JP2016000536A - Engine fuel injection control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection control device of an engine mounted in a vehicle, capable of eliminating a delay of the fuel injection timing of a fuel injection valve from a reference value set initially due to the adhesion of engine oil or the like to the injection nozzle of the fuel injection valve, by exerting simple control.SOLUTION: The vehicle is a hybrid electric vehicle that includes an engine 10 and a drive motor 40 and that can be driven only by the drive motor 40, and a fuel injection control device of the vehicle executes a fuel injection timing correction control to advance the fuel injection timing of a fuel injection valve of the engine 10 from the reference value while keeping the engine 10 at a constant revolving speed, and to correct the fuel injection timing of the fuel injection valve with respect to the reference value in response to a difference between an engine output detected after advancement and a reference engine output corresponding to the reference value at the constant revolving speed.

Description

  The present invention belongs to a technical field related to an engine fuel injection control device.

  Conventionally, an engine fuel injection valve is normally opened in response to a rise of a pulse signal applied to a drive circuit of the fuel injection valve and closed in response to a fall to inject fuel therebetween. It is like that.

  The fuel injection valve as described above has a problem that the injection amount characteristic changes due to the secular change of the movable part. Therefore, for example, in Patent Document 1, when the fuel injection valve is driven, the valve fully open or fully closed point is detected from the displacement point of the drive current that appears at the fully open position and the fully closed position of the valve. At least one of valve opening or valve closing delay time is detected from the relationship between one of the closing points and the rising or falling point of the pulse signal, and the pulse width is corrected based on the delay time. .

JP 2001-280189 A

  By the way, when the fuel injection valve is arranged in a place where engine oil or the like is likely to adhere to the injection port, the valve opening is delayed with respect to the rise of the pulse signal due to the influence of the viscosity of the attached oil. Further, the valve closing tends to be delayed with respect to the falling, and in this case, the valve opening delay time with respect to the rising edge is substantially the same as the valve closing delay time with respect to the falling edge. As a result, although the fuel injection amount by the fuel injection valve does not change much, the fuel injection timing is retarded with respect to the initially set basic value. Such a tendency is particularly noticeable in a fuel injection valve that injects gaseous fuel. When the fuel injection timing is delayed in this way, the fuel distribution in the combustion chamber of the engine changes, and the engine torque (and thus the engine output) that should be obtained corresponding to the basic value cannot be obtained.

  Therefore, as in Patent Document 1, it is conceivable to detect the valve opening delay time with respect to the rising or the valve closing delay time with respect to the falling and correct the fuel injection timing based on the delay time. However, in the correction method of Patent Document 1 described above, it is necessary to differentiate the change in the drive current of the valve and detect the inflection point of the differential value, resulting in complicated correction control.

  The present invention has been made in view of such a point, and an object of the present invention is to initially set the fuel injection timing of the fuel injection valve due to adhesion of engine oil or the like to the injection port of the fuel injection valve. The object is to eliminate the delay with respect to the basic value by simple control.

  In order to achieve the above object, according to the present invention, for a fuel injection control device for an engine mounted on a vehicle, the vehicle has the engine and a drive motor and can be driven only by the drive motor. It is a hybrid vehicle, and comprises engine output detection means for detecting the output of the engine and control means for controlling the operation of the engine, and the control means maintains the engine at a constant rotation while maintaining the fuel of the engine The fuel injection timing of the injection valve is advanced with respect to the initially set basic value, and the engine output detected by the engine output detecting means after the advanced angle corresponds to the basic value at the constant rotation. Fuel injection timing correction control for correcting the fuel injection timing of the fuel injection valve with respect to the basic value according to the difference from the basic engine output Is configured sea urchin, it has a configuration that.

  With the above configuration, when the fuel injection timing of the fuel injection valve is delayed with respect to the basic value, if the fuel injection timing is advanced with respect to the basic value, the engine output is increased to the basic value. The difference from the corresponding basic engine output (value obtained from experiments and calculations) is reduced. The fuel injection timing can be appropriately corrected by determining the advance amount of the fuel injection timing so that this difference is minimized and correcting the basic value with the advance amount. Therefore, by detecting the engine output and comparing the detected engine output with the basic engine output, the retardation amount of the fuel injection timing with respect to the basic value can be determined, and the fuel injection timing is set by the amount of the retardation amount. With a simple control of advancing, the delay with respect to the basic value of the fuel injection timing can be eliminated.

  Here, when the fuel injection timing correction control is executed, the engine output changes depending on the advance angle of the fuel injection timing. However, a vehicle equipped with the fuel injection control device of the present invention is a hybrid that can be driven only by a drive motor. Since the vehicle is a range extender EV vehicle (including a series-type hybrid vehicle) or a parallel hybrid vehicle in which the engine is connected to a drive motor via a clutch, the engine does not mechanically drive the vehicle. The fuel injection timing correction control can be executed, and the change in the engine output due to the execution of the fuel injection timing correction control can be prevented from affecting the running of the vehicle.

  In one embodiment of the engine fuel injection control device, the engine further includes a generator that is driven by the engine to generate power, and the engine is used only for power generation by the generator, and the engine output detection The means comprises power generation amount detection means for detecting the power generation amount by the generator corresponding to the engine output, and the control means includes the power generation amount by the generator detected by the power generation amount detection means, The fuel injection timing correction control is executed according to the difference from the basic power generation amount corresponding to the basic engine output.

  As a result, the amount of power generated by the generator, which corresponds to the engine output, can be detected easily and accurately, and therefore the accuracy of correction of the fuel injection timing can be improved.

