JP5808298B2 - Battery state determination device for internal combustion engine - Google Patents

Description

  The present invention relates to a battery state determination device for an internal combustion engine.

  Conventionally, an engine is provided with an idle stop function, and when the battery voltage value is lower than the determination value by comparing the value of the battery voltage with a determination value set in advance according to the magnitude of the electric load, the engine A vehicle that prohibits the operation of the idle stop function is known (for example, Patent Document 1). The above technique is to prevent a decrease in the output of the lead battery and to ensure the restart of the engine.

Japanese Patent No. 3520682

  However, since the internal resistance of the electric load is temperature-dependent, the determination value is set in consideration of the temperature range from the cold region to the tropical region. In other words, allowances are allowed for the upper and lower margins in the determination value determined in a standard temperature environment (for example, 25 degrees). Therefore, there is a risk that the idle stop frequency may be reduced.

The battery state determination apparatus for an internal combustion engine according to claim 1 detects a voltage of a battery that supplies power to a starter used for starting the internal combustion engine during a starter drive signal output period when the internal combustion engine is started. Among the battery voltages detected by the voltage detection unit, a calculation unit that calculates an average voltage value of the first half of the starter drive signal output period and an average voltage value of the second half, and a first half calculated by the calculation unit A determination unit that determines the magnitude of the average voltage value of the unit and the first threshold value, and that determines whether to permit or prohibit the operation of the idle stop function of the vehicle based on the determination result; And a charge control unit that determines the magnitude of the average voltage value of the latter half and the second threshold and controls the amount of charge of the battery based on the determination result.

  According to the present invention, based on the average voltage value of the battery in the first half and the average voltage of the battery in the second half at the starter driving time, it is determined whether or not the operation of the predetermined function provided in the vehicle is permitted. Control the amount of charge. As a result, it is possible to improve the determination accuracy of permission or prohibition of a predetermined function such as idle stop.

The block diagram which shows the structure of the battery state discrimination | determination apparatus by embodiment of this invention. A diagram schematically showing the behavior of the battery voltage at engine start The figure which shows typically the behavior of the battery voltage at the time of engine starting according to the state of the battery The figure explaining the correspondence of the result of state discrimination processing, idle stop permission judgment processing, and battery charge control The flowchart explaining operation | movement of the battery state discrimination | determination apparatus by embodiment

  A battery state determination device for an internal combustion engine according to an embodiment of the present invention will be described with reference to the drawings. The battery state determination device according to the present embodiment is an idle stop that automatically stops the engine temporarily when waiting for a signal or the like and then automatically restarts according to the driver's accelerator operation, for example, for the purpose of improving fuel economy performance or exhaust performance. It is mounted on a vehicle having a function. When the engine is started by cranking, the deterioration and charge state of the battery are detected, and based on these two pieces of battery information, whether or not the idle stop function is permitted is determined, and the battery charge control method is determined. .

  FIG. 1 is a diagram showing a configuration of a part of a vehicle 50 equipped with a battery state determination device according to the present embodiment. As shown in FIG. 1, a vehicle 50 includes a starter 101, a control device 102, a battery 103, a battery current sensor 104, a battery voltage sensor 105, an engine 106, various sensors / switches (hereinafter simply referred to as sensors). 107) and a generator 108.

  The starter 101 includes a starter motor 101a, a magnet switch 101b, a pinion clutch 101c, a pinion gear 101d, a shift lever 101e, and the like. The starter motor 101a and the magnet switch 101b are controlled by an output from a control device 102, which will be described later, via a starter motor energization switch 101f and a magnet energization switch 101g, respectively.

  The engine 106 is, for example, a gasoline engine or a diesel engine, and start and stop are controlled by a signal from the control device 102 described later. The engine 106 is provided with a ring gear 106a. As will be described later, when the engine 106 is automatically started, the engine 106 is connected to the starter 101 via the ring gear 106a.

  The generator 108 is attached to the engine 106 and is configured by an alternator or the like that generates electric power according to the driving of the engine 106. The battery 103 is, for example, a lead storage battery, and supplies power to the starter 101 when the engine 106 is started. Battery current sensor 104 detects the charging / discharging current of battery 103 and outputs the detected current value to control device 102. Battery voltage sensor 105 detects the voltage of battery 103 and outputs the detected voltage value to control device 102.

