JP2007040153A - Battery condition detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery condition detection device capable of an accurate condition determination irrespective of deterioration condition of the battery or the like. <P>SOLUTION: This battery condition detection device detects engine cranking rotation speed based on detection signal of a crank angle sensor 31, compares cranking rotation speed and predetermined engine ignitable rotation speed, and evaluates a condition of a buttery 1. Also the device evaluates the condition of the buttery 1 with considering a condition of variation of cranking rotation speed with time during engine cranking period. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a battery state detection device that manages the state of a battery.

  In the battery state determination in the conventional battery state detection device, the internal resistance of the battery is measured from the amount of decrease in the output voltage of the battery at the start of the engine and the current value flowing at that time, and based on the measured internal resistance value The degree of deterioration of the battery is determined.

  However, there are various types of battery deterioration conditions, such as when lattice corrosion and sulfation overlap, and depending on the deterioration conditions, the correlation between the actual internal resistance and the open circuit voltage of the battery deteriorates. The correlation between the resistance and the amount of decrease in the battery output voltage at the time of starting the engine may also deteriorate. In this case, accurate state determination becomes difficult with the above-described prior art in which the state determination is performed by directly using the output voltage drop amount.

  Therefore, an object to be solved by the present invention is to provide a battery state detection device capable of accurately determining a state regardless of a deterioration state of the battery or the like.

  In order to solve the above-mentioned problem, in the invention of claim 1, a battery state detection device for managing a state of a battery mounted on an automobile, the sensor unit detecting an operation state of a mechanism unit of an engine, and the sensor And a processing unit that detects a cranking rotation speed of the engine based on a detection result of the unit and detects the state of the battery in consideration of the cranking rotation speed.

  According to a second aspect of the present invention, in the battery state detection device according to the first aspect of the present invention, the processing unit considers whether or not the cranking rotational speed exceeds a predetermined reference rotational speed. Detect battery status.

  According to a third aspect of the present invention, in the battery state detection device according to the first aspect of the present invention, the processing unit detects the state of the battery in consideration of the change over time of the cranking rotational speed.

  According to a fourth aspect of the present invention, in the battery state detection device according to any one of the first to third aspects of the present invention, the sensor section is a crank angle sensor.

  According to a fifth aspect of the present invention, in the battery state detection device according to any one of the first to third aspects, the sensor section is a cam angle sensor.

  According to the first aspect of the invention, the cranking rotational speed of the engine is detected based on the detection result of the sensor unit that detects the operation state of the engine mechanical part, and the battery is considered in consideration of the cranking rotational speed. Since the state is detected, the state of the battery can be accurately detected in response to the actual situation without taking into consideration various conditions such as the battery mounting environment such as the deterioration state and temperature and the vehicle model of the automobile.

  In addition, since the cranking rotation speed is detected based on the detection result of the sensor section that detects the operation state of the engine mechanism section, the cranking rotation speed can be reliably and accurately detected.

  According to the second aspect of the present invention, in order to detect the state of the battery in consideration of whether or not the detected cranking rotational speed exceeds a predetermined reference rotational speed, the cranking is related to the output of the battery. The state of the battery can be detected by accurately determining whether or not the rotational speed has reached the rotational speed necessary for starting the engine.

  According to the third aspect of the present invention, the cranking rotation is detected in relation to the output of the battery during the cranking period in order to detect the state of the battery in consideration of the state of change of the detected cranking rotational speed with time. The state of the battery can be detected by accurately determining whether the number can maintain the number of revolutions necessary for starting the engine.

  According to the fourth aspect of the invention, the cranking rotational speed of the engine can be detected easily and accurately by using the detection result of the crank angle sensor.

  According to the fifth aspect of the present invention, the cranking rotational speed of the engine can be detected easily and accurately by using the detection result of the cam angle sensor.

<1. Principle>
As the battery mounted on the automobile, the present applicant changes the remaining charge amount for each of a new battery and a battery in various deteriorated states, and each state where the remaining charge amount is different. The battery was discharged at the time of engine start (predetermined discharge), and the output voltage before and during the battery discharge was measured. And the open circuit voltage value before performing each engine start discharge in each remaining charge state of each battery with different deterioration conditions, and the lower limit voltage value (discharge time voltage value) at the time of engine start discharge I investigated the relationship.

