Internal combustion engine control device and internal combustion engine control method

Abstract

An internal combustion engine control device is provided with a fuel injection control planning unit and a pressure value acquisition unit. The pressure value acquisition unit acquires the first fuel pressure value, the second fuel pressure value, and the calculated fuel pressure value. The first fuel pressure value is acquired from a pressurization operation timing of the fuel pump during a first period during which fuel is injected from the fuel injection valve for the first time thereafter. The second fuel pressure value is acquired during a second period, which is a period after the first period until the pressurization timing. The calculated fuel pressure value is calculated from the first fuel pressure value and the second fuel pressure value. Then, the fuel injection control planning unit selects the first fuel pressure value and the second fuel pressure value, calculates at least one of the fuel pressure values, and corrects the control amount of the fuel injection valve on the basis of the selected pressure value.

Description

Technical Field

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

[0002] As a device for supplying fuel to a plurality of cylinders of a vehicle engine, a fuel injection control device of a pressure accumulation type (common rail type) is known. This accumulates the fuel pressurized by a high-pressure fuel pump or the like in a fuel supply pipe, and injects it through a fuel injection valve provided on the fuel pipe. Further, the internal combustion engine control device controls in accordance with the operating state of the internal combustion engine so that the fuel pressure accumulated in the fuel pipe and the fuel injection amount of the injection valve become desired values. At this time, for example, a pressure value sampled by a pressure sensor at a predetermined cycle is known to be used in the control.

[0003] In the case of performing the above-described pressure accumulation type fuel injection control, the fuel pressure in the fuel pipe fluctuates moment by moment due to the supply (discharge) from the high-pressure fuel pump to the fuel pipe and the fuel injection from the fuel injection valve. In particular, when performing high-speed divided injection which is carried out in many internal combustion engines in recent years, there is a concern that the fuel pressure fluctuation (fuel pressure fluctuation) increases. On the other hand, in the above-described pressure sampling method, it may not be possible to successively capture these fluctuations, and there is a concern that the fuel pressure fluctuation directly affects the fuel injection amount. As a result, the mixing state of air and fuel supplied to the engine changes, and deterioration of exhaust gas and fuel consumption rate may occur.

[0004] In order to solve such a problem, for example, the technique described in Patent Document 1 is disclosed. In Patent Document 1, it is described that the fuel pressure change during fuel injection is calculated, and the fuel injection pulse width is corrected based on the fuel pressure change amount and the fuel pressure at the start of injection. Prior Art Documents Patent Documents

[0005] Patent Document 1: Japanese Patent Laid-Open No. 2008-38857 Summary of the Invention Problems to be Solved by the Invention

[0006] However, in the technique described in Patent Document 1, in order to obtain the fuel pressure change (fuel pressure fluctuation) during fuel injection, it is necessary to successively calculate based on the fuel pressure at the start of fuel injection sampled by the pressure sensor, using the discharge amount of the fuel pump and the injection amount of the fuel injection valve. As a result, in the technique described in Patent Document 1, there is a problem that the calculation load and the number of calculations increase. In particular, when performing high-speed divided injection, the technique described in Patent Document 1 is not satisfactory from the viewpoint of practical application.

[0007] In view of the above problems, an object of the present invention is to provide an internal combustion engine control device and an internal combustion engine control method that can prevent injection amount deviation caused by fuel pressure fluctuations, which are the main causes of deterioration of the exhaust gas or fuel consumption rate of the internal combustion engine, without increasing the computational load. Technical means for solving the problem

[0008] To solve the above problems, for example, the configuration described in the technical solution is adopted. The present invention includes a plurality of means for solving the above problems. For example, the internal combustion engine control device of the present invention is an internal combustion engine control device for controlling an internal combustion engine, which includes a reciprocating fuel pump that intermittently pressurizes fuel and discharges it into a fuel pipe, and a fuel injection valve for injecting the intermittently pressurized fuel. In addition, the internal combustion engine control device includes: a fuel injection control planning unit that plans control content related to the opening or closing of the fuel injection valve according to the operating state of the internal combustion engine; and a pressure value acquisition unit that acquires a pressure value from a pressure sensor provided on the internal combustion 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 acquired during a first period starting from the pressurization operation time of the fuel pump and ending at the first fuel injection from the fuel injection valve thereafter. The second fuel pressure value is acquired during a second period, which is the period from after the first period to the pressurization time. The calculated fuel pressure value is calculated from the first fuel pressure value and the second fuel pressure value. 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.

