Combustion engine control device and combustion engine control method

Abstract

This internal combustion engine control device includes a fuel injection control scheduling unit and a pressure value detection unit. The pressure value detection unit detects a first fuel pressure value, a second fuel pressure value, and a calculated fuel pressure value. The first fuel pressure value is detected during a first period from a time when the fuel pump increases the pressure until the fuel injection valve first injects fuel after the pressure increase time. The second fuel pressure value is detected during a second period that occurs after the first period and extends until the pressure increase time. The calculated fuel pressure value is calculated based on the first and second fuel pressure values.Then, the fuel injection control planning unit selects at least one of the first fuel pressure value, the second fuel pressure value, and the calculated fuel pressure value, and corrects the control amount of the fuel injection valve according to the selected pressure value.

Description

Technical FieldThis invention relates to an engine control apparatus and an engine control method.Background ArtThere is known an accumulator (common rail) fuel injection control device that supplies fuel to a plurality of cylinders of a vehicle engine. In this device, fuel pressurized using a high-pressure fuel pump or the like is accumulated in a fuel supply pipe and injected through a fuel injection valve installed in the fuel pipe. In addition, an engine control device controls the pressure of fuel accumulated in the fuel line and the amount of fuel injected by the injection valve to desired values according to the operating state of the engine. It is known in this case that, for example, pressure values sensed by a pressure sensor at a predetermined interval are used for the control.In the above-mentioned accumulator fuel injection control, the fuel pressure in the fuel line fluctuates from moment to moment due to the supply (discharge) from the high-pressure fuel pump to the fuel line and the fuel injection from the fuel injection valve. In particular, in distributed high-speed injection, which is common today in many internal combustion engines, there is a concern about increased fluctuations in fuel pressure. On the other hand, the above-described method of sensing the pressure may not be able to detect these fluctuations one by one, and there is a concern that the amount of fuel injected may be directly influenced by fluctuations in the fuel pressure. This allows the air-fuel mixture supplied to the engine to be changed, resulting in deterioration of emissions and fuel economy.In order to address these problems, for example, a technology described in Patent Literature 1 has been disclosed. Patent Literature 1 describes calculating the change in fuel pressure during fuel injection and correcting the fuel injection pulse width based on the amount of change in fuel pressure and fuel pressure at the start of injection.Citation ListPatent LiteraturePatent Literature 1: Japanese Unexamined Patent Application Publication No. 2008-38857Summary of the InventionTechnical ProblemHowever, in the technology described in Patent Literature 1, in order to determine a change in fuel pressure (variations in fuel pressure) during fuel injection, it is necessary to perform sequential calculations using the discharge rate of the fuel pump and the injection amount of the fuel injection valve based on the fuel pressure measured by the pressure sensor at the start of fuel injection. Therefore, in the technology described in Patent Literature 1, there arises a problem of an increased computational load and an increased number of computations. The technology described in Patent Literature 1 is undesirable from an implementation viewpoint, particularly when distributed high-speed injections are performed.In view of the above-described problems, an object of the present invention is to provide an engine control apparatus and an engine control method whereby variations in the injection amount due to fluctuations in the fuel pressure, which lead to deterioration of exhaust emissions and fuel economy of engines, can be prevented without increasing the computational load.Solution of the ProblemIn order to solve the above problem, configurations described in the claims are used, for example.This application has several means for solving the above problem. In one example, an engine control device according to the present invention is for controlling an engine, the engine control device including: a reciprocating fuel pump that intermittently increases the pressure of fuel and discharges the fuel whose pressure is intermittently increased into a fuel line; and a fuel injection valve for injecting the fuel whose pressure is intermittently increased. Further, the engine control device includes a fuel injection control planning unit that plans control contents related to opening or closing of the fuel injection valve according to an operation state of the engine, and a pressure value acquisition unit that acquires a pressure value from a pressure sensor provided in the engine.The pressure value acquisition unit acquires a first fuel pressure value, a second fuel pressure value, and a calculated