KR101487886B1 - Device of controlling a forklift by alternating current motor - Google Patents

Abstract

The present invention relates to a forklift control device through an alternating current motor operating method. More specifically, provided is a forklift control device through an alternating current motor operating method equipped with a circuit to restrain a current and detect a failed MOSFET for operation such that control of the forklift operated by the alternating current motor is performed in a more secure and reliable manner; and equipped also with an interface, speed control, and a forward and backward movement detection method appropriate for a forklift, a current detection method, and a forklift speed restraint function in an event of heat generation. According to the present invention, provided is an effect in controlling the forklift operated by the alternating current motor in a more secure and reliable manner by generating an optimal operation waveform with a digital signal processor (DSP).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a control device for a forklift,

The present invention relates to an AC motor drive control device for a forklift, and more particularly, to an AC motor drive control device for a forklift, which is provided with a breakdown detection and current limiting circuit of a drive MOSFET for more safe and reliable control of a forklift driven by an AC motor, The present invention is to provide an AC motor drive control device for a forklift having an interface suitable for a forklift, a speed control, a forward / backward detection method, a current detection method, and a forklift speed limit function in heat generation.

Forklifts are a representative product family of logistics equipment and are internationally used as power industrial trucks, which are self-propelled transport handling equipment. When a forklift is classified by its power source, it can be largely classified into a method using an engine type and a motor. Conventionally, an engine type is generally used, but there is a problem that an exhaust gas is generated, a running cost is high, It is not easy to carry out the operation.

An electric drive system using a motor has been proposed as a substitute for the engine type. In particular, a forklift using a DC motor has been widely used. A forklift driven by a DC motor is widely used because it has a simple merit of controlling a DC motor as a power source of the forklift. In comparison with an engine-driven forklift, it receives light in an environment where cleanliness is important because it does not generate exhaust gas. Life cycle costs, maintenance costs, vibration mitigation and worker fatigue. Although it is pointed out that the purchase cost is rather high, it is difficult to drive for a long time, and the battery is difficult to be replaced or charged, problems are gradually being improved due to continuous development of electronic control technology and battery technology.

DC motors have advantages in that they can be easily controlled in speed, but the structure of the motors is complicated and the cost is high. Research and development for replacing them with AC motors is ongoing. The use of an alternating current motor is remarkably large in torque and acceleration compared to a comparable vehicle using a direct current motor and maintains optimum performance even under load conditions. Even when the battery is 80% discharged, In case of DC motors, the brushes must be periodically replaced. Therefore, the cost for equipment and maintenance is continuously generated. However, when the AC motor is used, the cost is reduced.

In addition, in the case of an AC motor-driven forklift, there is little time delay at the time of forward / backward switching, and the responsiveness to the operation signal of the driver is high, so that precise control is possible and the battery can be recharged Thereby reducing energy costs. However, in the case of an AC motor, there is a problem that the speed control is complicated because an inverter is used to drive the AC motor. The price of the driving element for constituting the inverter is continuously lowered and the driving method is also improved. Forklifts are expected to increase.

However, the proposed AC motor drive type forklift control system is merely applied to the existing AC motor drive inverter module. Therefore, it is impossible to utilize the characteristics of the forklift truck and to control the forklift truck more safely and reliably And it is a situation that improvement is required.

In principle, it is possible to construct a variable-speed electric motor by combining an alternating-current motor and an inverter without considering an efficient operation of a forklift and use it for a forklift. In this case, however, problems due to time harmonics included in the output of the inverter, Unbalance, vibration and noise problems may occur. In some cases, this may cause malfunction of the motor and may have a fatal impact on the operating system.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems and it is an object of the present invention to provide an electronic control unit which generates an optimal driving waveform by a DSP in order to make the control of a forklift driven by an AC motor safer and more reliable, And to provide a forklift drive control device having an interface suitable for a forklift.

According to another aspect of the present invention, there is provided an apparatus for controlling a forklift of an AC motor drive system, the apparatus comprising: a traveling analog data input unit for receiving operation state check data of a forklift; a traveling operation switch input unit for sensing a state of the operation switch; A traveling control unit for controlling the forklift and changing and setting parameters used in the forklift by processing data and error detection data input through the traveling analog data input unit and the traveling operation switch input unit; A traveling motor drive waveform generating unit for supplying pulses; a traveling controller including a traveling communication unit for performing communication; a hydraulic analog data input unit for exchanging data by communication with the traveling controller and receiving data for checking the operating state of the forklift; And a lift and tilt switch A hydraulic control unit for controlling the operation of the forklift, and a control unit for controlling the operation of the forklift and the forklift, And a hydraulic controller including a hydraulic motor drive waveform generator for supplying control pulses for driving the hydraulic motor under the control of the hydraulic controller.

In addition, a monitor data input unit receiving overload of the traveling motor and the hydraulic motor and fuse check data, a key input unit for selecting a display mode and setting a parameter value, a monitor communication unit for exchanging data with a travel controller, And a display unit for processing data provided from the key input unit and the travel controller and displaying a character or figure to be displayed.