[0009] In addition, the internal combustion engine control method of the present invention is an internal combustion engine control method for controlling an internal combustion engine, which includes a reciprocating fuel pump that intermittently pressurizes fuel and discharges it into a fuel pipe, and a fuel injection valve for injecting the intermittently pressurized fuel. The internal combustion engine control method includes the following processes (1) to (4). (1) A process of acquiring a first fuel pressure value acquired during a first period, which is the period starting from the pressurization operation time of the fuel pump and ending at the first fuel injection from the fuel injection valve thereafter. (2) A process of acquiring a second fuel pressure value acquired during a second period, which is the period from after the first period to the pressurization time. (3) A process of calculating a calculated fuel pressure value using the first fuel pressure value and the second fuel pressure value. (4) A process of selecting at least one pressure value from 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. Effects of the Invention

[0010] According to the internal combustion engine control device and the internal combustion engine control method configured as described above, it is possible to prevent injection amount deviation caused by fuel pressure variation, which is the main cause of deterioration of exhaust gas or fuel consumption rate of the internal combustion engine, without increasing the calculation load. Subjects, configurations, and effects other than the above are clarified by the following description of the embodiments. Description of the Drawings

[0011] Figure 1 It is an overall configuration diagram of a fuel injection device controlled by an internal combustion engine device of an embodiment example. Figure 2 It is a timing chart showing an example of existing fuel injection control. Figure 3 It is a timing chart showing a first operation example in the fuel injection control of the internal combustion engine control device of the embodiment example. Figure 4 It is a flowchart showing a first operation example in the fuel injection control of the internal combustion engine control device of the embodiment example. Figure 5 It is a timing chart showing an example of a method for obtaining a pressure value in the internal combustion engine control device of the embodiment example. Figure 6 It is a timing chart showing a second operation example in the fuel injection control of the internal combustion engine control device of the embodiment example. Detailed Embodiments

[0012] Hereinafter, with reference to Figures 1 to 6 An embodiment example of the internal combustion engine control device and the internal combustion engine control method will be described. In addition, in each drawing, the same reference numerals are given to common components.

[0013] 1. Embodiment Example 1-1. Configuration Example of Fuel Injection Device First, with reference to Figure 1 A configuration example of a fuel injection device controlled by an internal combustion engine control device of an embodiment example (hereinafter referred to as "this example") will be described. Figure 1 It is an overall configuration diagram of a fuel injection device controlled by an internal combustion engine control device.

[0014] The internal combustion engine control device in this example is a control device for a four-stroke engine that controls an internal combustion engine that repeatedly performs four strokes: an intake stroke, a compression stroke, a combustion (expansion) stroke, and an exhaust stroke. The internal combustion engine is, for example, a multi-cylinder engine having 4 cylinders (cylinders). In addition, the number of cylinders of the internal combustion engine is not limited to 4, and it may have 3 or more than 6 cylinders.

[0015] The internal combustion engine has a fuel injection device 1 that injects fuel into the cylinders. As Figure 1 shown, the fuel injection device 1 includes a feed pump 2, a high-pressure fuel pump 3, a common rail 4, an injector 10 representing a fuel injection valve, and an internal combustion engine control device (ECU: Engine Control Unit) 7. Then, the fuel injection device 1 injects and supplies fuel to each cylinder of the internal combustion engine 9 at an appropriate timing.

[0016] In addition, the fuel injection device 1 sucks fuel from the fuel tank 50 via the feed pump 2. In addition, the feed pump 2 and the high-pressure fuel pump 3 are connected via a low-pressure pipe 8. The plunger 13 is slidably held in the high-pressure fuel pump 3. In addition, the high-pressure fuel pump 3 has a discharge valve 11, a pressurizing chamber 12, and a suction valve unit 30.

[0017] The suction valve unit 30 is connected to the low-pressure pipe 8 and sucks fuel via the low-pressure pipe 8. In addition, the solenoid-type suction valve unit 30 communicates with the pressurizing chamber 12. Moreover, the pressurizing chamber 12 is connected to the discharge valve 11.

