JP2000206215A - Power source diagnostic device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power source diagnostic device for a vehicle which performs abnormal deterioration diagnosis of a battery, by grasping a present terminal voltage and a current of the battery in a vehicle when the vehicle is started and while the vehicle is driven, and comparing the terminal voltage and the current with previously stored characteristic values of the battery when abnormality is generated. SOLUTION: A power source diagnostic device 1 for a vehicle consists of a current detecting means 3, a terminal voltage detecting means 4, a terminal voltage monitoring means 5, an abnormality judging means 6, a current restricting means 7, an abnormality warning means 8, a battery 2, an ignition switch 9, a backup power source 10, and a generator 11. Characteristic values of the battery when abnormality is generated are previously stored, and abnormality is judged by comparison with the characteristic values.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the characteristics of a battery in the event of an abnormality in a battery before starting the vehicle and when starting the vehicle or during operation of the vehicle, ascertaining the current battery current and voltage in the vehicle. A power supply diagnostic device for a vehicle capable of performing a failure deterioration diagnosis in comparison with a value.

[0002]

2. Description of the Related Art A conventional battery diagnosis method disclosed in Japanese Utility Model Laid-Open No. 1-67584 discloses a method of connecting a battery for diagnosis for a few seconds to a battery at many gas stations and car repair shops nationwide. It is known that the battery is discharged and the voltage of the terminal of the battery is compared with a reference battery terminal voltage to determine the quality.

A conventional battery diagnosis method disclosed in Japanese Patent Publication No. 1-39069 detects a battery discharge current and a battery terminal voltage during a large current discharge, and generates an electromotive force of the battery based on the detected values. And a short-circuit current, and substitutes this into a function representing the correlation between the maximum output and the remaining battery capacity experimentally obtained in advance to calculate the current remaining battery capacity. It is known to make predictions about the time of replacement.

FIG. 17 is a characteristic diagram showing a correlation between a battery discharge current and a terminal voltage for calculating a remaining battery charge in a conventional battery diagnosis method. In FIG. 17, the horizontal axis indicates the discharge current Ib, the vertical axis indicates the terminal voltage Vb of the battery, and the solid line a indicates the measured discharge characteristics (Vb-Ib characteristics).

In a discharge region of a large current, such as during starter driving (cranking), the discharge characteristics can be approximated by a straight line. Further, the electromotive force Eo of the battery is obtained from the value of Ib = 0 of the discharge characteristic approximated by the straight line, and the dead short current Is obtained by short-circuiting the battery is the value of Vb = 0 of the discharge characteristic approximated by the straight line. Required from.

The dead short current Is and the electromotive force Eo
Is multiplied by 4 to obtain a value Po that is four times the maximum power that can be extracted from the battery, and can be expressed by the area of the portion b. Further, the area of the portion c is Po / 4, which corresponds to the maximum output of the battery, and this area is the remaining capacity of the battery. The remaining battery capacity is used to prevent the battery from running out and to predict the time for replacement.

[0007]

The conventional battery diagnosis performed at many gas stations and car repair shops nationwide has a problem that the diagnosis cannot be made unless the user goes to a specific place having the diagnostic equipment, which is inconvenient. . In addition, there is a problem that the current battery capacity cannot be grasped when starting the vehicle and while driving the automobile, and it is not possible to cope with a running obstacle due to a shortage of the battery capacity.

FIG. 18 is a characteristic diagram showing a correlation between the discharge current of two batteries and the terminal voltage in the conventional battery diagnosis method. In FIG. 18, the conventional battery diagnosis method for detecting the battery discharge current and the battery terminal voltage during the large current discharge calculates the remaining capacity from the electromotive voltage and the short-circuit current of the battery. For example, a state where the deteriorated battery is charged at the end of the charge-discharge cycle (battery 1) and a state where the electromotive voltage is small and the short-circuit current is large, for example, the charge-discharge cycle is early but the depth of discharge is deep (battery 2) It cannot be distinguished from the remaining capacity of the battery.

Here, for example, the load current IL of the vehicle is
When taken out of the battery, battery 1 and battery 2
Then, the terminal voltage of the battery 1 is EL1, the terminal voltage of the battery 2 is EL2, the terminal voltage of the battery 2 is higher than the terminal voltage of the battery 1, and the terminal voltage has a difference (EL2>
EL1) occurs.

[0010] For example, the minimum operating voltage of a certain control device is Vth
Then, since the terminal voltage EL2 of the battery 2 is higher than the minimum operating voltage Vth (EL2> Vth), the battery 2 can be operated.
The battery 1 has a problem that a terminal voltage EL1 is lower than the minimum operating voltage Vth (EL1 <Vth), and there is a problem in that a control device that cannot operate becomes available.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to grasp the current terminal voltage and current of a battery in a vehicle before starting the vehicle and when starting the vehicle or while driving the vehicle. It is another object of the present invention to diagnose a battery abnormality or deterioration by comparing with a previously stored characteristic value of the battery at the time of abnormality.

[0012]

Means for Solving the Problems To solve the above-mentioned problems, the abnormality determining means of the vehicle power supply diagnostic apparatus according to the present invention comprises:
A storage means for storing a boundary value when the battery is abnormal is provided in advance, and the abnormality is determined based on the boundary value when the battery is abnormal, the terminal voltage value, and the discharge current value.

The abnormality determination means according to the present invention includes storage means for storing in advance a boundary value when the battery is abnormal, and determines abnormality based on the boundary value at the time of abnormality, the terminal voltage value and the discharge current value. Therefore, it is possible to warn the driver of a battery abnormality before or during traveling.

Further, the abnormality determining means according to the present invention is characterized in that, when the ignition switch is turned on and the electric component is not activated, when the terminal voltage value detected by the terminal voltage detecting means falls below a predetermined value, an abnormality is determined. It is characterized by determining.

[0015] The abnormality determining means according to the present invention, when the electrical component is not activated when the ignition switch is turned on,
When the terminal voltage value detected by the terminal voltage detection means falls below a predetermined value, it is determined that the battery is abnormal, so it is possible to detect deterioration and abnormality of the battery before starting the engine, and warn the driver of the abnormality of the battery. Can be.

Further, the abnormality determining means according to the present invention comprises:
A timer is provided, and when the terminal voltage value detected by the terminal voltage detecting means falls below a predetermined value within the time set by the timer at the time of cranking for starting the engine, it is determined that an abnormality has occurred.

The abnormality judging means according to the present invention includes a timer. When the terminal voltage value detected by the terminal voltage detecting means falls below a predetermined value within the time set by the timer during cranking for starting the engine, the abnormality judging means is provided. Therefore, the deterioration and abnormality of the battery during engine start can be detected, and the driver can be warned of the abnormality of the battery before traveling.

