JP2002152915A - Starting system for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain quick start in starting of an electric vehicle. SOLUTION: This starting system 10 comprises a door switch 12 for predicting whether driving will be conducted, a precharging circuit 18 and a discharging circuit 20 for performing charging and discharging into/from a capacitor 16 in a load 14, and a control means 22 for charging the capacitor 16 via the precharging circuit 18, when driving is predicted y the door switch 12. When a driver turns on an ignition switch 34, the capacitor 16 is charged fully, so that immediate starting can be made.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting system for quickly charging a load capacitor when starting an electric vehicle. The “electric vehicle” here includes a hybrid electric vehicle in addition to a pure electric vehicle.

[0002]

2. Description of the Related Art A large-capacity capacitor for absorbing noise and fluctuations in power supply voltage is connected to a load centered on a motor. In a conventional electric vehicle, when a driver turns on a key switch, precharging of a capacitor in a load starts, and after completion of the precharging, a main relay is turned on to be in a running state. Therefore, the time required for charging the capacitor, that is, 5 to 10 seconds, is required from when the key switch is turned on to when the vehicle can run. When the key switch is turned off at the time of stop, the capacitor in the load is immediately discharged. Therefore, at the next start-up, since the operation starts again from the precharge operation, it is not possible to start immediately after the key switch is turned on.

[0003]

A prior art for solving such a problem is disclosed in Japanese Patent Laid-Open No. 9-1495.
No. 09 discloses this. In this prior art, when a key is inserted into a key cylinder in a driver's seat, precharging of a capacitor is started without turning on a key switch. As a result, the time from inserting the key into the key cylinder to turning on the key switch can be shortened. However,
The inconvenience has not been solved, since the time is only a few seconds.

[0004]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a starting system for an electric vehicle which enables a quick start at the time of starting.

[0005]

SUMMARY OF THE INVENTION A starting system for an electric vehicle according to the present invention comprises a traveling predicting means for predicting whether or not to travel, and a charging / discharging means for charging and discharging a capacitor in a load. And control means for charging the capacitor via the charging / discharging means when the running is predicted by the running prediction means (claim 1).

[0006] When a driver opens a door, for example, from outside the vehicle, it means that most of the driver intends to travel. Therefore, traveling can be predicted by opening the door. The control means according to the present invention charges the capacitor at a stage where traveling is predicted before the key switch is turned on. Therefore, when the driver turns on the key switch, since the capacitor is already sufficiently charged, the driver can start immediately.

Further, the control means may discharge the capacitor via the charging / discharging means if the starting key switch is not turned on for a predetermined time after the traveling is predicted by the traveling prediction means. Item 2).

[0008] Even if the driver opens the door from outside the vehicle, for example,
It does not always run. For example, there is a case where luggage is taken out of the vehicle or a case where the user enters the vehicle and takes a rest. In such a case, if the capacitor is kept charged, power is consumed to maintain the state. Therefore, if the key switch does not turn on for a certain period of time even if traveling is predicted, by discharging the capacitor,
Power saving can be achieved.

Further, the control means may discharge the capacitor via the charging / discharging means when the key switch for starting is turned off and the running is no longer predicted by the running predicting means. 3).

[0010] Even if the key switch for starting is turned off,
It does not always stop. For example, there is also a case where the vehicle travels again after a short rest in the vehicle. In such a case, if the capacitor is discharged at the same time as the key switch is turned off, when the vehicle tries to run again, it starts charging the capacitor after the key switch is turned on. Would. Therefore, the capacitor is not discharged only when the key switch is turned off, and is discharged after traveling is no longer predicted. Thus, even if the key switch is turned off and then turned on again, the vehicle can immediately start.

Further, the control means discharges the capacitor via the charging / discharging means when a predetermined time has elapsed since the start key switch was turned off, even if the running was predicted by the running prediction means. (Claim 4).

[0012] Even if the starting key switch is turned off and the running is predicted, the running is not always performed immediately. For example, there is a case where the user takes a long rest in the car. In such a case, if the capacitor is kept charged for an excessively long time, the power for maintaining that state cannot be overlooked. Therefore, even if traveling is predicted, after a certain period of time, the capacitor is discharged to save power.

The traveling prediction means can be realized by a door switch for detecting opening and closing of a door, a sensor for detecting that a person is sitting on a seat, a sensor for detecting that a person has entered a vehicle, and the like ( Claims 5-7).

