of the fuel in the first supply path 23 There is no possibility that the concentration differs from the alcohol concentration of the fuel in the second supply path 24. For this reason, the execution of the one-side injection process is ended, and the normal injection process is performed. That is, the prohibition of fuel injection from the non-specific injection valve is canceled.

As mentioned above, according to the said structure and effect | action, in addition to the effect equivalent to the effect (2), (3), (5) and (7) of the said embodiment, the effect shown below can further be acquired.
(8) When the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18 may deviate, the one-side injection processing is performed. Is done. During the one-way injection process, fuel is injected from one of the first injection valve 17 and the second injection valve 18 while fuel is injected from the other injection valve. Since the fuel is not injected, an event in which fuels having different alcohol concentrations are supplied from separate injection valves in one cylinder 12 does not occur. Therefore, the combustion of the air-fuel mixture in the cylinder 12 due to the difference between the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18. The deterioration of characteristics can be suppressed.

  (9) In the control device 100 of the present embodiment, it is determined that refueling has been performed when the amount of fuel stored in the fuel tank 21 is increased. After determining that refueling has been performed in this way, after determining that the old fuel has disappeared from the common path 22, the alcohol concentration of the fuel in the first supply path 23 and the second supply are determined. It is determined whether or not there is a possibility that the alcohol concentration of the fuel in the path 24 is deviated. On the other hand, when an increase in the amount of fuel stored in the fuel tank 21 is not detected, it is not determined that refueling has been performed. When the fuel supply is not performed in this way, there is no possibility that the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 will deviate. Not implemented. Therefore, unnecessary implementation of the one-side injection process can be suppressed.

In addition, you may change each said embodiment into another embodiment as follows.
In each of the above embodiments, the remaining amount of the old fuel in the first supply path 23 and the remaining amount of the old fuel in the second supply path 24 are estimated and calculated, and the old fuel in the supply path is calculated based on the estimation result. Whether or not remains is determined. However, instead of using the remaining amount of old fuel in the supply path, the inflow amount of new fuel into the supply path is estimated, and it is determined whether or not old fuel remains in the supply path based on this estimation result. You may do it.

  That is, when the estimated value of the amount of new fuel flowing into the first supply path 23 is calculated, the total amount of fuel injection from each first injection valve 17 after the old fuel disappears from the common path 22. Z1 is an estimated value of the amount of new fuel flowing into the first supply path 23. When the estimated value of the new fuel inflow amount is equal to or greater than the first old fuel full value Y1MAX, it can be determined that no old fuel remains in the first supply path 23.

  Similarly, when the estimated value of the inflow amount of new fuel into the second supply path 24 is calculated, the fuel injection from each second injection valve 18 after the old fuel disappears from the common path 22 is calculated. The total amount Z2 is an estimated value of the amount of new fuel flowing into the second supply path 24. When the estimated value of the inflow amount of the new fuel is equal to or greater than the second old fuel full value Y2MAX, it can be determined that no old fuel remains in the second supply path 24.

  Further, in the second embodiment, the total amount Z3 of fuel injection from each of the injectors 17 and 18 after it is determined that refueling has been performed is the estimated value of the inflow amount of new fuel into the common path 22. Become. When the estimated value of the new fuel inflow is equal to or greater than the common old fuel full value Y3MAX, it can be determined that no old fuel remains in the common path 22.

  In each of the above embodiments, the remaining amount of the old fuel in the first supply path 23 and the remaining amount of the old fuel in the second supply path 24 are estimated and calculated, and the first supply path 23 is based on the estimation result. It is determined whether or not the alcohol concentration of the fuel in the fuel and the alcohol concentration of the fuel in the second supply path 24 are different. However, such a determination may be performed by a method different from the method using the estimated values Y1 and Y2 of the remaining amount of the old fuel in each supply path.

  For example, in a situation where the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18 are not deviated, the detection result from the air-fuel ratio sensor 113 is detected. The air-fuel ratio calculated on the basis of the above is almost the same as the theoretical value, that is, the required value of the air-fuel ratio, regardless of the above-mentioned injection ratio. However, if the alcohol concentration of the fuel injected from the first injection valve 17 and the alcohol concentration of the fuel injected from the second injection valve 18 deviate, as shown in FIG. The air / fuel ratio changes.

  That is, it is assumed that the alcohol concentration of the fuel injected from the first injection valve 17 is lower than the alcohol concentration of the fuel injected from the second injection valve 18. In this case, when the injection ratio increases and the fuel injection amount from the first injection valve 17 increases, the air-fuel ratio changes to the rich side. On the other hand, when the injection ratio is reduced and the fuel injection amount from the first injection valve 17 is reduced, the air-fuel ratio changes to the lean side.