Further, the abnormality determining means according to the present invention is characterized in that the battery terminal voltage when the vehicle is left unattended is detected by the terminal voltage detecting means, and when the terminal voltage value falls below a predetermined value, it is determined that there is an abnormality. .

The abnormality determining means according to the present invention detects the battery terminal voltage when the vehicle is left unattended by the terminal voltage detecting means, and determines that the battery voltage is abnormal when the terminal voltage value falls below a predetermined value. It is possible to detect the discharged state of the battery before traveling after forgetting to turn off the light.

Further, the abnormality determining means according to the present invention comprises:
The terminal voltage of the battery when the vehicle is left unattended is detected by the terminal voltage detecting means, and the terminal voltage value is stored in the storage means.

The abnormality determining means according to the present invention detects the terminal voltage of the battery when the vehicle is left unattended by the terminal voltage detecting means,
Since the terminal voltage value is stored in the storage means, the voltage state of the battery when the vehicle is not used can be detected at the time of starting the vehicle,
The driver can be warned of the possibility of running out of battery when the load increases.

Further, the storage means according to the present invention uses a nonvolatile storage element.

Since the storage means according to the present invention uses a nonvolatile storage element, the terminal voltage value that changes can be written or erased, and the stored contents will not be lost even when the power supply is stopped. Therefore, even if the engine is started by an engine jump start from the outside and the generator starts to generate power and the terminal voltage rises, a warning that the terminal voltage has been low can be issued simultaneously with the start, and the running vehicle It is possible to prevent the battery from running down due to an increase in the load.

Further, the storage means according to the present invention is characterized in that the storage can be erased, for example, when the battery is replaced.

The storage means according to the present invention is capable of storing and erasing data at the time of battery replacement, for example. Therefore, when the state at the time of battery replacement changes, it is easy to store and delete the state before battery replacement and store a new state. it can.

Further, the power supply diagnostic device for a vehicle according to the present invention includes a switching circuit for switching to a rechargeable backup power supply so that the terminal voltage detecting means and the abnormality determining means operate reliably when the terminal voltage of the battery drops. It is characterized by having.

The vehicle power supply diagnosis device according to the present invention includes the switching circuit for switching to the rechargeable backup power supply so that the terminal voltage detection means and the abnormality determination means operate normally when the terminal voltage of the battery drops. There is no state in which the terminal voltage detecting means and the abnormality determining means cannot operate, and the abnormality of the battery can be detected and stored at any time. Therefore, even when the battery completely rises and the engine is started from outside by an engine jump start, a battery abnormality warning can be issued at the time of the start.

Furthermore, the vehicle power supply diagnostic device according to the present invention is characterized in that when the abnormality determining means determines abnormality of the battery and failure of the generator for charging the battery, the current limiting device limits the current supply to the electric load of the vehicle. Means are provided.

The power supply diagnostic device for a vehicle according to the present invention is characterized in that when the abnormality of the battery and the failure of the generator for charging the battery are determined by the abnormality determining device, the current limiting device for limiting the current supply to the electric load of the vehicle. It is possible to operate the minimum necessary control device for running the vehicle.

The power supply diagnostic device for a vehicle according to the present invention is applied to an electric power steering device, and has control means for reducing the amount of assist acting on the steering system when the battery is abnormal or the generator fails. It is characterized by.

The power supply diagnostic device for a vehicle according to the present invention is applied to an electric power steering device, and has a control means for acting on the steering system when the battery is abnormal to reduce the assist amount, so that the current consumption from the power supply is greatly reduced. Can be reduced.

Further, the vehicle power supply diagnostic device according to the present invention is applied to a vehicle variable steering angle ratio steering device, and is characterized by comprising control means for switching the steering angle ratio when the battery is abnormal.

The power supply diagnostic device for a vehicle according to the present invention is applied to a variable steering angle ratio steering device for a vehicle. The control means for switching the steering angle ratio when the battery is abnormal can greatly reduce the current consumption from the power supply. it can.

[0034]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the present invention grasps the current terminal voltage and current of the battery in the vehicle before the vehicle is started, when the vehicle is started, or during the operation of the vehicle, and diagnoses abnormal deterioration of the battery.

FIG. 1 is an overall configuration diagram of a vehicle power supply diagnostic device according to the present invention. In FIG. 1, a vehicle power supply diagnosis device 1 includes a current detection unit 3, a terminal voltage detection unit 4, an abnormality determination unit 6, a current limit unit 7, an abnormality warning unit 8, a battery 2, an ignition switch 9, and a backup power supply 1.
0, a generator 11, and a diode 20.

The current detection means 3 includes, for example, a differential amplifier comprising an operational amplifier and a current detection resistor, A
/ D conversion means and the like, and the battery terminal voltage Vb supplied through the battery 2 and the ignition switch 9
The voltage drop generated by the current flowing through the current detection resistor is differentially amplified based on the current, and the current can be obtained from the relationship between the output voltage value and the current detection resistor, and the output voltage value is converted into a digital value. And further converts the current value into a corresponding current value and supplies it to the abnormality determination means 6 as the detected current signal Id.

FIG. 2 shows an embodiment of the current detecting means. 2, the current detecting means 3 includes resistors R1 to R4.
, A detection resistor Rd, a differential amplifier 30 for outputting the detected output voltage Ea, and current conversion means 29 for converting the output voltage Ea to a corresponding current value.

In the configuration of FIG. 2, when the detection voltage Vi across the detection resistor Rd and the input of the differential amplifier 30 are set as shown in FIG. 2, the output voltage Ea of the differential amplifier 30 is expressed by the following equation (1). You.

[0039]

Ea = (R2 / R1) * Vi

Here, R1 to R4 are resistors, Rd is a detection resistor, Ea is an output voltage, and Vi is a detection voltage across the detection resistor Rd. Further, in Equation 1, the resistance R1 and the resistance R3 are equal (R1 = R3), and the resistance R2 and the resistance R4 are equal (R2 =
R4) represents the relationship between Ea and Vi. Further, the output voltage Ea is set to R1 so that it becomes less than 5V (Ea <5V).
And R2 are set. As a result, the terminal current Ib is converted into a detection current signal Id.

The terminal voltage detecting means 4 comprises an operational amplifier, an inverting amplifier circuit composed of a resistor, A / D converting means, and the like. The terminal voltage Vb of the battery supplied from the battery 2 through the ignition switch 9 is: Since the output voltage of the inverting amplifier can be calculated from the resistance and the output voltage of the inverting amplifier, the output voltage of the inverting amplifier is converted into a digital value, and the terminal voltage Vb of the battery is determined as the terminal voltage signal Vd. 6

The terminal voltage detecting means 4 is used to detect the state of the battery when the vehicle is left unattended (half-door, long-term leaving, forgetting to turn off the light, etc.). Even if the ignition switch is turned off, the terminal voltage Vc of the battery is detected. Is detected. The terminal voltage Vc of the battery when the ignition switch is off is supplied to the abnormality determining means 6 as a terminal voltage signal Ve.

