JP2006081394A - On-vehicle battery surveillance apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the on-vehicle battery surveillance apparatus which can prevent a battery from going dead. <P>SOLUTION: In this on-vehicle battery control apparatus, a power consumption control part 19f makes an engine stoppage detecting part 19a detect the operation of an engine 21, under the condition that an air conditioner 9a is in operation further with a total supply current value detected by a current detecting part 11 that exceeds a second reference value I2, a level of SOC derived by a charge condition deriving part 19a is decided whether it is less than a third level L3, when it is less than the third level, a command of (the effect of operating the air conditioner 9a in a low power consumption mode), to the effect that the air quantity of the air conditioner 9a is to be switched over to a low level is planned so as to be output to the air conditioning control part (here, it is a junction box 23) for controlling the air conditioner 9a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an in-vehicle battery monitoring device that monitors a state of charge of a battery.

  In the conventional vehicle battery monitoring device, there is one that cuts off the power supply to the load in order to protect the battery in response to the increase in current consumption. However, as in the present invention, the state of charge of the battery (state of) It is not yet known what controls the power generation amount of the alternator based on the charge (so-called SOC)) and the current consumption value.

  For this reason, in the conventional on-board battery monitoring device, the alternator power generation is performed at a constant level while the engine is operating, regardless of the level of the battery charge state. However, when the engine is still running even when the supply current value supplied from the battery to the load is relatively small and there is no risk of running out of the battery, the alternator at a constant level Since power generation is performed, there is a problem that the battery is charged more than necessary and energy is wasted. For example, if the battery is fully charged (100%) and the battery continues to be charged, the generated power will be decomposed into heat or battery electrolyte solution (in the case of lead-acid batteries, water is decomposed). ) Is wasted.

  SUMMARY OF THE INVENTION In view of the above problems, the present invention has an object to provide an in-vehicle battery monitoring device capable of suppressing wasteful power generation by an alternator while controlling battery power generation by controlling the power generation amount of the alternator. To do.

  In order to solve the above problem, in the invention of claim 1, when the charge state detection unit that detects the charge state of the battery and the charge state detected by the charge state detection unit falls below a predetermined reference level, A power consumption management unit that switches the operation of the predetermined load to the low power consumption mode.

  According to a second aspect of the present invention, in the configuration of the first aspect, the in-vehicle battery monitoring device further includes a current detection unit that detects a current value supplied from the battery to each load, and the power consumption management unit includes: In a state where the total supply current value detected by the current detection unit is higher than a predetermined reference value, the operation of the predetermined load is changed to a low power consumption mode when the charging state is lower than a predetermined reference level. Switch.

  According to a third aspect of the present invention, in the configuration of the second aspect, the in-vehicle battery monitoring device further includes an engine stop detection unit that detects engine stop, and the power consumption management unit includes the current detection unit. In a state where the detected total supply current value exceeds a predetermined reference value and the engine stop detection unit detects the operation of the engine, the predetermined supply level is less than the predetermined reference level. Switch the load operation to low power consumption mode.

  According to a fourth aspect of the present invention, in the configuration according to any one of the first to third aspects, the charge state detection unit detects an SOC of the battery as the charge state, and the predetermined reference level is the The SOC is at a level of 40%.

  According to a fifth aspect of the present invention, in the configuration according to any one of the first to fourth aspects, the predetermined load is an air conditioner.

  According to a sixth aspect of the present invention, in the configuration of the fifth aspect, switching the operation of the air conditioner performed by the power consumption management unit to the low power consumption mode is to reduce the air volume of the air conditioner.

  Preferably, in the configuration of the in-vehicle battery monitoring device, the charge state detection unit that detects the charge state of the battery, the current detection unit that detects the current value supplied from the battery to each load, and the power generation amount of the alternator are adjusted. And the current value detected by the current detection unit is less than or equal to a first reference current value, and the charge state detected by the charge state detection unit exceeds a first reference level. In this case, it is preferable to include a power generation control unit that causes the power generation amount adjusting unit to suppress or reduce the power generation amount of the alternator to zero.

  Preferably, in the configuration of the in-vehicle battery monitoring device, a charge state detection unit that detects a charge state of the battery, a drive state detection unit that detects a drive state of a load to be detected that is driven by power supply from the battery, The power generation amount adjusting unit that adjusts the power generation amount of the alternator, and the driving state detecting unit detects that the load to be detected is in a driving stop state, and the charging state detected by the charging state detecting unit is A power generation control unit may be provided that causes the power generation amount adjustment unit to suppress or reduce the power generation amount of the alternator to zero when the second reference level is exceeded.