  Therefore, when the change in the air-fuel ratio is detected in accordance with the change in the injection ratio, the alcohol concentration of the fuel injected from the first injection valve 17 and the second injection valve 18 are injected. It may be determined that the alcohol concentration of the fuel deviates. Thus, the determination method using the air-fuel ratio can also be adopted in a control device applied to an engine that does not include the property detection sensor 114 and the storage amount detection sensor 115.

  FIG. 19 shows whether the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 differ due to the change in the air-fuel ratio AF accompanying the change in the injection ratio. An example of a processing routine executed by the property determination unit 205 to determine whether or not will be described.

  As illustrated in FIG. 19, the property determination unit 205 determines whether or not the ejection ratio has changed (step S91). If the spray distribution rate has not changed (step S91: NO), the property determination unit 205 ends this processing routine. On the other hand, when the injection ratio changes (step S91: YES), the property determination unit 205 determines the difference between the air-fuel ratio AF of the exhaust estimated based on the detection result of the air-fuel ratio sensor 113 and the required value AFR of the air-fuel ratio ( = | AF-AFR |) is determined, and it is determined whether or not the difference is greater than or equal to a determination value DAF (step S92). This determination value DAF is a value set for determining whether or not the air-fuel ratio AF has changed due to the change in the injection ratio. When the difference is less than the determination value DAF (step S92: NO), the property determination unit 205 determines that the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24 are the same. It is determined that there is no divergence (step S93), and this processing routine ends. On the other hand, when the difference is equal to or larger than the determination value DAF (step S92: YES), the property determination unit 205 determines the alcohol concentration of the fuel in the first supply path 23 and the alcohol concentration of the fuel in the second supply path 24. Are determined to be different from each other (step S94), and this processing routine is terminated.

  In the first embodiment, if the property detection sensor 114 can detect the alcohol concentration of the fuel in the common path 22, the detection position by the property detection sensor 114 is set upstream of the downstream end 22A. Also good.

  In the second embodiment, the property detection sensor 114 may be disposed in the fuel tank 21 instead of the storage amount detection sensor 115. In this case, when a change in the alcohol concentration of the fuel stored in the fuel tank 21 is detected, the alcohol concentration of the fuel stored in the fuel supply system 20 and the alcohol concentration of the fuel in the fuel tank 21 are determined. Can be determined to be deviated. When this is input to the common determination unit 206, the remaining amount of old fuel or the inflow amount of new fuel in the common path 22 is calculated. In this configuration, even if refueling is performed, when the alcohol concentration of the fuel in the fuel tank 21 hardly changes, the alcohol concentration of the fuel stored in the fuel supply system 20 and the alcohol concentration of the fuel in the fuel tank 21 are the same. Are not determined to be deviated from each other.

  -In 2nd Embodiment, when the operation part which the passenger | crew of a vehicle operates when refueling is provided in the vehicle, it determines with refueling having been performed when operation of the operation part was detected. You may do it.

  When the vehicle is a hybrid vehicle having a power source other than the engine 11, the one-side injection process may be performed even while the vehicle is running as long as the engine 11 is performing idle operation.

  The one-side injection process may be performed even when the engine 11 is not performing idle operation or while the vehicle is traveling. However, as described with reference to FIG. 2, when the operation region of the engine 11 is a region of high rotation and high load operation, one of the first injection valve 17 and the second injection valve 18. If the fuel injection from the engine is prohibited, the fuel supplied into the cylinder 12 may not satisfy the required amount. For this reason, when the engine 11 is operating in the region of the high rotation and high load operation, it is necessary to prohibit the one-way injection process.

  When the one-side injection process is performed even when the engine 11 is not in idle operation, an injection valve that performs fuel injection may be determined according to the operating state of the engine 11. For example, in the one-side injection process in a situation where the engine 11 is operated in an operation region where only port injection is performed, fuel is injected from the first injection valve 17 and fuel injection from the second injection valve 18 is performed. You may make it prohibit. Further, in the one-way injection process in a state where the engine 11 is operated in an operation region where only in-cylinder injection is performed, fuel is injected from the second injection valve 18 and fuel injection from the first injection valve 17 is performed. May be prohibited.

  Further, in the one-side injection processing in a situation where the engine 11 is operated in the operation region in which both port injection and in-cylinder injection are performed, an injection valve that performs fuel injection is determined based on the injection distribution ratio at that time. You may make it do. For example, when the injection division ratio is “0.5” or more, fuel may be injected from the first injection valve 17 and fuel injection from the second injection valve 18 may be prohibited. On the other hand, when the injection ratio is less than “0.5”, fuel may be injected from the second injection valve 18 and fuel injection from the first injection valve 17 may be prohibited.