  Here, the engine start discharge is a discharge (or an equivalent discharge) performed when the starter of the automobile is driven and the engine is started. The lower limit voltage value is the lowest value when the output voltage of the battery is reduced due to the discharge at the start of the engine.

  FIG. 1 is a graph of the test results. The horizontal axis corresponds to the open-circuit voltage value of the battery before the start of engine start discharge in each discharge test, and the vertical axis represents during engine start discharge in each discharge test. It corresponds to the lower limit voltage value of the battery. Further, the curve G1 in FIG. 1 is drawn based on the measurement result for a new battery, and the curves G2 to G5 are drawn based on the measurement result for a battery that has been used and deteriorated to some extent. Curves G1 to G5 are obtained as a result of tests on batteries having different deterioration conditions. Among these, the curves G2 to G4 correspond to the batteries that are repeatedly charged and discharged in a manner close to a normal use state, and the use period of the batteries becomes longer and the deterioration progresses in the order of the curves G2, G3, and G4. Curve G5 corresponds to a battery that is frequently overcharged. The curves G4 and G5 have different deterioration conditions (deterioration factors), but the degree of deterioration (deterioration degree) is almost the same.

  Specifically, when attention is paid to the curve G1 corresponding to the new battery, the lower limit voltage value when the engine start-up discharge is performed when the open-circuit voltage value is about 12.9 V (almost fully charged state) is about 9 This indicates that the lower limit voltage value when the engine start-up discharge is performed when the open-circuit voltage value is approximately 12.1V is approximately 8.1V. When attention is paid to the curve G4 corresponding to the battery having deteriorated, the lower limit voltage value when the engine start discharge is performed when the open circuit voltage value is about 12.5V is about 8.1V. ing.

  From the graph of FIG. 1, it is known that the corresponding curves G1 to G5 are shifted in the right direction (or lower right direction) of the graph as the deterioration of the battery proceeds. In particular, in a region where the lower limit voltage value is equal to or lower than a predetermined reference level (for example, 9 V), the rightward shift amount of the curves G2 to G5 with respect to the curve G1 tends to increase as the corresponding battery deteriorates. I know that

  In consideration of this, for example, the point P1 (VO, VL) on the graph of FIG. With reference to the corresponding point P2 (VN, VL), the degree of deterioration of the battery can be determined using the shift amount D shifted in the right direction of the horizontal axis. If the degree of deterioration of the battery is determined in this way, the relationship between the open circuit voltage value and the lower limit voltage value of the battery (for example, curves G1 to G5) can be defined according to the degree of deterioration. By only detecting, it is possible to predict the lower limit voltage value when starting the engine by driving the starter of the automobile. If the voltage level required to drive the starter is found on the other side, the voltage level required to drive the starter is set as the start limit level (for example, the start limit line L01 in FIG. 1). By comparing the predicted lower limit voltage value against the starting limit level, it is determined whether or not the lower limit voltage value is equal to or higher than the starting limit level (start limit line L01), that is, the starter is driven without any problem according to the lower limit voltage value. It is possible to determine whether or not it can be performed.

  However, the present applicant has found that the start limit line L01 has a large variation due to various factors such as the resistance value in the power supply circuit in the automobile, such as the vehicle type and individual differences of the automobile. On the other hand, since the battery is often mounted in common for a plurality of vehicle types, it is not desirable to uniformly determine the start limit line L01 in the combination of the vehicle and the battery mounted on the vehicle.

  Here, as a condition necessary for driving the starter by power supply from the battery, first, as a first condition, it is necessary to secure an operating voltage of the plunger for meshing the gear of the motor of the starter with the engine. is there. Further, as a second condition, it is necessary that the cranking rotational speed at the time of engine start (hereinafter referred to as “cranking rotational speed”) is equal to or higher than the engine ignition possible rotational speed (reference rotational speed). Furthermore, as a third condition, it is necessary to maintain the rotational speed during cranking when starting the engine.

  Therefore, in this embodiment, it is actually detected whether or not the above first to third conditions are satisfied, and based on the detection result, it is determined whether or not the battery is normal. Yes. This will be explained.