  Preferably, the in-vehicle battery monitoring device includes an engine stop detection unit that detects engine stop, a notification unit that can output at least one of sound and light, and engine stop by the engine stop detection unit. A notification control unit that outputs a predetermined notification through the notification unit when the state of charge detected by the charge state detection unit falls below a third reference level. Is good.

  Preferably, the in-vehicle battery monitoring device includes an engine stop detecting unit that detects stop of the engine, and a blocking unit that is interposed in a power path from the battery to the load so as to be able to block the power path. In a state where the engine stop is detected by the engine stop detection unit, when the state of charge detected by the charge state detection unit falls below a fourth reference level, the blocking unit blocks the current path. And a shut-off control unit.

  Preferably, the in-vehicle battery monitoring device consumes low power in response to a predetermined command given from the outside when the charge state detected by the charge state detection unit falls below a fifth reference level. It is preferable to further include a power consumption management unit that outputs the predetermined command to a load having a function of switching to a mode.

  Preferably, the charge state detection unit includes a specific gravity sensor that detects a specific gravity of the electrolyte of the battery, and a charge state derivation unit that derives the charge state based on a detection result of the specific gravity sensor. Is good.

  Preferably, the charge state detection unit includes a pH sensor that detects a pH of the battery electrolyte, and a charge state deriving unit that derives the charge state based on a detection value of the pH sensor. Is good.

  According to the first to sixth aspects of the invention, it is possible to prevent the battery from rising due to power consumption when the state of charge of the battery is reduced.

1. First Embodiment FIG. 1 is a block diagram of an in-vehicle battery monitoring device according to a first embodiment of the present invention. This in-vehicle battery monitoring device includes a specific gravity sensor 3 that detects the specific gravity of the electrolyte solution of the battery 1, a power generation amount adjustment unit 7 that controls the power generation amount of the alternator 5, and a supply current value that is supplied from the battery 1 to each load 9. A current detection unit 11 that detects the sum of the currents, a notification unit 13 that can output at least one of light and sound, a blocking unit 17 that conducts and blocks a current path 15 from the battery 1 to each load 9, and a microcomputer Etc., and a control unit 19 constituted by the like.

  The specific gravity sensor 3 detects the specific gravity of the electrolyte solution of the battery 1, and outputs a signal indicating the detected specific gravity value to a later-described charge state deriving unit 19 b of the control unit 19. The specific gravity sensor 3 and the charged state deriving unit 19b constitute a charged state detecting unit according to the present invention.

Here, the principle at the time of detecting SOC of the battery 1 based on the specific gravity of electrolyte solution is demonstrated easily. Here, a case where a lead acid battery is used for the battery 1 will be described. Lead-acid batteries, liquid using aqueous sulfuric acid (H ₂ 0 solution of H ₂ SO ₄₎ in the electrolyte, the electrode member composed mainly of lead dioxide in the positive electrode (PbO ₂₎ used, lead to a negative electrode (Pb) The electrode member which has as a main component is used. And the reaction at the time of discharge is

The reverse reaction occurs during charging.

As is clear from the reaction formula, as the discharge proceeds, sulfate ions (SO ₄ ²⁻ ) in the electrolyte solution are consumed, and lead sulfate (PbSO ₄ ) is deposited on the electrode. Since the amount of electrolyte in the battery provided in the battery 1 is finite, as the discharge proceeds, sulfate ions in the electrolyte are consumed, and the specific gravity of the electrolyte is reduced. Thus, the SOC of the battery provided in the battery 1 can be estimated from the specific gravity of the electrolytic solution. Table 1 illustrates the relationship between the specific gravity of the electrolyte of the lead acid battery and the electromotive force of the battery.

  From Table 1 above, it can be seen that the electromotive force of the battery tends to increase as the specific gravity of the electrolytic solution increases (that is, the concentration of the sulfuric acid aqueous solution increases). However, if it is too thick, the viscosity of the electrolyte will increase, leading to a decrease in the transport number of ions in the electrolyte, leading to a decrease in electromotive force or accelerated corrosion of the electrode, resulting in a decrease in the service life of the battery. Therefore, the specific gravity of the electrolytic solution is often set to 1.28 in a fully charged state (a state where the SOC is 100%).

  Thus, since the SOC level and the specific gravity of the electrolytic solution are substantially proportional, it is a simple and excellent method to estimate the SOC level from the specific gravity of the electrolytic solution. Here, exemplifying the relationship between the SOC level and the specific gravity of the electrolytic solution, when the SOC is 100% (during full charge), the specific gravity is 1.28, and when the SOC is 50% (full charge). The specific gravity is 1.20 when half the amount of electricity accumulated from the state is discharged).