  The control device 102 is configured by a CPU and other peripheral circuits, and is an arithmetic circuit that controls each component and executes various data processing. Further, the control device 102 functions as a battery state determination device, as will be described later. The control device 102 receives a detection signal from a sensor 107 that includes a crank angle sensor, a pinion rotation sensor, a brake switch, a vehicle speed sensor, and the like. The control device 102 performs normal fuel injection, ignition, and air amount control based on input detection signals from the various sensors 107. Further, the control device 102 determines whether or not an idle stop condition is satisfied based on information such as an operation state of the brake pedal and a vehicle speed. When the idle stop condition is satisfied, the control device 102 automatically stops the engine 106 by stopping the fuel supply to the engine 106.

  When an automatic restart request is input after the idle stop, the magnet energization switch 101g is turned on and the magnet switch 101b is energized in accordance with a pinion push command from the control device 102. Then, the shift lever 101e is pushed out and the pinion gear 101d is connected to the ring gear 106a. After the connection, when the starter motor 101a is rotated according to the pinion rotation command output from the control device 103 via the starter motor energization switch 101f, the pinion gear 101d is connected via the pinion clutch 101c connected to the starter motor 101a. Also rotate. As a result, the ring gear 106a also rotates with the rotation of the pinion gear 101d, so that the engine 106 is automatically started.

  The control device 102 functionally includes a voltage detection unit 102a, a current detection unit 102b, a calculation unit 102c, a determination unit 102d, a charge control unit 102e, and a stop instruction unit 102f. The voltage detection unit 102 a inputs the voltage value of the battery 103 detected by the battery voltage sensor 105. The current detection unit 102b inputs the current value of the charge / discharge current of the battery 103 detected by the battery current sensor 104. Based on the voltage value of the battery 103 input from the battery voltage sensor 105 by the voltage detection unit 102a, the calculation unit 102c calculates an average voltage value for each of a plurality of time segments obtained by dividing the drive period of the starter 101. The determination unit 102d compares the average voltage value of the first half of the driving period with the first threshold value among the average voltage values for each of the plurality of time segments calculated by the calculation unit 102c. The determination unit 102d determines whether the engine 106 is allowed to be idle-stopped or prohibited according to the comparison result regarding the average voltage in the first half.

  The charging control unit 102e compares the average voltage value in the second half of the driving period with the second threshold value. The charge control unit 102e controls the amount of charge of the battery 103 according to the comparison result by the determination unit 102d. When the determination unit 102d determines that the engine 106 is allowed to be idle stopped, the stop instruction unit 102f outputs an instruction signal to stop the engine 106 when the above-described idle stop condition is satisfied.

Hereinafter, battery state determination processing by the control device 102, idle stop permission determination processing and battery charging control according to the result of the battery state determination processing will be described. The control device 102 performs battery state determination processing, idle stop permission determination processing, and battery charging control each time the starter 101 is driven in response to a start request of the engine 106.
(1) Battery State Determination Process In the battery state determination process, first, the calculation unit 102c of the control device 102 calculates the average voltage value of the voltage value of the battery 103 input from the battery voltage sensor 105 during the drive period of the starter 101. An average value calculation process is performed. Then, the determination unit 102d and the charge control unit 102e perform a state determination process. As the state determination process, the determination unit 102d determines, based on the average voltage value calculated by the calculation unit 102c, whether the battery 103 has a low degree of deterioration or whether the battery 103 has a high degree of deterioration. As the state determination process, the charge control unit 102e determines the amount of charge of the battery 103 based on the average voltage value calculated by the calculation unit. Hereinafter, the average value calculation process and the state determination process will be described separately.

(1-1) Average Value Calculation Processing In this embodiment, the period during which the starter drive signal is output is divided into a delay time segment, a first time segment, and a second time segment, for example. Each time segment is stored in advance in a ROM (not shown) or the like provided in the control device 102. The delay time section may be 0. The calculation unit 102c calculates an average voltage value of the voltage value of the battery 103 input from the battery voltage sensor 105 during the first time interval. Furthermore, the calculation unit 102c calculates an average voltage value of the voltage values of the battery 103 input from the battery voltage sensor 105 during the second time interval.