(1-1. First condition)
As described above, first, as the first condition, it is necessary to ensure the operating voltage of the plunger for meshing the gear of the motor of the starter with the engine. FIG. 2 is a schematic diagram showing an example of a general starter ST. 2, reference numeral 1 denotes a battery, reference numeral 2 denotes a plunger, reference numeral 3 denotes a movable contact of the plunger 2, reference numeral 4 denotes a fixed contact, reference numeral 5 denotes a starter motor, and reference numeral 6 denotes a voltage supplied from the battery 1 to the plunger 2. The ignition switch 7 has an engine gear. When the ignition switch 6 is turned on, the plunger 2 of the starter ST is driven to bring the movable contact 3 into contact with the fixed contact 4, whereby the starter motor 5 is started, and the pinion gear 6b is moved in the direction of the arrow Q via the lever 6a. It moves in the direction and meshes with the gear 7 of the engine so that the rotation of the starter motor 5 can be transmitted to the engine. When the engine starts to rotate, the pinion gear 6b is disengaged from the engine gear. Therefore, it is necessary to secure the operating voltage of the plunger as a minimum.

  In this case, in this embodiment, a prescribed value of the minimum voltage (hereinafter referred to as “plunger drive minimum voltage Vc”) necessary for driving the plunger 2 is referred to, or the plunger drive minimum voltage Vc is measured in advance. In FIG. 3, the lower limit voltage VL that appears at time T01 when the ignition switch 6 for supplying power to the plunger 2 is turned on and an inrush current flows is equal to or higher than the plunger drive minimum voltage Vc (see step S04 in FIG. 9). By determining whether or not there is, it is determined whether or not the first condition is satisfied.

  As described above, when the first condition is satisfied, the starter motor 5 is engaged with the gear 7 of the engine by driving the plunger 2 of the starter ST shown in FIG. In this state, in this state, the rotation speed of the starter motor 5 is decelerated at a predetermined gear ratio (for example, 10: 1) to become the cranking rotation speed.

(1-2. Second condition)
However, even when the plunger 2 is driven without hindrance, the engine is not ignited if the cranking rotational speed is less than the engine ignitable rotational speed. In other words, when the voltage level from the battery 1 is low, the cranking rotational speed is lowered, and it may be impossible to ignite the engine. Therefore, as described above, as the second condition, it is necessary that the cranking rotational speed at the time of starting the engine is equal to or higher than the engine ignitable rotational speed. Therefore, in this embodiment, when starting the engine, the cranking rotational speed is detected, and the detected rotational speed is compared with the engine speed that can be ignited by the engine that has been detected by a standard value or a test in advance. To determine whether the engine can be ignited.

  FIG. 4 is a diagram showing the relationship between the cranking rotational speed and the engine torque. In FIG. 4, the horizontal axis represents the cranking rotational speed, and the vertical axis represents the engine torque. 4, reference characters L02a and L02b are torque-rotation characteristic lines (starter TN characteristic lines) in the starter motor 5, reference numeral L03 is an engine torque-rotation characteristic line (engine TN characteristic line), and reference numeral L04 is engine ignition. This is a possible speed line, and in FIG. 4, the engine ignitable speed is specified as n01.

  In general, the torque of the starter motor 5 has a negative correlation with the rotational speed, but also changes depending on the voltage applied to the starter motor 5. The lower the applied voltage, the lower the torque. For example, a first starter TN characteristic line L02a shown by a solid line in FIG. 4 shows a state in which an appropriate voltage is applied to the starter motor 5, and a second starter TN characteristic line L02b shown by a dotted line is The state where the applied voltage to the starter motor 5 is reduced is shown.

  In a state in which the starter motor 5 shows the first starter TN characteristic line L02a, the cranking rotation speed n02 is determined at the intersection P01 between the first starter TN characteristic line L02a and the engine TN characteristic line L03, and this cranking rotation. Since the number n02 is within the range of the engine ignition possible rotation number n01 or more, the engine can be started.

  On the other hand, in the state where the voltage applied to the starter motor 5 decreases and the second starter TN characteristic line L02b appears, the cranking rotation speed at the intersection P02 between the second starter TN characteristic line L02b and the engine TN characteristic line L03. Although n03 is determined, the cranking speed n03 is less than the engine ignition possible speed n01, so that the engine cannot be started.