  In the one-side injection process, fuel is injected from an injection valve to which fuel is supplied from the supply path in which the old fuel has not already left out of the first supply path 23 and the second supply path 24, and the old fuel still remains The fuel injection of the injection valve to which fuel is supplied from the supply path may be prohibited.

  In each of the above embodiments, the engine control device is applied to the engine 11 in which the injection valve that injects fuel into the intake passage 13 and the injection valve that directly injects fuel into the cylinder 12 are provided for each cylinder 12. An example was explained. However, the engine control device may be applied to other engines as long as the engine includes a plurality of injection valves capable of supplying fuel into one cylinder 12.

  For example, an engine control device may be applied to the engine 11A shown in FIG. That is, as shown in FIG. 20, the engine 11 </ b> A includes a second injection valve 18 that directly injects fuel into the cylinder 12 and a first injection valve 17 </ b> A that supplies fuel into the intake passage 13. . While the second injection valve 18 is provided for each cylinder 12, only one first injection valve 17A is provided. The first injection valve 17 </ b> A is arranged on the throttle valve 15 side of the intake passage 13 with respect to the branch point to each cylinder 12. Therefore, the fuel injected from the first injection valve 17 </ b> A is supplied into each cylinder 12 through the intake passage 13.

  The fuel supply system 20 of the engine 11A includes a second supply path 24 and a first supply path 23A that are connected to the downstream end 22A of the common path 22. The fuel supplied from the first supply path 23A is injected into the intake passage 13 by the first injection valve 17A.

  Even in such a configuration, when the alcohol concentration of the fuel in the second supply path 24 and the alcohol concentration of the fuel in the first supply path 23A are different from each other, fuels having different alcohol concentrations are separately injected. Therefore, the combustion characteristics of the air-fuel mixture may be deteriorated. For this reason, when the alcohol concentration of the fuel in the second supply path 24 and the alcohol concentration of the fuel in the first supply path 23A are deviated or possibly deviated, the one-side injection process is performed. By implementing the above, it is possible to suppress the deterioration of the combustion characteristics of the air-fuel mixture in the cylinder 12.

  In each of the above embodiments, an engine control device applied to the engine 11 that can use alcohol-mixed fuel is described. However, some engines cannot use alcohol-mixed fuel. In a control device applied to such an engine, it may be possible to detect or estimate whether the fuel is heavy or light and to perform one-way injection processing as necessary. That is, when the fuel used in the engine is gasoline, heavy fuel or light fuel may be selected on the fuel supply facility side depending on the season. Therefore, in a state where one of the heavy fuel and the light fuel is stored in the fuel supply system 20, the other fuel may be newly supplied into the fuel tank 21. In this case, since the properties of the old fuel and the new fuel are different, one of the old fuel and the new fuel is injected from the first injector 17 and the other fuel is the second injector. When injected from 18, the combustion characteristics of the air-fuel mixture in the cylinder 12 change. Therefore, it can be determined that the fuel in one of the first supply path 23 and the second supply path 24 is heavy fuel, and the fuel in the other supply path is light fuel. Sometimes, one-side injection processing may be performed.

  ・ If the engine has the possibility of changing the combustion characteristics of the air-fuel mixture in the cylinder 12 by injecting fuel with different properties from separate injection valves, use fuel other than gasoline or alcohol mixed fuel. The engine control device described above may be applied to the engine to be operated.

  DESCRIPTION OF SYMBOLS 11, 11A ... Engine, 12 ... Cylinder, 13 ... Intake passage, 14 ... Exhaust passage, 17, 17A ... First injection valve, 18 ... Second injection valve, 20 ... Fuel supply system, 21 ... Fuel tank, 22 ... Common path, 22A ... Downstream end of common path, 23, 23A ... First supply path, 24 ... Second supply path, 100 ... Control device, 114 ... Property detection sensor, 201 ... Injection control unit, 203 ... First 1 calculation unit, 204... Second calculation unit, 205... Property determination unit.

Claims (12)