  The power generation amount adjusting unit 7 controls the power generation amount of the alternator 5 under the control of a power generation control unit 19e of the control unit 19 described later. Here, by controlling the field current flowing in the field coil of the alternator 5 The power generation amount of the alternator 5 is controlled. For example, when the field current when normal power generation (100% power generation) according to the rotational speed of the engine 21 is performed is used as a reference value, and the field current is reduced to 50% of the reference value, accordingly The power generation amount of the alternator 5 is also reduced to 50%, and when the supply of field current is stopped, the power generation amount of the alternator 5 becomes zero.

  The current detection unit 11 detects the total amount of supply current value supplied from the battery 1 to each load 9 and outputs a signal indicating the detection value to the control unit 19.

  The notification unit 13 performs notification output by at least one of sound (or sound) and light under the control of a notification control unit 19d of the control unit 19 described later.

  Here, examples of the load 9 include an air conditioner, a night illumination lamp, an audio unit, and a brake lamp. These loads 9 are connected to a junction box 23 interposed in an energization path 15 from the battery 1, and the electric power from the battery 1 is supplied to each load 9 via the junction box 23. ing.

  The junction box 23 is provided with a shut-off unit 17 that is interposed in a current-carrying path 15 from the battery 1 to each load 9 and that conducts and shuts off the current-carrying path 15 under the control of a cut-off control unit 19g of the control unit 19 described later. It has been.

  An operation input for operating each load 9 is performed through an operation receiving unit 25 provided in the instrument panel unit, and an operation content input from the operation receiving unit 25 is determined by a predetermined signal according to a predetermined signal. To the power consumption manager 19 f of the control unit 19. Based on the given signal, the junction box 23 turns on and off and controls each load 9 based on the given signal, while the power consumption management unit 19f performs a predetermined management operation described later. Is supposed to do.

  The control unit 19 includes an engine stop detection unit 19a, a charge state deriving unit 19b, an idle up command unit 19c, a notification control unit 19d, a power generation control unit 19e, a power consumption management unit 19f, and a cutoff control unit 19g. These functional elements are actually realized by a microcomputer.

  The engine stop detection unit 19a detects the operation and stop of the engine 21 by detecting whether the ignition switch 27 is on or off. The charge state deriving unit 19b derives the SOC of the battery 1 based on the specific gravity value of the electrolyte solution of the battery 1 indicated by the signal from the specific gravity sensor 3.

  The power generation control unit 19e responds to the detection of the start of the engine 21 by the engine stop detection unit 19a, and outputs a command to the power generation amount adjustment unit 7 to set the power generation amount of the alternator 5 to 100% power generation. In a state where the stop detection unit 19a detects the operation of the engine 21 and the total supply current value detected by the current detection unit 11 is below a first reference value I1 (for example, 8A), the charge state deriving unit 19a Is determined whether the SOC level is higher than the first level L1 (here 60%) or the second level L2 (here 50%), and the SOC level is higher than the first level L1. In this case, a command for turning off the power generation of the alternator 5 is output to the power generation amount adjusting unit 7, and when the SOC level is between the second level L2 and the first level L1, the power generation amount adjustment is performed. 7, the power generation amount of the alternator 5 is output to 50%. When the SOC level is lower than the second level L2, the power generation amount adjustment unit 7 sets the power generation amount of the alternator 5 to 100%. A command to generate electricity is output.

  In the present embodiment, two threshold values of the first and second levels L1 and L2 are provided as threshold values for adjusting the power generation amount of the alternator 5. However, the threshold value is not limited to two, but one or three or more. But you can. Correspondingly, the power generation amount of the alternator 5 is changed in three stages of 100%, 50%, and 0%, but it may be changed in two stages or changed in four stages or more. It is also possible to arbitrarily set the percentage of power generation at each stage.

  Here, the first reference value I1 and the second reference value I2 to be described later have a relationship of I1 <I2, and the first and second levels L1 and L2 and the third level L3 to be described later are , L1> L2> L3.

  Whether the total supply current value detected by the current detection unit 11 exceeds the second reference value I2 (for example, 15A) when the engine stop detection unit 19a detects the operation of the engine 21 If the result of the determination is negative, the engine control unit 29 is output with an idle-up command for performing a predetermined level of idle-up.

