JPS606599A - Controller for battery forklift - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a patch lift-off control device, and particularly to a batch lift-off control device suitable for a case where a common battery power source is used as a power source for a traveling electric motor and a cargo handling electric motor. .

[Background of the invention]

For example, a seven-battery lift device, which is disclosed in Japanese Unexamined Patent Publication No. 57-2014, which operates two chopper control devices in parallel, performs cargo handling work in addition to running the device itself. Traveling is performed by the drive of a traveling electric motor, and cargo handling is
This is done by driving an electric motor for cargo handling. A battery is used as a power source for driving each electric motor. In order to reduce the number of batteries, a common battery is often used for the traveling electric motor and the cargo handling electric motor.

FIG. 1 shows a circuit configuration of a patch lift-off control device using such a common battery. The battery 1 is a common battery used for traveling and cargo handling. The traveling electric motor 20 consists of an armature 20B and an excitation coil 20A, and the cargo handling electric motor 30 consists of an armature 30B and an excitation coil 2.
Consists of OA.

A current detector 21°31 is connected in series to this motor 20, 301C.
Connect.

The transistor 22 is a chopper transistor, and the chopper control circuit 2 performs chopper control.

Thyristors 33 and 34 are chopper thyristors 1,
A chopper control circuit 3 performs chopper control. Thyristor 33 is a main thyristor, and 34 is an auxiliary thyristor. Furthermore, a diode 35, a coil 36, and a capacitor 37 are provided. The capacitor 37 serves as a commutation capacitor.

With this configuration, the chopper bias circuits 2 and 3 operate asynchronously δ, so that the driver's driving command (accelerator command)
2 chopper control circuits are activated and transistor 2 is activated.
2, and the chopper control circuit 3 turns the thyristors 33 and 34 off in response to the driver's cargo handling command (handle or switch command), which is not directly related to the travel command.
Perform N-0FF.

When the transistor 22 is turned on, current is supplied from the battery 1 to the electric motor 20 for driving, and the vehicle runs. When the thyristor 33 (or 34) is turned on, current is supplied from the battery 1 to the cargo handling motor 30 to perform cargo handling work.

When the thyristor 33 (or 34) is turned off, the capacitor 37 is charged via the diode 35 and the coil 36, and after charging is completed, the voltage is maintained at a constant voltage. The electric charge of the capacitor 37 is discharged after a predetermined time after the ignition of the thyristor 33 (or 34) starts, and the thyristor 33 (or 34) is turned off from ON to OFF at the extinguishing voltage.

FIG. 2 shows operating waveforms in such a conventional circuit.

The travel motor current (travel motor drive current) L is a current that corresponds to the chopper operation of the transistor 22. On the other hand, the cargo handling motor current (cargo handling motor drive current) J2 is a current corresponding to the chopper operation of the thyristor 33' (34). As described above, since travel and cargo handling are asynchronous, both current 11 and work 2 are asynchronous. When the voltage across the capacitor 8 is vc, it is charged to a constant voltage when the Zyristor is OFF, and when it reaches the arc-extinguishing voltage by discharging, the relay 33.34 is turned OFF (arc-extinguishing).

In the figure, the anode voltage of the auxiliary thyristor 34 is
Full disclosure7.

Now, when traveling and cargo handling overlap, there is a limit to the capacity of the battery power source, so traveling and cargo handling, especially cargo handling, may go out of control. This will be explained based on FIG.

In FIG. 2, when the cargo handling current 2 rises at point P, the thyristor 33 is turned on. While this is ON, the driving motor current at 9 points ■! rises, the transistor 22 becomes O
It becomes N. Current II and ■.

and is supplied from the battery 1, so when the two overlap, the battery voltage will drop rapidly. As a result, the charging current to the capacitor 37 decreases and the charging voltage does not increase, resulting in failure of commutation of the thyristor. Due to this commutation failure, the electrical engineer
does not rise as indicated by the dotted line S, but instead rises in the direction of a in the figure, leading to runaway cargo handling operations.

[Purpose of the invention]

The present invention is for cargo handling 13. The purpose of preventing f13J1 machine current is to provide a batch lift-off control device.

[Summary of the Invention] The present invention is characterized in that the travel command is prohibited when the travel command and the cargo handling command occur simultaneously during at least part of the time. Specifically, the thyristor 7 node voltage is input to the driving control circuit so that the driving command is not generated in accordance with the level of the anode voltage.

[Embodiments of the invention]

FIG. 3 shows an embodiment of the 7-oclift control device of the present invention. The chopper control circuit 2 was made to receive a signal of the auxiliary thyristor anode voltage. Furthermore, the internal configuration of the chopper control device 2 has been changed in accordance with its introduction. The internal configuration of the chopper control circuit 3 is the same as before.

The chopper control circuit 2 operates asynchronously with the normal-two chopper control circuit 3. However, when the cargo handling current ■2 flows, the chopper control circuit 2 turns the transistor 22 off.
Even if the chopper control circuit 2 is in operation to be set to N, the load handling current (2) causes the ON operation command of the chopper control circuit 2 to be stopped. In other words, when both are in operation condition, the current supply to the traveling electric motor is stopped and the current is made to flow only to the cargo handling electric motor.

FIG. 4 shows a forklift 7 centered on the chopper control circuit 2.
An example diagram of a control device is shown. Chopper control (path 2 has a constant I voltage circuit 40 that receives a battery voltage (for example, 48V) to obtain a predetermined constant voltage (for example, 101) and supplies this constant voltage as a free current power source for various types.Accelerator circuit 41 generates an accelerator signal corresponding to the driver's access operation during driving.