fuel pressure value. The first fuel pressure value is detected during a first period from a time when the fuel pump increases the pressure until fuel is first injected by the fuel injection valve after the pressure increase time. The second fuel pressure value is detected during a second period that occurs after the first period and reaches the pressure increase time point. The calculated fuel pressure value is calculated based on the first and second fuel pressure values. Then, the fuel injection control planning unit selects at least one of the first fuel pressure value, the second fuel pressure value, and the calculated fuel pressure value, and corrects the control amount of the fuel injection valve according to the selected pressure value.Further, an engine control method according to the present invention for controlling the engine including a reciprocating fuel pump that intermittently increases the pressure of fuel and discharges the fuel whose pressure is intermittently increased into a fuel line, and a fuel injection valve for injecting the fuel whose pressure is intermittently increased includes the following processes (1) to (4).(1) A process for detecting a first pressure value of fuel during a first period ranging from a time when the fuel pump increases the pressure to injecting fuel by the fuel injection valve for the first time after the pressure increase time.(2) A process for detecting a second fuel pressure value during a second period that occurs after the first period and reaches the pressure increase time point.(3) A process of calculating a fuel pressure value using the first and second fuel pressure values.(4) A process of selecting at least one of the first fuel pressure value, the second fuel pressure value, and the calculated fuel pressure value, and correcting the control amount of the fuel injection valve according to the selected pressure value.Advantageous Effects of the InventionIt is possible to prevent variations in the injection amount due to fluctuations in the fuel pressure causing deterioration in exhaust emissions and fuel economy of internal combustion engines without increasing the computational load.Objects, configurations, and effects other than those mentioned above will be understood from the description of the following embodiments.Brief Description of the DrawingsThe following are shown: FIG. 1 is a diagram showing the overall configuration of a fuel injection device controlled by an internal combustion engine device according to an embodiment, FIG. 2 is a timing chart showing an example of a conventional fuel injection control, FIG. 3 is a timing chart showing a first example of the fuel injection control process executed by the internal combustion engine control apparatus according to the embodiment, FIG. 4 is a timing chart showing the first example of the fuel injection control process executed by the internal combustion engine control apparatus according to the embodiment, FIG. 5 is a timing chart showing an example of a method for detecting a pressure value in the engine control device according to the embodiment; and FIG. 6 is a timing chart showing a second example of the fuel injection control process executed by the internal combustion engine control device according to the embodiment.DESCRIPTION OF EMBODIMENTSAn embodiment of an engine control apparatus and an engine control method will be described below with reference to FIGS. 1 to 6. Note that in the drawings, the same components are denoted by the same reference numerals.1. Embodiment1-1. Example of Configuration of Fuel InjectorFirst, an example of the configuration of a fuel injection device controlled by an engine control device according to an embodiment (hereinafter referred to as "this embodiment") will be described with reference to FIG. 1.FIG. 1 is a diagram of the overall configuration of the fuel injection device controlled by the internal combustion engine device.The internal combustion engine control device according to this embodiment controls a four-stroke engine in which four strokes of an intake stroke, a compression stroke, a combustion stroke (expansion stroke), and an exhaust stroke are repeated. This internal combustion engine is, for example, a four-cylinder multi-cylinder engine. Note that the number of cylinders of the internal combustion engine is not limited to four, and may include three or six or more cylinders.The internal combustion engine includes a fuel injection device 1 that injects fuel into the cylinders. As shown in FIG. 1, the fuel injection device 1 includes a feed pump 2, a high-pressure fuel pump 3, a common rail unit 4, an injector 10 representing a fuel injection valve, and an engine control device (ECU) 7. In addition, at the appropriate timings, the fuel injection device 1 injects fuel into each cylinder of an internal combustion engine 9 while supplying fuel thereto.The fuel injection device 1 also draws fuel from a fuel tank 50 via the feed pump 2, and the feed pump 2 and the high-pressure fuel pump 3 are connected by a low-pressure pipe 8. A plunger 13 is slidably received in the high pressure fuel pump 3. Further, the high pressure fuel pump 3 includes an outlet valve 11, a pressure chamber 12, and an inlet valve unit 30.The inlet valve unit 30 is connected to the low-pressure