[0014]

FIG. 1 is a block diagram showing an embodiment of an activation system according to the present invention. Hereinafter, description will be made based on this drawing.

The starting system 10 according to the present embodiment includes a door switch 12 as travel prediction means for predicting whether or not to travel, and charge / discharge means for charging and discharging a capacitor 16 in a load 14. Precharge circuit 18 and discharge circuit 20 and the door switch 12
Control means 22 (a part of the function of the controller 24) for charging the capacitor 16 via the precharge circuit 18 when the running is predicted.

The control means 22 also has the following three functions. . If the ignition switch 34 is not turned on for a predetermined time after the travel is predicted by the door switch 12, the capacitor 16 is discharged via the discharge circuit 20. . Ignition switch 3
When the switch 4 is turned off and the travel is no longer predicted by the door switch 12, the capacitor 16 is discharged via the discharge circuit 20. . If a certain time has passed since the ignition switch 34 was turned off,
The capacitor 16 is discharged through the discharge circuit 20 even if the traveling is predicted by the door switch 12.

The controller 24 has many functions in addition to the function as the control means 22 of the activation system 10. Hereinafter, the description of portions not directly related to the activation system 10 will be simplified. Description of many of the resistors will be omitted.

The controller 24 includes a CPU (microcomputer) 26 containing various programs,
The power supply unit 28 as a low-voltage power supply for the power supply 26, the transistors TR1 to TR7 operating as switches, the diodes D1 to D5 for backflow prevention, and the power supply unit 2
8 is provided with a relay RY or the like for supplying the relay RY. The CPU 26 has input terminals I1, I2, I3 and output terminals O1, O2,
O3 and O4 are provided.

On the input side of the controller 24, in addition to the door switch 12, a low-voltage battery 30, a room lamp 32 which is turned on when the door is opened and turned off when the door is closed, and an ignition switch 34 as a key switch for starting. Etc. are provided. The door switch 12 is closed when the door is opened, and is opened when the door is closed.

On the output side of the controller 24, in addition to the precharge circuit 18 and the discharge circuit 20, a high-voltage battery 36, a contactor 38 for supplying the power of the battery 36 to the load 14, a battery 36 and a capacitor 16 Is provided with a voltage detector 40 for detecting the voltage of. The precharge circuit 18 includes a relay 181 for charging the capacitor 16, a resistor 182 for limiting the charging current, and the like. The discharge circuit 20 includes a relay 201 for discharging the capacitor 16, a resistor 202 for consuming the discharge current, and the like.

An input terminal I1 of the CPU 26 inputs a signal corresponding to opening and closing of the door, that is, opening and closing of the door switch 12. When the door is opened, the door switch 12 is closed, the transistors TR1 and TR2 are turned on, and the diode D4 is turned on, so that a low-level voltage is input to the input terminal I1. Conversely, when the door is closed, the door switch 12 is opened, the transistors TR1 and TR2 are turned off, and the diode D4 is turned off, so that a high-level voltage is input to the input terminal I1. C
The input terminal I2 of the PU 26 is connected to the ignition switch 34.
Input a signal corresponding to the opening and closing of. When the ignition switch 34 is open, the transistor TR3 is turned off and the diode D5 is turned off, so that a high-level voltage is input to the input terminal I2. Conversely, when the ignition switch 34 is closed, the transistor TR3 is turned on and the diode D5 is turned on, so that a low-level voltage is input to the input terminal I2. The input terminal I3 of the CPU 26 inputs a signal corresponding to the voltage of the capacitor 16 via the voltage detector 40.

An output terminal O1 of the CPU 26 controls the operation of the contactor 38. When the output voltage of the output terminal O1 is at a high level, the transistor TR5 is turned on and the contactor 3
8 is closed. Conversely, when the output voltage of the output terminal O1 is at a low level, the transistor TR5 is turned off and the contact of the contactor 38 is opened. The output terminal O2 of the CPU 26 controls the operation of the precharge circuit 18. When the output voltage of the output terminal O2 is at a high level, the transistor TR6 is turned on and the contact of the relay 181 is closed. Conversely, the output terminal O2
Is low, the transistor TR6 is turned off and the contact of the relay 181 is opened. An output terminal O3 of the CPU 26 controls the operation of the discharge circuit 20.
When the output voltage of the output terminal O3 is at a high level, the transistor TR7 is turned on and the contact of the relay 201 is closed. vice versa,
When the output voltage of the output terminal O3 is at a low level, the transistor TR7 is turned off and the contact of the relay 201 is opened. CPU
An output terminal O4 of 26 controls the operation of the power supply unit.
When the output voltage of the output terminal O4 is at a high level, the transistor TR4 is turned on, the diode D2 is turned on, and the contact of the relay RY is closed. Conversely, when the output voltage of the output terminal O4 is at a low level, the transistor TR4 is turned off, the diode D2 is turned off, and the contact of the relay RY is opened.