In addition, the travel controller and the hydraulic controller may be implemented by a DSP (Digital Signal Processor).

The running analog data input unit includes a running motor current detecting unit for detecting a current value consumed by the traveling motor at the time of forklift traveling, a traveling motor speed detecting unit for detecting the traveling motor speed at the time of forklift traveling, and a traveling heat sink plate temperature detecting unit for detecting the temperature of the forklift A detecting unit for detecting a remaining battery level of the forklift battery when the forklift truck is running while a forklift truck is traveling; a traveling motor FET check unit for checking a field effect transistor for driving the traveling motor; and a voltage input to the accelerator, And an accelerator input detecting unit for detecting the accelerator.

The hydraulic analog data input unit may include a hydraulic motor current detector for detecting a current value consumed in the hydraulic motor when the forklift is unloaded, a hydraulic heat sink temperature detector for detecting the temperature of the heat sink during the unloading operation of the forklift, And a hydraulic motor FET check unit which checks a field effect transistor (FET) that drives the hydraulic motor.

The traveling controller includes a magnet driving unit for driving the magnet contactor by the traveling control unit, a traveling error display unit for detecting a contact and operation error generated in the magnet contactor and displaying a travel motor FET error input from the travel control unit, A driving motor drive waveform generator for generating a drive motor drive waveform when the magnet contactor is driven, and a drive motor speed detector for detecting a speed of the drive motor at the time of driving the forklift.

The hydraulic controller includes a hydraulic error display unit for displaying a hydraulic motor FET error input from the hydraulic control unit, a hydraulic motor drive waveform generating unit for generating a hydraulic motor drive waveform, and a hydraulic motor for detecting the speed of the hydraulic motor during unloading of the forklift truck. And may further include a speed detection unit.

According to another aspect of the present invention, there is provided a method of controlling a forklift of an AC motor driven type forklift, comprising the steps of: A step of inputting the current of the traveling motor, the speed of the traveling motor, the voltage of the accelerator, the remaining amount of the battery, the temperature of the heat sink, the abnormality of the hydraulic FET and the abnormality of the traveling FET, on of the forklift when the forward switch is on and performing the forward travel of the forklift when the forward switch is on and performing the reverse travel of the forklift when the backward switch is on, Or if the backward switch is not detected, sensing the on-off operation switch, and performing the unloading when the unloading switch is on It includes.

The step of performing the forward travel of the forklift may include the steps of turning on the hydraulic motor and sensing the on state of the accelerator, sensing the on state of the seating switch, Sensing on and sensing a side brake switch on; displaying a brake error if the foot brake switch and the side brake switch are on; sensing a voltage of the accelerator; And a step of controlling the motor speed so as to move forward if the accelerator voltage is within a set range, displaying an accelerator error when the accelerator voltage deviates from the set range, and detecting a reverse switch on when the accelerator is off Detecting a reverse switch on when the forward switch is off and stopping the motor when the reverse switch is on And stopping the motor when the backward traveling and the backward switch are off.

The step of performing the backward travel of the forklift may include the steps of turning on the inflow motor, sensing the accelerator on, sensing the on state of the seating switch, sensing a brake on when the foot brake switch and a side brake switch are on; sensing a brake error when the foot brake switch and a side brake switch are on; sensing a voltage of the accelerator; A step of controlling the motor speed to perform a backward travel if the accelerator voltage is within a set range, a step of displaying an accelerator error when the accelerator voltage is out of a set range, and a step of detecting a forward switch on when the accelerator is off Detecting the forward switch on when the reverse switch is off and stopping the motor when the forward switch is on And stopping the motor when the forward switch is off.

The loading and unloading may include delaying the operation of the hydraulic motor according to a preset delay time, driving the hydraulic motor, and driving the hydraulic motor when the lift switch is turned on to turn off the lift switch And a step of turning on the tilt switch when the lift switch is turned off and a step of driving the hydraulic motor to turn off the tilt switch when the tilt switch is turned on Performing a forking operation until the tilt switch is turned off, and sensing a tilt switch off.

According to the present invention, a forklift driven by an alternating-current motor can be controlled with a DSP (Digital Signal Processor) by generating an optimum driving waveform to control more safely and accurately.

Further, breakage of the driving MOSFET of the forklift driven by the alternating-current motor can be detected, and the current limiting circuit of the driving MOSFET can be provided.

Further, it is possible to control the speed of the forklift driven by the alternating-current motor, to detect the motor speed of the forklift, to control the forklift's control interface, to detect the forward and backward movement of the forklift, There is an effect.

1 is a block diagram of a traveling controller according to an embodiment of the present invention.
2 is a block diagram of a hydraulic controller according to an embodiment of the present invention.
3 is a flowchart illustrating a method of controlling an AC motor driven forklift according to an embodiment of the present invention.
FIG. 4 is a flowchart illustrating a forklift forward driving operation of an AC motor drive system according to an embodiment of the present invention.
5 is a flow chart of a forklift reverse travel of an AC motor drive system according to an embodiment of the present invention.
FIG. 6 is a flowchart illustrating an AC motor-driven forklift unloading according to an embodiment of the present invention.

