JPS60105978A - Abnormality alarm for battery - Google Patents

Abstract

PURPOSE:To facilitate the detection of abnormality in a battery by comparing the internal resistance value of the battery with a deterioration limit resistance value predetermined. CONSTITUTION:Voltage of a battery terminal 3 prior to the start of a starter motor 6 is memorized into an RAM22 with a microcomputer 14 through an A/D converter 13. Then, the voltage of the battery terminal during the cranking is memorized likewise. The microcomputer 14 reads in the rotational speed of the motor 6 corresponding to the revolutions of the crank shaft detected with a crank angle sensor 17 simultaneously. At this point, a load current of the motor 6 corresponding to the rotational speed of the motor 6 prememorized in an ROM21 is read out and the internal resistance value of the battery 1 is computed with the microcomputer 14 from the difference between the lead current and the battery terminal voltage before and during the operation of the starter motor. Then, the internal resistance value is compared with the deterioration limit resistance value prememorized in the ROM21 and when the internal resistance value > the deterioration limit resistance, the battery is determined to be abnormal to actuate and alarm 23 by an alarm signal from the microcomputer 14.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a battery abnormality warning device that has a simple configuration and can easily notify a battery abnormality.

(b) If the batteries of conventional technology vehicles are not used for a long period of time, the terminal voltage will drop due to self-discharge, or if the electrolyte is insufficient, the internal separators and electrode plates will deteriorate and the performance as a battery will deteriorate. become unable to demonstrate their abilities.

Therefore, optical methods and methods of checking battery capacity have been proposed as methods for checking abnormalities in batteries. In the optical method, a light emitting element and a light receiving element are installed inside the battery chamber, and when the electrolyte becomes dirty due to deterioration of the separator or electrode plates, the amount of light passing through decreases, so this can be detected optically. However, this method requires the provision of a light-emitting element and a light-receiving element, which results in a considerably complicated configuration and high cost. On the other hand, the method of checking the battery capacity is to connect a shunt from one terminal of the battery to the various loads and detect the state of charge of the battery to determine the remaining capacity of the battery (for example, Japanese Patent Laid-Open No. 53 79238), but in this case too, a shunt resistor is required, making the configuration considerably complicated and causing high costs.

(c) Object and structure of the invention The present invention has been made in view of the above points, and aims to easily notify abnormality of the battery with a simple structure. Tonne pressure and battery t1 voltage during cranking and '? i: For river measurement In addition to calculating the difference between them, detect the rotation speed of the crankshaft and calculate the starter load m flow corresponding to the rotation speed of the starter motor during cranking, which is preset based on the rotation speed. , calculate the average value of the battery internal resistance from both of these, and compare the resulting internal resistance value with the deterioration limit resistance value predetermined as the deterioration base coating,
When the internal resistance value exceeds the deterioration limit resistance value, it is determined that there is an abnormality in the battery and an alarm is issued.

FIG. 1 is an overall configuration diagram for clearly showing the configuration of the present invention.

The battery terminal voltage measuring means measures the battery terminal heavy pressure before the starter motor operates and the battery terminal heavy pressure during cranking, while the crankshaft rotation speed detection means detects the crankshaft rotation speed during cranking. ing.

The battery internal resistance calculation means calculates a battery internal resistance value from the difference between the starter load current and the voltage between the two battery terminals, which is determined from the characteristics of the rotational speed of the starter motor and the load current based on the rotational speed of the crankshaft. The battery internal resistance value obtained by this calculation is compared with the deterioration limit resistance value predetermined as a reference value when investigating the deterioration state by a ratio of 1!2, and as a result, the battery internal resistance value is When the resistance exceeds a deterioration limit resistance value predetermined as a deterioration standard, it is determined that there is an abnormality in the battery, and an alarm is issued by an alarm means.