FIG. 2 is a flowchart showing an example of the operation of the starting system 10 at the start of traveling. Less than,
The operation of the controller 24 will be mainly described with reference to FIGS.

First, when the driver opens the door from outside the vehicle to use the car, the door switch 12 is closed, TR1, TR1
2 turns on, the diode D3 conducts, the contact of the relay RY closes, and the power supply unit 28 starts operating, so that the controller 24 also starts operating (steps 101 and 102).
At the same time, by outputting a high-level voltage from the output terminal O4 of the CPU 26, the transistor TR4 is turned on, the diode D2 is turned on, and the contact of the relay RY is kept closed. By outputting a high-level voltage from the output terminal O2 of the CPU 26, the transistor TR6
ON, contact of relay 181 closed, precharge circuit 1
8 is started (step 103). Subsequently, the voltage of the capacitor 16 is input from the input terminal I3 of the CPU 26 via the voltage detection circuit 40, and when this voltage reaches a predetermined value (step 104), the output terminal O2 of the CPU 26
, The operation of the precharge circuit 18 is terminated (step 105).
Subsequently, the contact of the contactor 38 is closed by outputting a high-level voltage from the output terminal O1 of the CPU 26 (step 106).

When the driver turns on the ignition switch 34 (step 108), the transistor TR3 is turned on and the diode D5 is turned on, so that the input voltage at the input terminal I2 of the CPU 26 goes low. As a result, the vehicle enters a runnable state (step 109). The driver turns on the ignition switch 3
When 4 is turned on, since the capacitor 16 has already been charged, the vehicle can start immediately.

On the other hand, if the ignition switch 34 is not turned on even after the time A has elapsed (step 10).
7, 108), the contact of the contactor 38 is opened by outputting a low-level voltage from the output terminal O1 of the CPU 26 (step 110). Subsequently, by outputting a high-level voltage from the output terminal O3 of the CPU 26, the transistor TR7 is turned on, the contact of the relay 201 is closed, and the discharge circuit 20 is operated (step 1).
11). Subsequently, the CPU 26 via the voltage detection circuit 40
The voltage of the capacitor 16 is input from the input terminal I3 of the CPU, and when this voltage reaches a predetermined value (step 112), the CPU
The contact of the relay RY is opened by outputting a low-level voltage from the output terminal O4 (step 11).
3). As a result, the power supply voltage is not supplied from the power supply unit 28, and the operation of the controller 24 ends. Even if the opening / closing of the door is not detected in step 101,
If the ignition switch 34 is turned on, step 1
02 and subsequent processes are executed (step 114).

[0027] Even if the driver opens the door from outside the vehicle, the driver may take out the luggage from the vehicle or enter the vehicle and take a rest. In such a case, if the capacitor 16 is kept charged, power will be consumed to maintain the state. Therefore, if the ignition switch 34 is not turned on even when the time A has elapsed since the driver opened the door, the capacitor 16 is discharged (step 101).
To 107, 110 to 113).

FIG. 3 is a flowchart showing an example of the operation of the starting system 10 at the end of traveling. Less than,
The operation of the controller 24 will be mainly described with reference to FIGS.