  Thus, if the starter TN characteristic lines L02a and L02b, the engine TN characteristic line L03, and the engine ignitable rotation speed line L04 shown in FIG. 4 are known in advance, whether or not the start of cranking is realized. Can be determined.

  However, in general, the viscosity of the lubricating oil used in the starter motor 5 and the engine is significantly affected by the temperature, and there are other conditions such as the vehicle type and individual differences of the automobile, so the starter TN characteristic lines L02a, L02b, The engine TN characteristic line L03 varies greatly depending on various environmental conditions. Accordingly, it is not desirable to uniformly define the starter TN characteristic lines L02a and L02b and the engine TN characteristic line L03. The starter TN characteristic lines L02a and L02b and the engine can be parameterized in consideration of all environmental conditions. Defining the TN characteristic line L03 is too complicated and complicated.

  Therefore, in this embodiment, only the engine ignitable engine speed line L04 having a relatively small numerical variation is held as an eigenvalue, while the cranking engine speed nr is prepared with parameters and the like in FIG. Rather than calculating and calculating the intersection points P01 and P02, the actual cranking speed nr realized when the engine is started is detected, and this cranking speed nr is compared with the engine ignition possible speed n01. To determine whether the engine can be ignited.

  In this embodiment, as shown in FIG. 5, the cranking rotation speed nr is detected based on a detection signal output from the crank angle sensor (sensor unit) 31. The crank angle sensor 31 is disposed in the vicinity of a timing rotor 33 attached to a crankshaft (not shown) of the engine, and detects fluctuations in the magnetic field that occur every time the teeth of the timing rotor 33 pass in the vicinity thereof. The crank angle of the engine can be detected based on the detection signal of the crank angle sensor 31. The teeth of the timing rotor 33 have a part lacking, and the rotational angle position of the timing rotor 33 and the like can be grasped with reference to that part.

  More specifically, the crank angle sensor 31 includes a core 31a disposed close to the timing rotor 33, a magnetic field generation unit (for example, a magnetic field generating coil, a permanent magnet, etc.) 31b that applies a magnetic field to the core 31a, and a core 6 includes a detection coil (or a Hall element) 31c for detecting a change in the magnetic field in 31a, and the vibration waveform as shown in FIG. A detection signal is output.

  In this embodiment, the detection signal is waveform-shaped as shown in FIG. 6B, and the cranking rotation speed of the engine is detected using the shaped signal. For example, the cranking rotational speed is detected by measuring the time required for counting the number of peaks of the signal in FIG. 6B by one revolution of the crankshaft.

(1-3. Third condition)
However, in actual cranking at the time of starting the engine, in general, the engine does not start with only one rotation. For example, in a four-cylinder engine, it is known that the engine will not start unless cranking is performed about four times in total. If the voltage level from the battery 1 is low when the engine is started, the cranking speed gradually decreases during a certain period of cranking when the engine is started, and finally the ignition of the engine There may be situations where it becomes impossible. Therefore, as described above, as the third condition, it is necessary to maintain the rotation speed while cranking at the time of engine start. As means for determining the third condition, the following means can be considered.

  That is, as the means, the cranking speed of the engine is detected at the time of engine cranking, and the above-described change in the cranking speed within the cranking period 15 (see FIG. 3 etc.) A configuration for determining whether or not the third condition is satisfied is conceivable. This is because, as a result of the test, it has been found that when the engine start performance of the battery 1 is good, the cranking rotational speed tends to increase with time. Here, the cranking period 15 means that the engine starts from the time T01 when cranking is started by applying voltage to the plunger 2, and the output voltage of the battery 1 (voltage level of the positive terminal of the battery 1) starts cranking. This is the period up to time T02 when the open voltage VO of the previous battery 1 is exceeded.

  More specifically, when the cranking rotational speed increases with time, the third condition is satisfied, and the cranking rotational speed is constant or decreased with time. In this case, it is determined that the third condition is not satisfied.

  The cranking rotation speed is detected based on the detection signal of the crank angle sensor 31 as described above.

  Thus, in this embodiment, it is possible to easily determine whether or not the engine is started with respect to the output voltage of the battery 1 only by determining whether or not the first to third conditions are satisfied. Is possible. In particular, the viscosity of the lubricating oil generally used in the starter motor 5 and the engine is significantly affected by temperature, and various parameters are prepared due to other conditions such as vehicle type and individual differences. When complicated work is required, there is an advantage that it is possible to easily determine whether or not the engine is started simply by detecting the state (output voltage or the like) of the battery 1 realized in the cranking embodiment.

