JP6809058B2 - Automobile - Google Patents

Description

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

Conventionally, as an automobile of this type, an engine having a port injection valve and an in-cylinder injection valve, and a fuel supply device for supplying fuel to the port injection valve and the in-cylinder injection valve have been proposed (for example,). , 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 to which the port injection valve is connected, a check valve provided in the first passage, and a first passage. It is provided with a high-pressure fuel pump that pressurizes fuel on the port injection valve side of the check valve and supplies it to the second passage to which the in-cylinder injection valve is connected. 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.

Japanese Unexamined Patent Publication No. 2015-218595

In the above-mentioned automobile, if the target fuel pressure of the fuel supplied to the port injection valve is lowered after the engine starts to operate, the rotation speed of the feed pump is reduced and the discharge amount is reduced, so that the check valve in the first passage is stopped. The check valve may close when the fuel pressure on the feed pump side of the valve becomes lower than the fuel pressure on the port injection valve side. When the check valve is closed, the pulsation of the fuel pressure in the first passage generated by driving the high-pressure fuel pump becomes large, and the fuel supply device or the like may vibrate to generate an abnormal noise.

The main object of the automobile of the present invention is to suppress vibration of a fuel supply device for supplying fuel to an engine port injection valve or an in-cylinder injection valve to generate abnormal noise.

The automobile of the present invention has adopted the following means in order to achieve the above-mentioned main object.

The automobile of the present invention
An engine having a port injection valve for injecting fuel into an intake pipe and an in-cylinder injection valve for injecting fuel into a cylinder.
The fuel tank, the first pump that supplies the fuel of the fuel tank to the first passage to which the port injection valve is connected, and the fuel pressure provided in the first passage and on the first pump side are the port injection valve side. A check valve that opens when the fuel pressure is higher than the fuel pressure of the first 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 the check valve in the first passage. A fuel supply device having a second pump that pressurizes the fuel on the port injection valve side and supplies the fuel to the second passage to which the in-cylinder injection valve is connected.
A control device that controls the engine and the fuel supply device,
It is a car equipped with
The control device controls the first pump so that the first pump rotates at a target rotation speed based on the target fuel pressure of the fuel supplied to the port injection valve.
Further, in the control device, when the port side fuel pressure, which is the fuel pressure of the fuel supplied to the port injection valve, decreases in response to the decrease in the target fuel pressure, the degree of pulsation of the port side fuel pressure is more than a predetermined degree. In the case of, the target rotation speed is made larger than that in the case of less than the predetermined degree.
The gist is that.

In the automobile of the present invention, the first pump is controlled so that the first pump rotates at a target rotation speed based on the target fuel pressure of the fuel supplied to the port injection valve, and the port injection valve responds to a decrease in the target fuel pressure. When the fuel pressure on the port side, which is the fuel pressure of the fuel supplied to the vehicle, is decreasing, the target rotation speed is increased when the degree of pulsation of the fuel pressure on the port side is more than a predetermined degree and less than a predetermined degree. As a result, it is possible to prevent the fuel pressure on the first pump side from being lower than the fuel pressure on the port injection valve side (port side fuel pressure) as compared with the check valve in the first passage, and prevent the check valve from closing. It can be suppressed. As a result, it is possible to suppress an increase in the pulsation of the fuel pressure in the first passage generated by driving the second pump, and it is possible to suppress the vibration of the fuel supply device and the like to generate an abnormal noise.

In such an automobile of the present invention, when the pulsation amplitude as the pulsation amplitude of the port side fuel pressure is equal to or greater than a predetermined amplitude, the control device determines that the degree of pulsation of the port side fuel pressure is equal to or greater than the predetermined degree. It may be determined that the degree of pulsation of the port side fuel pressure is equal to or more than the predetermined degree when the inclination of the integrated value of the port side fuel pressure is equal to or more than a predetermined inclination. In this way, it is possible to determine whether or not the degree of pulsation of the port side fuel pressure is equal to or higher than a predetermined degree by using the amplitude of the pulsation of the port side fuel pressure and the slope of the integrated value of the port side fuel pressure.

