JP2015048750A - Fuel supply device of engine-mounted body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel supply device of an engine-mounted body which can perform the feedback control of a drive current of an electric motor which copes with an individual difference and a secular change of a fuel pump without increasing a cost.SOLUTION: A current control part 102d1 controls a current which is conducted to a motor part 101b for a prescribed time T after an ECU 102 is activated so as to be brought into a stationary state, a current detection part 102c detects a current in the stationary state within the prescribed time T, a voltage detection part 102b detects a voltage in the stationary state within the prescribed time T, a target current calculation part 102d2 calculates a target current which is conducted to the motor part 101b on the basis of the current and the voltage which are detected within the prescribed time T, and the current control part 102d1 starts the feedback control of the current which is conducted to the motor part 101b so that the current which is conducted to the motor part 101b approximates the target current which is calculated at the target current detection part 102d2 after the lapse of the prescribed time T.

Description

  The present invention relates to a fuel supply device for an engine mounting body, and more particularly to a fuel supply device for an engine mounting body including a fuel pump that pumps fuel to a fuel injection valve by driving an electric motor.

  In a fuel supply device for an engine mounted body such as a vehicle or a general-purpose machine equipped with an engine that is an internal combustion engine, an electric motor driven by electric power supplied from a power supply device of the engine mounted body is provided. Some have a fuel pump that is driven to pump fuel to the fuel injection valve.

  According to such a fuel supply device, the pressure regulator for maintaining a constant pressure of the fuel supplied to the fuel injection valve (hereinafter referred to as fuel pressure) can be omitted, so the configuration of the fuel supply device The cost can be reduced.

  Further, in such a fuel supply device, it is necessary to accurately control the fuel pressure to a desired value in response to individual differences in fuel pumps and changes with time.

  Under such circumstances, Patent Document 1 relates to an engine fuel supply apparatus and a fuel supply method, and the deviation between the rotational speed of the electric motor and the standard rotational speed of the electric motor stored in advance reflects the individual differences and changes over time of the fuel pump. In view of this, a configuration is disclosed in which the target value of the drive current of the electric motor is corrected based on this deviation, and the drive current of the electric motor is feedback-controlled to the target value thus corrected.

Japanese Patent Laid-Open No. 11-247696

  However, according to the study of the present inventor, the fuel supply device described in Patent Document 1 is intended to accurately control the fuel pressure to a desired value in response to individual differences and changes with time of the fuel pump. However, the target value of the drive current of the electric motor is corrected based on the deviation between the rotation speed of the electric motor and the standard rotation speed of the electric motor stored in advance, and the drive current of the electric motor is thus corrected. Since it has the structure which carries out feedback control to a target value, the rotational speed sensor for detecting the rotational speed of an electric motor inevitably becomes necessary. Therefore, in such a configuration, the configuration of the fuel supply device becomes complicated and the cost increases as much as the rotational speed sensor is provided.

  In other words, at present, in the fuel supply device of the engine mounting body including the fuel pump that pumps the fuel to the fuel injection valve by driving the electric motor, the necessity of providing an additional sensor or the like is eliminated and the cost is increased. There is a long-awaited realization of a novel configuration that can perform feedback control of the drive current of the electric motor that copes with individual differences and changes with time of the fuel pump without causing any change.

The present invention has been made through the above studies, and is equipped with an engine that can perform feedback control of the drive current of an electric motor that copes with individual differences and changes with time of the fuel pump without increasing the cost. An object of the present invention is to provide a fuel supply apparatus.

  In order to achieve the above object, the present invention includes a fuel injection valve provided in an engine of an engine mounted body, and an electric motor driven by electric power supplied from a power supply device of the engine mounted body, A fuel pump that pumps fuel to the fuel injection valve by driving an electric motor; and a control device that controls driving of the electric motor, and the pressure of the fuel pumped from the fuel pump to the fuel injection valve Is a fuel supply device for an engine-mounted body that depends on a current applied to the electric motor and a voltage applied to the electric motor, and the control device continues for a predetermined time from when the control device is activated. A current control unit configured to control a current supplied to the electric motor so as to be in a steady state; and a current in a steady state supplied to the electric motor within the predetermined time. A current detection unit; a voltage detection unit that detects a steady-state voltage applied to the electric motor within the predetermined time; and a current detected by the current detection unit within the predetermined time and the voltage detection unit. A target current calculation unit that calculates a target current to be supplied to the electric motor based on the detected voltage, and the current control unit supplies power to the electric motor after the predetermined time has elapsed. The first aspect is to start feedback control of the current supplied to the electric motor so that the current to be applied approaches the target current calculated by the target current calculation unit.