  In the case of the one embodiment, the battery further includes a battery that is charged with the power generated by the generator and supplies the charged power to the drive motor, and a battery remaining capacity detection unit that detects a remaining capacity of the battery. The control means is configured not to execute the fuel injection timing correction control when the remaining capacity of the battery detected by the remaining battery capacity detection means is equal to or less than a preset set capacity. Is preferred.

  This prevents battery deterioration by giving priority to battery charging and not performing fuel injection timing correction control when the battery needs to be charged quickly and has a very low remaining capacity. can do.

  In another embodiment of the fuel injection control device for the engine, the engine is connected to the drive motor via a clutch, and the hybrid vehicle includes the engine and the drive motor when the clutch is in an engaged state. On the other hand, when the clutch is in the disengaged state, it is configured to be driven only by the drive motor, and the control means controls the fuel injection timing correction control when the clutch is in the disengaged state. Is configured to run.

  Thus, in the parallel hybrid vehicle in which the engine is connected to the drive motor via the clutch, the fuel injection timing when the clutch is in the disengaged state (when the engine is not mechanically driving the vehicle). By executing the correction control, it is possible to prevent the change in the engine output due to the execution from affecting the running of the vehicle.

  As described above, according to the engine fuel injection control apparatus of the present invention, the fuel injection timing of the fuel injection valve of the engine is advanced with respect to the initially set basic value while maintaining the engine at a constant rotation. And the fuel injection timing of the fuel injection valve with respect to the basic value according to the difference between the engine output detected after the advance and the basic engine output corresponding to the basic value at the constant rotation. By executing the fuel injection timing correction control that corrects the fuel injection timing, the delay from the basic value of the fuel injection timing of the fuel injection valve due to adhesion of engine oil or the like to the injection port of the fuel injection valve can be controlled with simple control. This can be eliminated, and a decrease in engine torque due to the delay can be suppressed.

It is the schematic of the range extender EV vehicle by which the fuel-injection control apparatus of the engine which concerns on Embodiment 1 of this invention is mounted. It is a block diagram which shows the structure of the engine of the said vehicle, and its control system. It is a flowchart which shows the processing operation at the time of the drive of the engine by the control unit of the said vehicle. It is a figure which shows schematic structure of the drive system of the vehicle by which the fuel-injection control apparatus of the engine which concerns on Embodiment 2 of this invention is mounted. FIG. 5 is a flowchart showing a processing operation during engine operation by the vehicle control unit of FIG. 4. FIG. It is a flowchart which shows the processing operation at the time of the driving | operation of the engine by the control unit of the vehicle by which the air fuel ratio detection apparatus which concerns on the reference form of this invention is mounted.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic diagram of a vehicle 1 equipped with an engine fuel injection control apparatus according to Embodiment 1 of the present invention. The vehicle 1 is a so-called range extender EV vehicle (which can be said to be a series type hybrid vehicle in a broad sense), and includes an engine 10, a generator 20 driven by the engine 10 to generate electric power, and the generator The high-voltage and large-capacity battery 30 in which the power generated by the battery 20 is stored (charged), and both the generated power of the generator 20 driven by the engine 10 and the stored power (discharge power) of the battery 30 or And a drive motor 40 that is driven only by the discharge power of the battery 30 (in this embodiment, it is basically driven only by the discharge power of the battery 30 as will be described later). In the present embodiment, the engine 10 is started by a starter motor (not shown). However, the generator 20 may be changed to a motor generator, and the engine 10 may be started by driving the motor generator as a motor. Is possible.

  A first inverter 50 is provided between the generator 20 and the battery 30, and a second inverter 51 is provided between the battery 30 and the drive motor 40. The first inverter 50 and the second inverter 51 are connected to each other, and the battery 30 is connected to the connection line. The power generated by the generator 20 is supplied to the battery 30 via the first inverter 50 and also supplied to the drive motor 40 via the first and second inverters 50 and 51. Discharged power from the battery 30 is supplied to the drive motor 40 via the second inverter 51.

  The drive motor 40 is basically driven by the discharge power of the battery 30. When the output of the drive motor 40 is insufficient with only the discharge power of the battery 30, such as when the vehicle 1 is accelerated, the engine 10 is started. Thus, the power generated by the generator 20 is also supplied to the drive motor 40. The output of the drive motor 40 is transmitted to drive wheels 61 (left and right front wheels steered by the steering wheel 62) via a transmission and a differential device 60 (not shown), whereby the vehicle 1 travels.

  The drive motor 40 is capable of generating regenerative power, and operates as a generator when the vehicle 1 is decelerated, so that the battery 30 is charged with the generated power (regenerative power). When the remaining capacity (SOC) of the battery 30 falls below a predetermined capacity, the engine 10 is started and the battery 30 is charged with the generated power of the generator 20. The predetermined capacity is a capacity that is higher than the level that requires urgently required charging of the battery 30, and is a capacity that can be maintained at an appropriate level that is not too low and not too high as the remaining capacity of the battery 30. is there. The battery 30 can be externally charged by a power source external to the vehicle 1.

  The engine 10 is used only for power generation by the generator 20. The engine 10 is a gaseous fuel engine. In this embodiment, the hydrogen gas stored in the hydrogen tank 70 is a hydrogen engine supplied as fuel.