  FIG. 2 is a timing chart schematically showing a starter drive signal and voltage behavior of the battery 103 when the starter 101 is driven. FIG. 2A shows that the starter drive signal is turned on at time t1 and the starter drive signal is turned off at time t2. FIG. 2B shows the voltage of the battery 103 that changes when the starter drive signal is turned on. In FIG. 2B, the delay time segment is set to time T1 (time t1 to t3), the first time segment is set to time T2 (time t3 to t4), and the second time segment is set to time T3 (time t4 to t5). ing. As shown in FIG. 2B, the first time interval corresponds to the time of the first half of time t3 to time t5 excluding the delay time interval. The second time interval corresponds to the latter half of the times t3 to t5 excluding the delay time interval.

The calculation unit 102c calculates an integrated value ΣV _BRA obtained by integrating the voltage value of the battery 103 input during the first time interval. Then, calculating unit 102c, by using the integrated value [sigma] v _BRA, it calculates an average voltage value _{V BCRA} by the following equation (1).
V _BCRA = ΣV _BRA / T2 (1)

Similarly, the calculation unit 102c calculates an integrated value ΣV _BRB obtained by integrating the voltage value of the battery 103 input during the second time interval. Then, calculating unit 102c, by using the integrated value [sigma] v _BRB, calculates an average voltage value _{V BCRB} by the following equation (2).
V _BCRB = ΣV _BRB / T3 (2)

The average voltage values V _BCRA and V _BCRB calculated as described above are stored in a predetermined recording area in the control apparatus 102 when the ignition is turned off. When the time t2 when the starter drive signal is turned from ON to OFF is earlier than the time t5 when the second time interval ends at the next start request, the calculation unit 102c performs an average value calculation process in each time interval. Absent. In this case, the control device 102 reads the average values V _BCRA and V _BCRB calculated in the previous average value calculation process stored in the storage area, and uses them as a calculation result by the average value calculation process.

(1-2) State determination process The determination unit 102d determines the degree of deterioration of the battery 103 based on the average voltage value V _BCRA in the first time interval calculated by the calculation unit 102c. In this case, the determination unit 102d compares the average voltage value V _BCRA with the first threshold th _a . When the average voltage value V _BCRA is equal to or greater than the first threshold th _a , the determination unit 102d determines that the degree of deterioration of the battery 103 is small, for example, the state of the battery 103 is a relatively new state. When the average voltage value V _BCRA is less than the first threshold th _a , the determination unit 102d determines that the degree of deterioration of the battery 103 is large, for example, the state of the battery 103 is a relatively old state. The first threshold th _a is set to an optimum value through experiments or the like, and is stored in advance in a ROM (not shown) or the like in the control device 102.

The charge control unit 102e determines the amount of charge of the battery 103, that is, the degree of charge (for example, SOC) based on the average voltage value V _BCRB in the second time _interval calculated by the calculation unit 102c. In this case, the charging control unit 102e _compares the average voltage value V _BCRB with the second threshold th _b . When the average voltage value V _BCRB is greater than or _equal to the second threshold th _b , the charge control unit 102e determines that the amount of charge of the battery 103 is large. When the average voltage value V _BCRB is less than the second threshold th _b , the charge control unit 102e determines that the charge amount of the battery 103 is small. Note that the second threshold th _b is set to an optimum value through experiments or the like, and is stored in advance in a ROM (not shown) or the like in the control device 102.

  FIG. 3 schematically shows the result of the state determination process described above and the behavior of the voltage of the battery 103 during driving of the starter. FIG. 3A shows a case where the degree of deterioration of the battery 103 is small and the amount of charge of the battery 103 is large. FIG. 3B shows a case where the degree of deterioration of the battery 103 is small and the charge amount of the battery 103 is small. FIG. 3C shows a case where the degree of deterioration of the battery 103 is large and the amount of charge of the battery 103 is large. FIG. 3D shows a case where the degree of deterioration of the battery 103 is small and the charge amount of the battery 103 is small.