First, the driver operates the ignition switch 34.
Is turned off, the transistor TR3 is turned off and the diode D is turned off.
5 becomes non-conductive, and the input voltage of the input terminal I2 of the CPU 26 becomes a high level. As a result, the vehicle becomes incapable of running (step 201). Subsequently, when the driver opens the door from the inside of the vehicle, the door switch 12 is closed, TR1, TR2
On, the diode D4 becomes conductive, and the input voltage of the input terminal I1 of the CPU 26 becomes high level. As a result, it is recognized that the traveling has ended (step 202). Then, CP
By outputting a low-level voltage from the output terminal O1 of U26, the contact of the contactor 38 is opened (step 203). Subsequently, by outputting a high-level voltage from the output terminal O3 of the CPU 26, the transistor T
R7 is turned on, the contact of the relay 201 is closed, and the discharge circuit 20 is operated (step 204). Subsequently, the voltage of the capacitor 16 is input from the input terminal I3 of the CPU 26 via the voltage detection circuit 40, and when this voltage reaches a predetermined value (step 205), the output terminal O4 of the CPU 26
, The transistor TR4 is turned off, the diode D2 is turned off, and the relay R is turned off.
The Y contact is opened (step 206). This allows
Since the power supply voltage is no longer supplied from the power supply unit 28, the operation of the controller 24 ends. Note that the capacitor 16
If the ignition switch 34 is turned on again during the discharge of the current, the process proceeds to step 101 of FIG. 2 (step 207).

The driver operates the ignition switch 34.
When the time B has elapsed since the power supply was turned off, the capacitor 16 is discharged via the discharge circuit 20 even if the driver does not open the door from the inside of the vehicle (step 208). For example, when the capacitor 16 is kept charged for an excessively long time, such as when resting in a vehicle for a long time, it is impossible to overlook the power for maintaining the state. Therefore, even if the traveling is predicted, the power is saved by discharging the capacitor 16 when the time B has elapsed.

It is needless to say that the present invention is not limited to the above embodiment. For example, instead of the door switch 12, the traveling may be predicted by a pressure sensor, a micro switch, or the like that detects that a person is sitting on the seat, or an infrared sensor, an ultrasonic sensor, or the like that detects that a person has entered the vehicle. It may be.

[0032]

According to the starting system for an electric vehicle according to the present invention, the capacitor starts to be charged at the time when traveling is predicted, so that the capacitor is already sufficiently charged when the driver turns on the key switch. Can start immediately.

In addition, if the starting key switch is not turned on for a certain period of time after the running is predicted, the capacitor is discharged to take out luggage from the inside of the vehicle or take a rest in the vehicle. Power consumption can be reduced.

Further, by discharging the capacitor when the starting key switch is turned off and running is no longer predicted, the key switch is turned off and turned off again when the vehicle rests a little in the vehicle and runs again. Even if it is turned on, it can start immediately.

Furthermore, if a certain time has elapsed since the start key switch was turned off, the capacitor is discharged even if the running is predicted, so that unnecessary power consumption such as when the vehicle rests for a long time in the vehicle is reduced. Can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an electric vehicle starting system according to the present invention.

FIG. 2 is a flowchart illustrating an example of an operation at the start of traveling in the activation system of FIG. 1;

FIG. 3 is a flowchart illustrating an example of an operation at the end of traveling in the activation system of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Starting system 12 Door switch (running prediction means) 14 Load 16 Capacitor 18 Precharge circuit (charge / discharge means) 20 Discharge circuit (charge / discharge means) 22 Control means 34 Ignition switch (key switch)

Claims (7)

[Claims] 1. A travel prediction means for predicting whether or not to travel, a charge / discharge means for charging and discharging a capacitor in a load, and a charge / discharge means for predicting travel by the travel prediction means. Control means for charging the capacitor via discharging means; and a starting system for an electric vehicle. 2. The control unit discharges the capacitor via the charging / discharging unit if a start key switch is not turned on for a predetermined time after the traveling is predicted by the traveling prediction unit. Item 7. An electric vehicle starting system according to Item 1. 3. The control means discharges the capacitor via the charging / discharging means when a key switch for starting is turned off and running is no longer predicted by the running prediction means. 3. The starting system for an electric vehicle according to claim 1 or 2. 4. The control means, if a predetermined time has elapsed since the start key switch was turned off, even if the travel was predicted by the travel prediction means, the capacitor was charged via the charge / discharge means. The electric vehicle starting system according to claim 1, wherein the electric vehicle is discharged. 5. The starting system for an electric vehicle according to claim 1, wherein the travel prediction means is a door switch that detects opening / closing of a door. 6. The start-up system for an electric vehicle according to claim 1, wherein said travel prediction means is a sensor for detecting that a person is sitting on a seat. 7. The start-up system for an electric vehicle according to claim 1, wherein said travel prediction means is a sensor for detecting that a person has entered the vehicle.