JP2018021521A - Automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress occurrence of noise caused by an increase of the vibration of a fuel supply device or the like for supplying fuel to a port injection valve and an in-cylinder injection valve.SOLUTION: A fuel supply device includes: a fuel tank; a first pump for supplying fuel in the fuel tank to a first passage to which a port injection valve is connected; a check valve arranged at the first passage; and a second pump which pressurizes fuel more on the port injection valve side from the check valve in the first passage, and supplies it to a second passage to which an in-cylinder injection valve is connected. Then, the fuel supply device controls the first pump so that the fuel pressure of the fuel supplied to the port injection valve reaches target fuel pressure. Furthermore, the fuel supply device sets a first prescribed fuel pressure to the target fuel pressure at a start of an operation of an engine, and after that, when a rotation number of the engine goes out of a resonance region of the fuel supply device, switches the target fuel pressure to a second prescribed fuel pressure which is lower than the first prescribed fuel pressure.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an automobile, and more particularly, to an automobile provided with an engine and a fuel supply device.

  Conventionally, as this type of automobile, an automobile having an engine having a port injection valve and an in-cylinder injection valve, and a fuel supply device that supplies fuel to the port injection valve and the in-cylinder injection valve has been proposed (for example, , See Patent Document 1). Here, the fuel supply device includes a fuel tank, a feed pump that supplies fuel from the fuel tank to the first passage connected to the port injection valve, a check valve provided in the first passage, and a first passage. A high-pressure fuel pump that pressurizes fuel on the port injection valve side of the check valve and supplies the pressurized fuel to the second passage connected to the in-cylinder injection valve. In this automobile, the feed pump is controlled so that the fuel pressure of the fuel supplied to the port injection valve becomes the target fuel pressure.

JP2015-218595A

  In the above-described automobile, when the target fuel pressure of the fuel supplied to the port injection valve is lowered after the engine starts, the amount of fuel from the feed pump is reduced, so that the feed pump side is more than the check valve in the first passage. May become less than the fuel pressure on the port injection valve side and the check valve may close. When the check valve is closed, the pulsation of the fuel pressure in the first passage generated by driving the high-pressure fuel pump increases, and the vibration of the fuel supply device and the like may increase and generate abnormal noise.

  The main object of the automobile of the present invention is to suppress the occurrence of abnormal noise due to large vibrations of a fuel supply device that supplies fuel to a port injection valve and a cylinder injection valve.

  The automobile of the present invention has taken the following means in order to achieve the main object described above.

The automobile of the present invention
An engine having a port injection valve for injecting fuel into the intake pipe, and an in-cylinder injection valve for injecting fuel into the cylinder;
A fuel tank; a first pump for supplying fuel from the fuel tank to a first passage to which the port injection valve is connected; and a fuel pressure provided in the first passage and on the first pump side A check valve that opens when the fuel pressure is higher than the fuel pressure of the first injection pump and closes when the fuel pressure on the first pump side is equal to or lower than the fuel pressure on the port injection valve side, and more than the check valve in the first passage. A fuel supply device having a second pump for pressurizing the fuel on the port injector side and supplying the fuel to the second passage connected to the cylinder injection valve;
A control device for controlling the engine and the fuel supply device;
A car equipped with
The control device controls the first pump so that a fuel pressure of fuel supplied to the port injection valve becomes a target fuel pressure;
Further, the control device sets a first predetermined fuel pressure as the target fuel pressure at the start of operation of the engine, and then the target fuel pressure when the engine speed is outside the resonance region of the fuel supply device. Switching the fuel pressure to a second predetermined fuel pressure lower than the first predetermined fuel pressure;
This is the gist.

  In the automobile of the present invention, the first pump is controlled so that the fuel pressure of the fuel supplied to the port injection valve becomes the target fuel pressure. At the start of engine operation, the first predetermined fuel pressure is set as the target fuel pressure, and then the target fuel pressure is lower than the first predetermined fuel pressure when the engine speed is outside the resonance region of the fuel supply device. 2 Switch to the predetermined fuel pressure. Therefore, since the target fuel pressure is switched from the first predetermined fuel pressure to the second predetermined fuel pressure when the engine speed is outside the resonance region of the fuel supply device, the fuel pressure on the first pump side is higher than the check valve in the first passage. Even if the check valve closes when the fuel pressure is lower than the port injection valve side, the pulsation of the fuel pressure in the first passage generated by driving the second pump is less likely to increase, resulting in increased vibration of the fuel supply device and the like. It is possible to suppress the generation of abnormal noise in the fuel supply device or the like. Of course, when the engine is started, fuel atomization can be promoted by setting the target fuel pressure to a relatively high first predetermined fuel pressure. Moreover, the power consumption of the first pump can be suppressed by setting the target fuel pressure to a relatively low second predetermined fuel pressure thereafter.