  In addition to the first aspect, the present invention provides that the target current calculation unit is a standard voltage determined in consideration of a voltage detected by the voltage detection unit within the predetermined time and an individual difference of the fuel pump. And calculating the target current so that the absolute value of the deviation becomes small is a second aspect.

  In addition to the second aspect, the present invention provides that the target current calculation unit is a standard voltage determined in consideration of a voltage detected by the voltage detection unit within the predetermined time and an individual difference of the fuel pump. It is a second aspect that the deviation rate is calculated by dividing the deviation by the standard voltage, and the target current is calculated so that the absolute value of the deviation rate becomes small.

  According to the engine-equipped fuel supply device in the first aspect of the present invention described above, the current that is supplied to the electric motor continuously for a predetermined time from when the control device starts up the control device is in a steady state. A current control unit that controls the current, a current detection unit that detects a steady-state current that is applied to the electric motor within a predetermined time period, and a steady-state voltage that is applied to the electric motor within a predetermined time period A voltage detection unit, and a target current calculation unit that calculates a target current to be supplied to the electric motor based on the current detected by the current detection unit within a predetermined time and the voltage detected by the voltage detection unit. Then, after a predetermined time has elapsed, the current control unit starts feedback control of the current supplied to the electric motor so that the current supplied to the electric motor approaches the target current calculated by the target current calculation unit. Thus, since it is possible to perform feedback control of the current supplied to the electric motor without detecting the rotational speed of the electric motor, a rotational speed sensor or the like for detecting the rotational speed of the electric motor becomes unnecessary. Without increasing the cost, it is possible to accurately perform feedback control of the drive current of the electric motor that copes with individual differences and changes with time of the fuel pump.

  Further, according to the fuel supply device for an engine mounted body in the second aspect of the present invention, the target current calculation unit is determined in consideration of the voltage detected by the voltage detection unit within a predetermined time and the individual difference of the fuel pump. By calculating the deviation from the measured standard voltage and calculating the target current so that the absolute value of the deviation is small, the drive of the electric motor that copes with individual differences and aging of the fuel pump without increasing the cost Current feedback control can be accurately performed with a low calculation load.

  Further, according to the fuel supply device for an engine-mounted body in the third aspect of the present invention, the target current calculation unit is determined in consideration of the voltage detected by the voltage detection unit within a predetermined time and the individual difference of the fuel pump. By calculating the deviation rate from the standard voltage obtained by dividing the deviation specified in the second aspect by the standard voltage and calculating the target current so that the absolute value of the deviation rate becomes small, the cost can be reduced. Without increasing, it is possible to more accurately perform feedback control of the drive current of the electric motor that copes with individual differences and changes with time of the fuel pump.

FIG. 1A is a schematic diagram showing the configuration of an internal combustion engine and a fuel supply device in an embodiment of the present invention, and FIG. 1B is an ECU (Electronic Control Unit) of the fuel supply device in this embodiment. It is a circuit diagram which shows a structure. FIG. 2 is a schematic partial cross-sectional view showing the configuration of the fuel pump of the fuel supply device in the present embodiment. FIG. 3A is a diagram showing a regression line representing the relationship between the drive current and drive voltage of the motor unit of the fuel supply apparatus in the present embodiment, and FIG. 3B is the fuel supply apparatus in the present embodiment. It is a figure which shows the regression line showing the relationship between the voltage deviation rate and current deviation of a motor part. Moreover, FIG.3 (c) is a figure which shows the regression line showing the relationship between the voltage deviation and current deviation of the motor part of the fuel supply apparatus in the modification of this embodiment. FIG. 4 is a timing chart for explaining the fuel supply process of the fuel supply apparatus according to this embodiment.