  As shown in FIG. 2, the engine 10 is a twin-rotor (two-cylinder) rotary piston engine, and is roughly arranged in a rotor housing chamber 11 a formed in two saddle-shaped rotor housings 11 (inside cylinders). Each of the triangular rotors 12 is accommodated. The two rotor housings 11 are integrated with the side housings so as to be sandwiched between three side housings (not shown), and each rotor housing chamber 11a is composed of each rotor housing 11 and the side housings on both sides thereof. Is formed. In FIG. 2, the two rotor housings 11 (two cylinders) are shown in an unfolded state, and the eccentric shafts 13 respectively drawn in the central portions in the two rotor housings 11 are the same.

  Each of the rotors 12 has apex seals (not shown) at the apexes of the triangles, and the apex seals are in sliding contact with the inner surface of the trochoid of the rotor housing 11. Three working chambers (corresponding to combustion chambers) are defined in 11a (each cylinder). Each rotor 12 rotates around the eccentric shaft 13 in a state where the three apex seals of the rotor 12 are in contact with the inner peripheral surface of the trochoid of the rotor housing 11, and around the axis of the eccentric shaft 13. To revolve around. While the rotor 12 makes one revolution, the working chambers formed between the tops of the rotor 12 move in the circumferential direction, and the intake, compression, expansion (combustion), and exhaust strokes are performed. The rotating force is output from the eccentric shaft 13 as the output shaft through the rotor 12.

  An intake passage 14 is connected to each of the rotor accommodating chambers 11a so as to communicate with an intake opening that opens to the working chamber in the intake stroke, and communicates with an exhaust opening that opens to the working chamber in the exhaust stroke. An exhaust passage 15 is connected to the front. There is one intake passage 14 on the upstream side, but on the downstream side, the intake passage 14 branches into two branch passages and communicates with each of the rotor accommodating chambers 11a. On the upstream side of the branch portion of the intake passage 14 (upstream side of the port injection valve 17 described later), a cross-sectional area (valve opening degree) of the intake passage 14 is driven by a throttle valve actuator 90 such as a stepping motor. A throttle valve 16 for adjustment is provided. The throttle valve 16 adjusts the amount of intake air into each rotor accommodating chamber 11a (the working chamber in the intake stroke).

  A port injection valve 17 (first fuel injection valve) that injects hydrogen gas supplied from the hydrogen tank 70 into the intake passage 14 is provided in each branch passage downstream of the branch portion of the intake passage 14. It is arranged. The hydrogen gas injected by the port injection valve 17 is mixed with air (premixed state) and supplied to the working chamber in the intake stroke.

  Two exhaust passages 15 are provided on the upstream side so as to communicate with the respective rotor accommodating chambers 11a, but are joined together on the downstream side. A low temperature active three-way catalyst 81 and a NOx occlusion reduction catalyst 82 for purifying exhaust gas are disposed downstream of the merging portion of the exhaust passage 15. The low temperature active three-way catalyst 81 is a three-way catalyst having a catalyst activation temperature lower than that of the NOx storage reduction catalyst 82, and is disposed upstream of the NOx storage reduction catalyst 82. In FIG. 2, arrows shown in the intake passage 14 and the exhaust passage 15 indicate the flow of intake and exhaust.

  The NOx occlusion reduction catalyst 82 is configured, for example, by supporting a NOx occlusion agent such as barium (Ba) or potassium (K) on a carrier containing a noble metal such as platinum (Pt) or palladium (Pd). The NOx in the exhaust gas of the engine 10 is stored in a lean air-fuel ratio atmosphere, and the stored NOx is stored in the rich air-fuel ratio atmosphere and the temperature of the NOx storage-reduction catalyst 82 is the activity of the NOx storage-reduction catalyst 82. The NOx is released under an atmosphere at a predetermined temperature higher than the gasification temperature and is reduced to react with HC and CO in the exhaust gas to reduce.

  In each rotor housing 11 (each cylinder), a direct injection valve 18 (second cylinder) that directly injects hydrogen gas supplied from the hydrogen tank 70 into the working chamber (combustion chamber) in the compression stroke of the rotor accommodating chamber 11a. And two spark plugs 19 for igniting the hydrogen gas injected from the port injection valve 17 and the direct injection valve 18.

  The mass ratio of the fuel injection amount by the port injection valve 17 to the total fuel injection amount by the port injection valve 17 and the direct injection valve 18 (hereinafter referred to as the port injection ratio) and the direct injection valve 18 by the total fuel injection amount The mass ratio of the fuel injection amount (hereinafter referred to as direct injection ratio) basically includes the engine 10 having a target rotational speed (2000 rpm in the present embodiment) and a target combustion air-fuel ratio (A / F in the present embodiment). = 2.3) is set to a value (a value that can be determined in advance through experiments, calculations, etc.) that allows the target output torque (target power generation amount) to be obtained. The total fuel injection amount (combustion air-fuel ratio in the working chamber (combustion chamber)) is feedback-controlled by the output of an air-fuel ratio sensor 105 described later. Further, during the operation of the engine 10 (including the time of starting), the throttle valve 16 is always fully opened.

  In the present embodiment, the intake opening is configured to be opened and closed by the rotor 12 and fully closed during the compression stroke (so-called intake late closing configuration). In such a configuration of slow intake closing, the output torque of the engine 10 decreases due to a decrease in the effective compression ratio, but a turbocharger 85 is provided in order to prevent the output torque from decreasing. Further, in the configuration of the intake air late closing, the hydrogen gas injected from the port injection valve 17 and the intake air are about to be returned from the working chamber to the intake passage 14 through the intake opening in the compression stroke. This can be prevented by the supercharging pressure by the supercharger 85.