Applied to an engine capable of supplying fuel from both the first injection valve and the second injection valve into one cylinder;
A fuel supply system of the engine includes a first supply path for supplying fuel in a fuel tank to the first injection valve and a second supply path for supplying fuel in the fuel tank to the second injection valve. Have
In an engine control apparatus that controls fuel injection from the first injection valve and fuel injection from the second injection valve according to an operating state of the engine,
A property determining unit that determines whether or not the property of the fuel in the first supply path is deviated from the property of the fuel in the second supply path;
When the property determining unit determines that the property of the fuel in the first supply path is deviated from the property of the fuel in the second supply path, the first injection valve and the An engine control unit that performs a one-side injection process of injecting fuel from one of the second injection valves and prohibiting fuel injection from the other injection valve. apparatus. In the injection control unit, the property determination unit causes a difference between the property of the fuel in the first supply path and the property of the fuel in the second supply path in a situation where the engine is idling. The engine control device according to claim 1, wherein when it is determined that the one-way injection is performed, the one-side injection processing is performed. In the state where the vehicle is stopped, the injection control unit causes the property determination unit to deviate between the property of the fuel in the first supply path and the property of the fuel in the second supply path. The engine control device according to claim 1 or 2, wherein the one-side injection processing is performed when it is determined that the engine is present. When the properties of the fuel in the fuel tank have changed and the properties of the fuel in the fuel tank and the properties of the fuel stored in the fuel supply system have become different, the fuel in the fuel tank The fuel that has been stored in the fuel supply system before the change in the properties of the fuel is the old fuel, the fuel in the fuel tank is the new fuel,
Among the first supply path and the second supply path, a supply path in which old fuel remains is a specific supply path,
Of the first injection valve and the second injection valve, when the injection valve that injects fuel in the specific supply path is a specific injection valve,
In the one-side injection process, the injection control unit injects fuel from the specific injection valve, and from other injection valves other than the specific injection valve among the first injection valve and the second injection valve. The engine control device according to any one of claims 1 to 3, wherein fuel injection is prohibited. The fuel supply system has a common path connected to the fuel tank;
The upstream ends of both the first supply path and the second supply path are connected to the downstream end of the common path,
The common path is provided with a detection sensor for detecting the property of the fuel,
The property determination unit divides the property of the fuel in the first supply path from the property of the fuel in the second supply path on condition that the property of the fuel detected by the detection sensor has changed. The engine control apparatus according to claim 4, wherein it is determined whether or not the engine is operating. An estimated value of the remaining amount of old fuel in the first supply path based on the volume of the first supply path and the fuel injection amount from the first injection valve, or the first supply path A first calculation unit for calculating an estimated value of the amount of new fuel flowing into the interior;
An estimated value of the remaining amount of old fuel in the second supply path based on the volume of the second supply path and the fuel injection amount from the second injection valve, or the second supply path A second calculation unit that calculates an estimated value of the amount of new fuel flowing into the interior,
The property determination unit is configured to determine the property of the fuel in the first supply path and the fuel in the second supply path based on the calculation result by the first calculation unit and the calculation result by the second calculation unit. The engine control apparatus according to claim 4 or 5, wherein it is determined whether or not the property deviates. When the amount of fuel stored in the fuel tank increases, the fuel stored in the fuel supply system before the amount of fuel stored in the fuel tank increases is used as the old fuel. Fuel as new fuel,
Among the first supply path and the second supply path, a supply path in which old fuel remains is a specific supply path,
Of the first injection valve and the second injection valve, when the injection valve that injects fuel in the specific supply path is a specific injection valve,
In the one-side injection process, the injection control unit injects fuel from the specific injection valve, and from other injection valves other than the specific injection valve among the first injection valve and the second injection valve. The engine control device according to any one of claims 1 to 3, wherein fuel injection is prohibited. The property determining unit may diverge between the property of the fuel in the first supply path and the property of the fuel in the second supply path on the condition that the amount of fuel stored in the fuel tank has increased. The engine control apparatus according to claim 7, wherein a determination is made as to whether or not the engine is operating. An estimated value of the remaining amount of old fuel in the first supply path based on the volume of the first supply path and the fuel injection amount from the first injection valve, or the first supply path A first calculation unit for calculating an estimated value of the amount of new fuel flowing into the interior;
An estimated value of the remaining amount of old fuel in the second supply path based on the volume of the second supply path and the fuel injection amount from the second injection valve, or the second supply path A second calculation unit that calculates an estimated value of the amount of new fuel flowing into the interior,
The property determination unit is configured to determine the property of the fuel in the first supply path and the fuel in the second supply path based on the calculation result by the first calculation unit and the calculation result by the second calculation unit. The engine control device according to claim 7 or 8, wherein it is determined whether or not the property deviates. The value obtained by dividing the fuel injection amount from the first injection valve by the sum of the fuel injection amount from the first injection valve and the fuel injection amount from the second injection valve is used as the injection ratio. ,
The property determination unit is configured to change the property of the fuel in the first supply path and the second supply path when the air-fuel ratio of the exhaust gas flowing through the exhaust passage of the engine changes due to the change in the injection ratio. The engine control apparatus according to any one of claims 1 to 3, wherein it is determined that the fuel property is deviated. The fuel is a fuel containing alcohol,
The said property determination part determines whether the alcohol concentration of the fuel in the said 1st supply path | route differs from the alcohol concentration of the fuel in the said 2nd supply path | route. The engine control device according to any one of the above. The first injection valve is a valve that injects fuel into an intake passage, and the second injection valve is a valve that injects fuel into a cylinder. The engine control device according to Item.