<2. Configuration>
FIG. 7 is a block diagram of a battery state detection device according to one embodiment of the present invention. As shown in FIG. 7, the battery state detection device includes a current sensor 21, a voltage sensor 23, a processing unit 25, a storage unit 27, an output unit 29, and a crank angle sensor 31, and is mounted on a vehicle. The state of the battery 1 is managed.

  The current sensor 21 detects a current output from the battery 1 and a current input to the battery 1. The voltage sensor 23 has the above <1. The output voltage 13 of the battery 1 described in <Principle> is detected. The crank angle sensor 31 is <1. As described in <Principle>, a detection signal for detecting the cranking speed of the engine is supplied to the processing unit 25. The processing unit 25 includes a CPU (control unit) and the like, and performs various information processing operations (including control operations) for managing the battery 1. The storage unit 27 includes a rewritable nonvolatile memory such as a flash ROM. The output unit 29 is for outputting a determination result of the state of the battery 1, and for example, a display device such as a liquid crystal display panel, an audio output device, or the like is applied. In addition, when performing shut-off control or the like of various loads (for example, audio equipment) mounted on the vehicle according to the state of the battery 1, a load power supply control unit or the like is also applied as the output unit 29.

  Then, the output voltage of the battery 1 detected by the voltage sensor 23 is converted into digital data by an A / D converter (not shown) mounted in the processing unit 25, and then supplied to the processing unit 25. The detection signal of the angle sensor 21 is waveform-shaped as described above by a waveform shaping circuit (not shown), and is then supplied to the processing unit 25. Based on these input signals, the processing unit 25 performs the above <1. The first to third conditions described in <Principle> are determined, and whether or not the battery 1 is normal is output to the output unit 29. Further, it is necessary for various data processing operations performed by the processing unit 25, such as a program that defines the operating procedure for the CPU of the processing unit 25 to operate, the above-described minimum plunger drive voltage Vc, the engine ignition speed n01, and the like. Such information is stored in the storage unit 27 in advance.

  Then, as illustrated in FIG. 8, the processing unit 25 includes a first condition determining unit 25a that determines the first condition, a second condition determining unit 25b that determines the second condition, and a third condition. The third condition determination unit 25c that makes the above determination and a comprehensive determination as to whether or not the state of the battery 1 is normal based on the determination results of the condition determination units 25a to 25c, and outputs the comprehensive determination result And a general determination unit 25d that outputs to the unit 29.

<3. Operation>
An operation example of the battery state detection device having the above configuration will be described with reference to the flowchart shown in FIG.

  First, when the ignition switch 6 is turned on, the output voltage of the battery 1 is detected by the voltage sensor 23, and the detection result is output to the processing unit 25.

  Then, in step S01 in FIG. 9, the third condition determination unit 25c of the processing unit 25 operates the CPU in accordance with a program stored in advance in the storage unit 27. Based on this, the cranking speed nr is detected.

  In step S02, it is determined whether or not the third condition is satisfied, that is, whether or not the necessary cranking rotational speed can be maintained within the crank period 15 (particularly, the cranking period 15 at the next engine start). Is judged. As described above, this determination is made by determining whether or not the cranking rotational speed nr tends to increase with time during the cranking period 15 (note that the numerical conditions necessary for this determination, etc.) It is assumed that the data is stored in advance in the storage unit 27).

  If it is determined in step S02 that the cranking rotation speed can be maintained, the process proceeds to step S03. If it is determined that the cranking rotation speed cannot be maintained, the process proceeds to step S05.

  In step S03, in the second condition determination unit 25b of the processing unit 25, the CPU operates according to a program stored in advance in the storage unit 27, for example, whether the second condition is satisfied, that is, The cranking speed nr detected in step S01 is compared with the engine ignition speed n01 stored in advance in the storage unit 27 to determine whether or not the engine can be ignited. If it is determined in step S03 that the cranking rotation speed nr is equal to or greater than the engine ignition possible rotation speed n01, the process proceeds to step S04, while the cranking rotation speed nr is less than the engine ignition possible rotation speed n01. If it is determined, the process proceeds to step S05.