  Further, the idle-up command unit 19c is in a state where the engine stop detection unit 19a detects the operation of the engine 21 and the total supply current value detected by the current detection unit 11 exceeds the first reference value I1. Then, it is determined whether or not the SOC level derived by the charging state deriving unit 19b is lower than the third level L3 (here, 40%), and if it is lower, the engine control unit 29 is idled at a predetermined level. Outputs an idle up command to that effect. When the engine control unit 29 is given an idle-up command, the engine control unit 29 performs idle-up at a predetermined level and increases the amount of power generated by the alternator 5.

  The notification control unit 19d determines whether or not the SOC level derived by the charging state deriving unit 19b is lower than the second level L2 in a state where the engine stop detecting unit 19a detects the stop of the engine 21; If it is lower, the notification unit 13 causes the sound of the SOC of the battery 1 to be lowered (or to start the engine 21 and charge the battery 1) and / or light. A first warning output (notification output) is performed.

  In addition, the notification control unit 19d detects that the engine stop detection unit 19a has detected the operation of the engine 21, and the total supply current value detected by the current detection unit 11 exceeds the second reference value I2. It is determined whether or not the SOC level derived by the charge state deriving unit 19a is below the third level L3. If the SOC level is below the level, the sound or light indicating that the SOC of the battery 1 has decreased through the notification unit 13 The second warning output is performed by at least one of them.

  The shutoff control unit 19g determines whether or not the SOC level derived by the charging state deriving unit 19b is lower than the third level L3 in a state where the engine stop detecting unit 19a detects the stop of the engine 21; When it is below, the interruption | blocking part 17 is interrupted | blocked, electric power supply from the battery 1 is interrupted | blocked, and a battery rising is prevented. Moreover, when the engine stop detection unit 19a detects the start of the engine 21 in a state where the blocking unit 17 is blocked, the blocking control unit 19g causes the blocking unit 17 to conduct in response thereto.

  In the power consumption management unit 19f, the engine stop detection unit 19a detects the operation of the engine 21, the air conditioner 9a is in operation, and the total supply current value detected by the current detection unit 11 is the second reference value I2. If the SOC level derived by the charge state deriving unit 19a is below the third level L3, and if it is below, the air conditioner control unit (in this case) controls the air conditioner 9a. A command to switch the air volume of the air conditioner 9a to a low level (to operate the air conditioner 9a in the low power consumption mode) is output to the junction box 23). In response to this command, the junction box 23 switches the air volume of the air conditioner 9a to a low level.

  Here, an example of setting criteria for the values of the first and second reference values I1 and I2 is shown in Table 2 below. Table 3 shows an approximate current consumption value of each load 9 shown in Table 2. That is, when the on / off state of each load 9 is in the state of the left column of Table 2, the first and second reference values I1 are set so that the battery monitoring device performs the control operation shown in the right column of Table 2. , I2 are set. In Table 2, when idle up is performed, the alternator 5 generates 100% power.

  Next, the battery monitoring operation of the in-vehicle battery monitoring device will be described with reference to the flowcharts of FIGS.

  When the accessory switch is turned on in step S1 and the battery monitoring device is turned on, the process proceeds to step S2 where the engine stop detection unit 19a determines whether the engine 21 is stopped and the engine 21 is stopped. The process proceeds to step S3. If the engine 21 is operating, the process proceeds to step S9.

  In step S3, it is determined whether or not the SOC is higher than 50% by the notification control unit 19d. When the SOC is higher, the process returns to step S2, while when it is not higher, the process proceeds to step S4 and the notification control is performed. The first warning output (notification output) that the SOC of the battery 1 is lowered (or that the engine 21 should be charged and the battery 1 should be charged) is performed by the unit 19d through the notification unit 13. The process proceeds to step S5.

  In step S5, it is determined whether or not the SOC is higher than 40% by the shutoff control unit 19g. If so, the process proceeds to step S7. If not, the process proceeds to step S6. A cutoff command is output from the unit 19 to the cutoff unit 17, the power supply from the battery 1 is cut off, and the process proceeds to step S7.

  In step S7, it is determined whether or not the engine 21 has been started by the engine stop detection unit 19a. If the engine 21 has not been started, the process returns to step S5, and steps S5 to S5 are performed until the engine 21 is started. While the process of S7 is repeated, when the engine 21 is started, the process proceeds to step S8. In step S8, when the interruption | blocking part 17 is interrupted | blocked at that time, the interruption | blocking state of the interruption | blocking part 17 is cancelled | released by the interruption | blocking control part 19g, and it progresses to step S9.