As shown in FIG. 3, immediately after the starter driving signal is turned ON, the voltage value of the battery 103 detected by the battery voltage sensor 105 drops according to the degree of deterioration of the battery 103. When the degree of deterioration of the battery 103 is small, the amount of decrease is small, and when the degree of deterioration of the battery 103 is large, the amount of decrease is large. When the degree of deterioration of the battery 103 is small, as shown in FIGS. 3A and 3B, the voltage value of the battery 103 detected after the drop is about 8V. When it is larger, as shown in FIGS. 3C and 3D, the voltage value of the battery 103 detected after the drop is about 6V. The detected voltage value of the battery 103 drops once as described above, and then rises to the value of the charging voltage. For this reason, as the average voltage value ΣV _BCRA calculated in the first time interval is larger, the degree of deterioration of the battery 103 is smaller, and as the average voltage value ΣV _BCRB calculated in the second time _interval is larger, the charge amount of the battery 103 growing. The first threshold th _a and the second threshold th _b described above are set based on the relationship shown in FIG.

(2) Idle stop permission determination process The determination unit 102d determines whether to allow or prohibit idle stop for the engine 106 according to the result of the state determination process described above. The determination unit 102d permits an idle stop when the average voltage value V _BCRA is equal to or greater than the first threshold th _a , that is, when the degree of deterioration of the battery 103 is small. The determination unit 102d prohibits the idle stop when the average voltage value V _BCRA is less than the first threshold th _a , that is, when the degree of deterioration of the battery 103 is large.

  When the idling stop is permitted, the stop instructing unit 102f outputs an engine stop signal when it is determined that the idling stop condition is satisfied based on information such as an operation state of the brake pedal and a vehicle speed. As a result, the fuel supply to the engine 106 is stopped and the engine 106 is automatically stopped. When the idle stop is prohibited, the stop instructing unit 102f does not output an engine stop signal even if it is determined that the idle stop condition is satisfied based on information such as an operation state of the brake pedal and a vehicle speed. As a result, the fuel supply to the engine 106 is continued, and the operation is continued without automatically stopping the engine 106.

(3) Battery Charging Control The charging control unit 102e controls charging of the battery 103 by one of charging control according to the charging balance and charging priority control according to the result of the state determination process described above. When the average voltage value V _BCRB is equal to or greater than the second threshold th _b , that is, when the amount of charge of the battery 103 is large, the charge control unit 102e performs charge control of the battery 103 according to the charge balance. In this case, based on the charging / discharging current of the battery 103 detected by the battery current sensor 104, the charging control unit 102e has a constant value of Σ (charging amount−discharging amount) according to the state of the engine 106 and environmental changes. Control to be a value.

When the average voltage value V _BCRB is less than the second threshold th _b , that is, when the charge amount of the battery 103 is small, the charge control unit 102e performs control so that the charge of the battery 103 is given priority. In this case, the charging control unit 102e causes the generator 108 to perform a power generation operation. For example, the engine output shaft and the generator 108 are connected by a clutch, and the generator 108 is driven by the driving force of the engine.

  FIG. 4 shows the correspondence between the result of the state determination process, the idle stop permission determination process, and the battery charge control. In FIG. 4, state 1 is a case where the degree of deterioration of battery 103 is small and the amount of charge of battery 103 is large, and state 2 is a case where the degree of deterioration of battery 103 is small and the amount of charge of battery 103 is small. Show. State 3 indicates that the degree of deterioration of the battery 103 is large and the amount of charge of the battery 103 is large, and state 4 indicates that the degree of deterioration of the battery 103 is large and the amount of charge of the battery 103 is small. As shown in FIG. 4, in the case of the states 1 and 2, that is, when the degree of deterioration of the battery 103 is small, the operation of the idle stop function is permitted, and in the case of the states 3 and 4, that is, the deterioration of the battery 103 When the degree is large, the operation of the idle stop function is prohibited. In the case of states 1 and 3, that is, when the amount of charge of the battery 103 is large, the charging control of the battery 103 is performed according to the charge balance. The control for giving priority to the charging of the battery 103 is performed.