  The turbocharger 85 includes a compressor 85 a disposed on the upstream side of the throttle valve 16 in the intake passage 14 and a downstream side of the merging portion in the exhaust passage 15 and an upstream side of the three-way catalyst 81. It is comprised with the arrange | positioned turbine 85b. The turbine 85b is rotated by the exhaust gas flow, and the rotation of the turbine 85b activates the compressor 85a connected to the turbine 85b to compress the air taken into the intake passage 14. The compressed air is cooled by an intercooler 86 disposed downstream of the compressor 85 a in the intake passage 14.

  The vehicle 1 includes a battery current / voltage sensor 101 that detects a current flowing into and out of the battery 30 and a voltage of the battery 30, and an accelerator that detects an amount of depression of an accelerator pedal by a driver of the vehicle 1 (accelerator opening by a driver's operation). An opening sensor 102, a vehicle speed sensor 103 that detects the vehicle speed of the vehicle 1, a rotation angle sensor 104 that is provided on the eccentric shaft 13 and detects the rotation angle position of the eccentric shaft 13, and a low-temperature active three-way catalyst in the exhaust passage 15 An air-fuel ratio sensor 105 (configured by a linear O2 sensor in this embodiment) that is disposed between the turbine 81 and the turbine 85 b and detects the air-fuel ratio of the exhaust gas of the engine 10, and the rotor housing 11 Facing the formed water jacket (not shown), the water jacket An engine water temperature sensor 106 that detects the temperature of the engine cooling water flowing in the engine (engine water temperature), a tank pressure sensor 107 that detects the pressure in the hydrogen tank 70 (that is, the remaining amount of hydrogen gas in the hydrogen tank 70), and an intake passage. 14, an air flow sensor 108 for detecting the intake flow rate sucked into the engine 14, operation control of the engine 10, operation control of the first and second inverters 50 and 51 (that is, operation control of the generator 20 and the drive motor 40), and the like. A control unit 100 is provided. The rotational angle sensor 104 also serves as an engine rotational speed sensor that detects the rotational speed of the engine 10 (hereinafter referred to as engine rotational speed).

  The control unit 100 is a controller based on a well-known microcomputer, and includes a central processing unit (CPU) that executes a program, a memory that is configured by, for example, a RAM or ROM, and stores a program and data, and an electrical signal An input / output (I / O) bus. The control unit 100 includes a battery current / voltage sensor 101, an accelerator opening sensor 102, a vehicle speed sensor 103, a rotation angle sensor 104, an air-fuel ratio sensor 105, an engine water temperature sensor 106, a tank pressure sensor 107, an air flow sensor 108, and the like. An information signal is input.

  The generator 20 transmits information on the voltage and current generated by the generator 20 to the control unit 100. The control unit 100 inputs the information and generates power generated by the generator 20 from the information. (Power generation amount) is detected. Thus, the power generator 20 and the control unit 100 constitute power generation amount detection means (also engine output detection means) that detects the power generation amount by the power generator 20 corresponding to the engine output.

  The drive motor 40 transmits information on the rotational speed of the drive motor 40 and information on the regenerative power generation voltage and regenerative power generation current generated by the drive motor 40 to the control unit 100, and the control unit 100 transmits the information. The input is used to control the operation of the drive motor 40.

  Based on the input signal, the control unit 100 outputs a control signal to the throttle valve actuator 90, the port injection valve 17, the direct injection valve 18, and the spark plug 19 to control the engine 10, and Control signals are output to the first and second inverters 50 and 51 to control the generator 20 and the drive motor 40. The control unit 100 constitutes control means for controlling the operation of the engine 10.

  The control unit 100 controls the first and second inverters 50 and 51 to generate power from the generator 20 and the first mode in which the drive motor 40 is driven only with the discharged power from the battery 30 with the engine 10 stopped. A second mode in which the drive motor 40 is driven with the discharge power from the battery 30 while charging the battery 30 with the power, and a third mode in which the drive motor 40 is driven with the power from both the battery 30 and the generator 20. Switch to the mode. In this third mode, all of the power generated by the generator 20 is supplied to the drive motor 40, and a part of the power generated by the generator 20 is supplied to the drive motor 40 while the rest is supplied to the battery 30. Is included.

  The control unit 100 detects the remaining capacity (SOC) of the battery 30 based on the current flowing into and out of the battery 30 and the voltage of the battery 30 detected by the battery current / voltage sensor 101. Therefore, the battery current / voltage sensor 101 and the control unit 100 constitute battery remaining capacity detection means for detecting the remaining capacity of the battery 30. Then, when the SOC of the battery 30 is higher than the predetermined capacity, the control unit 100 selects the one mode. Even if the SOC of the battery 30 is higher than the predetermined capacity, the control unit 100 opens the accelerator due to a driver's acceleration request or the like. When the required output of the drive motor 40 based on the signals from the degree sensor 102 and the vehicle speed sensor 103 is large, the third mode is selected. Further, the control unit 100 selects the second mode when the SOC of the battery 30 is not more than the predetermined capacity. The first mode is selected when the remaining amount of hydrogen gas in the hydrogen tank 70 by the tank pressure sensor 107 falls below a preset value.

  When the engine 10 is in a stopped state, the control unit 100 checks the presence or absence of a power generation request based on the required output of the drive motor 40 and the SOC value of the battery 30, and when there is a power generation request, the starter motor Then, the engine 10 is started, and the engine 10 is operated to cause the generator 20 to generate power.