The abnormality judging means 6 is composed of various arithmetic circuits, processing circuits, signal generating circuits, memories and the like based on a microprocessor, and includes a correlation calculating means, a timer, an abnormality judging means, a memory erasing means and the like. Also, the abnormality determination means 6
Determines the battery as abnormal by comparing the detected current signal Id and the terminal voltage signal Vd detected by the current detecting means 3 and the terminal voltage detecting means 4 with the boundary value of the abnormal battery stored in the storage circuit. Then, the abnormal signal Kc is supplied to the current limiting means 7 and the abnormal warning means 8. Further, the abnormal signal Kc continues to be output until the battery is replaced.

The current limiting means 7 is constituted by a switching device such as a relay and a transistor. When the abnormality determining means 6 determines that the battery is abnormal, the abnormality determining means 6 supplies an abnormal signal Kc, and the current limiting means 7 operates while the vehicle is running. Current limiting signal Kd for interrupting current to electrical equipment (audio, air conditioner, navigation, etc.) that does not hinder current supply.
Is output.

Further, when the generator abnormality signal Ke is input from the generator 11, the current limiting means 7 causes little trouble even if the current supply is limited during running of the vehicle by the generator abnormality signal Ke. It outputs a current limiting signal Kd for interrupting current to electrical equipment (audio, air conditioner, navigation, etc.).

The abnormality warning means 8 is composed of a logic circuit which becomes a binary state such as a flip-flop and a lamp capable of displaying a visual indication, and the like. An abnormal signal Kc is supplied,
The logic circuit is started by this abnormal signal Kc, and a lamp is attached to display an abnormal state. Once this state is activated, it does not recover even if the terminal voltage Vb of the battery returns, and continues to issue a warning until it is released using a dedicated warning release unit (not shown).

Further, when the generator abnormality signal Ke is input from the generator 11, the abnormality warning means 8 activates a logic circuit in response to the generator abnormality signal Ke and turns on a lamp to indicate an abnormal state.

As the battery 2, a lead-acid battery containing a chargeable electrolyte is often used, and a 12V or 24V battery is used. The purpose of using the battery is to supply sufficient electric power to the starter when the engine is started. However, when the starter is operated, a large current is required to be discharged in a short time. As the discharge current increases, the voltage drop of the terminal voltage at the initial stage of the discharge increases, and the time required to reach the discharge end voltage also sharply decreases.

The backup power supply 10 is a battery intended to be used as a small-capacity backup power supply. The terminal voltage Vc of the battery 2 is reduced and the terminal voltage detection means 4 and the abnormality determination means of the vehicle power supply diagnosis device 1 are used. 6 is used in order to prevent the storage function of the storage unit 6 from becoming inoperable due to a voltage drop.
When c decreases, the terminal voltage detection means 4 and the abnormality determination means 6 can automatically switch to the backup power supply 10 by means of diodes incorporated therein, and the terminal voltage Vf of the backup power supply can be automatically switched to the terminal voltage detection means 4 and the abnormality determination means. 6 The diode 20 is a backflow prevention diode provided on the charging line of the backup power supply 10.

The generator 11 includes a generator driven by the engine, a rectifier, a backflow prevention diode, a regulator, a generation voltage abnormality detection circuit, etc., and rectifies an AC voltage generated by the generator to a DC voltage. In addition, the output voltage is controlled to be constant by a regulator to supply a direct current to the battery 2 and the battery 10 as a charging current, and a diode is internally connected to prevent a backflow of the current from the battery 2 and the battery 10. . Further, if there is an abnormality in the generated voltage by a generated voltage abnormality detection circuit (not shown) inside the generator, the generator abnormal signal K
e is output to the current limiting means 7 and the abnormality warning means 8.

FIG. 3 is a block diagram of a main part of the abnormality judging means according to the present invention. In FIG. 3, the abnormality determining means 6
Is composed of a comparison determining means 14, a storage means 15, a timer 16, and a storage erasing means 18. The comparison determining means 14 is composed of a microprocessor, various arithmetic units, a timer, a plurality of comparators, etc., and detects the detected current signal Id from the current detecting means 3.
Based on the simultaneous input of the terminal voltage signal Vd from the terminal voltage detection means 4 and the characteristic signal Hk supplied from the storage means 15, the characteristic signal Hk is compared with the characteristic signal Hk. The current is supplied to the current limiting means 7 and the abnormality warning means 8.

When the ignition switch 9 is turned on and the electrical components have not been started yet, the comparison determination means 14 inputs the terminal voltage signal Vd detected by the terminal voltage detection means 4 and stores the signal in advance. Set in the means 15;
The ignition switch 9 is compared with a predetermined voltage value when the ignition switch 9 is turned on. When the ignition switch 9 is lower than the predetermined value, it is determined that an abnormality has occurred.
c is supplied to the current limiting means 7 and the abnormality warning means 8.

Further, the comparison / determination means 14 inputs the terminal voltage signal Vd detected by the terminal voltage detection means 4 at the time of cranking of the engine start, and starts the timer from the input and when a predetermined time elapses. Of the terminal voltage signal Vd of
It is compared with a predetermined characteristic signal Hk supplied from the storage means 15, and when it is lower than this, the abnormal signal Kc is determined.
Is supplied to the current limiting means 7 and the abnormality warning means 8.

The characteristic signal Hk represents a boundary value signal of an abnormal value of the battery, a predetermined voltage signal when the ignition switch 9 is turned on, a battery voltage signal input from the terminal voltage detecting means 4, and the like.

The storage means 15 is constituted by a storage circuit such as a RAM or a ROM, and has a boundary value of a battery abnormal value inputted in advance, a predetermined voltage signal when the ignition switch 9 is turned on, and a terminal voltage detection means 4. The terminal voltage signal Ve and the like supplied from are stored. Further, the storage means 15 matches the timing when the detected current signal Id from the current detection means 3 and the terminal voltage signal Vd from the terminal voltage detection means 4 are simultaneously supplied to the comparison / determination means 14 to match the timing of the battery. The characteristic signal Hk of the boundary value of the abnormal value is supplied to the comparison determination means 14. Further, the storage unit 15 supplies the characteristic signal Hk at the time of turning on the ignition switch to the comparison determination unit 14 in response to the start signal Bc from the timer 16.

The timer 16 is constituted by a programmable timer capable of setting a predetermined time. When the cranking for starting the engine is started, the timer is started by a signal of an ignition switch, and outputs a start signal Bc after a lapse of a predetermined time.