The process by the control apparatus 102 is demonstrated using the flowchart of FIG. Each process shown in the flowchart of FIG. 5 is performed by executing a program in the control device 102. This program is stored in a memory (not shown), and is activated and executed by the control device 102 when a request for starting the engine 106 is input.
The engine start request is a command that is output within the engine control device 102 when the driver turns on the ignition switch and when the engine 106 that has been idle-stopped is restarted.

  When the engine start request is output, in step S1, it is determined whether or not the starter drive signal is changed from OFF to ON at the time of engine start by cranking. If the starter drive signal is ON, step S1 is affirmed and the process proceeds to step S2. When the starter drive signal is OFF, a negative determination is made in step S1, and the process ends.

  In step S2, it is determined whether an activation condition is satisfied. If the activation condition is satisfied, an affirmative determination is made in step S2 and the process proceeds to step S3. If the activation condition is not satisfied, a negative determination is made in step S2 and the process ends. Note that the control device 102 determines that the engine water temperature is higher than a predetermined value, the intake air temperature is higher than a predetermined value, the battery temperature is within a predetermined range, the engine oil temperature is higher than a predetermined value, and the starter drive signal is turned on. When the predetermined time has elapsed, it is determined that the activation condition is satisfied. The control device 102 inputs engine water temperature, intake air temperature, battery temperature, and engine oil temperature from various sensors 107. Further, the predetermined time after the starter drive signal is turned ON corresponds to the above-described delay time section T1. Note that the engine oil temperature may be excluded from the start conditions when the various sensors 107 do not include the oil temperature sensor.

In step S3, it is determined whether or not the starter drive signal remains ON. If the starter drive signal remains ON, step S3 is affirmed and the process proceeds to step S4. If the starter drive signal is OFF, a negative determination is made in step S3 and the process proceeds to step S11 described later. In step S4, the integrated value ΣV _BRA is calculated based on the voltage value input from the battery voltage sensor 105, and the process proceeds to step S5.

In step S5, it is determined whether or not the elapsed time from when the starter drive signal is turned on is within the range of time T2 (time t3 to t4) of the first time segment. If the elapsed time is within the range of time T2, an affirmative determination is made in step S5 and the process returns to step S4. If the elapsed time exceeds the range of time T2, a negative determination is made in step S5 and the process proceeds to step S6. In step S6, using the calculated integrated value ΣV _BRA , the average voltage value V _BCRA is calculated by equation (1), and the process proceeds to step S7.

In step S7, as in step S3, it is determined whether or not the starter drive signal remains ON. If the starter drive signal remains ON, an affirmative determination is made in step S7 and the process proceeds to step S8. If the starter drive signal is OFF, a negative determination is made in step S7 and the process proceeds to step S11 described later. In step S8, the integrated value ΣV _BRB is calculated based on the voltage value input from the battery voltage sensor 105, and the process proceeds to step S9.

In step S9, it is determined whether or not the elapsed time from when the starter drive signal is turned on is within the range of time T3 (time t4 to t5) of the second time segment. If the elapsed time is within the range of time T3, an affirmative determination is made in step S9 and the process returns to step S8. If the elapsed time exceeds the range of time T3, a negative determination is made in step S9, and the process proceeds to step S10. In step S10, average voltage value V _BCRB is calculated by equation (2) using calculated integrated value ΣV _BRB, and the process proceeds to step S12.

If step S3 is negatively determined, or if step S7 is negatively determined, the process proceeds to step S11. In step S11, the previous average voltage values ΣV _BRA and ΣV _BRB stored in the memory are read, and the process proceeds to step S12. In step S12, state determination processing is performed using the average voltage values ΣV _BRA and ΣV _BRB , and the process proceeds to step S13.

  In step S13, it is determined whether or not the result of the state determination process is state 1 shown in FIG. 4, that is, whether the degree of deterioration of the battery 103 is small and the amount of charge is large. In the case of the state 1, an affirmative determination is made in step S13 and the process proceeds to step S14. In step S14, the operation of the idle stop function is permitted, the battery 103 is set to be controlled according to the charge balance, and the process is terminated.