  In step S04, in the first condition determination unit 25a of the processing unit 25, whether or not the first condition is satisfied by operating the CPU according to a program stored in advance in the storage unit 27, for example, FIG. 3, it is determined whether or not the lower limit voltage VL that appears at time T01 (when the power supply ignition switch 6 for the plunger 2 is turned on) is less than the plunger drive minimum voltage Vc. If it is determined in step S03 that the lower limit voltage VL is equal to or higher than the plunger drive minimum voltage Vc, the process proceeds to step S06. On the other hand, if it is determined that the lower limit voltage VL is lower than the plunger drive minimum voltage Vc, Proceed to S05.

  In step S06, information indicating that the battery 1 is in a normal state is output to the output unit 29 through the comprehensive determination unit 25d.

  Thereafter, the process proceeds to step S07, where the balance of the amount of charge of the battery 1 detected by the current sensor 21 is integrated by the processing unit 25, and predetermined processing such as full charge determination in step S08 is performed. In this case, when it is determined that the battery is fully charged, control for preventing overcharging is performed by stopping regeneration of the battery 1 or the like.

  In step S05, information indicating that the battery 1 needs attention is output to the output unit 29. The output unit 29 performs a caution display indicating that the battery 1 needs attention, a sound output for prompting attention, and the like. Further, when a load power supply control unit is included as the output unit 29, etc., the load power supply control unit is used to cut off various loads (for example, audio devices) mounted on the vehicle according to the state of the battery 1 or the like. I do.

  And it progresses to step S09, the balance of the charge amount of the battery 1 detected by the current sensor 21 is integrated | accumulated in the process part 25, and it progresses to step S10. In step S10, it is determined whether or not the charge balance exceeds a predetermined value Pc considering dark current for a predetermined number of days (for example, one week) of the automobile. It is determined that the battery 1 is sufficiently charged even if the dark current of the minute is taken into consideration, and the process proceeds to step S11. In step S11, information indicating that the battery 1 is in a normal state is output to the output unit 29 through the comprehensive determination unit 25d. Thereafter, the processing after step S09 is repeated.

  On the other hand, if it is determined in step S10 that the charge balance is equal to or less than the predetermined value Pc, the process proceeds to step S12, and it is first determined in step S13 whether the battery is fully charged.

  If it is determined in step S13 that the battery is not fully charged, the process returns to step S09 and the subsequent processing is repeated.

  On the other hand, if it is determined in step S13 that the battery is fully charged, the process proceeds to step S14, and it is determined again whether the charge balance exceeds the predetermined value Pc. When it is determined that the charge balance exceeds the predetermined value Pc, it is determined that the battery 1 is sufficiently charged even when the dark current for a predetermined number of days of neglect is taken into consideration. The process proceeds to step S15. In step S15, information indicating that the battery 1 is in a normal state is output to the output unit 29 through the comprehensive determination unit 25d. Thereafter, the processing after step S09 is repeated.

  On the other hand, if it is determined in step S14 that the charge balance is equal to or less than the predetermined value Pc, it is determined that the amount of charge until the battery 1 is fully charged is small, and it is determined that the battery 1 is at the end of its life. In step S16, information to that effect is output to the output unit 29. In this case, a warning display indicating that the battery 1 has reached the end of life, an audio output related to the warning, and the like are performed. Further, when a load power supply control unit is included as the output unit 29, etc., the load power supply control unit is used to cut off various loads (for example, audio devices) mounted on the vehicle according to the state of the battery 1 or the like. I do.

  As described above, the correlation between the actual internal resistance and the open circuit voltage of the battery deteriorates depending on the deterioration state. As a result, the correlation between the actual internal resistance and the amount of decrease in the battery output voltage at the start of the engine Even if it becomes worse, accurate state determination becomes difficult with the prior art in which state determination is performed using the output voltage drop directly.

  However, in this embodiment, the cranking rotation speed of the engine is detected based on the detection signal of the crank angle sensor 31, and the first to first described above are based on the detection result and the monitoring result of the output voltage of the battery 1. 3 is actually detected, and based on the detection result, it is determined whether or not the battery 1 is normal. Therefore, the battery as in the method shown in FIG. It is not necessary to uniformly determine the characteristic curves G1 to G5 and the start limit line L01. Accordingly, it is possible to accurately determine whether or not the battery is normal in response to the actual situation without taking into consideration various conditions such as the battery mounting environment such as the deterioration state and temperature and the vehicle model.