  The control unit 100 operates the engine 10 at a target rotational speed (2000 rpm) and a target combustion air-fuel ratio (A / F = 2.3), and at that time, a port injection ratio and a direct injection ratio at which a target power generation amount is obtained. (The sum of the port injection ratio and the direct injection ratio is 100%). At this time, if the fuel injection timings of the port injection valve 17 and the direct injection valve 18 are in accordance with the initially set basic values, the target power generation amount can be obtained.

  Here, since engine oil is supplied to the inner peripheral surface of the trochoid of the rotor housing 11, the engine oil easily adheres to the injection port of the direct injection valve 18. When engine oil adheres to the injection port of the direct injection valve 18 in this way, the engine oil is affected by the viscosity of the attached engine oil and is opened with respect to the rise of a pulse signal that is a control signal to the direct injection valve 18. The valve is delayed and the closing of the valve tends to be delayed with respect to the falling. The delay time of the valve opening with respect to the rise and the delay time of the valve closing with respect to the fall are substantially the same, and the fuel injection amount by the direct injection valve 18 does not change much, but the fuel injection timing by the direct injection valve 18 (Hereinafter also referred to as direct injection timing) is retarded with respect to the basic value. When the direct injection timing is delayed in this way, the fuel distribution in the working chamber (combustion chamber) changes (a lot of fuel is distributed on the trailing side), and the target that should be obtained corresponding to the above basic value The engine torque (that is, the basic power generation amount (target power generation amount) corresponding to the basic engine output corresponding to the basic value at the target rotational speed) cannot be obtained.

  Therefore, when the power generation amount (actual power generation amount) by the power generator 20 detected by the power generation amount detection means is smaller than the target power generation amount and the difference between them is larger than a predetermined amount, the control unit 100 10 is held at a constant rotation (in this embodiment, 2000 rpm, which is the same as the target rotation speed), while the fuel injection timing of the direct injection valve 18 is advanced with respect to the initially set basic value, The fuel injection timing of the direct injection valve 18 is determined based on the difference between the actual power generation amount detected after advance and the target power generation amount (basic power generation amount) corresponding to the basic value at the constant rotation. Fuel injection timing correction control for correcting the value is executed.

  Below, the processing operation at the time of the driving | operation of the engine 10 by the control unit 100 is demonstrated based on the flowchart of FIG.

  In the first step S1, signals from various sensors are read, and in the next step S2, the required output of the drive motor 40 is calculated based on the signals from the accelerator opening sensor 102 and the vehicle speed sensor 103.

  In the next step S3, the presence or absence of a power generation request is confirmed based on the required output of the drive motor 40 and the SOC of the battery 30, and in the next step S4, it is determined whether or not there is a power generation request.

  When the determination in step S4 is NO, the process returns to step S1, while when the determination in step S4 is YES, the process proceeds to step S5 and the engine 10 is started.

  In the next step S6, the engine is operated at the target rotational speed and the target combustion air-fuel ratio, and at that time, the port injection ratio and the direct injection ratio at which the target power generation amount is obtained are set (the port injection ratio and the direct injection ratio). Total should be 100%).

  In the next step S7, it is determined whether the power generation amount (actual power generation amount) by the power generator 20 detected by the power generation amount detection means is smaller than the target power generation amount and the difference between them is larger than a predetermined amount α. To do. The predetermined amount α is such an amount that it can be determined that the actual power generation amount is clearly lower than the target power generation amount.

  If the determination in step S7 is NO, the process returns. If the determination in step S7 is YES, the process proceeds to step S8, and whether or not the SOC of the battery 30 is greater than a preset set capacity. Determine. The set capacity is a capacity that is smaller than the predetermined capacity and is a considerably small remaining capacity that requires the battery 30 to be quickly charged.

  If the determination in step S8 is NO, the process returns. That is, when the SOC of the battery 30 is equal to or less than the set capacity, the charging of the battery 30 is prioritized so that the fuel injection timing correction control is not executed.

  When the determination in step S8 is YES, the process proceeds to step S9 to advance the direct injection timing by a predetermined value while maintaining the engine 10 at a constant rotation (2000 rpm in the present embodiment). This predetermined value is a value that is as small as possible and the actual power generation amount clearly changes (the angle of the eccentric shaft 13 is, for example, 10 °).

  In the next step S10, it is determined whether or not the actual power generation amount has increased due to the advance angle of the direct injection timing, that is, whether or not the difference between the actual power generation amount and the target power generation amount has decreased. When the determination in step S10 is YES, the process returns to step S9 and the operations in steps S9 and S10 are repeated. That is, the direct injection timing is gradually advanced by a predetermined value from the basic value so that the actual power generation amount approaches the target power generation amount.

  On the other hand, when the determination in step S10 is NO, the process proceeds to step S11, where the direct injection timing is the previous direct injection timing (the direct injection timing before being advanced in the latest step S9). The actual power generation amount is corrected to a direct injection timing (which is closest to the target power generation amount), and then the process returns.

  Therefore, in the present embodiment, when the fuel injection timing of the direct injection valve 18 is delayed with respect to the basic value, the fuel injection timing of the direct injection valve 18 is set to the basic value while maintaining the engine 10 at a constant rotation. Direct injection injection according to the difference between the actual power generation detected after the advance and the basic power generation (target power generation) corresponding to the basic value at the constant rotation. Since the fuel injection timing correction control for correcting the fuel injection timing of the valve 18 with respect to the basic value is executed, the change in the drive current of the direct injection valve 18 is differentiated to detect the inflection point of the differential value. There is no need for complicated control, such as to perform, and the delay from the basic value of the fuel injection timing of the direct injection valve 18 can be eliminated by simple control.