  In such an automobile of the present invention, the control device sets the first predetermined fuel pressure to the target fuel pressure when a starting fuel pressure that is a fuel pressure of fuel supplied to the port injection valve at the start of operation of the engine is less than a threshold value. It may be set and held. If it carries out like this, when the starting fuel pressure is less than a threshold value, the power consumption of a 1st pump can be suppressed more.

  In the automobile of the present invention, the control device may be configured such that when the target fuel pressure is the first predetermined fuel pressure and the engine speed is within the resonance region and the engine speed is within the resonance region, the engine speed is The target fuel pressure may be switched to the second predetermined fuel pressure after changing the operating point of the engine so as to be outside the resonance region. In this way, by changing the engine operating point so that the engine speed is out of the resonance region, the vibration of the fuel supply device and the like is increased due to switching of the target fuel pressure, and abnormal noise is generated. Can be suppressed.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. FIG. 2 is a configuration diagram showing an outline of configurations of an engine 22 and a fuel supply device 60. It is explanatory drawing which shows an example of the fuel efficiency operation line of the engine 22, and a mode that the rotation speed Neef and the torque Tef are set. It is a flowchart which shows an example of the target fuel pressure setting routine performed by engine ECU24 of an Example. It is explanatory drawing which shows an example of the mode of the time change of the feed pump 62, fuel pressure Pfp, target fuel pressure Pfp *, and the rotation speed Ne of the engine 22. FIG. It is a flowchart which shows an example of the target fuel pressure setting routine of a modification. It is explanatory drawing which shows an example of the resonance avoidance operation line of the engine 22, and a mode that the rotation speed Nere and the torque Tere are set.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention, and FIG. 2 is a configuration diagram showing an outline of the configuration of an engine 22 and a fuel supply device 60.

  As shown in FIG. 1, the hybrid vehicle 20 of the embodiment includes an engine 22, a fuel supply device 60, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, and a hybrid electronic control unit. (Hereinafter referred to as “HVECU”) 70.

  The engine 22 is configured as an internal combustion engine that outputs power using a fuel such as gasoline or light oil. As shown in FIG. 2, the engine 22 includes a port injection valve 125 that injects fuel into the intake port and an in-cylinder injection valve 126 that injects fuel into the cylinder. The engine 22 includes the port injection valve 125 and the in-cylinder injection valve 126, so that the engine 22 can be operated in any of the port injection mode, the in-cylinder injection mode, and the common injection mode.

  In the port injection mode, air cleaned by the air cleaner 122 is sucked through the throttle valve 124 and fuel is injected from the port injection valve 125 to mix the air and fuel. Then, the air-fuel mixture is sucked into the combustion chamber via the intake valve 128 and is explosively burned by an electric spark by the spark plug 130. The reciprocating motion of the piston 132 pushed down by the energy is converted into the rotational motion of the crankshaft 26. . In the in-cylinder injection mode, air is sucked into the combustion chamber in the same manner as in the port injection mode, fuel is injected from the in-cylinder injection valve 126 during the intake stroke or the compression stroke, and explosive combustion is performed by an electric spark from the spark plug 130. Thus, the rotational movement of the crankshaft 26 is obtained. In the common injection mode, the fuel is injected from the port injection valve 125 when air is sucked into the combustion chamber, and the fuel is injected from the in-cylinder injection valve 126 in the intake stroke or the compression stroke. Thus, the rotational movement of the crankshaft 26 is obtained. These injection modes are switched based on the operating state of the engine 22.

  Exhaust gas from the combustion chamber is discharged to the outside air through a purification device 134 having a purification catalyst (three-way catalyst) that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). Is done.

  As shown in FIG. 2, the fuel supply device 60 is configured as a device that supplies fuel to the port injection valve 125 and the in-cylinder injection valve 126 of the engine 22. The fuel supply device 60 includes a fuel tank 61, a feed pump (first pump) 62 that supplies fuel from the fuel tank 61 to a low-pressure side passage (first passage) 63 to which the port injection valve 125 is connected, and a low-pressure side passage. And a high pressure side passage (second passage) to which the cylinder injection valve 126 is connected by pressurizing fuel on the side of the port injection valve 125 relative to the check valve 64 in the low pressure side passage 63. And a high-pressure fuel pump (second pump) 65 for supplying to 66.

  The feed pump 62 and the check valve 64 are disposed in the fuel tank 61. The feed pump 62 is configured as an electric pump that operates by receiving power supplied from the battery 50. The check valve 64 is opened when the fuel pressure (fuel pressure) on the feed pump 62 side in the low pressure side passage 63 is higher than the pressure on the port injection valve 125 side, and the pressure on the feed pump 62 side is set on the port injection valve 125 side. The valve is closed when the pressure is less than.