It is a block diagram which shows the outline of the structure of the hybrid vehicle 20. It is a block diagram which shows the outline of the structure of the engine 22 and the fuel supply device 60. It is a flowchart which shows an example of the target rotation speed setting routine. It is explanatory drawing which shows the mode of determining whether or not the degree of pulsation of a fuel pressure Pfp is large using the pulsation amplitude Apfp. It is a flowchart which shows an example of the target rotation speed setting routine. It is explanatory drawing which shows a mode of determining whether or not the degree of pulsation of a fuel pressure Pfp is large using the fuel pressure integrated value slope Spfps.

Next, a mode for carrying out the present invention will be described with reference to examples.

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 an electronic control unit for a hybrid. (Hereinafter referred to as "HVECU") 70 and.

The engine 22 is configured as an internal combustion engine that outputs power using fuel such as gasoline or light oil. As shown in FIG. 2, the engine 22 has a port injection valve 125 for injecting fuel into the intake port and an in-cylinder injection valve 126 for injecting fuel into the cylinder. By having the port injection valve 125 and the in-cylinder injection valve 126, the engine 22 can be operated in any of the port injection mode, the in-cylinder injection mode, and the shared injection mode. In the port injection mode, the air cleaned by the air cleaner 122 is sucked in through the throttle valve 124, and fuel is injected from the port injection valve 125 to mix the air and the fuel. Then, this air-fuel mixture is sucked into the combustion chamber via the intake valve 128, explosively burned by the electric spark of the spark plug 130, and 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 after reaching the compression stroke, and explosive combustion is performed by an electric spark from the spark plug 130. The rotation motion of the crankshaft 26 is obtained. In the shared injection mode, fuel is injected from the port injection valve 125 when air is sucked into the combustion chamber, fuel is injected from the in-cylinder injection valve 126 in the intake stroke and the compression stroke, and explosive combustion is performed by an electric spark from the spark plug 130. To obtain the rotational movement of the crankshaft 26. These injection modes are switched based on the operating state of the engine 22. Exhaust 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 of carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). Will be done.

As shown in FIG. 2, the fuel supply device 60 is configured as a device for supplying 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 the low pressure side passage (first passage) 63 to which the port injection valve 125 is connected, and a low pressure side passage. High-pressure side passage (second passage) to which the check valve 64 provided in 63 and the in-cylinder injection valve 126 are connected by pressurizing the fuel on the port injection valve 125 side of the check valve 64 in the low-pressure side passage 63. A high-pressure fuel pump (second pump) 65 for supplying to 66 is provided.

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

The high-pressure fuel pump 65 is a pump that is driven by power from the engine 22 (rotation of the camshaft) to pressurize the fuel in the low-pressure side passage 63. The high-pressure fuel pump 65 is connected to its suction port to open and close an electromagnetic valve 65a when pressurizing the fuel, and is connected to the discharge port to prevent backflow of fuel and maintain the fuel pressure in the high-pressure side passage 66. It has a check valve 65b and. When the electromagnetic valve 65a is opened during the operation of the engine 22, the high-pressure fuel pump 65 sucks fuel from the feed pump 62, and when the electromagnetic valve 65a is closed, the power from the engine 22 is used. The fuel supplied to the high-pressure side passage 66 is pressurized by intermittently feeding the fuel compressed by the operating plunger (not shown) into the high-pressure side passage 66 via 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 engine 22 and the fuel supply device 60 are operated and controlled by an electronic control unit for an engine (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 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 controlling the operation of the engine 22 and controlling the fuel supply device 60 are input to the engine ECU 24 via the input port. The signals input to the engine ECU 24 include, for example, the crank position θcr from the crank position sensor 140 that detects the rotational position of the crankshaft 26, and the cooling water temperature Tw from the water temperature sensor 142 that detects the temperature of the cooling water of the engine 22. Can be mentioned. Further, 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 can also be mentioned. Further, the throttle opening TH from the throttle valve position sensor 146 that detects 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 rotation speed Nfp of the feed pump 62 from the rotation speed sensor 62a attached to the feed pump 62 of the fuel supply device 60 and the port injection from the fuel pressure sensor 68 attached to the vicinity of the port injection valve 125 in the low pressure side passage 63. The fuel pressure Pfp of the fuel supplied to the valve 125 and 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 in-cylinder injection valve 126 in the high-pressure side passage 66 can also be mentioned.