  Further, since the vehicle 1 equipped with the fuel injection control device according to this embodiment is a range extender EV vehicle (including a series type hybrid vehicle), the engine 10 does not mechanically drive the vehicle 1, Even if the fuel injection timing correction control is executed during the operation of the engine 10, the change in the engine output due to the execution of the fuel injection timing correction control does not affect the running of the vehicle 1.

(Embodiment 2)
FIG. 4 is a schematic configuration diagram of a drive system of the vehicle 1 in which the engine fuel injection control device according to the second embodiment of the present invention is mounted. The same parts as those in FIG. 1 are denoted by the same reference numerals, detailed description thereof will be omitted, and different parts from the first embodiment will be mainly described.

  In the present embodiment, the vehicle 1 is a parallel hybrid vehicle in which the engine 10 is connected to the drive motor 40 via the clutch 15, and when the clutch 15 is in the engaged state, both the engine 10 and the drive motor 40 are used. On the other hand, when the clutch 15 is in the disengaged state, it is configured to be driven only by the drive motor 40.

  In FIG. 4, a transmission 45 is shown. Inside the transmission 45, there are a plurality of shift frictional engagement elements 45a for shifting gears (normally there are a plurality, but in FIG. 4, they are simplified to one. Are listed). In FIG. 4, one of the two drive wheels 61 (front wheel) is omitted.

  The generator 20 (here, an alternator) is connected to the engine 10 via the belt 11 and is driven by the engine 10 to generate power. The electric power generated by the generator 20 is stored (charged) in the high-voltage / large-capacity battery 30 via the first inverter 50. The stored power (discharge power) of the battery 30 is supplied to the drive motor 40 via the second inverter 51, and the drive motor 40 is driven with this discharge power.

  The configuration of the engine 10 is the same as that of the first embodiment, and the configuration of the control system including the control unit 100 is also the same as that of the first embodiment (see FIG. 2). However, in the control of the control unit 100, the control of the operation of the actuator for engaging and releasing the clutch 15 is added.

  The control unit 100 controls the first and second inverters 50 and 51 and the clutch 15 (the actuator) to release the clutch 15 and drive the vehicle 1 only by the drive motor 40 with the engine 10 stopped. 1 mode, the 2nd mode which drives vehicle 1 only with drive motor 40 in the release state of clutch 15 while charging battery 30 with the generated power of generator 20 driven by engine 10, and engagement of clutch 15 In the state, the mode is switched to the third mode in which the vehicle 1 is driven by both the engine 10 and the drive motor 40. The third mode includes a case where the battery 30 is charged with the generated power of the generator 20 driven by the engine 10 and a case where the battery 30 is not charged.

  When the SOC of the battery 30 is higher than the predetermined capacity, the control unit 100 selects the one mode. Even if the SOC of the battery 30 is higher than the predetermined capacity, the control unit 100 determines whether the accelerator opening sensor When the required output of the drive motor 40 based on the signals from 102 and the vehicle speed sensor 103 is large, the third mode is selected. Further, the control unit 100 selects the second mode when the SOC of the battery 30 is not more than the predetermined capacity. Further, when the remaining amount of hydrogen gas in the hydrogen tank 70 by the tank pressure sensor 107 is equal to or less than the set value, the first mode is selected.

  When the engine 10 is in a stopped state (the clutch 15 is normally in a disengaged state), the control unit 100 determines the engine 10 based on the required output of the drive motor 40 and the SOC value of the battery 30. When the driving request is confirmed and the vehicle 1 is driven by both the engine 10 and the drive motor 40 when the driving request is present, the clutch 15 is engaged after the engine 10 is started. On the other hand, when the driving request is made and the vehicle 1 is driven only by the drive motor 40, the engine 10 is started with the clutch 15 remaining in the released state.

  Below, the processing operation at the time of the driving | operation of the engine 10 by the control unit 100 is demonstrated based on the flowchart of FIG.

  In the first step S21, signals from various sensors are read, and in the next step S22, the required output of the drive motor 40 is calculated based on the signals from the accelerator opening sensor 102 and the vehicle speed sensor 103.

  In the next step S23, the presence or absence of an operation request for the engine 10 is confirmed based on the required output of the drive motor 40 and the SOC of the battery 30, and in the next step S24, it is determined whether or not there is an operation request for the engine 10. To do.

  If the determination in step S24 is NO, the process returns to step S21. If the determination in step S24 is YES, the process proceeds to step S25, and whether or not the vehicle 1 is driven only by the drive motor 40. Determine.

  When the determination in step S25 is YES, the process proceeds to step S26 to determine whether or not the SOC of the battery 30 is equal to or less than the predetermined capacity. When the determination in step S26 is NO, the process returns as it is. On the other hand, when the determination in step S26 is YES, the clutch 15 is released (usually, even if this operation is not performed) In step S28, the engine 10 is started.

  In the next step S29, similar to step S6 above, the engine is operated at the target rotational speed and the target combustion air-fuel ratio, and at that time, the port injection ratio and the direct injection ratio for obtaining the target power generation amount are set (port injection ratio). And the direct injection ratio are 100%).

  In the next step S30, as in step S7, the power generation amount (actual power generation amount) by the power generator 20 detected by the power generation amount detection means is smaller than the target power generation amount, and the difference between them is larger than the predetermined amount α. It is also determined whether or not the

  If the determination in step S30 is NO, the process returns as it is. If the determination in step S30 is YES, the process proceeds to step S31, and in steps S31 to S33, operations similar to those in steps S9 to S11 are performed (that is, Fuel injection timing correction control) is performed, and then the process returns.