The storage erasing means 18 comprises a non-lock switch, and one side is grounded. When the non-lock switch is pressed during battery replacement, the storage erasing unit 18 outputs a ground signal Hi to the storage unit 15 and resets the terminal voltage signal Ve stored in the storage unit 15 to a predetermined value.

FIG. 4 is a boundary characteristic diagram of an abnormal or normal battery according to the present invention. In FIG. 4, when the terminal voltage value and the battery current value within the range surrounded by the boundary characteristic C are detected, the battery is abnormal. The boundary characteristic C is
This is a boundary value characteristic calculated based on a battery voltage and a battery current when a large current (for example, cranking at the time of engine start or energization of a rear defogger) is taken out from the battery and when the IGSW is turned on.

The storage means 15 stores the value of the boundary characteristic C, and detects the detected current signal Id from the current detecting means 3 and the terminal voltage signal Vd from the terminal voltage detecting means 4.
Is compared with the battery current value and the terminal voltage value (boundary characteristic C) stored in the storage means 15 in advance, and when the detected value falls below the value stored in the storage means 15, it is determined that an abnormality has occurred. .

The determination of whether the battery is normal or abnormal is as follows.
It is performed at a fixed timing, but is always performed when the engine is started or when the rear defogger is energized within a predetermined time after the IGSW is turned on.

FIG. 5 is a characteristic diagram of the on / off state of the ignition switch according to the present invention and the terminal voltage of the battery. 5A shows the on / off state of the ignition switch, and FIG. 5B shows the terminal voltage when the ignition switch is on / off. Is determined.

When the ignition switch 9 is turned on, the battery terminal voltage signal Vb when no electrical components are activated is detected by the terminal voltage detecting means 4, and the detected battery terminal voltage signal Vd is determined to be abnormal. The comparison is made by the comparison / determination means 14 of the means 6, compared with the characteristic signal Hk from the storage means 15, and when it is smaller than the predetermined value Vg, it is determined that the battery is abnormal.

FIG. 6 is a characteristic diagram of the battery terminal voltage at the time of engine starting cranking according to the present invention. In FIG. 6, the terminal voltage Vb of the battery at the time of cranking is detected by the terminal voltage detecting means 4, and this value is compared by the comparing and judging means 14 of the abnormality judging means 6, and within a predetermined time (tc), the storing means 15 Value V determined from characteristic signal Hk from
When it becomes x or less, it is determined that the battery is abnormal. In this characteristic diagram, state A is a characteristic diagram when a normal battery is used, and state B is a deteriorated abnormal battery at the end of a charge / discharge cycle, for example.

FIG. 7 is a characteristic diagram of the on / off state of the ignition switch and the terminal voltage of the battery when the vehicle is left unattended (half door, forgetting to turn off the light, etc.) according to the present invention. 7A is a diagram in which an ignition switch is turned on and off, FIG. 7B is a diagram of a characteristic of a battery load current when, for example, forgetting to turn off a headlight, and FIG. FIG.

As shown in FIG. 7, when the ignition switch 9 is turned off, for example, if the user forgets to turn off the headlight, the battery current continues to flow, and as a result, the terminal voltage of the battery decreases. Even when the ignition switch 9 is turned off, the battery terminal voltage is detected and stored by the terminal voltage detection means 4 and the storage means 15.

Here, when the battery terminal voltage falls below the predetermined value Vy, the terminal voltage detecting means 4 and the storing means 15 cannot operate. Therefore, the terminal is switched to the backup power supply and the terminal voltage detecting means 4 and the storing means 15 operate normally. This ensures that the battery terminal voltage can be stored. When the battery terminal voltage falls below the predetermined value Vy, a lamp is provided in the abnormality warning means 8 when the next ignition switch 9 is turned on to display an abnormal state and a warning is issued.

Even when the battery is over-discharged to the extent that the engine cannot be started, and even when the engine is started by a jump start from the outside, the stored data of the previous battery state that the battery terminal voltage has fallen below the predetermined value Vy is read. However, a lamp is provided in the abnormality warning means 8 to display an abnormal state and issue a warning. Once this warning is issued, it does not stop even if the battery voltage returns, and continues to be issued until it is canceled using a warning canceling device (not shown).

FIG. 8 is a basic configuration diagram of an embodiment in which the vehicle power supply diagnostic device according to the present invention is used for a variable steering angle ratio steering device. Further, the steering device is provided with an electric power steering device 97. Then, an auxiliary torque corresponding to the steering torque is applied to the rack shaft. 8, a variable steering angle ratio steering device 41 includes a steering wheel 44, a steering shaft 45, a universal joint 46,
The input shaft 47 and the output shaft (pinion) 48 of the variable steering angle ratio mechanism 65, and the rack shaft 4 that engages with the pinion of the output shaft 48
9, a steering wheel 50, and a vehicle power supply diagnostic device 1.

The variable steering angle ratio steering device 41 constitutes a motor system of the drive system of the variable steering angle ratio mechanism 65 and a sensor system of the variable steering angle ratio mechanism 65, and detects the actual steering angle ratio. The vehicle includes a steering angle ratio sensor 52 that converts the actual steering angle ratio CJ into an electric actual steering angle ratio CJ, and a vehicle speed sensor 51 that detects the vehicle speed V of the vehicle.

Further, the variable steering angle ratio steering device 41 includes a steering angle ratio control means 54 which is a control system of the variable steering angle ratio mechanism 65,
A steering angle ratio motor M2 as a drive system is provided.

When the driver operates the handle 44,
The rotation angle according to the steering angle is the steering shaft 4
5 and through the universal joint 46 to the input shaft 47 of the variable steering angle ratio mechanism 65.

On the outer periphery of the input shaft 47, there is provided a movable housing (not shown) which rotates about the center (O) while eccentrically moving the center (A) of the input shaft 47. This movable housing is provided with a steering angle ratio motor M2. Worm gear (not shown) connected to
To rotate. The amount of displacement of the movable housing rotated by the worm gear is detected by the steering angle ratio sensor 52, and an electric signal corresponding to the amount of displacement is transmitted to the steering angle ratio control means 54 as an actual steering angle ratio signal CJ of the variable steering angle ratio mechanism 65. Supply. Further, an electric signal corresponding to the vehicle speed detected by the vehicle speed sensor 51 is supplied to the steering angle ratio control means 54 as a vehicle speed signal V.

The steering angle ratio control means 54 outputs a target steering angle ratio signal CS corresponding to the vehicle speed signal V supplied from the vehicle speed sensor 51.
Is generated, the motor voltage VM2 is controlled based on the deviation (CS-CJ) between the target steering angle ratio signal CS and the actual steering angle ratio signal CJ, and the steering angle ratio motor M2 is PWM-driven through the worm gear. To rotate the movable housing to control the actual steering angle ratio signal CJ and the target steering angle ratio signal CS to be equal.