  The high-pressure fuel pump 65 is a pump that is driven by power from the engine 22 (rotation of the camshaft) and pressurizes the fuel in the low-pressure side passage 63. The high-pressure fuel pump 65 is connected to the suction port and opens and closes when the fuel is pressurized. The high-pressure fuel pump 65 is connected to the discharge port to prevent the back flow of the fuel and holds the fuel pressure in the high-pressure side passage 66. And a check valve 65b. The high-pressure fuel pump 65 sucks fuel from the feed pump 62 when the electromagnetic valve 65a is opened during operation of the engine 22, and uses the power from the engine 22 when the electromagnetic valve 65a is closed. The fuel supplied to the high pressure side passage 66 is pressurized by intermittently feeding the fuel compressed by the operating plunger (not shown) to the high pressure side passage 66 through the check valve 65b. When the high pressure fuel pump 65 is driven, the fuel pressure in the low pressure side passage 63 and the fuel pressure in the high pressure side passage 66 pulsate according to the rotation of the engine 22 (rotation of the camshaft).

  The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24. Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port. .

  Signals from various sensors necessary for controlling the operation of the engine 22 and controlling the fuel supply device 60 are input to the engine ECU 24 via an input port. Examples of signals input to the engine ECU 24 include a crank position θcr from the crank position sensor 140 that detects the rotational position of the crankshaft 26, and a coolant temperature Tw from the coolant temperature sensor 142 that detects the temperature of coolant in the engine 22. Can be mentioned. Another example is the cam position θca from the cam position sensor 144 that detects the rotational position of the intake camshaft that opens and closes the intake valve 128 and the exhaust camshaft that opens and closes the exhaust valve. Further, the throttle opening TH from the throttle valve position sensor 146 for detecting the position of the throttle valve 124, the intake air amount Qa from the air flow meter 148 attached to the intake pipe, and the temperature sensor 149 attached to the intake pipe. The intake air temperature Ta can also be mentioned. In addition, the air-fuel ratio AF from the air-fuel ratio sensor 135a attached to the exhaust pipe and the oxygen signal O2 from the oxygen sensor 135b attached to the exhaust pipe can also be mentioned. Further, the fuel pressure Pfp of the fuel supplied to the port injection valve 125 from the fuel pressure sensor 68 attached in the vicinity of the port injection valve 125 in the low pressure side passage 63 of the fuel supply device 60 and the cylinder in the high pressure side passage 66 of the fuel supply device 60. The fuel pressure Pfd of the fuel supplied to the in-cylinder injection valve 126 from the fuel pressure sensor 69 attached in the vicinity of the inner injection valve 126 can also be mentioned.

  Various control signals for controlling the operation of the engine 22 or controlling the fuel supply device 60 are output from the engine ECU 24 via the output port. Examples of the signal output from the engine ECU 24 include a drive signal to the port injection valve 126, a drive signal to the in-cylinder injection valve 126, a drive signal to the throttle motor 136 that adjusts the position of the throttle valve 124, and an integral with the igniter. A control signal to the ignition coil 138 can be given. Further, a drive control signal to the feed pump 62 and a drive control signal to the electromagnetic valve 65a of the high-pressure fuel pump 65 can be cited.

  The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 140.

  As shown in FIG. 1, the planetary gear 30 is configured as a single pinion type planetary gear mechanism. The sun gear of planetary gear 30 is connected to the rotor of motor MG1. The ring gear of the planetary gear 30 is connected to a drive shaft 36 that is coupled to the drive wheels 39a and 39b via a differential gear 38. A crankshaft 26 of the engine 22 is connected to the carrier of the planetary gear 30 via a damper 28.

  The motor MG1 is configured as, for example, a synchronous generator motor, and the rotor is connected to the sun gear of the planetary gear 30 as described above. The motor MG2 is configured as, for example, a synchronous generator motor, and a rotor is connected to the drive shaft 36. Inverters 41 and 42 are connected to motors MG <b> 1 and MG <b> 2 and to battery 50 via power line 54. The motors MG1 and MG2 are driven to rotate by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42 by a motor electronic control unit (hereinafter referred to as “motor ECU”) 40.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The motor ECU 40 receives signals from various sensors necessary for driving and controlling the motors MG1 and MG2, for example, rotational positions θm1 from rotational position detection sensors 43 and 44 that detect rotational positions of the rotors of the motors MG1 and MG2. , Θm2, and the temperature tm2 of the motor MG2 from the temperature sensor that detects the temperature of the motor MG2 are input via the input port. From the motor ECU 40, switching control signals to a plurality of switching elements (not shown) of the inverters 41 and 42 are output via an output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position detection sensors 43, 44.

  The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydride secondary battery, and is connected to the inverters 41 and 42 via the power line 54. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as “battery ECU”) 52.

  Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input port. Examples of signals input to the battery ECU 52 include a battery voltage Vb from a voltage sensor 51 a installed between terminals of the battery 50, a battery current Ib from a current sensor 51 b attached to an output terminal of the battery 50, and a battery 50. The battery temperature Tb from the temperature sensor 51c attached to can be mentioned. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the storage ratio SOC based on the integrated value of the battery current Ib from the current sensor 51b. The storage ratio SOC is a ratio of the capacity of power that can be discharged from the battery 50 to the total capacity of the battery 50.

  Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port in addition to the CPU. Signals from various sensors are input to the HVECU 70 via input ports. Examples of the signal input to the HVECU 70 include an ignition signal from the ignition switch 80 and a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81. Further, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, and the vehicle speed sensor 88 The vehicle speed V can also be mentioned. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port.

  The hybrid vehicle 20 of the embodiment configured in this manner travels in a hybrid travel (HV travel) mode or an electric travel (EV travel) mode. Here, the HV traveling mode is a mode in which the engine 22 is operated while the engine 22 is operated, and the EV traveling mode is a mode in which the engine 22 is not operated.

  In the HV traveling mode, the HVECU 70 first sets the required torque Td * required for the drive shaft 36 based on the accelerator opening Acc and the vehicle speed V, and the rotational speed Nd of the drive shaft 36 is set to the set required torque Td *. To calculate the required power Pd * required for the drive shaft 36. Here, as the rotational speed Nd of the drive shaft 36, for example, the rotational speed Nm2 of the motor MG2 or the rotational speed obtained by multiplying the vehicle speed V by a conversion factor can be used. Subsequently, the required power Pe * required for the vehicle is calculated by subtracting the charge / discharge required power Pb * (a positive value when discharging from the battery 50) based on the storage ratio SOC of the battery 50 from the required power Pd *. Then, the target rotational speed Ne * and the target torque Te * as operating points of the engine 22 are set based on the required power Pe *. In the embodiment, basically, a fuel consumption operation line for efficiently operating the engine 22 is selected as an execution operation line, and the number of revolutions according to the required power Pe * and the execution operation line (fuel consumption operation line). Neef and torque Tef were set as target rotational speed Ne * and target torque Te *. FIG. 3 is an explanatory diagram showing an example of a fuel efficiency operation line of the engine 22 and a state in which the rotational speed Neef and the torque Tef are set. The engine speed Neef and the torque Tef of the engine 22 can be obtained as an intersection of the fuel efficiency operation line of the engine 22 and a curve with a constant required power Pe *. Next, the torque command Tm1 * of the motor MG1 is set so that the rotational speed Ne of the engine 22 becomes the target rotational speed Ne *, and the torque command Tm2 of the motor MG2 is output so that the required torque Td * is output to the drive shaft 36. Set *. Then, the target rotational speed Ne * and the target torque Te * of the engine 22 are transmitted to the engine ECU 24, and torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40. When the engine ECU 24 receives the target rotational speed Ne * and the target torque Te * of the engine 22, the engine ECU 24 controls the intake air amount of the engine 22 so that the engine 22 is operated based on the target rotational speed Ne * and the target torque Te *. Fuel injection control, ignition control, etc. are performed. The engine ECU 24 also controls the fuel supply device 60 when the engine 22 is operated. Specifically, the feed pump 62 is controlled so that the fuel pressure Pfp of the fuel supplied to the port injection valve 125 becomes the target fuel pressure Pfp *, and the fuel pressure Pfd of the fuel supplied to the in-cylinder injection valve 126 becomes the target fuel pressure Pfd *. Thus, the electromagnetic valve 65a of the high-pressure fuel pump 65 is controlled. As the target fuel pressure Pfd *, for example, about several MPa to about several tens of MPa can be used. A method for setting the target fuel pressure Pfp * will be described later. When motor ECU 40 receives torque commands Tm1 * and Tm2 * of motors MG1 and MG2, switching control of a plurality of switching elements of inverters 41 and 42 is performed such that motors MG1 and MG2 are driven by torque commands Tm1 * and Tm2 *. To do. In this HV travel mode, when the stop condition of the engine 22 is satisfied, such as when the required power Pe * reaches the stop threshold value Pstop or less, the operation of the engine 22 is stopped and the EV travel mode is entered.