  In step S9, the alternator 5 is set to 100% power generation by the power generation control unit 19e through the power generation amount adjustment unit 7, and the process proceeds to step S10, where the total supply current value by the power generation control unit 19e and the idle up command unit 19c is the first reference value. It is determined whether or not the value I1 is exceeded. If not, the process proceeds to step S11. If it exceeds, the process proceeds to step S15.

  In step S11, it is determined whether or not the SOC exceeds 60% by the power generation control unit 19e. If the SOC exceeds 60%, the process proceeds to step S12, and the power generation control unit 19e causes the power generation amount adjustment unit 7 to move to step S12. , The power generation of the alternator 5 is turned off, and the process returns to step S10. On the other hand, if it is below 60%, the process proceeds to step S13.

  In step S13, it is determined whether or not the SOC is higher than 50% by the power generation control unit 19e. If it is higher than 50%, the process proceeds to step S14, and the power generation control unit 19e causes the power generation amount adjustment unit 7 to increase. Then, the alternator 5 is switched to 50% power generation, and the process returns to step S10. On the other hand, if it is below 50%, the process returns to step S9, and the alternator 5 is switched to 100% power generation.

  In step S15, it is determined whether or not the SOC is higher than 40% by the idle up command unit 19c. If the SOC is higher, the process proceeds to step S17. If not, the process proceeds to step S16. The up command unit 19c outputs an idle up command to the engine control unit 29, performs a predetermined level of idle up, and proceeds to step S17.

  In step S17, it is determined whether or not the total supply current value exceeds the second reference value by the idle-up command unit 19c, the power consumption management unit 19f, and the notification control unit 19d. On the other hand, if it exceeds, the process proceeds to step S18, where an idle up command is output from the idle up command unit 19c to the engine control unit 29, a predetermined level of idle up is performed, and the process proceeds to step S19. Note that in steps S18 and S16, if idle up has already been performed, idle up is not performed.

  In step S19, it is determined whether or not the SOC exceeds 40% by the power consumption management unit 19f and the notification control unit 19d. If it exceeds, the process returns to step S10. If not, the step returns to step S10. Proceed to S20.

  In step S20, when the air conditioner 9a is in operation, the power consumption management unit 19f switches the air volume of the air conditioner 9a to the low level through the junction box 23, and the process proceeds to step S21. Through the second warning output indicating that the SOC of the battery 1 is reduced, and the process returns to step S10.

  As described above, according to the present embodiment, the engine 21 is in operation, the total power supply value from the battery 1 is not more than the first reference value, and the SOC of the battery 1 is not less than 60% or 50%. In this case, since the power generation amount of the alternator 5 is suppressed to zero or 50% through the power generation amount control unit 7 by the power generation control unit 19e, wasteful power generation by the alternator 5 can be suppressed. As a result, energy loss due to power generation can be suppressed while preventing the battery from running out.

  When the SOC of the battery 1 falls below 50% while the engine 21 is stopped, the notification control unit 19d indicates that the SOC of the battery 1 has decreased through the notification unit 13 (or the engine 21 is started and the battery 1 is to be charged), the user recognizes the decrease in the SOC of the battery 1 to reduce power consumption, or Appropriate measures such as charging of the battery 1 by starting the engine 21 can be taken, and the battery can be prevented from running out while the engine 21 is stopped.

  Further, when the SOC of the battery 1 falls below 40% in a state where the engine 21 is stopped, the power supply from the battery 1 is cut off through the shut-off unit 17 by the shut-off control unit 19g. Further, it is possible to reliably prevent the battery from being exhausted due to the power consumption when the engine 21 is stopped.

  Further, when the engine 21 is operating, the total power supply value from the battery 1 is equal to or lower than the first reference value, and the SOC of the battery 1 is lower than 40%, and the engine 21 is operating. When the total power supply value from the battery 1 exceeds the second reference value, idle-up is performed by the idle-up command unit 19c, and the power generation amount of the alternator 5 is increased. The battery can be prevented from rising due to an increase in power.

  Furthermore, when the engine 21 is operating and the total power supply value from the battery 1 exceeds the second reference value (here, idle-up is performed), the SOC of the battery 1 is 40%. When the air flow rate is lower than the value, the power consumption management unit 19f allows the air volume of the air conditioner 9a to be switched to a low level through the junction box 23, and the notification control unit 19d allows the SOC of the battery 1 to be switched through the notification unit 13. Since the second warning output indicating that the battery has been lowered is performed, it is possible to prevent the battery from being discharged due to power consumption when the SOC of the battery 1 is lowered, and the user recognizes that the SOC is lowered. Therefore, it is possible to take appropriate measures such as suppressing power consumption.