The steering angle ratio control means 54 generates a target steering angle ratio signal CS1 corresponding to the abnormal signal Kc supplied from the vehicle power supply diagnostic device 1, and converts the target steering angle ratio signal CS1 to the target steering angle signal CS1. Ratio signal CS and a deviation (CS) from the actual steering angle ratio signal CJ.
-CJ), the motor voltage VM2 is controlled, and when there is an abnormality in the battery and the power supply, the steering wheel rotation angle with respect to the rack stroke increases.

The target steering angle ratio signal CS defines a target ratio of the steering angle (β) of the steered wheels 50 to the steering angle (α) of the steering wheel 44. When the steering angle (α) is set to 60 degrees while the signal CS is set to 0.5, the turning angle (β) is a target value that is set to 30 degrees.

The actual steering angle ratio signal CJ is a value actually embodied by the variable steering angle ratio mechanism 65 when the target steering angle ratio signal CS is set by the vehicle speed signal V. The rotational motion of the pinion of the output shaft 48 with respect to the actual steering angle (α) is converted into the linear motion of the rack shaft 49, and the steering wheels 50
Is the ratio of the actual turning angle (β) when turning.

FIG. 9 is a block diagram of a main part of an embodiment in which the vehicle power supply diagnosis device according to the present invention is used for a variable steering angle ratio steering device. In FIG. 9, the variable steering angle ratio steering device 4
1 is a vehicle speed sensor 51, a steering angle ratio sensor 52, a steering angle ratio control means 54, a variable steering angle ratio mechanism 65, a steering angle ratio motor M2,
And a vehicle power supply diagnostic device 1. The vehicle speed sensor 51 is
The vehicle speed is converted into an electric signal and supplied to the steering angle ratio control means 54 as a vehicle speed signal V.

The steering angle ratio sensor 52 is constituted by a displacement sensor or the like. The steering angle ratio motor M2 detects the displacement amount TM of the variable housing that rotates with the rotation of the worm gear of the variable steering angle ratio mechanism 65. The displacement amount TM is supplied to the variable steering angle ratio mechanism 65, and the variable steering angle ratio mechanism 65 outputs a mechanical position signal Pj.
Is supplied to the steering angle ratio sensor 52, converts this mechanical position signal Pj into an electric signal, and supplies it as an actual steering angle ratio signal CJ to the deviation calculating means 62 of the steering angle ratio control means 54.

The steering angle ratio control means 54 is composed of various arithmetic means, processing means, memory, analog circuits and the like based on a microprocessor, and includes a target steering angle ratio setting means 61, a deviation calculation means 62, a steering angle ratio drive control. Means 63, and a steering angle ratio motor driving means 64.

The target steering angle ratio setting means 61 is constituted by a memory such as a ROM, and includes a vehicle speed signal V-target steering angle ratio CS data shown in FIG. 10 determined in advance based on design values and experimental values, and an abnormal signal Kc. Is stored, and when the vehicle speed signal V is supplied from the vehicle speed sensor 51, the corresponding target steering angle ratio CS data is read out and the target steering angle ratio signal CS is supplied to the deviation calculating means 62. I do.

When the abnormality signal Kc is supplied from the vehicle power supply diagnosis device 1, the target steering angle ratio setting means 61 reads out the target steering angle ratio CS1 data smaller than the normal target steering angle ratio CS and outputs the target steering angle ratio CS1. The steering angle ratio signal CS1 is supplied to the deviation calculating means 62 as the target steering angle ratio signal CS to change the steering angle ratio. As a result, the steering torque is reduced, so that the assist torque generated by the electric power steering device is reduced, and the current consumption in the electric power steering device can be suppressed.

When the abnormal signal Kc is supplied, the steering angle ratio control means 54 does not generate the target steering angle ratio signal CS corresponding to the vehicle speed signal V, even if the vehicle speed signal V is present, and outputs the abnormal signal Kc.
Is generated, and the steering wheel rotation angle with respect to the rack stroke is increased. At this time, since the target steering angle ratio signal CS1 is constant irrespective of the vehicle speed signal V, it is not necessary to drive the steering angle ratio motor M2 while the abnormal signal KC is being output, thereby suppressing current consumption. it can.

The target steering angle ratio signal CS represents the ratio (βS / α) of the target turning angle βS of the steered wheels 50 to the steering angle α of the steering wheel 44 shown in FIG. 8, as shown in FIG. ,
It is set to decrease as the vehicle speed signal V increases. In addition, the actual steering angle ratio signal CJ is a ratio of the actual steering angle βJ of the steered wheels 50 to the steering angle α of the steering wheel 44 (βJ /
α).

FIG. 11 is a characteristic diagram of the rack stroke and the steering wheel rotation angle of the variable steering angle ratio steering apparatus. In FIG. 11, when the vehicular power diagnosis device 1 is normal, the steering angle ratio is set such that the steering wheel steering angle is 180 degrees to 360 degrees on one side and the rack is fully stall on one side. Then, the steering angle ratio setting is changed such that the steering wheel steering angle is 540 degrees on one side and the rack is fully stall on one side.

As described above, when the vehicular power supply diagnostic device 1 detects an abnormality, the abnormality warning means 8 warns the abnormality and the variable steering angle ratio steering device 41 reduces the steering angle ratio from that in the normal case, and the electric power is diagnosed. The power consumption of the electric power steering device is suppressed by reducing the assist amount by the power steering device.

The deviation calculating means 62 has a subtraction function, and the target steering angle ratio signal C supplied from the target steering angle ratio setting means 61 is provided.
A deviation ΔC (= CS−CJ) between S and the actual steering angle ratio signal CJ supplied from the steering angle ratio sensor 52 is calculated, and the deviation signal ΔC is supplied to the steering angle ratio drive control means 63.

The steering angle ratio drive control means 63 includes a PID (proportional / integral / differential) controller, a PWM signal, an ON signal,
The drive control signal V02 is constituted by a control signal generating means for generating a hybrid signal of the OFF signal, and the drive control signal V02 is changed based on the deviation signal ΔC supplied from the deviation calculation means 62.
4

The steering-ratio-ratio motor driving means 64 is composed of four FETs (field-effect transistors) or IGBTs (insulated gate bipolar transistors) having a relatively small power capacity. Based on the drive control signal V02 supplied from 63, a PWM (pulse width modulation) motor voltage VM2 is generated to drive the steering angle ratio motor M2 by PWM to rotate the steering angle ratio motor M2 forward or reverse. .

The steering angle ratio control means 54 supplies a negative feedback (NFB) by supplying the actual steering angle ratio signal CJ from the steering angle ratio sensor 52 to the deviation calculating means 62.
k) Form control.