  In the EV travel mode, the HVECU 70 sets the required torque Td * of the drive shaft 36 based on the accelerator opening Acc and the vehicle speed V, sets a value 0 to the torque command Tm1 * of the motor MG1, and sets the required torque Td *. The torque command Tm2 * of the motor MG2 is set, and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40. When motor ECU 40 receives torque commands Tm1 * and Tm2 * of motors MG1 and MG2, switching control of a plurality of switching elements of inverters 41 and 42 is performed such that motors MG1 and MG2 are driven by torque commands Tm1 * and Tm2 *. To do. In this EV travel mode, when the start condition of the engine 22 is satisfied, such as when the required power Pe * calculated in the same manner as in the HV travel mode reaches a start threshold Pstart greater than the stop threshold Pstop, the engine 22 22 is started to shift to the HV traveling mode.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly the processing when setting the target fuel pressure Pfp * of the fuel supplied to the port injection valve 125 will be described. FIG. 4 is a flowchart illustrating an example of a target fuel pressure setting routine executed by the engine ECU 24 of the embodiment. This routine is executed when the operation of the engine 22 is started.

  When the target fuel pressure setting routine is executed, the engine ECU 24 first inputs the fuel pressure Pfp of the fuel supplied to the port injection valve 125 from the fuel pressure sensor 68 (step S100), and compares the input fuel pressure Pfp with the threshold value Pfpref (step S100). Step S110). When the fuel pressure Pfp is less than the threshold value Pfpref, a relatively low predetermined fuel pressure Pfpno is set to the target fuel pressure Pfp * (step S120), and this routine is terminated. Here, for example, 380 kPa, 400 kPa, 420 kPa, or the like can be used as the predetermined fuel pressure Pfpno. The threshold value Pfpref can be, for example, the same value as the predetermined fuel pressure Pfpno or a value slightly lower than that. In this way, by setting the target fuel pressure Pfp * to a relatively low predetermined fuel pressure Pfpno, the power consumption of the feed pump 62 is suppressed as compared with the case where the target fuel pressure Pfp * is set to a relatively high later-described predetermined fuel pressure Pfpup. can do.

  When the fuel pressure Pfp is greater than or equal to the threshold value Pfpref in step S110, a predetermined fuel pressure Pfpup higher than the predetermined fuel pressure Pfpno is set as the target fuel pressure Pfp * (step S130). Here, for example, 510 kPa, 530 kPa, 550 kPa, or the like can be used as the predetermined fuel pressure Pfpup. In this way, by setting the target fuel pressure Pfp * to a relatively high predetermined fuel pressure Pfpup, atomization of fuel can be promoted as compared with the case where the target fuel pressure Pfp * is set to the predetermined fuel pressure Pfpno.

  Subsequently, after a predetermined time T1 has elapsed (step S140), the rotational speed Ne of the engine 22 is input (step S150). Here, for example, 5 seconds, 6 seconds, 7 seconds, or the like can be used as the predetermined time T1. Further, the rotation speed Ne of the engine 22 is inputted as a value calculated based on the crank angle θcr from the crank position sensor 140.

  When the engine speed Ne of the engine 22 is thus input, it is determined whether the input engine speed Ne is within the resonance region or outside the resonance region of the fuel supply device 60 (step S160). When the rotational speed Ne of the engine 22 is within the resonance region of the fuel supply device 60, the process returns to step S150. When the rotational speed Ne of the engine 22 is outside the resonance region of the fuel supply device 60, the target fuel pressure Pfp * is set to the predetermined fuel pressure. The routine switches from Pfpup to a predetermined fuel pressure Pfpno (step S170), and this routine ends. Thus, by setting the target fuel pressure Pfp * to a relatively low predetermined fuel pressure Pfpno, the power consumption of the feed pump 62 can be suppressed as compared with the case where the target fuel pressure Pfpup is maintained.

  Consider a case where the target fuel pressure Pfp * is switched (decreased) from the predetermined fuel pressure Pfpup to the predetermined fuel pressure Pfpno. When the target fuel pressure Pfp * is decreased, the amount of fuel from the feed pump 62 is reduced, so that the pressure on the feed pump 62 side of the low pressure side passage 63 becomes lower than the pressure on the port injection valve 125 side. Thus, the check valve 64 may close. When the check valve 64 is closed, the pulsation of the fuel pressure in the low-pressure side passage 63 generated by driving the high-pressure fuel pump 65 increases, and the fuel supply device 60 (low-pressure side passage 63, fuel tank 61, etc.) or the fuel supply device 60 The vibration of the vehicle body where the vehicle is placed becomes large, and abnormal noise may occur. The above-described resonance region of the fuel supply device 60 is a region of the rotational speed Ne of the engine 22 in which vibrations of the fuel supply device 60 and the vehicle body and the like are likely to generate abnormal noise when the target fuel pressure Pfp * is reduced. Determined. The resonance region of the fuel supply device 60 can be determined according to the distance between the check valve 64 and the high pressure fuel pump 65 in the low pressure side passage 63, the distance between the port injection valve 125 and the high pressure fuel pump 65, and the like. , The range from about 1000 rpm to about 1200 rpm. In the embodiment, when the rotational speed Ne of the engine 22 is outside the resonance region of the fuel supply device 60, the check valve 64 is closed by reducing the target fuel pressure Pfp * from the predetermined fuel pressure Pfpup to the predetermined fuel pressure Pfpno. However, since the pulsation of the fuel pressure in the low-pressure side passage 63 is difficult to increase, the vibration of the fuel supply device 60 and the vehicle body is hardly increased, and the generation of noise in the fuel supply device 60 and the vehicle body is suppressed. Can do.