  Hereinafter, a fuel supply device for an engine mounting body in an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

[Configuration of internal combustion engine]
First, the configuration of the internal combustion engine 1 to which the fuel supply device S according to the present embodiment is applied will be described in detail with reference to FIG.

  FIG. 1A is a schematic diagram showing the configuration of the internal combustion engine 1 and the fuel supply device S in the present embodiment.

  As shown in FIG. 1A, the internal combustion engine 1 is mounted on an engine mounting body (not shown) and includes a cylinder block 2. A cooling water passage 3 through which cooling water for cooling the cylinder block 2 and the inside thereof is circulated is formed in the side wall of the cylinder block 2. The cooling water passage 3 is provided with a water temperature sensor 4 for detecting the temperature of the cooling water flowing through the cooling water passage 3.

  In FIG. 1A, for convenience of explanation, the internal combustion engine 1 is shown as a single cylinder. However, the internal combustion engine 1 may have a plurality of cylinders, and the arrangement of the cylinders is in series and horizontally opposed. Or V-type or the like. In FIG. 1A, for convenience of explanation, the internal combustion engine 1 is shown as a water-cooled type, but it may be an air-cooled type. In such a case, the temperature of the internal combustion engine 1 is used instead of the water temperature sensor 4. A temperature sensor capable of detecting the above may be attached to the cylinder block 2 or the like.

A piston 5 is disposed inside the cylinder block 2. The piston 5 is connected to a crank 7 via a connecting rod 6. A crank angle sensor 8 that detects the rotation angle of the crank 7 is provided in the vicinity of the crank 7 so as to detect the rotation speed of the internal combustion engine 1. A cylinder head 9 is mounted on the upper portion of the cylinder block 2. An internal space defined by the upper surface of the piston 5 and the inner surfaces of the cylinder block 2 and the cylinder head 9 is a combustion chamber 10.

  The cylinder head 9 is provided with a spark plug 11 that ignites the air-fuel mixture in the combustion chamber 10. The ignition operation of the spark plug 11 is controlled by the ECU 102 controlling energization to an ignition coil (not shown).

  The cylinder head 9 is provided with an intake valve 13 that allows the combustion chamber 10 and the intake passage 12 to communicate with each other in an openable and closable manner. The intake passage 12 is formed in an intake pipe IM fixed to the cylinder head 9, and the intake pipe IM is disposed on the upstream side of the fuel injection valve 14 that injects fuel into the intake passage 12 and the fuel injection valve 14. The throttle valve 15 is provided. The fuel injection valve 14 may inject fuel directly into the combustion chamber 10.

  An exhaust pipe EM is fixed to the cylinder head 9 on the opposite side of the intake pipe IM, and an exhaust passage 16 communicating with the combustion chamber 10 is formed in the exhaust pipe EM. The cylinder head 9 is provided with an exhaust valve 17 that allows the combustion chamber 10 and the exhaust passage 16 to communicate freely.

[Configuration of fuel supply system]
Next, with reference to FIG. 1A and FIG. 1B, the configuration of the fuel supply apparatus S in the present embodiment will be described in detail.

  FIG. 1B is a circuit diagram showing a configuration of the ECU 102 of the fuel supply apparatus S in the present embodiment.

  The fuel supply device S in the present embodiment is a device that supplies fuel to the fuel injection valve 14, and includes a fuel tank 100, a fuel pump 101, and an ECU (Electronic Control Unit) 102 as shown in FIG. I have. The fuel tank 100 stores fuel to be supplied to the fuel injection valve 14.

  The fuel pump 101 has a motor unit 101b (see FIG. 2), which is an electric motor driven by electric power supplied from a power supply device 103 such as a battery or a generator, and the fuel pipe 104 is driven by driving the motor unit 101b. Then, the fuel stored in the fuel tank 100 is pumped to the fuel injection valve 14. Details of the configuration of the fuel pump 101 will be described later.