  By the way, as a method for detecting the state of charge of the battery 1, for example, there is a method of detecting the voltage between the output terminals of the battery 1 and deriving the SOC based on the detected value. It is difficult to accurately detect the true electromotive force of the battery 1 due to the change in the current value supplied from the battery, and it is difficult to accurately detect the SOC.

  On the other hand, according to the present embodiment, the specific gravity of the electrolyte solution of the battery 1 is detected, and the SOC is directly derived based on the detected value, so that the SOC of the battery 1 is accurately detected. It is possible to reliably prevent the battery from running out.

2. Second Embodiment FIG. 4 is a block diagram of an in-vehicle battery monitoring device according to a second embodiment of the present invention. In the battery monitoring device according to the first embodiment described above, battery monitoring is performed based on the total supply current value or the like, whereas the battery monitoring device according to the present embodiment drives each load 9. It is characterized in that the battery monitoring is performed based on the state or the like, and the parts corresponding to those of the battery monitoring apparatus according to the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

  In the present embodiment, instead of the above-described current detection unit 11, a drive state detection unit 31h that detects the drive state of each load 9 is provided in the control unit 31, and each functional element 31c to 31g of the control unit 31 is provided. However, the assigned battery monitoring operation is performed based on the driving state of each load 9 detected by the driving state detection unit 31h.

  The drive state detection unit 31h receives a signal indicating the input content for the operation of each load 9 input from the operation reception unit 25 from the operation reception unit 25. The drive state control unit 31h Is configured to detect the driving state (ON, OFF, etc.) of each load 9 based on this input signal.

  Among the functional elements of the control unit 31, the functions of the engine stop detection unit 31a, the charge state deriving unit 31b, and the shutoff control unit 31g are the same as the engine stop detection unit 19a, the charge state deriving unit 19b, and the shutoff control unit 19 described above. Since it is the same as that of the control part 19g, description is abbreviate | omitted.

  The power generation control unit 31e outputs a command to the power generation amount adjustment unit 7 to set the power generation amount of the alternator 5 to 100% power generation in response to detection of the start of the engine 21 by the engine stop detection unit 31a. Pre-registered load 9 (here, air conditioner 9a, night illumination lamp 9b) in which stop detection unit 31a detects the operation of engine 21 and drive state detection unit 31h consumes power equal to or higher than the first power consumption level. In the state where all of the audio units 9c (not shown in FIG. 4) are detected to be off, the SOC level derived by the charge state deriving unit 31a is the first level L1 (60% here). Alternatively, it is determined whether or not the second level L2 (here, 50%) is exceeded. If the SOC level exceeds the first level L1, the power generation amount adjusting unit 7 is turned on. A command to turn off the power generation of the generator 5 is output, and when the SOC level is between the second level L2 and the first level L1, the power generation amount adjustment unit 7 generates 50% of the power generation amount of the alternator 5 When the SOC level is lower than the second level L2, a command for changing the power generation amount of the alternator 5 to 100% power generation is output to the power generation amount adjusting unit 7.

  In the present embodiment, two threshold values of the first and second levels L1 and L2 are provided as threshold values for adjusting the power generation amount of the alternator 5. However, the threshold value is not limited to two, but one or three or more. But you can. Correspondingly, the power generation amount of the alternator 5 is changed in three stages of 100%, 50%, and 0%, but it may be changed in two stages or changed in four stages or more. It is also possible to arbitrarily set the percentage of power generation at each stage.

  The idle-up command unit 31c includes at least one of the loads 9 in which the engine stop detection unit 31a detects the operation of the engine 21 and the driving state detection unit 31h consumes power equal to or higher than the first power consumption level. In a state where it is detected that one is ON, it is determined whether or not the SOC level derived by the charge state deriving unit 31a is below the third level L3 (40% in this case). Then, an idle-up command is output to the engine control unit 29 to effect a predetermined level of idle-up.

  Further, the idle-up command unit 31c is equal to or higher than the second power consumption level that is greater than the first power consumption level by the driving state detection unit 31h in a state where the engine stop detection unit 31a detects the operation of the engine 21. It is determined whether or not an on state of a pre-registered load 9 (here, the air conditioner 9a) that consumes the electric power is detected. If the air conditioner 9a is on, the engine control unit 29 has a predetermined level. Outputs an idle-up command for performing idle-up.

