JP2586173B2 - Charging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Regarding a charging device suitably applicable to electric vehicles and the like, there is provided a charging device capable of recognizing that a contact abnormality such as a welding accident of a contact in a magnet switch has occurred. For this purpose, the opening and closing of the contacts is controlled by a control signal from a control device, and accordingly, a magnet switch for controlling the energization / de-energization of the battery is provided, and the magnet is provided in the control device. Data storage means for storing data corresponding to the voltage between the terminals of the battery immediately before the excitation of the drive coil of the switch is released; and data storage between the terminals of the battery after a lapse of a predetermined time after the excitation of the drive coil of the magnet switch is released. Data detection means for detecting data corresponding to the voltage,
Data comparison means for comparing the data obtained by the data detection means with the data read from the data storage means, so that the comparison means can determine whether the contacts of the magnet switch are normal or abnormal. Characteristic charging device.

[Industrial applications]

The present invention relates to a charging device that can be suitably applied to an electric vehicle and the like.

[Conventional technology]

Some electric vehicles such as forklifts are equipped with a charging device. The charging device includes a transformer, a rectifier circuit, a magnet switch for opening / closing an electric circuit, a plug for connecting the charging device to an external three-phase AC power supply, and the like.

Each phase voltage from the three-phase AC power supply introduced through the plug is configured to be applied to the transformer via the magnet switch, and the voltage dropped by the transformer is converted to DC by the rectifier circuit. And applied to the battery. The battery is housed in a housing provided below the driver's seat.

ON / OFF of the magnet switch is controlled by a control signal provided from a control device via a timer unit. The control device has a display panel for displaying various states, such as charging or ending, with LEDs or the like, and is installed in a place that is easy to see from the driver's seat.

A CPU, a ROM, and the like are provided in the control device, and a program having a flow as shown in FIG. 4 is written in the ROM. The CPU is a voltage at which the voltage between the terminals of the battery reaches about 80% of the rated voltage when the charging of the battery is in progress (hereinafter, referred to as a turning point voltage).
Are investigating whether or exceeds the (step S _1). If the terminal voltage of the battery does not exceed the rolling pole voltage repeats execution of Step S _1. In the meantime, the battery is being charged, and the voltage between its terminals gradually increases. Then, when the terminal voltage of the battery exceeds the rolling pole voltage to start the final timer for determining the end of charging (step S _2). Predetermined time has elapsed, the final timer when the time is up, turns off the magnet switch (Step S _3). As a result, the power supply to the transformer is cut off, and the charging of the battery is completed.

[Problems to be solved by the invention]

By the way, since the magnet switch opens and closes a large current path, it is likely that the contacts are welded and the electric circuit is not actually cut off even though the magnet switch is de-energized. May occur. In such a case, although the charging of the battery should have been already completed, the charging is actually continued, and as a result, the battery is overcharged. As a result, the life of the battery is significantly shortened, resulting in an economic loss. In addition, there is a problem that it is very dangerous if an electric circuit is interrupted when the electric circuit is touched because the electric circuit is interrupted.

In view of the foregoing, an object of the present invention is to provide a charging device capable of recognizing that a contact abnormality such as a welding accident of a contact in a magnet switch has occurred.

[Means for solving the problem]

FIG. 1 is a principle configuration diagram for explaining the present invention. In FIG. 1, each phase voltage from the three-phase AC power supply is configured to be applied to a transformer in the AC / DC converter 3 via contacts 2a, 2b, and 2c of the magnet switch 1, respectively. The magnet switch 1 is controlled by a magnet switch driving circuit 5 provided in a control device 4. The magnet switch 1 responds to a change in the state of excitation and non-excitation of a driving coil 6 by the magnet switch driving circuit 5. Contact 2
Opening / closing of a, 2b, 2c is controlled. The magnet switch drive circuit 5 receives a control signal from the data processor 8.

The DC voltage of the AC / DC converter 3 is applied to a battery 7 and is input to an analog input terminal of an A / D converter in the data processor 8. The data processor 8 has a CPU, which is configured to be able to write data corresponding to the voltage between the terminals of the battery 7 immediately before the excitation of the drive coil 6 is released to the data storage means 9. is there.

Then, the data processor 8 controls the driving coil 6
Is operated as data detecting means for detecting data corresponding to the voltage between the terminals of the battery 7 after a lapse of a predetermined time after the excitation is released. Further, a comparison means 10 for comparing the data obtained by the data detection means with the data read from the data storage means 9 is provided, and a signal obtained by the comparison means 10 sounds a buzzer or a chime (not shown). Is used as a signal for controlling The contacts 2a, 2b, and 2c of the magnet switch 1 are of a type that is closed when the drive coil 6 is excited and is opened when the excitation is released. It is also possible to use a magnet switch of the type in which the contacts are opened when excited and closed when the excitation is released. In that case, the relationship of the displacement of the contact point to the excitation / non-excitation of the drive coil in the above description is reversed.

[Action]

The data storage means 9 corresponds to the voltage between the terminals of the battery 7 just before the time required to complete the charging of the battery 7 elapses, that is, just before the excitation of the drive coil 6 is released. Is stored. Data corresponding to the voltage between the terminals of the battery 7 after a lapse of a predetermined time after the excitation of the drive coil 6 is released is obtained from the data detection means. The data and the data read from the data storage means 9 are as follows. The comparison is performed by the comparing means 10.

The voltage across the terminals of a battery that has just completed charging is
At the initial stage, it has a property of rapidly falling until a certain voltage is settled. Therefore, if the contacts 2a, 2b, 2c of the magnet switch 1 are normal, the data is stored in the data storage means 9. The numerical value of the existing data is larger than the numerical value of the data obtained by the data detecting means.