The oscillation circuit 42 receives the accelerator signal output from the accelerator circuit 41 as input, and generates a pulse signal having a duty ratio corresponding to the accelerator signal.

In addition to the duty ratio, a circuit that changes the oscillation frequency according to the accelerator signal may be used.

44 gate circuits, timer circuits, or Schmitt trigger circuits. The base current control circuit 43 is the transistor 2
20 pace current supply control is performed.

Furthermore, the anode voltage of the auxiliary thyristor 34 becomes an input to the gate circuit 44 via a diode 45, a resistor 46, an inverter 51, a resistor 52, and a diode 53. Here, among the resistors 46 and 50, the voltage dividing resistor diode 45 has the role of rectifying, and the diode 53 has the role of blocking reverse flow. The capacitor 48 has the role of high frequency removal. diode 4
9 has a function of removing the excessive voltage when the voltage at the auxiliary thyristor 7) is excessive (more than IOV).

The operation will be explained using the time chart shown in FIG. The accelerator circuit 41 generates an accelerator signal corresponding to the amount of accelerator operation in response to the driver's accelerator operation. Oscillation circuit 4
2 is the duty ratio (
This signal turns on and off the transistor 22 via the gate circuit 44 and the base current control circuit 43. This transistor 2
2, a traveling motor current I flows as shown in FIG.

On the other hand, the cargo handling chopper control circuit (not shown) operates asynchronously with the traveling chopper control circuit 2, and the cargo handling motor current 2 flows as shown in Fig. 5 in accordance with the driver's cargo handling instructions. . The auxiliary thyristor anode voltage ■, also depends on this cargo handling motor current ■2, H,! =L is repeated.

Now, at the P position, the cargo handling motor current ■2 starts up.

Next, at Q position 6, the running motor current 11 becomes N as shown by the dotted line.
Assume a case where l-hies occur. Due to the cargo handling motor current I2, the auxiliary Zyristor anode voltage, that is, the commutation voltage 2, changes from H to L by the width τ0 (during the commutation section) of the cargo handling motor current I2. In this interval of width τ0, the output Vl of the inverter 51 is H, and otherwise the output V+ of the inverter 51 is L.

Now, when the input of the Gert circuit 44 (the output via the diode 53 and the output via the resistor 55) is H, the transistor 22 is OFF, and when either output is L, the transistor 22 is ON. It is assumed that a gate circuit 44 and a control circuit 43 are configured. According to this configuration, one section τ. Then, the transistor 22 is turned off. Therefore, the driving motor current I! does not flow, and only the cargo handling motor electric current 2 flows. Therefore, normal commutation control is possible without the capacitor charging voltage being insufficient as in the conventional case. After the interval τ0, that is, after time t2 (Q1 position), the output V1 of the inverter 51 changes from H to L, and the gate circuit 44 outputs pulses from the oscillation circuit 55 only after t2 (interval τ!) and turns on the transistor 22 according to this pulse. In addition, the driving motor Kameryu I! is only for one pulse",!I:<,71
The current I+ in the section of only
It becomes a signal with a shorter pulse interval than the original pulse interval within. Therefore, a slight error occurs, but since it is not often that cargo handling and traveling commands are given at the same time, problems tend to occur.

Furthermore, although FIG. 5 shows an example in which the P position and Q position match, the present invention can also be applied to a case where the Q position occurs after the P position (as in FIG. 2). Needless to say.

Similarly, in the above embodiment, the configuration is such that the signal input to the input stage of the gate circuit 44 is controlled, but the method of controlling the base current control circuit can also be applied as soon as the oscillation output of the oscillation circuit is controlled.

In the embodiment of FIG. 4, a thyristor is provided in place of the transistor 22, and the present invention can also be applied to a forklift control device in which chopper control is performed by a thyristor chopper control circuit provided separately with this thyristor.

[Barrier effect]

Even in the event of a failure, the cargo handling command can be prioritized, thereby preventing failure of commutation and preventing runaway cargo handling.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a configuration diagram of a conventional forklift control device, Fig. 2 is a time chart thereof, Fig. 3 is a diagram of an embodiment of a 7-off lift control device of the present invention, and Fig. 4 is a diagram of a conventional forklift control device. FIG. 5, which is an embodiment diagram centered on the chopper control circuit 2 of the present invention, shows its time chart. 1... Battery, 20... Travel electric motor (motor)
, 30... Cargo handling electric motor (MOZ), 22... Transistor, 33.34... Thyristor, 2... Transistor chopper control circuit, 3... Thyristor chopper (control circuit, 41...・Accelerator circuit, 42...Oscillation circuit, 43...Base current control circuit, 44...Gate circuit, 51...Inverter. Agent: Masami Akimoto, patent attorney

Claims (1)

[Claims] 1. A single battery power source, a traveling electric motor using the battery power source as a power source, a cargo handling electric motor using the battery power source as a power source, and a single battery power source connected to the traveling electric motor via the battery power source. a first switch means for turning on and off to flow a drive current for running; a first chopper means for controlling on/off driving of the first switch means in accordance with a running command from a driver; a second switch means consisting of a thyristor that turns on and off in order to flow a cargo handling drive current to the electric motor via the battery power supply; and controlling the on and off driving of the second switch means in accordance with a cargo handling command from a driver. Second to do
chopper means, and the second chopper means takes in the commutation voltage of the thyristor of the second switch means and turns off the first switch means during the commutation period. Batch ref-off control device configured as follows. 2. The batch lift-off control device according to claim 1, wherein the first switch means is constituted by a transistor. 3. The batch lift-off control device according to claim 1, wherein the first switch means is constituted by SIRISK.