  The ECU 102 is an arithmetic processing unit such as a microcomputer, and has a memory and a timer (not shown). The memory stores a necessary control program and control data, and the ECU 102 reads the necessary control program and control data from the memory and executes the control program to control the operation of the entire fuel supply device S. It is a control device. The timer measures the execution time of a specific process in the fuel supply process of the fuel supply apparatus S.

  Specifically, the ECU 102 includes a drive circuit 102a, a voltage detection unit 102b, a current detection unit 102c, and a CPU (Central Processing Unit) 102d. In the figure, the drive circuit 102a and the voltage detection unit 102b are respectively shown as functional blocks when the CPU 102d executes the control program.

The drive circuit 102a controls the power supply from the power supply device 103 to the motor unit 101b by controlling the connection / disconnection between the negative electrode of the motor unit 101b and the ground terminal G in accordance with a control signal from the CPU 102d. Is controlled. In the drawing, an NPN bipolar transistor is shown as an example of the drive circuit 102a.

  The voltage detection unit 102b detects a voltage value applied to the motor unit 101b, and inputs the detected voltage value to the CPU 102d. In the drawing, as an example of the voltage detection unit 102b, an operational amplifier or a comparator in which a non-inverting input terminal and an inverting input terminal are respectively connected to the positive side and the negative side of the motor unit 101b is shown.

  The current detection unit 102c detects a current value energized in the motor unit 101b as a voltage drop amount of the resistance element R, and inputs the detected current value to the CPU 102d. In the figure, as an example of the current detection unit 102c, the non-inverting input terminal and the inverting input terminal correspond to the positive side and the negative side of the resistance element R connected between the driving circuit 102a and the ground terminal G, respectively. Shows an operational amplifier or a comparator connected to each other.

  The CPU 102d is an arithmetic processing unit, and includes a current control unit 102d1 and a target current calculation unit 102d2 as functional blocks when executing the control program. Details of the functions of these units will be described later.

[Configuration of fuel pump]
Next, with reference to FIG. 2, the structure of the fuel pump 101 in this embodiment is demonstrated in detail.

  FIG. 2 is a schematic partial cross-sectional view showing the configuration of the fuel pump 101 of the fuel supply apparatus S in the present embodiment.

  As shown in FIG. 2, the fuel pump 101 in the present embodiment includes a pump unit 101a that pumps fuel from the fuel tank 100 to the fuel injection valve 14, and a motor unit 101b that drives the pump unit 101a. The motor unit 101b is an output shaft of the electric motor by driving the built-in electric motor with electric power from the power supply device 103 such as a battery (not shown) mounted on the engine mounting body, and the pump unit A rotary shaft 110 that is coaxial with the central axis Z of the motor 101a and the motor 101b can be driven to rotate. Such an electric motor is typically a direct current motor controlled by PWM (Pulse Width Modulation). Further, the pump unit 101 a includes a rotor 111 that is pivotally supported by the rotation shaft 110. The rotor 111 is accommodated in an accommodation chamber defined between a lower cover 112 having a groove 113 and a housing 114 having a groove 115.

  In the fuel pump 101 having such a configuration, when the motor unit 101b drives and rotates the rotating shaft 110, the rotor 111 fixed to one end of the rotating shaft 110 is rotated at a high speed and formed in the rotor 111. The fin portion stirs the fuel in the storage chamber at high speed. Thereby, a pressure gradient is generated between the suction port 113 a of the groove 113 formed in the lower cover 112 and the discharge port 115 a of the groove 115 formed in the housing 114. For this reason, the fuel in the fuel tank 100 is sucked into the fuel pump 101 through the suction port 113a of the groove 113 after passing through a filter (not shown). The fuel sucked from the fuel tank 100 in this way is sent from the lower side to the upper side in the drawing through the storage chamber and the discharge port 115 a of the groove 115, and is discharged from the fuel pump 101 to the fuel pipe 104. And pumped to the fuel injection valve 14.

[Fuel supply processing]
In the fuel supply device S of the present embodiment having the above-described configuration, the ECU 102 performs the following fuel supply processing to cope with individual differences and changes with time of the fuel pump 101 without increasing the cost. Feedback control of the drive current of the motor unit 101b is performed. Hereinafter, the operation of the ECU 102 when the fuel supply process is executed will be described in detail with reference to FIGS. 3 and 4.