[0018] One end of the plunger 13 is inserted into the pressurizing chamber 12 to increase or decrease the volume of the pressurizing chamber 12. In addition, the other end of the plunger 13 abuts against a cam 5 mounted on the shaft of the internal combustion engine 9. Moreover, the plunger 13 reciprocates in the high-pressure fuel pump 3 by the rotation drive of the cam 5. Due to the reciprocating motion of the plunger 13, the volume of the pressurizing chamber 12 expands and contracts.

[0019] Here, the cam 5 is mounted on a shaft that drives an intake valve or an exhaust valve (not shown) of the internal combustion engine 9. And the shaft obtains power through the variable valve mechanism 40. Therefore, when the variable valve mechanism 40 is driven, a phase difference is generated between the internal combustion engine 9 and the high-pressure fuel pump 3.

[0020] In addition, the high-pressure pipe 14 is connected to the discharge valve 11 of the high-pressure fuel pump 3. The common rail 4 is connected to the high-pressure pipe 14. The common rail 4 constitutes a high-pressure fuel path communicating with the discharge port of the high-pressure fuel pump 3. Moreover, the common rail 4 is a pressure accumulator for accumulating the fuel pumped from the high-pressure fuel pump 3 and maintaining the fuel pressure at a specified pressure corresponding to the operating state of the internal combustion engine 9. On this common rail 4, an injector 10 is connected according to the intake of the cylinders of the internal combustion engine 9. The injector 10 injects the fuel supplied via the common rail 4 into each cylinder of the internal combustion engine 9. In addition, the injector 10 has a solenoid direct-acting actuator. And the injector 10 controls the on-off valve according to the energization time of the solenoid.

[0021] As described above, in the high-pressure fuel pump 3, the plunger 13 is driven up and down by the cam 5. Thereby, the volume of the pressurizing chamber 12 expands and contracts, sucking and pressurizing the fuel and supplying it to the discharge valve 11. When the pressure in the pressurizing chamber 12 is higher than the pressure in the high-pressure pipe 14 and the common rail 4, the discharge valve 11 opens, and the fuel is pumped into the high-pressure pipe 14 and the common rail 4.

[0022] Here, when the plunger 13 moves from the top dead center to the bottom dead center, the volume of the pressurizing chamber 12 expands. Along with this, the fuel supplied from the feed pump 2 is sucked into the pressurizing chamber 12. If the intake valve is open when the plunger 13 moves from the bottom dead center to the top dead center, the fuel in the pressurizing chamber 12 flows back toward the fuel tank 50 through the low-pressure pipe 8.

[0023] If the intake valve is closed when the plunger 13 moves from the bottom dead center to the top dead center, the pressurization of the fuel remaining in the pressurizing chamber 12 starts. Moreover, when the pressure is higher than the pressure in the common rail 4, the discharge valve 11 opens, and the fuel is pumped.

[0024] 1-2. Configuration example of the internal combustion engine control device The ECU 7 has a CPU that performs calculations according to a pre-determined program and controls each device; storage areas such as a RAM and a ROM that record programs, data, and calculation results; and an interface for inputting and outputting signals. In addition, the ECU 7 is connected to a pressure sensor 6, a crank angle sensor 15, an accelerator opening sensor 16, etc., and inputs the signals detected by each sensor.

[0025] Here, the pressure sensor 6 detects the pressure in the common rail 4. The crank angle sensor 15 detects the crank angle. The accelerator opening sensor 16 detects the opening of the accelerator.

[0026] The ECU 7 detects the operating state of the internal combustion engine 9 based on the detection signals from the various sensors. Then, the ECU 7 performs energization control on the suction valve unit 30 provided on the suction side of the high-pressure fuel pump 3. Thereby, the ECU 7 controls the discharge amount of the high-pressure fuel pump 3 and controls the discharge pressure. Further, the ECU 7 controls the injection pulse width Ti(n) of the injector 10 for each cylinder and controls the amount of fuel supplied to the internal combustion engine 9. Here, n represents the cylinder number.