However, the contacts 2a of the magnet switch 1,
When abnormalities such as welding occur in 2b and 2c, actually, the charging is not completed and is still continued, so that there is almost no difference between the numerical values of the two data.

Therefore, based on these differences, the contacts 2a, 2b,
When there is an abnormality in 2c, the output state of the comparing means 10 can be changed. With this change, control can be performed so that a buzzer or a chime (not shown) sounds, whereby it is possible to recognize that an abnormality has occurred in the contacts of the magnet switch.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a circuit diagram of a charging device for explaining an embodiment of the present invention. In the figure, terminals T, S, and R of a plug 11 connected to a three-phase AC power supply line are connected to the primary winding of a transformer 12 via contacts 2a, 2b, and 2c of a magnet switch 1, respectively. One end of the drive coil 6 of the magnet switch 1 is connected to the terminal R of the plug 11, and the other end of the drive coil 6 is connected to the drive coil of the thermal relay 13.
14 and the contacts in the timer unit 15
Is connected to the terminal S of FIG. Thus, the drive coil 14
When the timer unit 15 times out, the excitation is released. The terminal R of the plug 11 is also connected to the timer unit 15.

A plurality of rectifying diodes are connected to the secondary winding of the transformer 12, and the DC voltage rectified by these diodes is applied to the battery 7 via the fuse 16.

The control device 4 has a microcomputer control system (MCS) 17 and a display panel 18 for displaying various states such as charging or completion of charging with LEDs or the like, so that it can be easily seen from the driver's seat. It is installed in.

The voltage between the terminals of the battery 7 is input to an analog input terminal of an A / D converter in the MCS 17. The MCS 17 has a CPU, and the CPU
The data corresponding to the voltage between the terminals of the battery 7 immediately before the excitation is released can be written in the memory.

The MCS 17 outputs a control signal to a control input terminal of the timer unit 15 so that the start operation of the timer unit 15 can be controlled. Then, the A / D converter detects data corresponding to a voltage between terminals of the battery 7 after a lapse of a predetermined time after the excitation of the drive coil 6 is released.

The MCS 17 has a ROM in which a program having a flow as shown in FIG. 3 is written. The CPU
When the charging of the battery 7 is in progress, the terminal voltage of the battery 7 is checked whether exceeds the rolling pole voltage (Step S _10). If the voltage between the terminals of the battery 7 does not exceed the inversion point voltage,
Repeating the execution of S _10. During this time, the battery 7 is being charged, and the voltage between its terminals gradually increases. Eventually, when the voltage between the terminals of the battery 7 exceeds the inversion point voltage, a control signal is output from the MCS 17 to the control input terminal of the timer unit 15 that determines the end of charging, and the timer unit 15 is started (step S _11). Predetermined time has elapsed, the timer unit 15 writes data corresponding to the terminal voltage of the battery 7 to the verge of times up to the memory (step S _12). In addition,
Since the time at which the timer unit 15 times up is known in advance, the MCS 17 also has a program for measuring the time, and the time is managed by this.

When the timer unit 15 times out, the magnet switch is turned off. Next, another timer program is executed and waits for, for example, 5 minutes (step
S _13). Detecting data corresponding to the elapsed after the terminal voltage of the battery 7 in this time (step S _14). Next, to determine whether to both by comparing the data written in the detected data and the step S ₁₂ for example there is a difference of more than 1V (step S _15). As a result, if there is a difference of 1 V or more, the process ends normally. The difference is to warn that there is abnormal to the contact of the magnet switch 1 by a buzzer or chime, not shown in the case is less than 1V (step S _16).

〔The invention's effect〕

As described above in detail, according to the present invention, abnormalities such as welding of the contacts of the magnet switch, which cannot be known with the conventional charging device, can be recognized and can be dealt with. Therefore, it is possible to prevent the battery from being overcharged due to such a failure. Further, without being aware of such a failure, there is no danger of touching a circuit that is energized and causing an electric shock.

[Brief description of the drawings]

FIG. 1 is a principle configuration diagram illustrating the present invention, FIG. 2 is a circuit configuration diagram of a charging device illustrating an embodiment of the present invention, and FIG. 3 is a control flow for knowing an abnormality of a contact point of a magnet switch. FIG. 4 is a flowchart showing a control flow in a conventional charging device. 1 ... magnet switch, 4 ... control device, 8 ... data processor, 9 ... data storage means, 10 ... comparison means.

Claims (2)

(57) [Claims] An opening / closing of a contact is controlled by a control signal from a control device, and a magnet switch for controlling energization / de-energization of a battery is thereby provided. A driving coil of the magnet switch is provided in the control device. Data storage means for storing data corresponding to the terminal voltage of the battery immediately before the excitation of the battery is released, and corresponding to the terminal voltage of the battery after a lapse of a predetermined time after the excitation of the drive coil of the magnet switch is released. Data detecting means for detecting data; and data comparing means for comparing data obtained by the data detecting means with data read from the data storage means. A charging device characterized in that abnormality can be determined. 2. The control device according to claim 1, further comprising a magnet switch for controlling opening and closing of the contact by a control signal from the control device, thereby controlling energization / de-energization of the battery. Data storage means for storing data corresponding to the voltage between the terminals of the battery immediately before exciting the battery, and data corresponding to the voltage between the terminals of the battery after a lapse of a predetermined time after exciting the drive coil of the magnet switch. Data detecting means for detecting, and data comparing means for comparing the data obtained by the data detecting means with the data read from the data storing means, wherein the comparing means determines whether the contact of the magnet switch is normal or abnormal. A charging device characterized in that it can be determined.