line 8 and draws in fuel via said line. The solenoid coil inlet valve unit 30 also communicates with the pressure chamber 12, and in addition, the common rail unit 4 is connected to the high pressure line 14.One end of the piston 13 is inserted into the pressure chamber 12 and increases or decreases the volume of the pressure chamber 12, and the other end of the piston 13 abuts a cam 5 attached to a shaft of the engine 9. In addition, the plunger 13 reciprocates inside the high-pressure fuel pump 3 when the cam 5 is rotationally driven. This reciprocation of the piston 13 causes the volume of the pressure chamber 12 to be increased and decreased.Here, the cam 5 is mounted on a shaft that drives an intake valve or exhaust valve (not shown) of the internal combustion engine 9. In addition, the shaft receives power via a variable valve mechanism 40. Therefore, if the variable valve mechanism 40 is driven, a phase difference occurs between the engine 9 and the high pressure fuel pump 3.Further, the high pressure line 14 is connected to the discharge valve 11 of the high pressure fuel pump 3. In addition, the common rail unit 4 is connected to the high pressure line 14. The common rail unit 4 forms a high-pressure fuel path that communicates with the outlet port of the high-pressure fuel pump 3. In addition, the common rail unit 4 is an accumulator for accumulating the fuel pumped by the high pressure fuel pump 3 and maintaining the fuel pressure at a predetermined value according to the operating state of the engine 9. The injectors 10 inject the fuel supplied via the common rail unit 4 into the cylinders of the internal combustion engine 9. Further, the injectors 10 are each provided with a solenoid coil linear actuator. In addition, the opening / closing of the valve of the injector 10 is controlled by the duration of energization of the solenoid coil.As described above, the plunger 13 inside the high-pressure fuel pump 3 is urged upward and downward by the cam 5. This causes the volume of the pressurizing chamber 12 to increase and decrease, whereby fuel is drawn in and pressurized to supply it to the discharge valve 11. When the pressure in the pressure chamber 12 becomes higher than the pressure in the high pressure pipe 14 and the common rail unit 4, the discharge valve 11 opens and pumps the fuel into the high pressure pipe 14 and the common rail unit 4.Here, the volume of the pressure chamber 12 increases as the piston 13 moves from the top to the bottom dead center. Thereby, the fuel supplied from the feed pump 2 is drawn into the pressurizing chamber 12. If the intake valve is open while the piston 13 moves from bottom to top dead center, the fuel in the pressurizing chamber 12 returns to the fuel tank 50 through the low pressure line 8.If the inlet valve is closed when the piston 13 moves from the bottom to the top dead center, the increase in the pressure of the fuel remaining in the pressurizing chamber 12 is initiated. Then, when the pressure exceeds the pressure in the common rail unit 4, the exhaust valve 11 opens and the fuel is pumped.1-2. Example of Configuration of Engine Control DeviceThe ECU 7 includes a CPU that performs calculations according to a predetermined program and controls each device, memory areas such as a RAM and a ROM that store programs, data, and calculation results, and an interface that inputs and outputs signals, and the like. The ECU 7 is connected to a pressure sensor 6, a crank angle sensor 15, an accelerator position sensor 16, and the like, and receives signals detected by each sensor.Here, the pressure sensor 6 detects the pressure in the common rail unit 4. The accelerator position sensor 16 detects the accelerator position.The ECU 7 detects the operation state of the engine 9 based on the detection signals of each sensor. The ECU 7 then controls the supply of electricity to the intake valve unit 30 provided on the intake side of the high-pressure fuel pump 3. Further, the ECU 7 controls the injection pulse width Ti(n) of the injector 10 of each cylinder and the amount of fuel supplied to the engine 9. Note that n indicates the cylinder number.The ECU 7 further includes a pressure value acquisition unit 64 and a fuel injection control planning unit 63 (see FIG. 4 ). The pressure value acquisition unit 64 acquires a first fuel pressure value (first pressure) 60 and a second fuel pressure value (second pressure) 61 described later on the basis of the detection value input from the pressure sensor 6. The pressure value acquisition unit 64 calculates a fuel pressure value (calculated pressure) 62 from the first fuel pressure value (first pressure) 60 and the second fuel pressure value (second pressure) 61. In addition, the fuel injection control planning unit 63 schedules control contents related to opening or closing the valve of the injector 10 according to the operating state of the internal combustion engine 9, and corrects the control amount of the injector 10. Further, the fuel injection control planning unit 63 corrects the control amount of the injector 10 in the manner of the injection pulse width Ti and the operation timing according to the selected pressure value.2. Example of Fuel Injection Control ProcedureNext, an example of the fuel injection control operation will be described