[0027] In addition, the ECU 7 has a pressure value acquisition unit 64 and a fuel injection control planning unit 63 (refer to Figure 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, which will be described later, based on the detection value input from the pressure sensor 6. The pressure value acquisition unit 64 calculates an arithmetic fuel pressure value (arithmetic pressure) 62 based on the first fuel pressure value (first pressure) 60 and the second fuel pressure value (second pressure) 61. Then, the fuel injection control planning unit 63 plans the control content for opening or closing the valve of the injector 10 based on the operating state of the internal combustion engine 9 and corrects the control amount of the injector 10. The fuel injection control planning unit 63 selects, for example, the injection pressure, that is, selects one or more pressure values from a plurality of fuel pressure values. In addition, the fuel injection control planning unit 63 corrects the control amount such as the injection pulse width Ti and the operation timing of the injector 10 based on the selected pressure value.

[0028] 2. Control operation example of fuel injection Next, with reference to Figures 2 to 4 an operation example of fuel injection control will be described.

[0029] 2-1. Existing operation example First, with reference to Figure 2 an operation example of existing fuel injection control will be described. Figure 2 is a timing chart showing an example of the control in an existing injection control device. In addition, in the example shown in Figure 2 , an example of performing three-stage (three times) multi-stage injection during the intake stroke in the combustion cycle of the internal combustion engine 9 is shown.

[0030] As shown in Figure 2 , the common rail pressure shown in the lowermost part of the figure rises at a certain moment by the pressurization of the high-pressure fuel pump 3. Then, when an injection pulse is input to the injector 10, fuel is injected, and thus the common rail pressure decreases more and more as the number of injections increases. And in the next cycle, the pressure rises again due to the pressurization of the high-pressure fuel pump 3. Through this repetition, periodic fuel pressure fluctuations are generated for the fuel cycle.

[0031] In addition, the pressurization timing of the high-pressure fuel pump 3 varies independently of the combustion cycle mainly for the following two reasons. The first reason is that the pressurization timing varies with the energization timing of the suction valve unit 30. And the second reason is that the high-pressure fuel pump 3 itself obtains a driving force from the shaft via the variable valve mechanism 40, and the operating phase changes.

[0032] Moreover, for the fluctuating fuel pressure, in the existing control operation example, the representative fuel pressure value (hereinafter referred to as the representative pressure) is obtained by the pressure sensor 6 provided on the fuel pipe. The representative pressure is calculated, for example, based on the pressure values sampled at a specified cycle or their average value. And in the existing ECU, this representative pressure is used as the injection pressure, and the injection pulse width Ti of the injector 10 is corrected to obtain the required injection amount.

[0033] However, as Figure 2 shown, 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. As a result, the mixing state of the air and fuel supplied to the internal combustion engine changes, and deterioration of exhaust gas and fuel consumption rate may occur. In the example shown in Figure 2 , the first-stage injection in the three-stage injection is performed at a fuel pressure higher than the representative pressure, and the injection amount becomes excessive, and the third-stage injection is performed at a fuel pressure lower than the representative pressure, and the injection amount becomes insufficient.

[0034] 2-2. The first operation example of this example Next, with reference to Figures 3 to 4 , the first operation example of the fuel injection control of this example will be described. Figure 3 is a timing chart showing the first operation example of the fuel injection control of this example.

[0035] As Figure 3 shown, in the first operation example of this example, the pressure value acquisition unit 64 of the ECU 7 sets the high side as the first fuel pressure value (first pressure) 60 and the low side as the second fuel pressure value (second pressure) 61 within the above-mentioned fuel pressure variation range. The acquisition methods of the first pressure 60 and the second pressure 61 are the same as those of the representative pressure shown in Figure 2 , and are sampled by the pressure sensor 6 at a specified cycle. Then, the pressure value acquisition unit 64 of the ECU 7 sets the high side of the sampled pressure values as the first pressure 60 and the low side as the second pressure 61. In addition, the first pressure 60 and the second pressure 61 are set based on the pressure values obtained in the cycle before the injection control is performed.

[0036] Here, when the acquisition periods of the first pressure 60 and the second pressure 61 are taken as the first period and the second period, the first period is the period from the pressurization operation moment (pressurization moment) of the high-pressure fuel pump 3 to the moment when the injector 10 first injects fuel thereafter. The second period is the period from the previous injection moment to the next pressurization moment.