  If the result of the state determination process is not state 1, a negative determination is made in step S13 and the process proceeds to step S15. In step S15, it is determined whether or not the result of the state determination process is state 2 shown in FIG. 4, that is, whether the degree of deterioration of the battery 103 is small and the amount of charge is small. In state 2, step S15 is affirmed and it progresses to step S16. In step S16, idling stop is permitted, the battery 103 is set to be controlled with charge priority, and the process ends.

  If the result of the state determination process is not state 2, a negative determination is made in step S15 and the process proceeds to step S17. In step S17, it is determined whether or not the result of the state determination process is state 3 shown in FIG. 4, that is, whether the degree of deterioration of the battery 103 is large and the amount of charge is large. In the case of the state 3, an affirmative determination is made in step S17 and the process proceeds to step S18. In step S18, idle stop is prohibited, the battery 103 is set to be controlled according to the charge balance, and the process is terminated.

  If the result of the state determination process is not state 3, that is, state 4 (when the degree of deterioration of the battery 103 is large and the amount of charge is small), a negative determination is made in step S17 and the process proceeds to step S19. In step S19, idle stop is prohibited, the battery 103 is set to be controlled with charge priority, and the process ends.

According to the battery state determination device according to the above-described embodiment, the following operational effects can be obtained.
(1) The battery state determination device 1 includes a battery voltage sensor 105, a calculation unit 102c, a determination unit 102d, and a charge control unit 102f. The battery voltage sensor 105 detects the voltage of the battery 103 that supplies power to the starter 101 used for starting the engine 106 when the engine 106 is started. The calculation unit 102c, among the voltage values of the battery 103 detected by the battery voltage sensor 105 when the starter 101 is started, calculates the average voltage value ΣV _BCRA of the first half of the driving period of the starter 101 and the average voltage value V _{BCRB of the} second half. And calculate. The determination unit 102d determines the magnitude of the first half average voltage value ΣV _BCRA calculated by the calculation unit 102c and the first threshold value th _a, and permits or prohibits an idle stop included in the vehicle based on the determination result. Determine whether. The charge control unit 102e determines the magnitude of the latter half average voltage value ΣV _BCRB calculated by the calculation unit 102c and the second threshold th _b, and controls the charge amount of the battery 103 based on the determination result.

  In the prior art, when determining whether or not to stop the engine when the idle stop condition is satisfied, the magnitude relationship between the determination value set according to the electrical load at that time and the battery voltage is compared. In this case, the determination value is determined in consideration of the temperature range from the cold region to the tropical region. As a result, as described above, the margin for the determination value is increased, and the idle stop frequency is inevitably reduced.

According to the device of the present invention, by calculating the average voltage value ΣV _BCRA of the battery at the time of starter driving, the voltage value in consideration of the environmental condition and the like is compared with the first threshold value th _a . The accuracy of determination of permission or prohibition can be improved. As a result, the frequency at which idle stop is executed is improved. In addition, since the amount of charge of the battery 103, that is, the amount of power generated by the generator 108 can be controlled according to the amount of charge of the battery 103 when the starter 101 is driven, the fuel efficiency when the vehicle 50 is traveling can be improved. Furthermore, as described above, the voltage value of the battery 103 detected at the time of starter driving can be used for both the determination of permission or prohibition of idle stop and the control of the charge amount of the battery 103, so that the processing is efficient. Can be done well.

(2) The battery state determination device 1 includes the stop instruction unit 102f. When the determination unit 102d determines that the idle stop is permitted, the stop instruction unit 102f instructs the engine 106 to stop when the idle stop condition is satisfied. If the determination unit 102d determines that the idle stop is prohibited, the stop instruction unit 102f does not instruct the engine 106 to stop even if the idle stop condition is satisfied. As described above, in the embodiment, the degree of deterioration of the battery 103 is determined based on the average voltage at the time of cranking, and whether the idle stop is permitted or not is determined based on the determination result. According to the apparatus of the embodiment, the idle stop condition can be accurately determined, and the frequency with which the idle stop is executed is improved.