This negative feedback (NFB: Negative Feedbac)
By the k) control, the variable steering angle ratio mechanism 65 allows the deviation ΔC (= C) between the target steering angle ratio signal CS and the actual steering angle ratio signal CJ in a short time.
S-CJ) becomes 0, and the actual steering angle ratio signal CJ matches the target steering angle ratio signal CS (CJ = CS). For example, when the steering angle ratio is 0.5
If the handle 44 shown in FIG.
When the steering wheel 50 is turned by 30 degrees (steering angle 30 °), the steered wheels 50 follow and rotate by 15 degrees (steering angle 15 °).

The principle of the variable steering angle ratio steering device 41 will be described with reference to FIG. FIG. 12 is a diagram illustrating the operation principle of the variable steering angle ratio steering device according to the present invention. In FIG. 12, A
The point is the center of rotation of the input shaft 47. As described above, the movable housing is rotated by driving the steering angle ratio motor M2 based on the target steering angle ratio signal (CS) corresponding to the vehicle speed signal V. Can be moved in the X1 direction or the X2 direction.

Point B is the center of rotation of the output shaft 48, and point C is located at a position eccentric from point B by a certain distance.
If the relationship of points is compared to a millstone, point C is the action point and point B is the center of the millstone. Since the rotation of point A is transmitted to point C,
Assuming that the distance from the point A to the point A is b and the distance from the point B to the point C is b, the relationship between the steering angle α and the rotation angle γ of the pinion is expressed by Equation 2. The turning angle β is represented by β = K * γ (K: constant).

[0093]

## EQU2 ## b * sin γ = (b * cos γ−a) * tan α

Although FIG. 12 shows the case where the steering wheel 44 is turned clockwise (right steering), the same applies to the case where the steering wheel 44 is turned counterclockwise (left steering). The specific configuration of the variable steering angle ratio steering device 41 is as follows.
As known from Japanese Patent Application Laid-Open No. 7-257406,
Detailed description is omitted.

FIG. 13 is a characteristic diagram of the steering angle α-rotation angle γ of the pinion of the variable steering angle ratio mechanism according to the present invention. In FIG. 13, the rotation angle γ of the pinion with respect to the steering angle α is, for example, a distance a = aO from the point B to the point A in a low vehicle speed region.
If (= 0), the ratio between the rotation angle γ of the pinion and the steering angle α is 1.

When the vehicle speed is in the middle vehicle speed range, the ratio between the pinion rotation angle γ and the steering angle α (steering angle ratio) is smaller than 1 when the distance a from the point B to the point A is a = a1.

Further, when the vehicle speed is in a high vehicle speed region, the vehicle speed is changed from the point B to the point A.
At the point distance a = a2, the ratio of the pinion rotation angle γ to the steering angle α (steering angle ratio) becomes a value smaller than 1.

As described above, the variable steering angle ratio steering device 41 sets the pinion rotation angle γ (resulting in the turning angle β) with respect to the steering angle α as the vehicle speed changes from a low vehicle speed to a high vehicle speed. , A fast steering characteristic is obtained, and a stable steering characteristic is obtained at a high vehicle speed.

The variable steering ratio steering device 41 changes the pinion rotation angle γ with respect to the steering angle α using the vehicle speed as a parameter by changing the distance a from point B to point A by the steering angle ratio motor M2. , But the abnormal signal Kc
Is supplied, the distance a is set to a fixed value a = a3 (a3> a2). Therefore, even if the vehicle speed changes, the distance a does not change. Therefore, the steering angle ratio motor M2 is not driven, so that the current consumption is reduced. Can be suppressed.

FIG. 14 is a basic configuration diagram of an embodiment in which the vehicle power supply diagnostic device according to the present invention is used for an electric power steering device. In FIG. 14, the electric power steering device 31 includes a vehicle speed sensor 93, a steering torque sensor 92, an electric motor driving unit 35, an electric motor 36, an electric motor torque signal detecting unit 37, a control unit 38, and a vehicle power supply diagnosis device 1. Also, the electric power steering device 31
Is connected to a pinion 76a of a rack & pinion mechanism 76 provided in a steering gear box 75 via a connecting shaft 74 provided with universal joints 74a and 74b to a steering shaft 73 provided integrally with the steering wheel 72. To constitute the manual steering force generating means 77.

Rack teeth 78a meshing with the pinion 76a
The rack shaft 78 which reciprocates by meshing with them connects left and right front wheels 80 as rolling wheels to both ends thereof via tie rods 79.

Thus, the steering wheel 7
At the time of 2 steering, the front wheels 8 are driven by manual steering via a normal rack & pinion type manual steering force generating means 77.
Rolling 0 changes the direction of the vehicle.

In order to reduce the steering force by the manual steering force generating means 77, the motor 36 for supplying the steering assist force is disposed coaxially with the rack shaft 78, and the ball screw mechanism 91 provided coaxially with the rack shaft 78. And acts on the rack shaft 78 (ball screw shaft 91a).

In the steering gear box 75,
A steering torque sensor 92 for detecting the direction and magnitude of the driver's manual steering torque is provided.
Provides a control means 38 with a steering torque signal Ts of an analog electric signal corresponding to the detected steering torque. The vehicle speed sensor 93 detects an electric pulse signal having a frequency corresponding to the speed of the vehicle, and outputs the vehicle speed signal Vs to the control unit 38.
To provide.

The control means 38 is composed of various arithmetic means, processing means, signal generating means, memory, etc. based on a microprocessor. The motor control signal VO (for example, a motor control signal VO) corresponding to the steering torque signal Ts using the vehicle speed signal Vs as a parameter. An ON signal, an OFF signal, and a PWM signal) are generated to control the driving of the motor driving means 35.

The control means 38 reads out the target torque signal IT1 data corresponding to the abnormal signal Kc supplied from the vehicle power supply diagnostic device 1, sets the target torque signal IT1 as the target torque signal IT, To limit the motor current.

The motor driving means 35 is constituted by a bridge circuit using four switching elements such as, for example, FETs (field effect transistors). The motor control means comprises a switch on / off signal and a PWM signal provided by the control means 38. In the signal VO, two pairs of Fs, each pair of two on the diagonal,
By controlling the drive of each pair of ETs, the voltage value and direction of the motor voltage VM supplied to the motor 36 are set. The direction of the motor voltage VM is determined according to the polarity of the motor control signal VO output from the control means 38.

The motor torque signal detecting means 37 differentially amplifies the voltage drop of the motor current IM flowing through a current detecting element (for example, a resistor) connected in series with the motor 36,
The motor current signal IMO corresponding to the amplified output is supplied to the control means 38.

Incidentally, the motor torque signal detecting means 37
The motor current IM detected by the current detecting element (for example, a resistor) is converted into a motor current signal IMO and fed back to the control means 38 (negative feedback) to form a feedback path of a steering control system.