Various control signals for controlling the operation of the engine 22 and controlling the fuel supply device 60 are output from the engine ECU 24 via the output port. The signals output from the engine ECU 24 include, for example, 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 for adjusting the position of the throttle valve 124, and an igniter. A control signal to the modified ignition coil 138 can be mentioned. Further, a drive control signal to the feed pump 62 and a drive control signal to the solenoid valve 65a of the high-pressure fuel pump 65 can also be mentioned.

The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotation 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 rotor of the motor MG1 is connected to the sun gear of the planetary gear 30. A drive shaft 36 connected to the drive wheels 39a and 39b via a differential gear 38 is connected to the ring gear of the planetary gear 30. The 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 motor generator, and as described above, the rotor is connected to the sun gear of the planetary gear 30. The motor MG2 is configured as, for example, a synchronous generator motor, and a rotor is connected to a drive shaft 36. The inverters 41 and 42 are connected to the motors MG1 and MG2 and also to the battery 50 via the power line 54. The motors MG1 and MG2 are rotationally driven by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42 by an electronic control unit for a motor (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 has signals from various sensors required to drive and control the motors MG1 and MG2, for example, rotation positions θm1 from rotation position detection sensors 43 and 44 that detect the rotation positions of the rotors of the motors MG1 and MG2. , Θm2, the temperature tm2 of the motor MG2 from the temperature sensor that detects the temperature of the motor MG2, and the like are input via the input port. From the motor ECU 40, switching control signals and the like to a plurality of switching elements (not shown) of the inverters 41 and 42 are output via the output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the rotation speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotation positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from the rotation position detection sensors 43 and 44.

The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydrogen secondary battery, and is connected to the inverters 41 and 42 via a 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. The signals input to the battery ECU 52 include, for example, the battery voltage Vb from the voltage sensor 51a installed between the terminals of the battery 50, the battery current Ib from the current sensor 51b attached to the output terminal of the battery 50, and the battery 50. The battery temperature Tb from the temperature sensor 51c attached to the above 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 the ratio of the capacity of electric 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 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 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 operating 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 a communication port.

In the hybrid vehicle 20 of the embodiment configured in this way, the required driving force of the drive shaft 36 is set based on the accelerator opening degree Acc and the vehicle speed V, and the required power corresponding to the required driving force is output to the drive shaft 36. In addition, the engine 22 and the motors MG1 and MG2 are operated and controlled. The operation modes of the engine 22 and the motors MG1 and MG2 include the following modes (1) to (3).
(1) Torque conversion operation mode: The engine 22 is operated and controlled so that the power corresponding to the required power is output from the engine 22, and all the power output from the engine 22 is the planetary gear 30 and the motors MG1 and MG2. Mode in which the motors MG1 and MG2 are driven and controlled so that the required power is output to the drive shaft 36 by torque conversion by (2) Charge / discharge operation mode: The sum of the required power and the power required for charging / discharging the battery 50. The engine 22 is operated and controlled so that the power corresponding to the above is output from the engine 22, and all or part of the power output from the engine 22 is charged and discharged from the battery 50 to the planetary gear 30 and the motors MG1 and MG2. Mode in which the motors MG1 and MG2 are driven and controlled so that the required power is output to the drive shaft 36 by torque conversion by (3) Motor operation mode: The operation of the engine 22 is stopped and the required power is transferred to the drive shaft 36. Mode to drive and control the motor MG2 so that it is output

Further, in the hybrid vehicle 20 of the embodiment, the engine ECU 24 also controls the fuel supply device 60 (control of the electromagnetic valve 65a of the feed pump 62 and the high-pressure fuel pump 65) when the engine 22 is operated. In the control of the feed pump 62, the target rotation speed Nfp * of the feed pump 62 is set based on the target fuel pressure Pfp * of the fuel supplied to the port injection valve 125, and the rotation speed Nfp of the feed pump 62 becomes the target rotation speed Nfp *. The feed pump 62 is controlled so as to be. The target fuel pressure Pfp * is set to a relatively high predetermined fuel pressure Pfp1 at the start of operation of the engine 22, and when the predetermined time T1 elapses, the target fuel pressure Pfp * is switched to a predetermined fuel pressure Pfp2 lower than the predetermined fuel pressure Pfp1. Here, as the predetermined fuel pressure Pfp1, for example, 510 kPa, 530 kPa, 550 kPa or the like can be used, and as the predetermined fuel pressure Pfp2, 380 kPa, 400 kPa, 420 kPa or the like can be used. Further, for the predetermined time T1, for example, 5 seconds, 6 seconds, 7 seconds, or the like can be used. By setting the target fuel pressure Pfp * in this way, it is possible to promote atomization of fuel immediately after the start of operation of the engine 22 as compared with the case where the target fuel pressure Pfp * is set to the predetermined fuel pressure Pfp2. After the elapse of the predetermined time T1 from the start of the operation of 22, the power consumption of the feed pump 62 can be suppressed as compared with the one in which the target fuel pressure Pfp * is held at the predetermined fuel pressure Pfp1. The method of setting the target rotation speed Nfp * will be described later. Since the control of the solenoid valve 65a of the high-pressure fuel pump 65 does not form the core of the present invention, detailed description thereof will be omitted.