with reference to FIGS. 2 to 4.2-1. Example of Conventional OperationFirst, an example of the conventional fuel injection control process will be described with reference to FIG. 2.FIG. 2 is a timing chart showing an example of control executed by the conventional injection control apparatus. Note that in the example shown in FIG. 2, three-stage (three times) injection is performed during the intake stroke of the combustion cycle of the internal combustion engine 9.As shown in FIG. 2, the common rail pressure shown below in the figure increases at a certain time due to the increase in pressure by the high-pressure fuel pump 3. Thereafter, when the injector 10 receives injection pulses, fuel is injected and the common rail pressure decreases as the number of injections increases. Then, the pressure again increases in the next cycle due to the increase in pressure by the high-pressure fuel pump 3. This repetition causes periodic fuel pressure fluctuations in the fuel cycle.It is noted that the timing of the pressure increase by the high-pressure fuel pump 3 changes independently of the combustion cycle mainly for the following two reasons. The first reason is that the timing of the increase in pressure depends on the timing of the energization of the intake valve unit 30. The second reason is that the high-pressure fuel pump 3 itself receives a driving force from the shaft via the variable valve mechanism 40, and the operation phase fluctuates.Then, in a conventional example of a control operation for the varying fuel pressure, a representative fuel pressure value (hereinafter referred to as representative pressure) is detected by the pressure sensor 6 provided in the fuel line. The representative pressure is calculated from, for example, pressure values sampled at a predetermined period or from their average value. Then, this representative pressure is used in the conventional ECU as the pressure in injection, and the injection pulse width Ti of the injector 10 is corrected to obtain the required injection amount.However, as shown in FIG. 2, the fuel pressure at the actual injection timing may deviate from the representative pressure. In this case, a deviation occurs between the actual injection amount and the required injection amount. This may change the air-fuel mixture supplied to the engine, resulting in degradation of emissions and fuel economy. In the example shown in FIG. 2, the first stage of the three-stage injection occurs at a fuel pressure exceeding the representative pressure, resulting in an excessively high injection amount, and the third stage occurs at a fuel pressure below the representative pressure, resulting in an insufficient injection amount.2-2. First Example of Operation According to This EmbodimentNext, a first example of an operation of the fuel injection control according to this embodiment will be described with reference to FIGS. 3 to 4.FIG. 3 is a timing chart showing the first example of an operation of the fuel injection control according to this embodiment.As shown in FIG. 3, in the first example of operation according to this embodiment, the pressure value acquisition unit 64 of the ECU 7 acquires the higher side of the mentioned fuel pressure fluctuation range as the first fuel pressure value (first pressure) 60 and the lower side as the second fuel pressure value (second pressure) 61. the first pressure 60 and the second pressure 61 are acquired in a predetermined cycle similarly to the representative pressure shown in FIG. 2 by sensing with the pressure sensor 6. Then, the pressure value acquisition unit 64 of the ECU 7 sets the higher side of the sampled pressure values as the first pressure 60 and the lower side as the second pressure 61. Note that the first pressure 60 and the second pressure 61 are set based on the pressure values acquired in the cycle preceding the injection control.Here, if the periods for detecting the first pressure 60 and the second pressure 61 are first and second periods, respectively, the first period is the period from the time of the pressure increase (pressure increase time) by the high-pressure fuel pump 3 to the time at which fuel is subsequently injected by the injector 10 for the first time. Moreover, the second period is the period from the previous injection timing to the next pressure increase timing.Next, the pressure value acquisition unit 64 of the ECU 7 performs calculation from the two acquired pressure values to determine the calculated fuel pressure value (calculated pressure) 62. In the conventional example of control operation, if the representative pressure is a pressure value sampled in a period independent of the combustion cycle, the value may not necessarily represent the median of the fuel pressure fluctuation, for example. Even in this case, the median of the fuel pressure fluctuation can be accurately reflected by setting the mean value or the median of the first pressure 60 and the second pressure 61 as the calculated pressure 62. The pressure value acquisition unit 64 then outputs the first pressure 60, the second pressure 61, and the calculated pressure 62 to the fuel injection control planning unit 63.Thereby, the fuel injection control planning unit 63 of the ECU 7 can acquire a plurality of pressure values, namely, the first pressure 