FIG. 15 is a block diagram showing a main part of an embodiment in which the vehicle power supply diagnosis device according to the present invention is used for an electric power steering device. In FIG. 15, the electric power steering device 31 includes a control unit 38, an electric motor driving unit 35, an electric motor 36, and an electric motor torque signal detecting unit 3.
7. The vehicle power supply diagnostic device 1 is provided.

The steering torque signal T is obtained by a steering torque sensor constituted by a displacement sensor using a differential transformer or the like.
The steering torque applied to the steering wheel 72 shown in FIG. 14 is converted into an electric signal and supplied to the control means 38. The vehicle speed signal V detected by the vehicle speed sensor is
It is supplied to the control means 38.

The motor torque detecting means 37 includes a motor 36
A corresponding motor torque signal IMT is generated from the motor current IM flowing through the motor, and the motor torque signal IMT is supplied to the control means 38.

The control means 38 comprises various arithmetic means based on a microprocessor, processing means, a memory, an analog circuit and the like, and includes a target torque signal setting means 32, a deviation calculation means 33, and a drive control means 34.

The target torque signal setting means 32 is composed of a memory such as a ROM, and has a normal steering torque signal T using a vehicle speed signal V as a parameter determined in advance based on design values and experimental values as shown in FIG. -The target torque signal IT data and the steering torque signal T at the time of abnormality corresponding to only the steering torque signal T-The target torque signal IT1 data are stored, and the steering torque signal T and the vehicle speed signal V are supplied. The normal target torque signal IT data is read, and the target torque signal IT is supplied to the deviation calculating means 33.

Further, when the abnormal signal Kc is supplied from the vehicle power supply diagnostic device 1, the target torque signal setting means 32
The target torque signal IT1 data at the time of abnormality corresponding to the steering torque is read, and the target torque signal IT1 is supplied to the deviation calculating means 33 as the target torque signal IT to limit the motor current.

When the abnormal signal Kc is supplied, the control means 38 supplies the target torque signal IT data in the normal state corresponding to the steering torque signal T and the vehicle speed signal V even if the steering torque signal T and the vehicle speed signal V are supplied. , The target torque signal IT1 at the time of abnormality corresponding to only the steering torque signal T
Is generated, and the target torque signal IT1 is
It is supplied to the deviation calculating means 33 as T to reduce the assist amount acting on the steering system.

As described above, when the vehicle power supply diagnosis device 1 detects an abnormality, the abnormality warning means 8 warns the abnormality and controls the power steering to reduce the assist amount for reducing the steering force. In addition, the current consumption from the power supply system is greatly reduced.

The deviation calculating means 33 has a subtraction function, and a deviation ΔI (= IT−IT) between the target torque signal IT supplied from the target torque signal setting means 32 and the motor torque signal IMT supplied from the motor torque detecting means 37. IMT) and supplies the deviation signal ΔI to the drive control means 34.

The drive control means 34 comprises a PID (proportional / integral / differential) controller, a motor control signal generating means for generating a hybrid signal of a PWM signal, an ON signal and an OFF signal, and the like. When ΔI is supplied, the deviation signal ΔI is subjected to PID (proportional / integral / differential) control, and a motor control signal VO1 which is a composite signal of a PWM signal, an ON signal, and an OFF signal is supplied to the motor driving means 35.

The motor driving means 35 comprises four FETs (field effect transistors) or IGs having a large power capacity.
A drive control signal V01 which is constituted by a BT (insulated gate bipolar transistor) or the like and is supplied from the drive control means 34
, A PWM (pulse width modulation) motor voltage VM1 is generated, and the motor 36 is PWM-driven to rotate the motor 36 forward or reverse.

As described above, when the vehicular power supply diagnostic device is abnormal, the variable steering angle ratio steering device is controlled to change the steering angle ratio to reduce the assist amount of the electric power steering device, or to control the electric power steering device. Is reduced to limit the current consumption of the battery.

[0122]

As described above, the abnormality judging means of the power supply diagnostic device for a vehicle according to the present invention includes the storage means for preliminarily storing the boundary value when the battery is abnormal. It is possible to determine an abnormality based on the voltage value and the discharge current value, warn the driver of a battery abnormality before or during traveling, and prevent a sudden engine stall or a vehicle control device from stopping functioning. it can.

Further, the abnormality determining means according to the present invention determines that an abnormality has occurred when the terminal voltage value detected by the terminal voltage detecting means has fallen below a predetermined value when the electrical component is not activated when the ignition switch is turned on. However, the deterioration and abnormality of the battery can be detected before the engine is started, the driver can be warned of the abnormality of the battery, and the running out of the battery during traveling can be prevented in advance.

Furthermore, the abnormality determining means according to the present invention
A timer is provided, and when the terminal voltage value detected by the terminal voltage detection means falls below a predetermined value within a predetermined time during cranking of the engine start, it is determined that an abnormality has occurred. Can be detected, the driver can be warned of a battery abnormality before traveling, and the running out of battery during traveling can be prevented in advance.

Further, the abnormality determining means according to the present invention detects the battery terminal voltage when the vehicle is left unattended by the terminal voltage detecting means and determines that the battery voltage is abnormal when the terminal voltage value falls below a predetermined value. The battery discharge state can be detected before traveling after doors and lights have been turned off, etc.), and the driver can be warned of the possibility of a dead battery when the load increases, and sudden engine stalls and vehicle control devices function. Stoppage can be prevented.

The abnormality determining means according to the present invention detects the terminal voltage of the battery when the vehicle is left unattended by the terminal voltage detecting means.
Since the terminal voltage value is stored in the storage means, the voltage state of the battery when the vehicle is not used can be detected at the time of starting the vehicle,
The driver can be warned of the possibility of running out of battery when the load increases.

Further, since the storage means according to the present invention uses a nonvolatile storage element, it is possible to write or erase a terminal voltage value which changes, and the stored contents are not erased even when the power supply is stopped. Thus, it is possible to detect the state of discharge of the battery and warn the driver of the possibility of running out of the battery when the load increases, and to prevent sudden engine stall or stoppage of the function of the vehicle control device.

Further, since the storage means according to the present invention can be stored and erased when the battery is replaced or the like, it is easy to record in a new state when the state is changed by the battery replacement.

Further, the vehicle power supply diagnosis apparatus according to the present invention includes a switching circuit for switching to a rechargeable backup power supply so that the terminal voltage detection means and the abnormality determination means operate normally when the terminal voltage of the battery drops. Therefore, there is no state in which the terminal voltage detecting means and the abnormality determining means cannot operate, the abnormality of the battery can be detected and stored at any time, and the discharge state of the battery can be detected before traveling, and the battery when the load increases can be detected. It is possible to reliably warn the driver of the possibility of climbing and to prevent sudden engine stall or stoppage of the function of the vehicle control device.