  The notification control unit 31d determines whether or not the SOC level derived by the charge state deriving unit 31b is lower than the second level L2 in a state where the engine stop detection unit 31a detects the stop of the engine 21. If it is lower, the notification unit 13 causes the sound of the SOC of the battery 1 to be lowered (or to start the engine 21 and charge the battery 1) and / or light. A first warning output (notification output) is performed.

  Further, in the notification control unit 31d, the load 9 (air conditioner 9a) in which the engine stop detection unit 31a detects the operation of the engine 21 and the driving state detection unit 31h consumes power equal to or higher than the second power consumption level. In the state where it is detected that the battery is turned on, it is determined whether or not the SOC level derived by the charge state deriving unit 31a is lower than the third level L3. The second warning output is performed by at least one of sound and light indicating that the SOC of the battery has decreased.

  The power consumption management unit 31f is in a state where the engine stop detection unit 31a detects the operation of the engine 21 and the drive state detection unit 31h detects that the air conditioner 9a is turned on. It is determined whether or not the SOC level derived from is lower than the third level L3. If the SOC level is lower, a command to switch the air volume of the air conditioner 9a to a low level is sent to the junction box 23 that controls the air conditioner 9a. Output.

  Next, the battery monitoring operation of this in-vehicle battery monitoring device will be described with reference to the flowcharts of FIGS. 5 and 6, steps S1 ′ to S9 ′ have substantially the same contents as steps S1 to S9 according to the flowcharts of FIG. 2 and FIG. 3 described above. Description will be made from step S10 ′.

  In step S10 ′, at least one of the loads 9 that consumes power equal to or higher than the first power consumption level, such as the night illumination lamp 9b and the audio unit 9c, through the driving state detection unit 31h by the power generation control unit 31e and the idle up command unit 31c. A determination is made as to whether one is on. If the determination result is affirmative, the process proceeds to step S15 ′, whereas if the determination result is negative, the process proceeds to step S11 ′.

  In step S11 ′, it is determined whether or not the SOC is over 60% by the power generation control unit 31e. If it is over 60%, the process proceeds to step S12 ′, and the power generation control unit 31e adjusts the power generation amount. The power generation of the alternator 5 is turned off through the unit 7, and the process returns to step S10 '. On the other hand, if it is below 60%, the process proceeds to step S13'.

  In step S13 ′, it is determined whether or not the SOC is higher than 50% by the power generation control unit 31e. If it is higher than 50%, the process proceeds to step S14 ′, and the power generation control unit 31e adjusts the power generation amount. The alternator 5 is switched to 50% power generation through the unit 7 and returns to step S10 '. On the other hand, if it is below 50%, the process returns to step S9' and the alternator 5 is switched to 100% power generation.

  In step S15 ′, it is determined whether or not the SOC is higher than 40% by the idle-up command unit 31c. If it is higher, the process proceeds to step S17 ′. If not, the process proceeds to step S16 ′. Then, an idle up command is output from the idle up command unit 31c to the engine control unit 29, a predetermined level of idle up is performed, and the process proceeds to step S17 ′.

  In step S17 ′, the load 9 (air conditioner 9a) that consumes power equal to or higher than the second power consumption level is turned on by the idle-up command unit 31c, the power consumption management unit 31f, and the notification control unit 31d through the driving state detection unit 31h. If it does not exceed, the process returns to step S10 ′. If it exceeds, the process proceeds to step S18 ′, and an idle up command is output from the idle up command unit 31c to the engine control unit 29. Then, a predetermined level of idle-up is performed, and the process proceeds to step S19 ′. Note that in steps S18 'and S16', if idle up has already been performed, idle up is not performed.

  In step S19 ′, it is determined whether or not the SOC of the power consumption management unit 31f and the notification control unit 31d exceeds 40%. If so, the process returns to step S10 ′, but does not exceed. Advances to step S20 ′.

  In step S20 ′, the power consumption management unit 31f switches the air volume of the air conditioner 9a to the low level through the junction box 23, and the process proceeds to step S21 ′. The notification control unit 21 decreases the SOC of the battery 1 through the notification unit 13. A second warning output indicating that this is being performed is performed, and the process returns to step S10 ′.

  As described above, according to the present embodiment, it is possible to obtain the same effects as those of the first embodiment, such as being able to suppress energy loss due to power generation while preventing the battery from running out.

  In the second embodiment described above, the battery monitoring is performed by detecting the on / off state of each load 9, but supply current data indicating the supply current supplied to each load 9 is detected in advance as a driving state. Stored in the unit 31h, and based on the supplied current data, the driving state detecting unit 31h calculates the total current value consumed by all the loads 9 in the on state, and monitors the battery based on the calculated value. You may make it perform.