(3) The battery state determination device 1 includes a battery current sensor 104 that detects a charge / discharge current of the battery 103. The charge control unit 102e controls the charge / discharge amount of the battery 103 according to the charge / discharge current detected by the battery current sensor 104 when the average voltage value ΣV _BCRB of the latter half is equal to or greater than the second threshold th _b . Then, when the average voltage value ΣV _BCRB of the second half is smaller than the second threshold th _b , the charging control unit 102e charges the battery 103 regardless of the charging / discharging current. In other words, when the average voltage value ΣV _BCRB in the latter half is smaller than the second threshold th _b , the generator 108 attached to the engine 106 is caused to generate power regardless of the charge / discharge current. As a result, the amount of charge of the battery 103 can be controlled according to the amount of charge of the battery 103 when the starter 101 is driven, that is, the amount of power generated by the generator 108 can be controlled.

  In the above apparatus, when the charge level is lower than a predetermined value, the generator generates power regardless of the measured value of the battery charge / discharge current. This is called battery priority. When the charge level is higher than a predetermined value, the charge amount is controlled so that the charge balance is uniform according to the measured value of the battery charge / discharge current.

An outline of a method for controlling battery charging with priority is, for example, as follows.
When the degree of charge of the battery is less than a predetermined value, the electric load is driven with the power generated by the generator, and the battery is charged with surplus power.

  As long as the characteristics of the present invention are not impaired, the present invention is not limited to the above-described embodiments, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

For example, the average voltages ΣV _BCRA and ΣV _BCRB are calculated during cranking, but the average voltage may be calculated at the end of cranking.
Also, the degree of charge of the battery is determined based on the voltage value in the latter half, and when the degree of charge is less than a predetermined value, the generator is driven, and the electric load is driven by the battery power and the generated power. The battery was charged. When the degree of charge exceeds a predetermined value, the amount of charge is controlled so that the battery voltage becomes a predetermined target value. However, the present invention is not limited to the embodiment. For example, when the degree of charge is less than a predetermined value, control may be performed such that the generator is driven more frequently than when the degree of charge is greater than or equal to a predetermined value.

101 ... Starter, 102 ... Control device,
102a ... voltage detection unit, 102b ... current detection unit,
102c: a calculation unit, 102d: a determination unit,
102e ... charge control unit, 102f ... stop instruction unit,
103 ... Battery, 104 ... Battery current sensor,
105 ... Battery voltage sensor, 106 ... Engine

Claims (4)

A voltage detection unit that detects a voltage of a battery that supplies power to a starter used for starting the internal combustion engine during a starter drive signal output period at the start of the internal combustion engine;
Of the voltage of the battery detected by the voltage detection unit, a calculation unit that calculates an average voltage value of the first half of the starter drive signal output period and an average voltage value of the second half,
The magnitude of the average voltage value of the first half calculated by the calculation unit and the first threshold value is determined, and based on the determination result, it is determined whether the operation of the idle stop function of the vehicle is permitted or prohibited. A determination unit;
A charge control unit that determines the magnitude of the average voltage value of the latter half calculated by the calculation unit and a second threshold value, and controls a charge amount of the battery based on a determination result; A battery state determination device for an internal combustion engine. The battery state determination device for an internal combustion engine according to claim 1,
When it is determined by the determination unit that the operation of the idle stop function is permitted, the stop of the internal combustion engine is instructed when the idle stop condition is satisfied, and the operation of the idle stop function is determined by the determination unit. In this case, the internal combustion engine battery state determination device further includes a stop instructing unit that does not instruct the stop of the internal combustion engine even if the idle stop condition is satisfied. The battery state determination device for an internal combustion engine according to claim 1,
A current detection unit for detecting a charge / discharge current of the battery;
The charge control unit controls the charge / discharge amount of the battery according to the charge / discharge current detected by the current detection unit when the average voltage value of the latter half is equal to or greater than the second threshold, The battery state determination device for an internal combustion engine, wherein the battery is charged regardless of the charge / discharge current when an average voltage value in the latter half is smaller than the second threshold value. The battery state determination device for an internal combustion engine according to claim 3,
When the average voltage value in the latter half is smaller than the second threshold value, the charge control unit causes a generator provided attached to the internal combustion engine to perform a power generation operation regardless of the charge / discharge current. A battery state determination device for an internal combustion engine.

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