  3 (a) and 3 (b) are respectively a regression line representing the relationship between the drive current and drive voltage of the motor unit 101b of the fuel supply apparatus S and the voltage deviation rate and current of the motor unit 101b in this embodiment. It is a figure which shows the regression line showing the relationship with a deviation. FIG. 4 is a timing chart for explaining the fuel supply process of the fuel supply apparatus S in the present embodiment.

  In the fuel supply apparatus S of the present embodiment, regression representing the relationship between the drive current I and the drive voltage V of the motor unit 101b so that individual differences and changes with time of the fuel pump 101 can be dealt with when executing the fuel supply process. The data of the straight line RL1 and the data of the regression line RL2 representing the relationship between the voltage deviation rate RDV of the motor unit 101b and the current deviation (current correction amount) DI are stored in advance in the memory of the ECU 102.

  For the regression line RL1 and the regression line RL2, it is necessary to obtain the regression line RL2 after obtaining the regression line RL1. First, a method for determining the regression line RL1 will be described with reference to FIG.

  First, when obtaining the regression line RL1, the standard fuel pressure Ps is determined in accordance with the specifications of the fuel supply device S in the present embodiment.

  Next, the fuel pressures of a plurality of (for example, five) fuel pumps 101 are measured, and one fuel pump is selected as a standard product from these. Such a standard fuel pump is typically selected from among a plurality of fuel pumps whose fuel pressures have been measured, those whose measured fuel pressure is the median value.

  Next, for such a standard product, when the standard fuel pressure Ps is detected by the fuel pressure sensor, the current supplied to the motor unit 101b and the voltage applied to the motor unit 101b are set to the standard current value Is and the standard voltage value, respectively. Measured as Vs. Further, for such a standard product, the value of the voltage V applied to the motor unit 101b is measured at a plurality of points while changing the value of the current I supplied to the motor unit 101b. In addition, as the voltage applied to the motor unit 101b, a voltage between terminals of the motor unit 101b is measured.

  Next, as shown in FIG. 3A, the value of the current I energized in the motor unit 101b and the value of the voltage V applied to the motor unit 101b corresponding to the measured current value are expressed as standard current values. After creating a scatter diagram by plotting in a Cartesian coordinate system including Is and the standard voltage value Vs, the horizontal axis is the current I energized to the motor unit 101b and the vertical axis is the voltage V energized to the motor unit 101b. The equation of the regression line RL1 representing the relationship between the current I and the voltage V is calculated through the standard current value Is and the standard voltage value Vs by performing linear approximation using these plotted values. Here, the data of the equation calculated in this way is stored in the memory of the ECU 102 as data of the regression line RL1. Although illustrated in the figure, the value of the current I applied to the motor unit 101b is changed for the standard product, and the value of the voltage V applied to the motor unit 101b is measured correspondingly, and the standard current is measured. The number of points plotted on the scatter diagram including the value Is and the standard voltage value Vs is 7 points corresponding to the number of measurement points.

  Next, a plurality of (for example, four) fuel pumps 101 other than the standard product are energized to the motor unit 101b when the standard fuel pressure Ps is detected by the fuel pressure sensor by the same measurement as that of the standard product. The current value i and the voltage value v applied to the motor unit 101b are measured.

  Next, with respect to the plurality of fuel pumps 101 other than the standard product, the voltage deviation rate RDV (RDV) using the measured current value i and voltage value v and the previously measured standard current value Is and standard voltage value Vs. = (Vs−v) / Vs) and current deviation DI (DI = − (Is−i)) are calculated. Here, the voltage deviation rate RDV is a value normalized by dividing the difference between the standard voltage value Vs and the measured voltage value v by the standard voltage value Vs.