[0037] Then, the pressure value acquisition unit 64 of the ECU 7 calculates an arithmetic fuel pressure value (arithmetic pressure) 62 through arithmetic operations based on the two acquired pressure values. For example, in an existing control operation example, when the representative pressure is set to the pressure value sampled at a cycle independent of the combustion cycle, this value may not necessarily be able to capture the central value of the fuel pressure fluctuation. Even in this case, by setting the average value or the central value of the first pressure 60 and the second pressure 61 as the arithmetic pressure 62, the central value of the fuel pressure fluctuation can be accurately captured. Then, the pressure value acquisition unit 64 outputs the first pressure 60, the second pressure 61, and the arithmetic pressure 62 to the fuel injection control plan unit 63.

[0038] Thus, the fuel injection control plan unit 63 of the ECU 7 can acquire multiple pressure values of the first pressure 60, the second pressure 61, and the arithmetic pressure 62. Then, the fuel injection timing plan unit 63 selects which pressure value is close to the injection pressure when injecting fuel later among the multiple pressure values. Then, the fuel injection control plan unit 63 corrects the injection pulse width Ti according to the selected pressure value.

[0039] In addition, in the selection of the pressure value, the correspondence relationship between the injection timing and the pressurization timing of the corrected injection is used. Specifically, as Figure 3 shown, for the first-stage injection which is the first injection after the pressurization moment, the first pressure 60 is selected. Then, for the second-stage injection which occurs after the fuel pressure drops after receiving the first-stage injection, the arithmetic pressure 62 is selected. In addition, for the third-stage injection which occurs after the fuel pressure drops further, the second pressure 61 is selected.

[0040] As a result, in the operation example of the fuel injection in this example, injection pulse width correction is performed such that the pulse width of the first stage < the pulse width of the second stage < the pulse width of the third stage, and the deviation of the injection amount caused by the fuel pressure fluctuation can be reduced. In addition, when the delay time between the cycle of acquiring the pressure value and the injection timing reflecting the correction is small, for example, the pressure value acquired in the previous cycle can also be used to correct the injection pulse width of the next cycle.

[0041] [Operation flow of the first operation example] Next, with reference to Figure 4 the operation flow of the first operation example will be described. Figure 4It is a flowchart showing the first operation example in the fuel injection control of the internal combustion engine control device in this example.

[0042] As Figure 4 shown, first, the ECU 7 calculates the pressurization timing of the high-pressure fuel pump 3 based on the operating state of the internal combustion engine 9, etc. (step S10). Then, the fuel injection control planning unit 63 of the ECU 7 calculates the injection timing (control content) of the injector 10 based on the operating state, etc. (step S21).

[0043] Then, the ECU 7 uses the pressure value acquisition unit 64 to acquire the first fuel pressure value (first pressure) 60 (step S30). In addition, the ECU 7 uses the pressure value acquisition unit 64 to acquire the second fuel pressure value (second pressure) 61 (step S31). Then, the pressure value acquisition unit 64 calculates the calculated fuel pressure value (calculated pressure) 62 based on the acquired first pressure 60 and second pressure 61 (step S32).

[0044] Next, the fuel injection control planning unit 63 selects a pressure value close to the actual injection pressure from among the multiple pressure values of the first pressure 60, the second pressure 61, and the calculated pressure 62 (step S40). The actual injection pressure in step S40 is measured in advance and the data stored in the storage unit of the ECU 7 is used.

[0045] Then, the fuel injection control planning unit 63 calculates a correction value of the injection pulse width Ti based on the selected pressure value (step S41). Next, the fuel injection control planning unit 63 outputs a control signal to the injector 10 so as to become the calculated corrected injection pulse width Ti (step S42). Thus, the first operation example of the fuel injection control of the internal combustion engine control device in this example is completed.

[0046] In addition, in this example, as the pressure values acquired and calculated by the pressure value acquisition unit 64 and selected by the fuel injection control planning unit 63, an example in which the three pressure values of the first pressure 60, the second pressure 61, and the calculated pressure 62 are set is described, but it is not limited to this. For example, the pressure value acquisition unit 64 may further calculate the median value of the first pressure 60 and the calculated pressure 62 and the median value of the second pressure 61 and the calculated pressure 62, and the fuel injection control planning unit 63 may select a specified pressure value from among the five pressure values. In this way, the pressure values calculated by the pressure value acquisition unit 64 are not limited to one, and two or more pressure values may be calculated. In addition, the number of pressure values acquired and calculated by the pressure value acquisition unit 64 is preferably set according to the number of stages of the injected fuel.