Next, the operation of the hybrid vehicle 20 of the embodiment configured in this way, particularly the operation when setting the target rotation speed Nfp * of the feed pump 62 of the fuel supply device 60 will be described. FIG. 3 is a flowchart showing an example of a target rotation speed setting routine executed by the engine ECU 24 of the embodiment. This routine is executed at the start of operation of the engine 22.

When the target rotation speed setting routine is executed, the engine ECU 24 first sets the rotation speed Nfp1 of the feed pump 62 corresponding to the target fuel pressure Pfp * (predetermined fuel pressure Pfp1) to the target rotation speed Nfp * of the feed pump 62. (Step S100), it waits for the above-mentioned predetermined time T1 to elapse (the target fuel pressure Pfp * switches from the predetermined fuel pressure Pfp1 to the predetermined fuel pressure Pfp2) (step S110). Therefore, the feed pump 62 is controlled so that the rotation speed Nfp of the feed pump 62 becomes the target rotation speed Nfp * (= Nfp1) from the start of operation of the engine 22 until the lapse of a predetermined time T1.

When the predetermined time T1 elapses in this way, it is determined that the feedback control for setting the target rotation speed Nfp * of the feed pump 62 is started (step S120), and the fuel pressure Pfp of the fuel supplied to the port injection valve 125 and the amplitude of its pulsation are determined. The pulsation amplitude Apfp is input as (step S130). Here, the fuel pressure Pfp is assumed to be a value detected by the fuel pressure sensor 68. Further, as the pulsation amplitude Apfp, a value calculated as a difference between the maximum value and the minimum value of the fuel pressure Pfp in a predetermined time or a predetermined cycle (for example, one cycle) of the pulsation of the fuel pressure Pfp is input.

Subsequently, the feed is fed by the following equation (1) using the rotation speed Nfp2 (<Nfp1) of the feed pump 62 corresponding to the target fuel pressure Pfp * (predetermined fuel pressure Pfp2) and the difference between the target fuel pressure Pfp * and the fuel pressure Pfp. The provisional rotation speed Nfptpm as a provisional value of the target rotation speed Nfp * of the pump 62 is calculated (step S140). Here, the equation (1) is a relational expression in the feedback control for setting the fuel pressure Pfp to the target fuel pressure Pfp *, and in the equation (1), the “kp” of the second term on the right side is the gain of the proportional term. “Ki” in the third term on the right side is the gain of the integral term. In the embodiment, the proportional integral control is used for the calculation of the temporary rotation speed Nfptpm, but the proportional control may be used or the proportional integral differential control may be used.

Nfptmp = Nfp2 + kp ・ (Pfp * -Pfp) + ki ・ ∫ (Pfp * -Pfp) dt (1)

When the fuel pressure Pfp and the pulsation amplitude Apfp of the fuel supplied to the port injection valve 125 are input in this way, the input pulsation amplitude Apfp is compared with the threshold value Apfpref (step S150). When the pulsation amplitude Apfp is less than the threshold value Apfpref, it is determined that the degree of pulsation of the fuel pressure Pfp is not large (small) (step S160), and the provisional rotation speed Nfptpm of the feed pump 62 is set to the target rotation speed Nfp * (step S160). Step S162). On the other hand, when the pulsation amplitude Apfp is equal to or higher than the threshold value Apfpref, it is determined that the degree of pulsation of the fuel pressure Pfp is large (step S170), and the value obtained by adding the predetermined rotation speed α to the provisional rotation speed Nfptpm of the feed pump 62 is the target rotation speed Nfp. Set to * (step S172). Then, it is determined whether or not the operation of the engine 22 is continued (step S180), and when it is determined that the operation of the engine 22 is continued, the process returns to step S130 and the processes of steps S130 to S180 are repeatedly executed. If it is determined in step S180 that the operation of the engine 22 is not continued (operation is stopped) during the operation, this routine is terminated.