  Finally, as shown in FIG. 3B, the value of the voltage deviation rate RDV and the value of the current deviation DI calculated for each of the fuel pumps 101 other than the standard product are shown, and the horizontal axis represents the voltage deviation rate RDV, Then, after plotting in a Cartesian coordinate system with the current deviation DI on the vertical axis and creating a scatter diagram, the relationship between the voltage deviation rate RDV and the current deviation DI is obtained by linear approximation using these plotted values. The equation of the regression line RL2 to be expressed is calculated. The data of the equation calculated in this way is stored in the memory of the ECU 102 as data of the regression line RL2. The regression line RL2 is a straight line having a negative slope passing through the origin, and the absolute value of the current deviation DI increases as the absolute value of the voltage deviation rate RDV increases. When such a scatter diagram is created by plotting the values of the voltage deviation rate RDV and the current deviation DI calculated for each of the fuel pumps 101 other than the standard product, these plotted values themselves are also generated. Although it is arranged almost linearly, this was first discovered by the present inventors.

  Next, the specific operation of the fuel supply process using the data of the regression line RL1 and the regression line RL2 obtained as described above will be described in detail with reference to FIG.

  As shown in FIG. 4A to FIG. 4D, in the fuel supply process in the present embodiment, first, when the current control unit 102d1 starts the ECU 102 (time t = 0), the drive circuit 102a is turned on. By controlling, the motor unit 101b starts to be driven using the power from the power supply device 103 (time t = t1). At this time, as shown in FIG. 4A, the current control unit 102d1 drives the motor unit 101b with a constant current and a constant voltage so as to control the duty ratio of the motor unit 101b to a constant value such as 100%. To do. However, as shown in FIG. 4B and FIG. 4C, the drive current of the motor unit 101b suddenly rises immediately after time t = t1, then falls to a constant value Ia, and converges. The driving voltage 101b rises gently after time t = t1 and converges to a constant value Va. At the same time, as shown in FIG. 4D, the current control unit 102d1 starts counting a timer that measures the driving time of the motor unit 101b. That is, the current control unit 102d1 has a constant current value for the current continuously supplied to the motor unit 101b within a predetermined time T after the timer is actually started after the ECU 102 is activated. The duty ratio is controlled so as to be in a steady state where the value is Ia. Note that the time from when the ECU 102 is activated until the timer starts counting is extremely short.

  Next, as shown in FIG. 4B and FIG. 4C, the target current calculation unit 102d2 uses the current detection unit 102c and the voltage detection unit 102b to calculate the drive current supplied to the motor unit 101b. The current value Ia and the voltage value Va of the drive current applied to the motor unit 101b are respectively measured, the drive current of the motor unit 101b converges to a constant value Ia, and the drive voltage of the motor unit 101b is constant value Va. Confirm that the steady state is reached.

  Next, the target current calculation unit 102d2 calculates the standard voltage value V0 related to the motor unit 101b by substituting the measured steady-state current value Ia into the equation of the regression line RL1. In addition, the target current calculation unit 102d2 uses the measured deviation rate ((Va−V0) / V0) of the steady state voltage value Va as the voltage deviation rate RDVa (RDVa = (Va−V0) for the motor unit 101b. / V0).

Next, as shown by the dotted line in FIG. 4B, the target current calculation unit 102d2 calculates the current correction amount DIa by substituting the calculated voltage deviation rate RDVa into the equation of the regression line RL2, and the steady state Of the current value Ia and the current correction amount DIa (Ia + DIa) is calculated as the target current value of the motor unit 101b (time t = ts). That is, the target current calculation unit 102d2 calculates the absolute value of the deviation rate between the voltage value Va measured by the voltage detection unit 102b and the standard voltage value V0 determined in consideration of individual differences and changes over time of the fuel pump 101. The target current value of the motor unit 101b is calculated so that becomes smaller.

  Next, as shown in FIG. 4 (d), the current control unit 102d1 drives the motor unit 101b based on the count value of the timer, and actually starts a count for a predetermined time T after the timer starts counting. It is determined whether or not.