[0047] 2-3. Method for acquiring pressure value Next, with reference to Figure 5 an example of the method for acquiring the pressure value will be described. Figure 5 This is a timing chart showing an example of a method for obtaining pressure values.

[0048] In the above description, only the fuel pressure fluctuations caused by the pressurization of the high-pressure fuel pump 3 and the injection of the injector 10 have been described. However, as Figure 5 shown, the actual pressure waveform is considered to be accompanied by high-frequency pulsations. As one of the main causes of high-frequency pulsations, liquid resonance in the piping system composed of the high-pressure piping 14 and the common rail 4, etc. can be considered. Therefore, when randomly sampling the first pressure 60 and the second pressure 61, it is possible to sample the fluctuations in the high-frequency pulsation part.

[0049] In contrast, the pressure value acquisition unit 64 of this example samples multiple times at intervals longer than the period of the high-frequency pulsations in each period, for example. Then, the pressure value acquisition unit 64 performs an averaging process on the multiple sampled pressure values, thereby obtaining the first pressure 60 and the second pressure 61. Furthermore, the pressure value acquisition unit 64 can also sample in multiple cycles formed by pressurization and injection, perform an averaging process to obtain each pressure value. Thus, it is possible to accurately obtain the first pressure 60 and the second pressure 61 without being affected by the fluctuations in the high-frequency pulsation part.

[0050] In this way, according to the internal combustion engine control device of this example, it is possible to prevent injection quantity deviation caused by fuel pressure fluctuations without increasing the computational load.

[0051] 2-4. Second operation example of this example Next, with reference to Figure 6 the second operation example of the fuel injection control of this example will be described. Figure 6 This is a timing chart showing the second operation example of the fuel injection control of this example.

[0052] In recent years, from the viewpoint of improving combustion, there has been an increasing tendency for internal combustion engines that divide and inject fuel in multiple combustion strokes. Moreover, in Figure 6 the second operation example shown, it is applicable to the case where the required injection quantity obtained according to the operating state of the internal combustion engine 9 is divided into a main injection that is more than half of the required injection quantity and a sub-injection that injects a smaller amount than the main injection.

[0053] As Figure 6 shown, in addition to the main injection during the intake stroke of the internal combustion engine 9, a small amount of sub-injection is also performed during the compression stroke. As the fuel pressure fluctuations accompanying this, depending on the pressurization timing of the high-pressure fuel pump 3 and the injection timing of the injector 10, two cases can be considered: case 1 where the pressurization timing is not included between the main injection and the sub-injection, and case 2 where the pressurization timing is included.

[0054] In this case, it is preferable to select the pressure value according to whether the sub-injection is performed during the first period or the second period shown in the first operation example. Specifically, as Figure 6 shown, in Case 1 that does not include the pressurization moment ( Figure 6 the case shown by the solid line), the first pressure 60 is selected as the pressure value during sub-injection. In addition, in Case 2 that includes the pressurization moment ( Figure 6 the case shown by the dotted line), the second pressure 61 is selected as the pressure value during sub-injection. Then, the fuel injection control planning unit 63 corrects the injection pulse width Ti according to the selected pressure value.

[0055] As a result, injection pulse width correction is performed such that the sub-injection pulse width in Case 1 > the sub-injection pulse width in Case 2. Thereby, it is possible to reduce the injection amount deviation of the sub-injection caused by the fuel pressure fluctuation. Furthermore, since more than half of the required injection amount is injected by the main injection, it is considered that the overall fuel pressure fluctuation is dominated by the main injection. Thus, regarding the correction of the main injection, the same method as in the first operation example can be applied, and it is also possible to reduce the injection amount deviation of the main injection.

[0056] In this way, also in the second operation example in which sub-injection is performed, similar to the first operation example, it is possible to prevent injection amount deviation caused by fuel pressure fluctuation without increasing the calculation load.

[0057] In addition, the present invention is not limited to the embodiments shown in the above drawings, and various modifications can be made without departing from the gist of the invention described in the technical solution.