FIG. 4 is an explanatory diagram showing how the pulsation amplitude Apfp is used to determine whether or not the degree of pulsation of the fuel pressure Pfp is large. It should be noted that the fuel pressure Pfp and the pulsation amplitude Apfp are considered to be actually affected by the rotation speed Nfp of the feed pump 62 (whether the target rotation speed Nfp * is the provisional rotation speed Nfptp or the rotation speed (Nfptp + α)), but it is understood. It is shown schematically for the sake of simplicity. When operating the engine 22, as shown in the figure, after switching the target fuel pressure Pfp * from the predetermined fuel pressure Pfp1 to the predetermined fuel pressure Pfp2 at time t11, when the pulsation amplitude Apfp is less than the threshold value Apfpref (time t11 to t12, From t13 to), it is determined that the degree of pulsation of the fuel pressure Pfp is not large, and when the pulsation amplitude Apfp is equal to or greater than the threshold value Pfpref (time t12 to t13), it is determined that the degree of pulsation of the fuel pressure Pfp is large. Then, the feed pump 62 is controlled by using the target rotation speed Nfp * of the feed pump 62 according to the determination result. Specifically, when it is determined that the degree of pulsation of the fuel pressure Pfp is not large, the provisional rotation speed Nfptpm of the feed pump 62 obtained by the equation (1) is set to the target rotation speed Nfp * to control the feed pump 62. When it is determined that the degree of pulsation of the fuel pressure Pfp is large, the feed pump 62 is controlled by setting the value obtained by adding the predetermined rotation speed α to the provisional rotation speed Nfptp of the feed pump 62 to the target rotation speed Nfp *.

Now, consider the case where the target fuel pressure Pfp * is switched from the predetermined fuel pressure Pfp1 to a predetermined fuel pressure Pfp2 lower than that. When the target fuel pressure Pfp * is lowered, the target rotation speed Nfp * becomes smaller and the discharge amount of the feed pump 62 becomes smaller. Therefore, the fuel pressure on the feed pump 62 side is higher than that on the check valve 64 in the low pressure side passage 63. The check valve 64 may close when the fuel pressure is equal to or less than the fuel pressure on the 125 side. 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 becomes large, and the fuel supply device 60 (low-pressure side passage 63, fuel tank 61, etc.) and the fuel supply device 60 The vibration of the vehicle body on which the fuel pump is placed may become large and abnormal noise may occur. In the embodiment, after the target fuel pressure Pfp * is lowered, when the pulsation amplitude Apfp is equal to or higher than the threshold value Apfpref, the target rotation speed Npf * of the feed pump 62 is increased and the discharge amount of the feed pump 62 is increased as compared with the case where the pulsation amplitude Apfp is less than the threshold value Apfpref. Therefore, it is possible to prevent the fuel pressure on the feed pump 62 side from becoming lower than the fuel pressure on the port injection valve 125 side as compared with the check valve 64 in the low pressure side passage 63, and it is possible to suppress the check valve 64 from closing. can do. As a result, it is possible to suppress an increase in the pulsation of the fuel pressure in the low pressure side passage 63 generated by driving the high pressure fuel pump 65, and the fuel supply device 60 (low pressure side passage 63, fuel tank 61, etc.), the vehicle body, and the like can be suppressed. It is possible to suppress vibration and generation of abnormal noise. The above-mentioned predetermined rotation speed α is preferably set so as to prevent the check valve 64 from closing.