Figure 2 shows the block lines (thresholds) of a practical example of the battery abnormality alarm system according to the present invention. 1 is /xtary, 2 is its isolateral internal resistance, 3
is a starter unit consisting of a positive terminal (terminal) of a battery 1, a starter relay 5, and a starter motor 6; starter relay 5tj has a coil 5a and a contact 5b; It is being 7 is a starter cable connected between the battery terminal 3 and the starter unit 4; 8 is a fuse; 9 is an ignition switch; by turning on ignition contact I or starter contact S with switch 9, battery terminal 3 is connected to the starter unit 4; 3 supplies power supply voltage to an ignition load (not shown) via a line 10. Note that 11 is a harness directly connected to the battery terminal 3 in order to supply power supply voltage to various other loads.

12 is a signal line for detecting the terminal voltage of battery 1 terminal 3, which is necessary when investigating abnormalities in battery 1; 13;
14 is a microcomputer (hereinafter referred to as "microcomputer"); 15 is a signal line connected to the starter contact S to detect that the engine starting system is in operation;] 6 is a signal Buffer for the starter signal from line 15. 17 is a crank angle sensor for detecting the rotation speed of the engine crankshaft (not shown), and this crank angle sensor 17 detects the so-called starter during cranking when the crankshaft is rotating to start the engine. The rotation speed of the motor 6 can be detected. ] 9 is a signal line connected to the crank angle sensor J7, 20 is a buffer for the rotational speed signal from the signal line 19, and 2] is a program and predetermined reference data for causing the microcomputer 14 to perform predetermined arithmetic processing. is stored in advance in the ROM, and the reference data is the characteristics shown in Figure 4 showing the relationship between the rotational speed and load current of the series motor used in starter motor 6, and the internal resistance of battery 1. There is a predetermined deterioration limit resistance value rO as a reference when all the deterioration states of No. 2 are investigated. 22
1'i/23ij is an alarm device that issues an alarm based on a picture signal outputted from a microcomputer 14 and a RAM that sequentially stores data necessary for detecting an abnormality in the tree 1. In place of the alarm 230, a display may be used which displays two indications to notify the user of any abnormalities in the system.

Next, the operation of the above alarm device will be explained based on the flowchart shown in FIG.

In the microcomputer 14, the voltage o of the battery terminal 3 before the starter motor 6 of the engine starting system is activated is determined at a predetermined interval as shown in FIG. Read in T1 (
F-1), its terminal voltage Vo is temporarily stored in the RAM 22.

Next, determine whether the starter motor 6 is operating or not.C
F-2), if the starter motor is fully activated (the starter motor starts operating at time t in FIG. 5), 1 is added to the contents of the counter n (F-3). Note that when the starter motor is not operating, the starter signal from the starter contact S is manually input to the microcomputer 14 via the signal line 15 and buffer 16 at intervals, so that the battery terminal 1a voltage read at this time is ■Write o with microcomputer 141. d is retained, and the previously read data of the terminal voltage vo is lost.

After the starter motor operates, one terminal of the battery is cranked at a predetermined interval T2 as shown in FIG.
Voltage ■1l (Vs1 to V, 7) is read and stored. At the same time, the microcomputer 14 reads the rotational speed KN8 of the starter motor 6 corresponding to the crankshaft rotational speed detected by the crank angle sensor 17 (F-4), and thereafter corresponds to the rotational speed NII as shown in FIG. The load current of the starter motor 6 stored in advance in the ROM 2 is read out in this manner (F-5), and the resistance value R of the internal resistance 2 of the battery 1 is calculated based on the following calculation formula.

R= (Vo V8n) / 1. In (in this formula, n indicates the nth memory data) Next, the sum of the internal resistance values determined by n calculations is calculated, and the average value of the inner Hm resistance values is calculated based on the following formula.・Ru (F-7).

r; ΣR/ n In this way, the average internal resistance value r of battery 1
When the error occurs, 7 lag F is set to 1 to indicate that the calculation of the internal resistance average value has been completed.