60, the second pressure 61, and the calculated pressure 62. The fuel injection timing planning unit 63 then selects that one of the plurality of pressure values which is closest to the injection pressure when the following injection is performed. The fuel injection timing planning unit 63 then corrects the injection pulse width Ti according to the selected pressure value.Note that the pressure value is selected using the correspondence between the injection timing and the pressure increase timing of the injection to be corrected. Specifically, as shown in FIG. 3, the first pressure 60 is selected for the first-stage injection, which is the first injection after the pressure increase timing. Then, the calculated second-stage injection pressure 62 occurring after the fuel pressure has decreased after the first-stage injection is selected. Then, the second third-stage injection pressure 61 occurring after the fuel pressure further decreases is selected.Thereby, the correction of the injection pulse width in the example of the fuel injection according to this embodiment is performed such that the first-stage pulse width<the second-stage pulse width<the third-stage pulse width holds, thereby enabling a reduction in variations in the injection amounts due to variations in the fuel pressure. Note that if there is little time left for the correction between the cycle of detecting the pressure value and the injection timing, for example, the pressure value detected in the previous cycle may be used to correct the injection pulse width in the next cycle.[Operation Procedure in First Operation Example]Next, the operation in the first operation example will be described with reference to FIG. 4.FIG. 4 is a flowchart showing a first example of the processing in the fuel injection control of the engine control device according to this embodiment.As shown in FIG. 4, first, the ECU 7 calculates the timing of the pressure increase by the high-pressure fuel pump 3 according to the operating state or the like of the internal combustion engine 9 (step S 10). Next, the fuel injection control planning unit 63 calculates the injection timing (control contents) of the injector 10 according to the operation state or the like (step S 21).Then, the ECU 7 acquires the first fuel pressure value (first pressure) 60 using the pressure value acquisition unit 64 (step S 30). The ECU 7 also detects the second fuel pressure value (second pressure) 61 using the pressure value detection unit 64 (step S 31). The pressure value acquisition unit 64 then calculates the fuel pressure value (calculated pressure) 62 based on the acquired first pressure 60 and the second pressure 61 (step S 32).Next, the fuel injection control planning unit 63 selects a value closest to the actual injection pressure from among the plurality of pressure values of the first pressure 60, the second pressure 61, and the calculated pressure 62 (step S 40). As the actual injection pressure in step S 40, data measured in advance and stored in the storage unit of the ECU 7 is used.Then, the fuel injection control planning unit 63 calculates a correction value for the injection pulse width Ti based on the selected pressure value (step S 41). Next, the fuel injection control planning unit 63 outputs a control signal to the injector 10 to achieve the calculated corrected injection pulse width Ti (step S 42). Thereby, the description of the first example of the operation flow in the fuel injection control of the internal combustion engine control device according to this embodiment will be completed.Note that, in this embodiment, an example in which the pressure values acquired and calculated by the pressure value acquisition unit 64 and selected by the fuel injection control planning unit 63 are the three mentioned pressure values, namely, the first pressure 60, the second pressure 61, and the calculated pressure 62, has been described, but the present invention is not limited thereto. For example, the pressure value acquisition unit 64 may further calculate the median of the first pressure 60 and the calculated pressure 62 and the median of the second pressure 61 and the calculated pressure 62, and the fuel injection control planning unit 63 may select a predetermined pressure value from among these five pressure values. In this way, the pressure value calculated by the pressure value acquisition unit 64 is not limited to one, and two or more pressure values may be calculated. Note that it is preferable that the number of pressure values acquired and calculated by the pressure value acquisition unit 64 is set according to the number of stages at which fuel is injected.2-3. Method for Detecting Pressure ValuesNext, an example of a method for detecting pressure values will be described with reference to FIG. 5.FIG. 5 is a timing chart showing an example of a method for detecting pressure values.In the above explanation, only the fuel pressure fluctuations due to the pressure increase by the high-pressure fuel pump 3 and the injection by the injector 10 have been described. However, it is assumed that the actual pressure waveform is accompanied by a high frequency pulsation as shown in FIG. 5. A possible cause of a high-frequency pulsation is a liquid resonance in the piping system consisting of the