Then, as shown in FIG. 4A to FIG. 4D, the current control unit 102d1 drives the motor unit 101b at a timing when a predetermined time T has elapsed (time t = t2). Feedback control of the drive current of the motor unit 101b is started so that the drive current becomes the calculated target current. During such feedback, the drive voltage of the control motor unit 101b is constant.
[Modification]

  In the present embodiment, instead of the regression line RL2 shown in FIG. 3B, a modified example using the regression line RL2 ′ shown in FIG. 3C can be configured. The regression line RL2 'is obtained by using the voltage deviation DV instead of the voltage deviation rate RDV.

  FIG.3 (c) is a figure which shows the regression line showing the relationship between the voltage deviation and current deviation of the motor part of the fuel supply apparatus in the modification of this embodiment.

  Specifically, also in this modified example, when the standard fuel pressure Ps is detected by the fuel pressure sensor for a plurality of (for example, four) fuel pumps 101 other than the standard product, by the same measurement as that of the standard product. The current value i applied to the motor unit 101b and the voltage value v applied to the motor unit 101b are measured.

  Next, voltage deviation DV (DV = DV = DV = DV = DV = DV = DV = DV = DV = DV = DV = DV = DV = DV = DV = DV = DV = DV) A value of (Vs−v) and a value of current deviation DI (DI = − (Is−i)) are calculated.

  Finally, as shown in FIG. 3C, the values of the voltage deviation DV and the current deviation DI calculated for each of the plurality of fuel pumps 101 other than the standard products are shown, the horizontal axis shows the voltage deviation DV, and the vertical A scatter diagram is created by plotting the Cartesian coordinate system with the axis as the current deviation DI, and then linear approximation is performed using these plotted values, thereby representing a regression line representing the relationship between the voltage deviation DV and the current deviation DI. Calculate the equation for RL2 ′. The data of the equation calculated in this way is stored in the memory of the ECU 102 as data of the regression line RL2 '. The regression line RL2 'is a straight line having a negative slope through the origin, and the absolute value of the current deviation DI increases as the absolute value of the voltage deviation DV increases. Further, when such a scatter diagram is created by plotting the value of the voltage deviation DV and the value of the current deviation DI calculated for each of the plurality of fuel pumps 101 other than the standard product, these plotted values themselves are almost the same. Although this is arranged in a straight line, this was first discovered by the present inventors.

Thus, instead of the regression line RL2 defined using the voltage deviation rate RDV normalized by the standard voltage value Vs, the regression defined using the voltage deviation DV not normalized by the standard voltage value Vs. By using the straight line RL2 ′, the regression line RL2 ′ is defined, and the calculation load when the fuel injection process is performed using the regression line RL2 ′ can be further reduced.

  As is clear from the above description, according to the fuel supply device S for an engine mounted body in the embodiment of the present invention, the current control unit 102d1 energizes the motor unit 101b for a predetermined time T from when the ECU 102 is activated. The current detection unit 102c detects the steady-state current that is supplied to the motor unit 101b within a predetermined time T, and the voltage detection unit 102b detects that the current detection unit 102c is within the predetermined time T. The steady-state voltage applied to the motor unit 101b is detected, and the target current calculation unit 102d2 converts the current detected by the current detection unit 102c within the predetermined time T and the voltage detected by the voltage detection unit 102b. Based on this, a target current to be energized to the motor unit 101b is calculated, and further, the current control unit 102d1 energizes the motor unit 101b after a predetermined time T has elapsed. Flow starts feedback control of the current applied to the motor unit 101b so as to approach the target current calculated by the target current calculating section 102D2. As a result, feedback control of the current supplied to the motor unit 101b can be performed without detecting the rotation speed of the motor unit 101b, so that a rotation speed sensor for detecting the rotation speed of the motor unit 101b is unnecessary. Therefore, it is possible to perform feedback control of the drive current of the motor unit 101b that copes with individual differences and changes with time of the fuel pump 101 without increasing the cost.

  Further, according to the fuel supply device for an engine mounted body in the embodiment of the present invention, the target current calculation unit 102d takes into account the voltage detected by the voltage detection unit 102b within a predetermined time and the individual difference of the fuel pump 101. By calculating the deviation DV from the set standard voltage and calculating the target current so that the absolute value of the deviation DV becomes small, the individual differences and changes with time of the fuel pump 101 were dealt with without increasing the cost. Feedback control of the drive current of the motor unit 101b can be performed with a low calculation load with high accuracy.