After starting the engine, when it is determined in step CF-, 2) that the operation of the stark motor 6 has ended, the contents of the counter n are set to zero ( That is, n-0) F
-9), in step (F-1n) flag FL is set to 5
It is determined whether the position is φ or not. As a result, 1 in 7 lag F
If it is, it is assumed that the internal resistance average value has already been calculated, and compare the internal resistance average value r of the battery 1 obtained in step (F, -7) with the deterioration limit resistance value rQ stored in advance in the ROM 21. F-11), resulting in r)'r
(If it is 1, it is determined that there is an abnormality in the battery 1, and the microcomputer 14 outputs a flash signal and the alarm 23 issues an alarm. Thereafter, when the engine is started next time, the internal resistance 2 average value r In order to be able to perform calculations, set zero to flag F (F13) and set internal resistance r to zero (F-14).Meanwhile, step (F-1
In o), if flag F is not set to 1, the microcomputer 14 erases the previously stored terminal voltage of battery 1 terminal 3, and the terminal voltage at that time, that is, battery open rj!
1 voltage is stored (F-15).

In this way, the difference VO-Ver between the battery terminal voltage V before starter motor operation, that is, before cranking, and the battery terminal voltage 8 during cranking is determined, and the rotation speed of the crankshaft is detected and based on that rotation speed. The starter load current I8 corresponding to the rotational speed N8 of the starter motor during cranking is calculated from both of them, and the average value r of the battery internal resistance is calculated from the internal resistance value rk. . In comparison, the internal resistance value r is the deterioration limit resistance value r.

When the value exceeds 1, it is determined that there is an abnormality in the battery 1 and an alarm is issued, so that the occupant can easily know the abnormality of the battery from the alarm. In addition, the microcomputer, crank angle sensor, etc. used in the alarm system of the present invention have already been used in various engine control systems, so they can be used instead of the conventional ones. As in, h'j m never approaches or separates.

(e) As described in detail, the present invention measures the battery terminal voltage before starter operation and the battery terminal voltage during cranking, calculates the difference between them, and measures the crankshaft Detect the rotation speed of the motor, calculate the starter load current corresponding to the rotation speed of the starter motor during cranking based on the rotation speed, and calculate the average value of the internal resistance from both of these. The internal resistance value is compared with a predetermined deterioration limit resistance value as a deterioration standard, and if the internal resistance value exceeds the deterioration limit resistance value, it is determined that there is an abnormality in the battery and an alarm is issued. Through the special report, Kamigai can easily find out about the abnormality of the battery. Further, since no new sensor is required to carry out the present invention, the configuration of the sensor does not become complicated as in the past, which is preferable from the viewpoint of cost.

[Brief explanation of the drawing]

FIG. 1 is an overall diagram showing the structure of the battery abnormality alarm device according to the present invention, FIG. 2 is a block diagram of an embodiment of the battery abnormality alarm device according to the present invention, and FIG. A flowchart is shown to explain the operation of the alarm device shown in Fig. 2, Fig. 4 is a characteristic diagram showing the relationship between the rotational speed of the series motor and the load current, and Fig. 5 shows the sampling situation of the battery terminal voltage. It is a diagram. DESCRIPTION OF SYMBOLS 1...Battery, 2...Equilateral internal resistance of the battery, 3...One terminal of the battery, 4...Starter unit, 5-...Starter relay, 6...Starter motor, 14... Microcomputer, 17... Crank angle sensor,
21... ROM, 22... RAM, 23... Information device special i'F/1iFA person Nissan Motor Co., Ltd. Attorney Hiroo Tsuchi Suzuki Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] A battery terminal voltage measuring means for measuring a battery terminal voltage before starter motor operation and a battery terminal voltage during cranking, a crankshaft rotation speed detection means for detecting a crankshaft rotation speed, and a crankshaft rotation speed detection means for detecting a crankshaft rotation speed. battery internal resistance calculation means for calculating an internal resistance value of the battery from a difference between the starter load current and the voltage between the two battery terminals, which is determined based on the characteristics of the rotational speed of the starter motor and the load current, which are preset based on the characteristics; Comparing means for comparing a battery internal resistance value and a deterioration limit resistance value predetermined as a deterioration standard, and outputting an alarm signal when the battery internal resistance value exceeds the deterioration limit resistance value; and a 01J alarm signal. MW that issues an alarm based on
1. An abnormality warning device for a battery, characterized in that it has means.