  FIG. 5 is an explanatory diagram showing an example of a temporal change in the feed pump 62, the fuel pressure Pfp, the target fuel pressure Pfp *, and the engine speed Ne. As shown in the figure, when the engine 22 is started and the operation is started (time t11), when the fuel pressure Pfp is equal to or higher than the threshold value Pfpref, the target fuel pressure Pfp * is set to a relatively high predetermined fuel pressure Pfpup. Thereby, the atomization of the fuel immediately after the start of operation of the engine 22 can be promoted. Thereafter, when the predetermined time T1 has elapsed and the rotational speed Ne of the engine 22 is outside the resonance region of the fuel supply device 60 (time t12), the target fuel pressure Pfp * is decreased to the predetermined fuel pressure Pfpno. Thereby, the power consumption of the feed pump 62 can be suppressed. Moreover, even if the check valve 64 is closed due to the target fuel pressure Pfp * being lower than the fuel pressure Pfp, the rotational speed Ne of the engine 22 is outside the resonance region of the fuel supply device 60. Since the pulsation of the fuel pressure in the passage 63 is unlikely to increase, vibrations of the fuel supply device 60 and the vehicle body are unlikely to increase, and generation of abnormal noise in the fuel supply device 60 and the vehicle body can be suppressed.

  In the hybrid vehicle 20 of the embodiment described above, after the predetermined fuel pressure Pfpup is set to the target fuel pressure Pfp * at the start of operation of the engine 22, the predetermined time T1 has elapsed and the rotational speed Ne of the engine 22 is equal to that of the fuel supply device 60. When outside the resonance region, the target fuel pressure Pfp * is switched (reduced) to a predetermined fuel pressure Pfpno lower than the predetermined fuel pressure Pfpup. Thus, even if the pressure on the feed pump 62 side of the low pressure side passage 63 is lower than the pressure on the port injection valve 125 side than the check valve 64 and the check valve 64 is closed, the fuel pressure in the low pressure side passage 63 is reduced. By making the pulsation difficult to increase, it is difficult to increase the vibration of the fuel supply device 60 and the vehicle body, and the generation of abnormal noise in the fuel supply device 60 and the vehicle body can be suppressed.

  In the hybrid vehicle 20 of the embodiment or the modified example, after the predetermined fuel pressure Pfpup is set to the target fuel pressure Pfp *, the predetermined time T1 has elapsed and the engine speed Ne is outside the resonance region of the fuel supply device 60. The target fuel pressure Pfp * is switched to a predetermined fuel pressure Pfpno lower than the predetermined fuel pressure Pfpup. However, even after the predetermined fuel pressure Pfpup is set to the target fuel pressure Pfp *, the target fuel pressure Pfp * is set when the rotational speed Ne of the engine 22 is outside the resonance region of the fuel supply device 60 even if the predetermined time T1 has not elapsed. It is good also as what switches to the predetermined fuel pressure Pfpno lower than the predetermined fuel pressure Pfpup.

  In the hybrid vehicle 20 of the embodiment, the target fuel pressure setting routine of FIG. 4 is executed. However, instead of the target fuel pressure setting routine of FIG. 4, the target fuel pressure setting routine of FIG. 6 may be executed. The target fuel pressure setting routine of FIG. 6 is the same as the target fuel pressure setting routine of FIG. 4 except that the processes of steps S200 to S240 are executed instead of the processes of steps S150 and S160 of the target fuel pressure setting routine of FIG. Are the same. Therefore, the same process is given the same step number, and the detailed description thereof is omitted.

  In the target fuel pressure setting routine of FIG. 6, when the predetermined time T1 has elapsed after setting the predetermined fuel pressure Pfpup to the target fuel pressure Pfp * (steps S130 and S140), the engine ECU 24 inputs the engine speed Ne (step S130). S200), it is determined whether the input rotational speed Ne of the engine 22 is within the resonance region or outside the resonance region of the fuel supply device 60 (step S210). When the rotational speed Ne of the engine 22 is outside the resonance region of the fuel supply device 60, the target fuel pressure Pfp * is switched from the predetermined fuel pressure Pfpup to the predetermined fuel pressure Pfpno (step S170), and this routine ends.