Further, the power supply diagnostic device for a vehicle according to the present invention has a current limiting device for limiting a current supply to an electric load of a vehicle when abnormality of the battery and failure of a generator for charging the battery are determined by the abnormality determining means. By this means, it is possible to operate the minimum necessary control device for running the vehicle, and it is possible to prevent the battery from running down while the vehicle is running.

Further, the vehicle power supply diagnosis device according to the present invention is applied to an electric power steering device, and the current consumption from the power supply is greatly reduced by a control means for reducing the amount of assist acting on the steering system when the battery is abnormal. The battery can be prevented from running out while the vehicle is running.

Further, the power supply diagnostic device for a vehicle according to the present invention is applied to a variable steering angle ratio steering device for a vehicle, and current consumption from the power supply can be greatly reduced by control means for switching the steering angle ratio when the battery is abnormal. In addition, it is possible to prevent the battery from running down while the vehicle is running.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a vehicle power supply diagnostic device according to the present invention.

FIG. 2 is a configuration diagram of an embodiment of a current detection unit.

FIG. 3 is a block diagram of a main part of an abnormality determination unit according to the present invention.

FIG. 4 is a boundary characteristic diagram of an abnormal or normal battery according to the present invention.

FIG. 5 is a characteristic diagram of an on / off state of an ignition switch and a terminal voltage of a battery according to the present invention.

FIG. 6 is a characteristic diagram of a battery terminal voltage at the time of engine starting cranking according to the present invention.

FIG. 7 is a characteristic diagram of an on / off state of an ignition switch and a terminal voltage of a battery at the time of leaving the vehicle (half door, forgetting to turn off a light, etc.) according to the present invention;

FIG. 8 is a basic configuration diagram of an embodiment of a vehicle steering device using the vehicle power supply diagnostic device according to the present invention for a variable steering angle ratio steering device;

FIG. 9 is a block diagram of a main part of an embodiment in which the vehicle power supply diagnosis device according to the present invention is used for a variable steering angle ratio steering device.

FIG. 10 shows vehicle speed signal V-target steering angle ratio CS data

FIG. 11 is a characteristic diagram of a rack stroke and a steering wheel rotation angle of a steering device of a vehicle.

FIG. 12 is an explanatory view of the operation principle of the variable steering angle ratio steering device according to the present invention.

FIG. 13 shows a steering angle α- of the variable steering ratio mechanism according to the present invention.
Pinion rotation angle γ characteristic diagram

FIG. 14 is a basic configuration diagram of an embodiment in which the vehicle power supply diagnosis device according to the present invention is used for an electric power steering device.

FIG. 15 is a block diagram of a main part of an embodiment in which the vehicle power supply diagnostic device according to the present invention is used in an electric power steering device.

FIG. 16 is a characteristic diagram of the steering torque signal T-target torque signal IT1 when the vehicle power supply diagnostic device is normal and abnormal.

FIG. 17 is a characteristic diagram showing a correlation between a battery discharge current and a terminal voltage for calculating a remaining battery charge in a conventional battery diagnosis method.

FIG. 18 is a characteristic diagram showing a correlation between discharge currents and terminal voltages of two batteries in a conventional battery diagnosis method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vehicle power supply diagnostic device, 2 ... battery, 3 ... current detection means, 4 ... terminal voltage detection means, 6 ... abnormality determination means, 7 ...
Current limiting means, 8: abnormality warning means, 9: ignition switch, 10: backup power supply, 11: generator, 1
4 ... Comparison judgment means, 15 ... Storage means, 16 ... Timer, 1
8: memory erasing means, 20: diode, 29: current converting means, 38, 55 ... control means, 41: variable steering angle ratio steering device, 31, 43, 97 ... electric power steering device,
54... Steering angle ratio control means.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Yamawaki 1-4-1 Chuo, Wako-shi, Saitama Pref. Honda Research Institute, Inc. (72) Inventor Katsuji Watanabe 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (Reference) 2G016 CA03 CB05 CB11 CB12 CB21 CC04 CC06 CC15 CC27 CC28 CD14 CE00 5G003 BA01 EA06 EA08

Claims (11)

[Claims] 1. A terminal voltage detecting means for detecting a terminal voltage of a battery mounted on a vehicle, a current detecting means for detecting a discharging current of the battery, and detecting an abnormality based on the detected terminal voltage value and discharging current value. Abnormality determining means for determining,
In the vehicle power supply diagnostic device, the abnormality determination means includes storage means for previously storing a boundary value at the time of abnormality of the battery, and based on the boundary value at the time of abnormality, the terminal voltage value, and the discharge current value. A power supply diagnosis device for a vehicle, wherein the power supply diagnosis device determines an abnormality by performing the determination. 2. The abnormality determination means determines that an abnormality has occurred when the terminal voltage value detected by the terminal voltage detection means has become equal to or less than a predetermined value when the electrical component is not activated when an ignition switch is turned on. 2. The method according to claim 1, wherein
The power supply diagnostic device for a vehicle according to the above. 3. The abnormality determination means includes a timer, and when the terminal voltage value detected by the terminal voltage detection means falls below a predetermined value within a time set by a timer during cranking of engine start, The power supply diagnosis device for a vehicle according to claim 1, wherein the power supply diagnosis device determines that the abnormality is abnormal. 4. The abnormality determination means detects a terminal voltage of the battery when the vehicle is left unattended by the terminal voltage detection means,
2. The power supply diagnosis apparatus for a vehicle according to claim 1, wherein when the terminal voltage value becomes equal to or less than a predetermined value, it is determined that there is an abnormality. 5. The abnormality determination means detects a terminal voltage of the battery when the vehicle is left unattended by the terminal voltage detection means,
The power supply diagnostic device for a vehicle according to claim 1, wherein the terminal voltage value is stored in a storage unit. 6. The power supply diagnostic device for a vehicle according to claim 5, wherein said storage means uses a nonvolatile storage element. 7. The vehicle power supply diagnostic device according to claim 1, wherein the storage means erases the storage when the battery is replaced. 8. A rechargeable backup power supply, and a switching circuit for switching to a backup power supply so that at least the terminal voltage detection means and the abnormality determination means operate normally when the terminal voltage of the battery drops. The power supply diagnostic device for a vehicle according to claim 1, wherein: 9. A current limiting means for limiting current supply to an electric load of a vehicle when abnormality of the battery and failure of a generator for charging the battery are detected by abnormality determination means. The vehicle power supply diagnostic device according to claim 1. 10. The vehicle according to claim 1, further comprising control means applied to an electric power steering apparatus, wherein the control means reduces an assist amount acting on a steering system when the battery is abnormal or the generator fails. Power supply diagnostic device. 11. Applicable to a variable steering angle ratio steering device for a vehicle,
2. A control means for switching a steering angle ratio when the battery is abnormal and when the generator fails.
The power supply diagnostic device for a vehicle according to the above.