In the hybrid vehicle 20 of the embodiment described above, when the fuel pressure Pfp decreases in response to the switching from the predetermined fuel pressure Pfp1 of the target fuel pressure Pfp * to the predetermined fuel pressure Pfp2, the pulsation amplitude Apfp as the pulsation amplitude of the fuel pressure Pfp. When is greater than or equal to the threshold value Amplitude, the target rotation speed Nfp * of the feed pump 62 is made larger than when the threshold value is less than the threshold value Amplitude, and the feed pump 62 is controlled. As a result, it is possible to prevent the fuel pressure on the feed pump 62 side from becoming lower than the fuel pressure on the port injection valve 125 side as compared with the check valve 64 in the low pressure side passage 63, and it is possible to suppress the check valve 64 from closing. can do. As a result, it is possible to suppress an increase in the pulsation of the fuel pressure in the low pressure side passage 63 generated by driving the high pressure fuel pump 65, and the fuel supply device 60 (low pressure side passage 63, fuel tank 61, etc.), the vehicle body, and the like can be suppressed. It is possible to suppress vibration and generation of abnormal noise.

In the hybrid vehicle 20 of the embodiment, it is determined whether or not the degree of pulsation of the fuel pressure Pfp is large by using the pulsation amplitude Apfp. However, instead of the pulsation amplitude Apfp, the fuel pressure as the slope of the integrated value of the fuel pressure Pfp is determined. The integrated value slope Spfps may be used to determine whether or not the degree of pulsation of the fuel pressure Pfp is large. In this case, the engine ECU 24 may execute the target rotation speed setting routine of FIG. 5 instead of the target rotation speed setting routine of FIG. Here, the target rotation speed setting routine of FIG. 5 is the same as the target rotation speed setting routine of FIG. 3 except that the processing of steps S230 and S250 is executed instead of the processing of steps S130 and S150. Therefore, the same step numbers are assigned to the same processes, and detailed description thereof will be omitted. In the target rotation speed setting routine of FIG. 5, when the engine ECU 24 determines that the feedback control for setting the target rotation speed Nfp * of the feed pump 62 is started (step S120), the fuel pressure Pfp and the fuel pressure integrated value slope Spfps are input. (Step S230). Here, the fuel pressure integrated value slope Spfps is a value calculated as the slope (change amount per unit time) of the fuel pressure Pfp integrated value from the fuel pressure sensor 68 after the operation of the engine 22 is started. And said. Subsequently, the temporary rotation speed Nfptpm of the feed pump 62 is calculated (step S140), and the fuel pressure integrated value slope Spfps is compared with the threshold Spfpsref (step S250). When the fuel pressure integrated value slope Spfps is less than the threshold value Spfpsref, it is determined that the degree of pulsation of the fuel pressure Pfp is not large (small) (step S160), and the provisional rotation speed Nfptpm of the feed pump 62 is set to the target rotation speed Nfp *. (Step S162). On the other hand, the fuel pressure integrated value slope Spfps is the threshold Sp.
When it is fpsref or more, it is determined that the degree of pulsation of the fuel pressure Pfp is large (step S170), and the value obtained by adding the predetermined rotation speed α to the provisional rotation speed Nfptpn of the feed pump 62 is set to the target rotation speed Nfp * (step S172). ). Then, it is determined whether or not the operation of the engine 22 is continued (step S180), and when it is determined that the operation of the engine 22 is continued, the process returns to step S230 and the operation of the engine 22 is not continued (operation stopped). If it is determined, this routine is terminated.

FIG. 6 is an explanatory diagram showing how the fuel pressure integrated value slope Spfps is used to determine whether or not the degree of pulsation of the fuel pressure Pfp is large. The fuel pressure Pfp, the fuel pressure integrated value, and the fuel pressure integrated value slope Spfps are actually affected by the rotation speed Nfp of the feed pump 62 (whether the target rotation speed Nfp * is the provisional rotation speed Nfptpm or the rotation speed (Nfptpm + α)). However, it is shown schematically for easy understanding. When operating the engine 22, as shown in the figure, after switching the target fuel pressure Pfp * from the predetermined fuel pressure Pfp1 to the predetermined fuel pressure Pfp2 at the time t21, when the fuel pressure integrated value slope Spfps is less than the threshold value Spfpsref (time t21 to 1). t22, t23 ~), it is determined that the degree of pulsation of the fuel pressure Pfp is not large, and when the fuel pressure integrated value slope Spfps is equal to or greater than the threshold value Spfpsref (time t22 to t23), it is determined that the degree of pulsation of the fuel pressure Pfp is large. Then, as described above, the feed pump 62 is controlled by using the target rotation speed Nfp * of the feed pump 62 according to the determination result.