high-pressure piping 14, the common rail unit 4 and the like. Therefore, if the first pressure 60 and the second pressure 61 are sampled at random, there is a possibility that the variations of the high-frequency pulsation are sampled.On the other hand, the pressure value acquisition unit 64 according to this embodiment performs a multiple sampling during each period, for example, for a period longer than the cycle of the high-frequency pulsation. The pressure value acquisition unit 64 then performs averaging on the plurality of sampled pressure values to thereby acquire the first pressure 60 and the second pressure 61. Further, the pressure value acquisition unit 64 may perform sampling over a plurality of cycles formed by the pressure increase and injection and averaging to obtain each pressure value. This enables accurate detection of the first pressure 60 and the second pressure 61 without being affected by variations in the high-frequency pulsation.In this way, the internal combustion engine control device according to this embodiment can prevent variations in the injection amount due to fuel pressure fluctuations without increasing the calculation load.2-4. Second Example of Operation According to This EmbodimentNext, a second example of an operation of the fuel injection control according to this embodiment will be described with reference to FIG. 6.FIG. 6 is a timing chart showing the second example of an operation of the fuel injection control according to this embodiment.In recent years, with a view to improving combustion, there has been a trend toward an increasing number of internal combustion engines with fuel injection divided into a plurality of combustion cycles. In addition, the second example of the operation shown in FIG. 6 is applied to the case where the injection is divided into a main injection in which more than half of the required injection amount determined according to the operation state of the internal combustion engine 9 is injected and a secondary injection in an injection amount smaller than that in the main injection.As shown in FIG. 6, the secondary injection is performed with a smaller injection amount during the compression stroke in addition to the main injection during the intake stroke of the internal combustion engine 9. There are two possible cases of fuel pressure fluctuations associated therewith, namely a case 1 in which there is no pressure increase time between the main injection and the secondary injection, and a case 2 in which a pressure increase time occurs depending on the pressure increase time of the high-pressure fuel pump 3 and the injection time of the injector 10.In this case, the pressure value is preferably selected depending on whether the secondary injection is performed during the first or second period as shown in the first example of the operation. Specifically, as shown in FIG. 6, in case 1 in which no pressure increase time occurs (indicated by the solid line in FIG. 6 ), the first pressure 60 is selected as the pressure value during the secondary injection. Also, in Case 2 in which a pressure increase time occurs (indicated by the dot-dash line in FIG. 6 ), the second pressure 61 is selected as a pressure value during the secondary injection. The fuel injection timing planning unit 63 then corrects the injection pulse width Ti according to the selected pressure value.Thereby, the correction of the injection pulse width is performed so that the secondary injection pulse width in Case 1 is larger than the secondary injection pulse width in Case 2, which enables to reduce variations in the injection amount in the secondary injection occurring due to fuel pressure fluctuations. Further, since more than half of the required injection amount is injected by the main injection, it is considered that the total variation of the fuel pressure is dominated by the main injection. This enables applying a similar method to the first example of the operation for correcting the main injection and also reducing the variation of the injection amount in the main injection.In this way, in the second example of the operation in which the secondary injection is performed, as in the first example of the operation, variations in the injection amount due to fuel pressure fluctuations can be prevented without increasing the calculation load.It is to be understood that the present invention is not limited to the embodiment described above and illustrated in the drawings, and that various modifications are possible without departing from the spirit of the invention as set forth in the claims.For example, the above embodiments have been described in detail to facilitate understanding of the present invention, and the present invention is not necessarily limited to having all the described configurations. In addition, a part of the configuration of one embodiment may be replaced with the configurations of other embodiments, and the configuration of the one embodiment may also be added to the configurations of other embodiments. In addition, a part of the configuration of each of the embodiments may be added to, taken out from, and replaced with other configurations.List of reference characters1 Fuel injection device 2 Feed pump 3 High-pressure fuel pump 4 Common rail unit 5 Cam 6 Pressure sensor 7 ECU (Engine Control Device) 8 Low-pressure line 9 Engine 10 Injector 11 Exhaust valve 12 Pressure chamber 13 Piston 14 High-pressure line 15 Crank angle sensor 16 Accelerator position sensor 30 Intake valve unit 40 Variable valve mechanism 50 Fuel tank 60 First fuel pressure value (first pressure) 61 Second fuel pressure value (second pressure) 62 Calculated fuel pressure value (calculated pressure) 63 Fuel injection control planning unit 64 Pressure value acquisition unitReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedJP 2008-38857