[0058] For example, the above-described embodiment examples are examples that illustrate the configurations of the device and the system in detail and specifically for easy understanding, and are not necessarily limited to examples having all the described configurations. In addition, a part of the configuration of the embodiment described here can be replaced with the configuration of other embodiments, and the configuration of other embodiments can also be added to the configuration of a certain embodiment. In addition, for a part of the configuration of the embodiment, addition, deletion, and replacement of other configurations can also be performed. Symbol description

[0059] 1…Fuel injection device, 2…Feed pump, 3…High-pressure fuel pump, 4…Common rail, 5…Cam, 6…Pressure sensor, 7…ECU (Internal combustion engine control device), 8…Low-pressure piping, 9…Internal combustion engine, 10…Injector, 11…Discharge valve, 12…Pressurizing chamber, 13…Plunger, 14…High-pressure piping, 15…Crank angle sensor, 16…Throttle opening sensor, 30…Suction 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 section, 64…Pressure value acquisition section.

Claims

1. An internal combustion engine control device for controlling an internal combustion engine, the internal combustion engine having a reciprocating fuel pump that intermittently pressurizes fuel and discharges it into a fuel pipe, and a fuel injection valve for injecting the intermittently pressurized fuel, characterized in that Comprising: A fuel injection control planning unit that plans control content related to opening or closing of the fuel injection valve according to the operating state of the internal combustion engine; and A pressure value acquisition unit that acquires a pressure value from a pressure sensor provided on the internal combustion engine, The pressure value acquisition unit acquires: A first fuel pressure value acquired during a first period starting from the pressurization operation timing of the fuel pump and until the first fuel injection from the fuel injection valve thereafter; A second fuel pressure value acquired during a second period, which is the period from after the first period until the pressurization timing; And An arithmetic fuel pressure value calculated from the first fuel pressure value and the second fuel pressure value, The fuel injection control planning unit selects at least one of the first fuel pressure value, the second fuel pressure value, and the arithmetic fuel pressure value, and corrects the control amount of the fuel injection valve according to the selected pressure value.

2. The internal combustion engine control device according to claim 1, characterized in that The pressure value acquisition unit performs the following processing: Calculates the first fuel pressure value according to the average value of multiple fuel pressure values acquired during the first period, Calculates the second fuel pressure value according to the average value of multiple fuel pressure values acquired during the second period.

3. The internal combustion engine control device according to claim 2, characterized in that The pressure value acquisition unit performs the following processing: Calculates the first fuel pressure value according to the average of multiple fuel pressure values acquired during multiple first periods of multiple strokes of the internal combustion engine, Calculates the second fuel pressure value according to the average of multiple fuel pressure values acquired during multiple second periods of multiple strokes of the internal combustion engine.

4. The internal combustion engine control device according to claim 1, characterized in that The arithmetic fuel pressure value is the average value of the first fuel pressure value and the second fuel pressure value.

5. The internal combustion engine control device according to claim 1, characterized in that At the first injection timing of the fuel injection valve, a main injection that injects more than half of the required injection amount calculated according to the operating state of the internal combustion engine is performed, and at a second injection timing after the first injection timing, a sub-injection that injects an amount less than the main injection is performed, The fuel injection control planning unit performs the following processing: When the execution of the sub-injection is planned during the first period, corrects the control amount of the fuel injection valve for the sub-injection based on the first fuel pressure value, When the execution of the sub-injection is planned during the second period, corrects the control amount of the fuel injection valve for the sub-injection based on the second fuel pressure value.

6. An internal combustion engine control method for controlling an internal combustion engine, the internal combustion engine having a reciprocating fuel pump that intermittently pressurizes fuel and discharges it into a fuel pipe, and a fuel injection valve for injecting the intermittently pressurized fuel, characterized in that it includes the following processing: A process of obtaining a first fuel pressure value acquired during a first period, where the first period starts from the pressurization operation time of the fuel pump and is the period until the first fuel injection from the fuel injection valve thereafter; A process of obtaining a second fuel pressure value acquired during a second period, where the second period is the period from after the first period until the pressurization time; A process of calculating an arithmetic fuel pressure value using the first fuel pressure value and the second fuel pressure value; and A process of selecting at least one of the first fuel pressure value, the second fuel pressure value, and the arithmetic fuel pressure value and correcting the control amount of the fuel injection valve according to the selected pressure value.

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