  When the determination in step S25 is NO, the process proceeds to step S34, the engine 10 is started, and the clutch 15 is engaged in the next step S35. In the next step S36, both drive control for driving the vehicle 1 by both the engine 10 and the drive motor 40 is executed, and then the process returns.

  Therefore, also in the present embodiment, as in the first embodiment, by executing the fuel injection timing correction control, the delay from the basic value of the fuel injection timing of the direct injection valve 18 can be eliminated by simple control. . In a parallel hybrid vehicle in which the engine 10 is connected to the drive motor 40 via the clutch 15, when the engine 10 is in operation and the clutch 15 is in a released state (the engine 10 mechanically moves the vehicle 1). Since the fuel injection timing correction control is executed when the vehicle is not driven), it is possible to prevent the change in the engine output due to the execution of the fuel injection timing correction control from affecting the travel of the vehicle 1.

  In the first and second embodiments, the fuel injection timing of the direct injection valve 18 is corrected in the fuel injection timing correction control. However, in the same manner as the correction of the fuel injection timing of the direct injection valve 18, The fuel injection timing of the port injection valve 17 may be corrected. That is, since the supercharging pressure by the turbocharger 85 is low at a low engine speed when the engine 10 is started, the fuel and intake air injected from the port injection valve 17 by the above-described structure of the intake air slow closing is used. The compressed air is returned from the working chamber to the intake passage 14 through the intake opening in the compression stroke, and accordingly, the engine oil flows into the intake passage 14, whereby the injection port of the port injection valve 17 is also This is because the engine oil adheres and the fuel injection timing of the port injection valve 17 may be delayed with respect to the basic value, similarly to the fuel injection timing of the direct injection valve 18. The delay of the fuel injection timing of the port injection valve 17 does not affect the engine output torque (and hence the engine output or the amount of power generation) as much as the delay of the fuel injection timing of the direct injection valve 18, but due to long-term use. When the fuel injection timing of the port injection valve 17 is greatly delayed, the correction of the fuel injection timing of the port injection valve 17 is also very effective.

(Reference form)
In this reference embodiment, the vehicle 1 will be described as a range extender EV vehicle (series hybrid vehicle) having the same configuration as that of the first embodiment. The vehicle 1 is equipped with an air-fuel ratio detection device that detects the air-fuel ratio of exhaust gas according to the present embodiment. The air-fuel ratio detection device executes feedback control of the combustion air-fuel ratio (total fuel injection amount) of the engine 10 based on the air-fuel ratio sensor 105 configured by a linear O2 sensor and the output value of the air-fuel ratio sensor 105. The control unit 100 is provided.

  When the air-fuel ratio sensor 105 (linear O2 sensor) is flooded, its output characteristics change (especially, it tends to output an output value corresponding to the rich side). In particular, when the fuel is hydrogen gas, since a large amount of water is generated by combustion, the air-fuel ratio sensor 105 is likely to be wet. When the air-fuel ratio sensor 105 is flooded in this way and the output value of the air-fuel ratio sensor 105 changes from the initial output value before flooding, the target combustion air-fuel ratio cannot be obtained, and the actual power generation amount and the target power generation amount The difference will be larger. In particular, when an output value corresponding to the rich side is output, the combustion air-fuel ratio becomes leaner than the target combustion air-fuel ratio, and even if it becomes lean like this, the output value becomes the rich side. As a result, the actual power generation amount becomes lower than the target power generation amount. Therefore, in this reference embodiment, the control unit 100 changes the output value of the air-fuel ratio sensor 105 while keeping the engine 10 at a constant rotation, and the engine output detected by the engine output detection means before and after the change, respectively. Based on (actual power generation amount before and after the change), the sensor output correction control for correcting the output value of the air-fuel ratio sensor 105 (correcting uniformly over the entire sensor detection range) is executed.

  Below, the processing operation at the time of the driving | operation of the engine 10 by the control unit 100 is demonstrated based on the flowchart of FIG.

  In steps S51 to S56, the same operations as in steps S1 to S6 are performed, and in the next step S57, the combustion air-fuel ratio in the working chamber (combustion chamber) based on the output value of the air-fuel ratio sensor 105 (linear O2 sensor) is determined. Execute feedback control.

  In the next step S58, it is determined whether or not the absolute value of the value obtained by subtracting the actual power generation amount from the target power generation amount is larger than the predetermined amount α. If the determination in step S58 is NO, the process returns as it is. If the determination in step S58 is YES, the process proceeds to step S59, and whether or not the NOx occlusion amount of the NOx occlusion reduction catalyst 82 is smaller than a predetermined threshold value. Determine. The predetermined threshold is a value close to the amount that requires the stored NOx to be released. That is, there is a possibility that a large amount of NOx may be generated due to a change in the combustion air-fuel ratio when the sensor output correction control is executed, and the NOx occlusion amount is greater than or equal to the predetermined threshold value so that the generated NOx can be reliably occluded. In this case, the sensor output correction control is not executed. The NOx occlusion amount of the NOx occlusion reduction catalyst 82 can be calculated from the operation history of the engine 10, and the control unit 100 integrates the NOx occlusion amount based on the operation state during the operation of the engine 10. . Therefore, the control unit 100 constitutes NOx occlusion amount detection means for detecting the NOx occlusion amount of the NOx occlusion reduction catalyst 82.