  Further, since the state of the battery 1 is evaluated by comparing the detected cranking rotational speed with a preset engine ignitable rotational speed, the cranking rotational speed is necessary for starting the engine in relation to the output of the battery 1. Therefore, the state of the battery 1 can be determined by accurately determining whether or not the rotation speed has reached a certain value.

  Further, in order to determine whether or not the battery 1 is normal in consideration of the detected change in the cranking speed over time, the cranking speed is determined in relation to the output of the battery 1 during the cranking period 15. Therefore, the state of the battery 1 can be determined by accurately determining whether or not the engine can maintain the rotational speed necessary for starting the engine.

  Furthermore, since the cranking rotational speed is detected based on the detection signal of the crank angle sensor 31, the cranking rotational speed can be detected reliably and accurately.

  In the above embodiment, the cranking rotation speed is detected using the detection signal of the crank angle sensor 31. However, the detection of other sensors that detect the operating state of the engine mechanism such as the cam angle sensor is detected. You may make it detect cranking rotation speed using a signal.

  In the above embodiment, it is determined whether or not the lower limit voltage VL is equal to or higher than the plunger drive minimum voltage Vc in the first condition. However, whether or not the lower limit voltage VL is equal to or higher than the starter motor start minimum voltage. It can be judged. Here, the starter motor starting minimum voltage is not only the drive voltage of the plunger 2 necessary for the movable contact 3 of the plunger 2 to be connected to the fixed contact 4 but also the starter after the movable contact 3 of the plunger 2 is connected to the fixed contact 4. This also takes into account the drive voltage necessary for the motor 5 to rotate. When the starter motor 5 is driven, the viscosity of the lubricating oil is significantly affected by the temperature. Therefore, the starter motor starting minimum voltage that varies depending on the temperature environment may be stored in the storage unit 27 in advance.

  In the above embodiment, all of the first to third conditions are determined. However, if at least the second or third condition is included, either one of them or You may make it judge by combining two.

It is a graph which shows the measurement result which measured the open circuit voltage and the lower limit voltage at the time of engine starting about the battery from which a deterioration condition and charge remaining amount differ. It is a schematic diagram which shows an example of a general starter. It is a figure which shows the change of the output voltage of a battery in the case of engine starting. It is a figure which shows the relationship between cranking rotation speed and an engine torque. It is a figure which shows roughly the structure of a crank angle sensor and its periphery. It is a figure which shows the detection signal of a crank angle sensor, and the signal which waveform-shaped it. It is a block diagram which shows the battery state detection apparatus which concerns on one embodiment of this invention. It is a block diagram which shows the process part of the battery state detection apparatus which concerns on one embodiment of this invention. It is a flowchart which shows operation | movement of the battery state detection apparatus which concerns on one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery 2 Plunger 5 Starter motor 6 Ignition switch 7 Gear 10 Engine cylinder part 13 Output voltage 15 Cranking period 21 Current sensor 23 Voltage sensor 25 Processing part 25a 1st condition judgment part 25b 2nd condition judgment part 25c 3rd Condition determination unit 25d Total determination unit 27 Storage unit 29 Output unit 31 Crank angle sensor

Claims (5)

A battery state detection device for managing the state of a battery mounted on an automobile,
A sensor unit for detecting an operation state of an engine mechanism unit;
A processing unit that detects the cranking rotational speed of the engine based on the detection result of the sensor unit and detects the state of the battery in consideration of the cranking rotational speed;
A battery state detection device comprising: The battery state detection device according to claim 1,
The processing unit detects a state of the battery in consideration of whether or not the cranking rotational speed exceeds a predetermined reference rotational speed. The battery state detection device according to claim 1,
The processing unit detects a state of the battery in consideration of a state of change of the cranking rotation speed with time, and a battery state detection device. In the battery state detection device according to any one of claims 1 to 3,
The battery state detection device, wherein the sensor unit is a crank angle sensor. In the battery state detection device according to any one of claims 1 to 3,
The battery state detection device, wherein the sensor unit is a cam angle sensor.

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