  When the rotational speed Ne of the engine 22 is within the resonance region of the fuel supply device 60 in step S210, an operation point change command for the engine 22 is transmitted to the HVECU 70 (step S220). When the HVECU 70 receives the operation point change command for the engine 22, the target rotation as the operation point of the engine 22 is set so that the target rotation speed Ne * (rotation speed Ne) of the engine 22 is outside the resonance region of the fuel supply device 60. The number Ne * and the target torque Te * are changed. In the embodiment, the operation line for execution of the engine 22 is switched from the fuel efficiency operation line to the resonance avoidance operation line, and the rotation speed Nere and the torque Tere corresponding to the required power Pe * and the execution operation line (resonance avoidance operation line) are set. The target rotational speed Ne * and the target torque Te * are set. Here, the resonance avoidance operation line is an operation line in which at least a portion of the fuel efficiency operation line in which the rotation speed Ne of the engine 22 is within the resonance region of the fuel supply device 60 is shifted outside the resonance region on the high rotation speed low torque side. It is. FIG. 7 is an explanatory diagram showing an example of a resonance avoidance operation line of the engine 22 and how the rotation speed Nere and the torque Tere are set. The rotation speed Nere and the torque Tere of the engine 22 can be obtained as an intersection of the resonance avoidance operation line of the engine 22 and a curve with a constant required power Pe *. In FIG. 7, the fuel efficiency operation line, the rotational speed Neef, and the torque Tef are also shown for reference. As can be seen from FIG. 7, by switching the execution operation line from the fuel efficiency operation line to the resonance avoidance operation line, the target rotation speed Ne * (rotation speed Ne) of the engine 22 is shifted from the rotation speed Neef to the rotation speed Nere. The rotational speed Ne of the engine 22 can be shifted outside the resonance region of the fuel supply device 60.

  Subsequently, the engine speed Ne of the engine 22 is input (step S230), and it is determined whether the input engine speed Ne is within the resonance region or outside the resonance region of the fuel supply device 60 (step S240). When the rotational speed Ne is within the resonance region of the fuel supply device 60, the process returns to step S230. In this way, it waits for the rotational speed Ne of the engine 22 to be outside the resonance region of the fuel supply device 60.

  When the rotational speed Ne of the engine 22 is outside the resonance region of the fuel supply device 60, the target fuel pressure Pfp * is switched from the predetermined fuel pressure Pfpup to the predetermined fuel pressure Pfpno (step S170), and this routine ends. As a result, the target fuel pressure is compared with the embodiment (when the operation line for executing the engine 22 is held by the fuel efficiency operation line and the engine 22 waits for the rotational speed Ne to be outside the resonance region of the fuel supply device 60). It is possible to further suppress an increase in the time until the Pfp * is switched from the predetermined fuel pressure Pfpup to the predetermined fuel pressure Pfpno. As a result, the power consumption of the feed pump 62 can be further suppressed. The execution operation line of the engine 22 is assumed to return from the resonance avoidance operation line to the fuel consumption operation line when a predetermined time T2 (for example, several seconds) elapses after the target fuel pressure Pfp * is switched.

  In this modification, when the target fuel pressure Pfp * is the predetermined fuel pressure Pfpup and the predetermined time has elapsed and the rotational speed Ne of the engine 22 is within the resonance region of the fuel supply device 60, the operation operation line for the engine 22 is operated as a resonance avoidance operation. By switching to the line, the rotational speed Ne of the engine 22 is shifted outside the resonance region of the fuel supply device 60. However, without providing the resonance avoidance operation line, when the target fuel pressure Pfp * is the predetermined fuel pressure Pfpup and the predetermined time has elapsed and the rotational speed Ne of the engine 22 is within the resonance region of the fuel supply device 60, the fuel supply device 60 A rotational speed that is slightly larger than the upper limit rotational speed of the resonance region is set as the target rotational speed Ne * of the engine 22, and the required power Pe * is divided by the target rotational speed Ne * of the engine 22 to obtain the target torque Te * of the engine 22 By setting, the rotational speed Ne of the engine 22 may be shifted outside the resonance region of the fuel supply device 60.

  In the hybrid vehicle 20 of the embodiment or the modified example, as described in the target fuel pressure setting routine of FIGS. 4 and 6, when the fuel pressure Pfp is less than the threshold value Pfpref at the start of operation of the engine 22, the target fuel pressure Pfp * is set to the predetermined fuel pressure Pfpno. When the fuel pressure Pfp is greater than or equal to the threshold value Pfpref at the start of operation of the engine 22, the predetermined fuel pressure Pfpup is set to the target fuel pressure Pfp *, and then the rotational speed Ne of the engine 22 is set to the resonance of the fuel supply device 60. The target fuel pressure Pfp * is switched (reduced) to the predetermined fuel pressure Pfpno when out of the region. However, the target fuel pressure Pfp is set when the rotational speed Ne of the engine 22 is outside the resonance region of the fuel supply device 60 after the predetermined fuel pressure Pfpup is set to the target fuel pressure Pfp * regardless of the fuel pressure Pfp at the start of operation of the engine 22. * May be switched (reduced) to a predetermined fuel pressure Pfpno.