When the above-mentioned pulsation amplitude Apfp is relatively large, the maximum value of the fuel pressure Pfp in a predetermined cycle (for example, one cycle) of the fuel pressure Pfp is relatively large, so that the fuel pressure integrated value slope Spfps is also considered to be relatively large. Therefore, even when the fuel pressure integrated value slope Spfps is used instead of the pulsation amplitude Apfp, the target rotation speed Nfp * of the feed pump 62 is made larger than when the fuel pressure integrated value slope Spfps is equal to or more than the threshold Spfpsref and less than the threshold Spfpsref. By controlling the feed pump 62, the same effect as in the embodiment can be obtained.

In the hybrid vehicle 20 of the embodiment, when a predetermined time T1 elapses from the start of operation of the engine 22 (when the target fuel pressure Pfp * is switched from the predetermined fuel pressure Pfp1 to the predetermined fuel pressure Pfp2), the target rotation speed Nfp * of the feedback pump 62 is set. Although the feedback control is started, the feedback control may be performed from the start of the operation of the engine 22.

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 so-called one-motor hybrid vehicle may be configured in which a motor is connected to a drive shaft connected to the drive wheels via a transmission and an engine is connected to the rotation shaft of the motor via a clutch. Further, a so-called series hybrid vehicle may be configured in which a traveling motor is connected to a drive shaft connected to the drive wheels and a power generation motor that exchanges electric power with the traveling motor is connected to the output shaft of the engine. Further, it may be configured as an automobile that travels by using only the power from the engine without providing a motor.

The correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem 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 target rotation speed setting routine of FIG. 3 is executed, and the engine 22 and the fuel supply device 60 are controlled. The engine ECU 24 corresponds to a "control device".

As for the correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem, the invention described in the column of means for solving the problem in the examples is carried out. Since it is an example for specifically explaining the form for solving the problem, the elements of the invention described in the column of means for solving the problem are not limited. That is, the interpretation of the invention described in the column of means for solving the problem should be performed based on the description in the column, and the examples are the inventions described in the column of means for solving the problem. It is just a concrete example.

Although the embodiments for carrying out the present invention have been described above with reference to examples, the present invention is not limited to these examples, and various embodiments are used without departing from the gist of the present invention. Of course, it can be done.

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

20 hybrid vehicle, 22 engine, 24 electronic control unit for engine (engine ECU), 26 crank shaft, 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 rotation position detection sensor, 50 battery, 51a voltage sensor, 51b current sensor, 51c temperature sensor, 52 electronic control unit for battery (battery ECU), 54 power line, 60 fuel supply device , 61 fuel tank, 62 feed pump, 62a rotation speed sensor, 63 low pressure side passage, 64 check valve, 65 high pressure fuel pump, 65a electromagnetic valve, 65b check valve, 66 high pressure side passage, 68, 69 fuel pressure sensor, 70 hybrid Electronic control unit (HVECU), 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 ignition plug, 132 piston, 134 purification device, 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 (1)

An engine having a port injection valve for injecting fuel into an intake pipe and an in-cylinder injection valve for injecting fuel into a cylinder.
The fuel tank, the first pump that supplies the fuel of the fuel tank to the first passage to which the port injection valve is connected, and the fuel pressure provided in the first passage and on the first pump side are the port injection valve side. A check valve that opens when the fuel pressure is higher than the fuel pressure of the first 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 the check valve in the first passage. A fuel supply device having a second pump that pressurizes the fuel on the port injection valve side and supplies the fuel to the second passage to which the in-cylinder injection valve is connected.
A control device that controls the engine and the fuel supply device,
It is a car equipped with
The control device controls the first pump so that the first pump rotates at a target rotation speed based on the target fuel pressure of the fuel supplied to the port injection valve.
Further, the control device has a pulsation amplitude as a pulsation amplitude of the port side fuel pressure when the port side fuel pressure, which is the fuel pressure of the fuel supplied to the port injection valve, decreases in response to the decrease of the target fuel pressure. When is greater than or equal to the predetermined amplitude , the pulsating amplitude is larger than that when the amplitude is less than the predetermined amplitude , and the fuel pressure on the first pump side is higher than the fuel pressure on the port injection valve side than the check valve in the first passage. the sets the target rotational speed so also increases,
Automobile.

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