  Further, according to the fuel supply device for an engine mounted body in the embodiment of the present invention, the target current calculation unit 102d takes into account the voltage detected by the voltage detection unit 102b within a predetermined time and the individual difference of the fuel pump 101. By calculating the deviation rate RDV from the determined standard voltage by dividing the deviation DV by the standard voltage and calculating the target current so that the absolute value of the deviation rate RDV becomes small, without increasing the cost, The feedback control of the drive current of the motor unit 101b that copes with the individual difference and the change with time of the fuel pump 101 can be performed with higher accuracy.

  In the present invention, the type, arrangement, number, and the like of the members are not limited to the above-described embodiments, and the constituent elements thereof are appropriately replaced with those having the same operational effects, and the gist of the invention is not deviated. Of course, it can be appropriately changed within the range.

  As described above, the present invention provides a fuel supply device for an engine-mounted body capable of performing feedback control of the drive current of an electric motor that copes with individual differences in fuel pumps and changes over time without increasing costs. It is expected that it can be widely applied to a fuel supply device for an engine-mounted body such as a motorcycle because of its universality.

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Cylinder block 3 ... Cooling water passage 4 ... Water temperature sensor 5 ... Piston 6 ... Connecting rod 7 ... Crank 8 ... Crank angle sensor 9 ... Cylinder head 10 ... Combustion chamber 11 ... Spark plug 12 ... Intake passage 13 ... Intake air Valve 14 ... Fuel injection valve 15 ... Throttle valve 16 ... Exhaust passage 17 ... Exhaust valve 100 ... Fuel tank 101 ... Fuel pump 101a ... Pump part 101b ... Motor part 102 ... ECU
102a ... Drive circuit 102b ... Voltage detection unit 102c ... Current detection unit 102d ... CPU
DESCRIPTION OF SYMBOLS 102d1 ... Current control part 102d2 ... Target electric current calculation part 103 ... Power supply device 104 ... Fuel piping 110 ... Rotating shaft 111 ... Rotor 112 ... Lower cover 113 ... Groove part 113a ... Inlet port 114 ... Housing 115 ... Groove part 115a ... Discharge port S ... Fuel supply apparatus

Claims (3)

A fuel injection valve provided in the engine of the engine mounted body;
A fuel pump that has an electric motor driven by electric power supplied from the power supply device of the engine-mounted body, and that pumps fuel to the fuel injection valve by driving the electric motor;
A control device for controlling the driving of the electric motor;
With
A fuel supply device for an engine-mounted body in which the pressure of fuel pumped from the fuel pump to the fuel injection valve depends on a current applied to the electric motor and a voltage applied to the electric motor,
The controller is
A current control unit for controlling the current supplied to the electric motor to be in a steady state continuously for a predetermined time from when the control device is activated;
A current detector that detects a steady-state current that is energized to the electric motor within the predetermined time;
A voltage detector that detects a steady-state voltage applied to the electric motor within the predetermined time;
A target current calculation unit that calculates a target current to be supplied to the electric motor based on the current detected by the current detection unit and the voltage detected by the voltage detection unit within the predetermined time;
Have
The current control unit performs feedback control of the current supplied to the electric motor so that the current supplied to the electric motor approaches the target current calculated by the target current calculation unit after the predetermined time has elapsed. A fuel supply device for an engine mounted body, characterized by starting.   The target current calculation unit calculates a deviation between a voltage detected by the voltage detection unit within the predetermined time and a standard voltage determined in consideration of individual differences of the fuel pump, and the absolute value of the deviation is calculated. The fuel supply device for an engine mounted body according to claim 1, wherein the target current is calculated so that the value becomes smaller.   The target current calculation unit calculates a deviation rate between the voltage detected by the voltage detection unit within the predetermined time and the standard voltage determined in consideration of individual differences of the fuel pump, and the deviation. 3. The fuel supply device for an engine mounted body according to claim 2, wherein the target current is calculated by dividing by the standard voltage so that an absolute value of the deviation rate becomes small.

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