[0005]

Claims

An internal combustion engine control device for controlling an internal combustion engine, comprising: a reciprocating fuel pump that intermittently increases the pressure of fuel and discharges the fuel whose pressure is intermittently increased into a fuel line; and a fuel injection valve for injecting the fuel whose pressure is intermittently increased, the internal combustion engine control device comprising: a fuel injection control planning unit that plans control contents related to opening or closing of the fuel injection valve according to an operation state of the internal combustion engine; and a pressure value acquisition unit that acquires a pressure value from a pressure sensor provided in the internal combustion engine, wherein the pressure value acquisition unit acquires: a first fuel pressure value generated during a first period from a time point at which the fuel pump increases the pressure, until first injecting fuel by the fuel injection valve after the pressure increase time is detected, a second fuel pressure value detected during a second time period, which is the time period occurring after the first time period and reaching the pressure increase time, and a calculated fuel pressure value calculated based on the first and second fuel pressure values, wherein the fuel injection control planning unit selects at least one of the first fuel pressure value, the second fuel pressure value, and the calculated fuel pressure value, and corrects a control amount of the fuel injection valve according to the selected pressure value.The internal combustion engine control device according to claim 1, wherein the pressure value acquisition unit calculates the first fuel pressure value from an average value of a plurality of fuel pressure values acquired during the first period, and calculates the second fuel pressure value from an average value of a plurality of fuel pressure values acquired during the second period.The internal combustion engine control device according to claim 2, wherein the pressure value acquisition unit calculates the first fuel pressure value from an average value of a plurality of the fuel pressure values acquired during a plurality of the first periods over a plurality of strokes of the internal combustion engine, and calculates the second fuel pressure value from an average value of a plurality of the fuel pressure values acquired during a plurality of the second periods over a plurality of strokes of the internal combustion engine.The internal combustion engine control device according to claim 1, wherein the calculated fuel pressure value is an average value of the first fuel pressure value and the second fuel pressure value.The internal combustion engine control device according to claim 1, wherein at a first injection timing of the fuel injection valve, a main injection in which more than half of a required injection amount determined according to the operating state of the internal combustion engine is injected is performed, and at a second injection timing after the first injection timing, a secondary injection having an injection amount smaller than the injection amount of the main injection is performed, wherein the fuel injection control planning unit corrects the control amount of the fuel injection valve for the secondary injection based on the first fuel pressure value if the execution of the secondary injection is planned in the first period, and corrects the control amount of the fuel injection valve for the secondary injection based on the second fuel pressure value if the execution of the secondary injection is planned in the second period.An internal combustion engine control method for controlling an internal combustion engine, comprising: a reciprocating fuel pump that intermittently increases the pressure of fuel and discharges the fuel whose pressure is intermittently increased into a fuel line; and a fuel injection valve for injecting the fuel whose pressure is intermittently increased, the method comprising: detecting a first fuel pressure value during a first period ranging from a time when the fuel pump increases the pressure to the first time injecting fuel by the fuel injection valve after the pressure increase time; detecting a second fuel pressure value during a second period occurring after the first period and ranging to the pressure increase time, calculating a fuel pressure value using the first and second fuel pressure values, and selecting at least one of the first fuel pressure value, the second fuel pressure value, and the calculated fuel pressure value, and correcting the control amount of the fuel injection valve according to the selected pressure value.

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