  Further, in each of the above-described embodiments, the SOC of the battery 1 is derived by detecting the specific gravity of the electrolyte solution of the battery 1 using the specific gravity sensor 3. However, instead of the specific gravity sensor 3, a pH sensor is used. The SOC of the battery 1 may be derived by detecting the pH of the electrolyte solution of the battery 1.

Hereinafter, the SOC derivation principle using the pH of the electrolytic solution will be briefly described. The standard electrode potentials E ₍₁₎ ⁰ and E ₍₂₎ ⁰ corresponding to the chemical formulas (1) and (2) shown in the above formula 1 are
E ₍₁₎ ⁰ = 1.68V, E ₍₂₎ ⁰ = -0.41V
The standard electromotive force E ⁰ of the lead acid battery is
E = E ₍₁₎ ^0- E ₍₂₎ ⁰ = 2.09V
It is.

In an actual battery reaction, sulfate ions (SO ₄ ²⁻ ) and oxonium ions (H ₃ O ⁺ ) (hereinafter abbreviated as H ⁺ ) in the electrolytic solution change depending on the charge / discharge status. The above electromotive force is not always obtained. This concentration dependency is shown as follows using the activity a (substance) of a substance involved in the reaction such as sulfate ion and oxonium ion. That is, the electromotive force E is

It is. The activity of water, solid layer lead sulfate and lead oxide present in large excess is set to 1,
When approximating to a (SO ₄ ²⁻ ) = a (H ⁺ ) / 2 (where “=” means near equal), log (a (H ⁺ )) is replaced with −pH. ,
E = E ⁰ − (3RT / F) ln4−2.303 (3RT / F) pH
Is obtained. Here, R is a gas constant (8.314 J / (K · mol), T is an absolute temperature, and F is a Faraday constant (9.648 × 10 ⁴ coulomb / mol). Since the electromotive force correction is possible, there is an advantage that the SOC corresponding to the ambient temperature can be obtained.

It is a block diagram of the vehicle-mounted battery monitoring apparatus which concerns on 1st Embodiment of this invention. It is a flowchart which shows the battery monitoring operation | movement by the battery monitoring apparatus of FIG. It is a flowchart which shows the battery monitoring operation | movement by the battery monitoring apparatus of FIG. It is a block diagram of the vehicle-mounted battery monitoring apparatus which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the battery monitoring operation | movement by the battery monitoring apparatus of FIG. It is a flowchart which shows the battery monitoring operation | movement by the battery monitoring apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery 3 Specific gravity sensor 5 Alternator 7 Electric power generation amount adjustment part 9 Load 11 Current detection part 13 Notification part 15 Current path 17 Shut-off part 19,31 Control unit 19a, 31a Engine stop detection part 19b, 31b Charge state derivation part 19c, 31c Idle Up command section 19d, 31d Notification control section 19e, 31e Power generation control section 19f, 31f Power consumption management section 19g, 31g Shut-off control section 27 Ignition switch 31h Drive state detection section

Claims (6)

A charge state detection unit for detecting a charge state of the battery;
A power consumption management unit that switches the operation of a predetermined load to a low power consumption mode when the charge state detected by the charge state detection unit falls below a predetermined reference level;
A vehicle-mounted battery monitoring device comprising: The in-vehicle battery monitoring device is
A current detection unit for detecting a current value supplied from the battery to each load;
The power consumption management unit operates the predetermined load when the state of charge is below a predetermined reference level in a state where the total supply current value detected by the current detection unit is higher than a predetermined reference value. The vehicle-mounted battery monitoring device according to claim 1, wherein the vehicle-mounted battery monitoring device is switched to a low power consumption mode. The in-vehicle battery monitoring device is
An engine stop detector for detecting engine stop;
In the state where the total supply current value detected by the current detection unit exceeds a predetermined reference value and the engine stop detection unit detects the operation of the engine, the power consumption management unit The in-vehicle battery monitoring device according to claim 2, wherein when the predetermined level falls below a predetermined reference level, the operation of the predetermined load is switched to a low power consumption mode. The charge state detection unit detects the SOC of the battery as the charge state,
4. The on-vehicle battery monitoring device according to claim 1, wherein the predetermined reference level is a level at which the SOC is 40%.   The in-vehicle battery monitoring device according to claim 1, wherein the predetermined load is an air conditioner.   The on-vehicle battery monitoring device according to claim 5, wherein the operation of the air conditioner performed by the power consumption management unit is switched to a low power consumption mode by lowering an air volume of the air conditioner.

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