  In the next step S60, when the actual power generation amount is larger than the target power generation amount while maintaining the engine 10 at a constant rotation (2000 rpm in the present embodiment), the output value of the air-fuel ratio sensor 105 (linear O2 sensor). When the actual power generation amount is smaller than the target power generation amount, the output value is changed to the lean side by the first predetermined value. (Change uniformly over the entire sensor detection range). The first and second predetermined values are values that are as small as possible and in which the actual power generation amount clearly changes, similar to the predetermined values in the first and second embodiments (the first and second predetermined values). The values may be the same value or different values).

  In the next step S61, it is determined whether or not the difference between the actual power generation amount and the target power generation amount is small. If the determination in step S61 is NO, the process directly returns. That is, even if the output value of the air-fuel ratio sensor 105 is changed as in step S60, if the actual power generation amount does not change so that the difference between the actual power generation amount and the target power generation amount becomes small before and after the change, Return is made assuming that the output value of the air-fuel ratio sensor 105 is not abnormal.

  On the other hand, when the determination in step S61 is YES, the process proceeds to step S62 to determine whether or not the absolute value of the value obtained by subtracting the actual power generation amount from the target power generation amount is equal to or less than the predetermined amount α. If the determination in step S62 is no, the process returns to step S60. That is, the output value is gradually changed to the rich side by the first predetermined value or the second predetermined value is gradually changed to the lean side so that the actual power generation amount approaches the target power generation amount. Go. On the other hand, when the determination in step S62 is YES, the process proceeds to step S63, and the output value of the air-fuel ratio sensor 105 is corrected to the output value after the last change in step S60 (uniformly over the entire sensor detection range). To correct).

  Therefore, in the present embodiment, the output value of the air-fuel ratio sensor 105 is changed while holding the engine 10 at a constant rotation, and the air-fuel ratio is determined based on the engine outputs respectively detected by the engine output detection means before and after the change. Since the sensor output correction control for correcting the output value of the sensor 105 is executed, even if the output characteristics change due to the flooding of the air-fuel ratio sensor 105 (linear O2 sensor), the control before the flooding can be performed with simple control. A correct output value can be obtained.

  In the reference embodiment, the vehicle 1 is a range extender EV vehicle (series hybrid vehicle) having the same configuration as that of the first embodiment. However, a hybrid vehicle (parallel type) having the same configuration as that of the second embodiment is used. Hybrid vehicle). In this case, sensor output correction control is executed when the clutch 15 is in the released state.

  The present invention is not limited to the embodiment described above, and can be substituted without departing from the spirit of the claims.

  For example, in the above embodiment and the reference embodiment, the engine 1 is a hydrogen rotary engine using hydrogen gas as a fuel. However, a reciprocating engine using hydrogen gas as a fuel may be used, and a gas other than hydrogen gas (for example, Further, a rotary engine or a reciprocating engine using natural gas (CNG) as fuel may be used.

  The above-described embodiments are merely examples, and the scope of the present invention should not be interpreted in a limited manner. The scope of the present invention is defined by the scope of the claims, and all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  INDUSTRIAL APPLICABILITY The present invention is useful for an engine fuel injection control device mounted on a hybrid vehicle that has an engine and a drive motor and can be driven only by the drive motor.

1 vehicle (hybrid vehicle)
10 engine 15 clutch 20 generator (power generation amount detection means) (engine output detection means)
30 battery 40 drive motor 100 control unit (control means) (power generation amount detection means)
(Engine output detection means) (Battery remaining capacity detection means)
101 Battery current / voltage sensor (Battery remaining capacity detection means)

Claims (4)

An engine fuel injection control device mounted on a vehicle,
The vehicle is a hybrid vehicle that has the engine and a drive motor and can be driven only by the drive motor,
Engine output detection means for detecting the output of the engine;
Control means for controlling the operation of the engine,
The control means advances the fuel injection timing of the fuel injection valve of the engine with respect to the initially set basic value while maintaining the engine at a constant rotation, and detects the engine output after the advance. The fuel injection timing for correcting the fuel injection timing of the fuel injection valve with respect to the basic value according to the difference between the engine output detected by the means and the basic engine output corresponding to the basic value at the constant rotation An engine fuel injection control device configured to perform correction control. The fuel injection control device for an engine according to claim 1,
A generator that is driven by the engine to generate electricity;
The engine is used only for power generation by the generator,
The engine output detection means comprises power generation amount detection means for detecting the amount of power generated by the generator corresponding to the engine output,
The control means executes the fuel injection timing correction control in accordance with a difference between the power generation amount detected by the power generation amount detection means and the basic power generation amount corresponding to the basic engine output. A fuel injection control device for an engine characterized by being configured. The fuel injection control device for an engine according to claim 2,
A battery that is charged with power generated by the generator and supplies the charged power to the drive motor;
A battery remaining capacity detecting means for detecting the remaining capacity of the battery;
The control means is configured not to execute the fuel injection timing correction control when the remaining capacity of the battery detected by the remaining battery capacity detecting means is equal to or less than a preset set capacity. An engine fuel injection control device. The fuel injection control device for an engine according to claim 1,
The engine is connected to the drive motor via a clutch,
The hybrid vehicle is configured to be driven by both the engine and the drive motor when the clutch is in an engaged state, and is driven only by the drive motor when the clutch is in a released state.
The engine fuel injection control device according to claim 1, wherein the control means is configured to execute the fuel injection timing correction control when the clutch is in a released state.

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