  In the hybrid vehicle 20 of the embodiment or the modified example, the target fuel pressure Pfp * is quickly switched from the predetermined fuel pressure Pfpup to the predetermined fuel pressure Pfpno as described in the target fuel pressure setting routine of FIGS. 4 and 6. However, when the target fuel pressure Pfp * is switched from the predetermined fuel pressure Pfpup to the predetermined fuel pressure Pfpno, the target fuel pressure Pfp * may be gradually changed using a slow change process such as a rate process. In this case, for example, the target fuel pressure Pfp * may be changed from several kPa to several tens of kPa per several milliseconds from the predetermined fuel pressure Pfpup to the predetermined fuel pressure Pfpno.

  In the hybrid vehicle 20 of the embodiment, the engine ECU 24, the motor ECU 40, and the HVECU 70 are provided. However, the engine ECU 24, the motor ECU 40, and the HVECU 70 may be configured as a single electronic control unit.

  In the embodiment, the engine 22 and the motor MG1 are connected to the drive shaft 36 connected to the drive wheels 39a and 39b via the planetary gear 30, and the motor MG2 is connected to the drive shaft 36. However, a configuration of a so-called one-motor hybrid vehicle in which a motor is connected to a drive shaft connected to a drive wheel via a transmission and an engine is connected to a rotation shaft of the motor via a clutch. Alternatively, a so-called series hybrid vehicle may be configured in which a travel motor is connected to a drive shaft coupled to a drive wheel and a power generation motor that exchanges electric power with the travel motor is connected to an output shaft of the engine. Furthermore, it is good also as a structure of the motor vehicle which drive | works using only the motive power from an engine, without providing a motor.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to the “engine”, the fuel supply device 60 corresponds to the “fuel supply device”, the engine that executes the target fuel pressure setting routine of FIG. 4 and controls the engine 22 and the fuel supply device 60. The ECU 24 corresponds to a “control device”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the automobile manufacturing industry.

  20 hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 planetary gear, 36 drive shaft, 38 differential gear, 39a, 39b drive wheel, 40 electronic control unit for motor (motor) ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 51a voltage sensor, 51b current sensor, 51c temperature sensor, 52 battery electronic control unit (battery ECU), 54 power line, 60 fuel supply device , 61 Fuel tank, 62 Feed pump, 63 Low pressure side passage, 64 Check valve, 65 High pressure fuel pump, 65a Solenoid valve, 65b Check valve, 66 High pressure side passage, 68, 69 Fuel pressure sensor, 70 Hybrid Electronic control unit (HV ECU), 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 122 air cleaner, 124 throttle Valve, 125 port injection valve, 126 In-cylinder injection valve, 128 Intake valve, 130 Spark plug, 132 Piston, 134 Purifier, 135a Air-fuel ratio sensor, 135b Oxygen sensor, 136 Throttle motor, 138 Ignition coil, 140 Crank position sensor, 142 water temperature sensor, 144 cam position sensor, 146 throttle valve position sensor, 148 air flow meter, 149 temperature Sensor, MG1, MG2 motor.

Claims (2)

An engine having a port injection valve for injecting fuel into the intake pipe, and an in-cylinder injection valve for injecting fuel into the cylinder;
A fuel tank; a first pump for supplying fuel from the fuel tank to a first passage to which the port injection valve is connected; and a fuel pressure provided in the first passage and on the first pump side A check valve that opens when the fuel pressure is higher than the fuel pressure of the first injection pump and closes when the fuel pressure on the first pump side is equal to or lower than the fuel pressure on the port injection valve side, and more than the check valve in the first passage. A fuel supply device having a second pump for pressurizing the fuel on the port injector side and supplying the fuel to the second passage connected to the cylinder injection valve;
A control device for controlling the engine and the fuel supply device;
A car equipped with
The control device controls the first pump so that a fuel pressure of fuel supplied to the port injection valve becomes a target fuel pressure;
Further, the control device sets a first predetermined fuel pressure as the target fuel pressure at the start of operation of the engine, and then the target fuel pressure when the engine speed is outside the resonance region of the fuel supply device. Switching the fuel pressure to a second predetermined fuel pressure lower than the first predetermined fuel pressure;
Automobile. The automobile according to claim 1,
The control device is configured so that when the target fuel pressure is the first predetermined fuel pressure and a predetermined time has elapsed and the engine speed is within the resonance region, the engine speed is outside the resonance region. Switching the target fuel pressure to the second predetermined fuel pressure after changing the operating point of the engine;
Automobile.

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