The embodiments of the present invention are described in sufficient detail to enable those skilled in the art to realize the invention by those skilled in the art and other embodiments may be used and various modifications may be made within the scope of the present invention . Accordingly, the following detailed description is not intended to limit the scope of the invention, but should be defined by the claims.

Meanwhile, the symbols used in the present invention have the same meaning throughout the specification.

The present invention relates to a forklift control apparatus of an AC motor drive type and includes a traveling controller 100, a traveling power supply unit 200, a traveling FET driving unit 300, a traveling auxiliary power supply unit 400, a hydraulic controller 500, A power supply unit 600, a hydraulic FET driving unit 700, and a hydraulic auxiliary power supply unit 800.

1 is a block diagram of a traveling controller according to an embodiment of the present invention.

1, the traveling controller 100 includes a traveling analog data input unit 110, a traveling operation switch input unit 120, a traveling communication unit 130, a traveling control unit 140, a magnet driving unit 150, An error display unit 160, a traveling motor driving waveform generating unit 170, and a traveling motor speed detecting unit 180, and generates a driving motor driving waveform to control the traveling motor.

 The running analog data input unit 110 includes a running motor current detecting unit 111, a traveling motor speed detecting unit 112, a traveling heat sink temperature detecting unit 113, a traveling battery remaining amount detecting unit 114, a traveling motor FET checking unit 115, An input detecting unit 116 and receives inputs of the current of the traveling motor, the speed of the traveling motor, the voltage of the accelerator, the remaining amount of the battery, the temperature of the heat sink and the field effect transistor (FET).

The driving motor current detection unit 111 detects the current value consumed by the traveling motor at the time of traveling, the traveling motor speed detection unit 112 detects the traveling motor speed at the time of traveling, and the traveling heat sink temperature detection unit 113 detects the heat sink temperature The driving battery remaining amount detecting unit 114 detects the remaining amount of the battery connected to the traveling motor and the traveling motor FET check unit 115 checks whether or not an FET (Field Effect Transistor) connected to the traveling motor is abnormal , The accelerator input detecting unit 116 detects the voltage input to the accelerator.

The travel operation switch input unit 120 includes a key switch for turning on the power supply of the forklift, a seating switch for being turned on when the driver is seated, a forward / backward changeover switch for selecting forward travel or backward travel, ), And an operation switch including a brake switch for turning on the brake.

The traveling communication unit 130 communicates with a monitor, and may be a serial communication or a CAN communication.

The travel control unit 140 processes the data input from the traveling analog data input unit 110 and the traveling operation switch input unit 120 to control the traveling motor. The traveling motor current, the traveling motor speed, the temperature of the heat sink in the traveling controller, the traveling motor FET, the remaining amount of the traveling battery, and the voltage of the accelerator are controlled to be optimum, and the forklift Forward or backward.

Meanwhile, the travel control unit 140 may be implemented by a DSP (Digital Signal Processor).

The magnet driving unit 150 drives the magnet contactor under the control of the travel control unit 140. The magnet driving unit 150 includes a main magnet contactor for supplying power to the respective attachments of the forklifts, a forward magnet contactor for supplying power to the traveling motor at the time of forward travel, a backward magnet contactor for supplying power to the traveling motor at the time of backward travel, A steering magnet contactor for causing the hydraulic motor to stop by a predetermined value when the switch is in the neutral state, a by-pass on duty when the power is supplied to the traveling motor is greater than a predetermined value, A bypass magnet contactor that is turned on to protect the FET when the speed of the traveling motor is higher than a predetermined value, a field-weakening magnet contactor that connects to the resistance when the speed of the traveling motor becomes lower than a predetermined speed .

 The traveling error display unit 160 detects and displays an operation error of the contact and the magnet contactor generated in the magnet contactor and displays an operation error input in the traveling analog data input unit 110.

The traveling motor drive waveform generator 170 generates control pulses for driving motor drive in accordance with the control of the travel controller 170 and supplies the generated control pulses for driving motor drive to the driving FET driver 300. [

The running motor speed detecting section 180 detects the speed from the running motor and transmits it to the running control section 140. [

The driving power supply unit 200 supplies power to the traveling controller 100 and the driving FET driving unit 300 when the magnet contactor is turned on.

The driving FET driving unit 300 receives power from the driving power supply unit 200 and receives a control pulse for driving motor driving waveform from the driving motor driving waveform generator 170 and drives the driving motor FET according to the control pulse for driving motor driving .

The auxiliary driving power supply unit 400 turns off the magnet contactor in the magnet driving unit 150 when an overload occurs in the traveling motor FET so that when the driving control unit 140 and the traveling motor are not supplied with power, (100).

2 is a block diagram of a hydraulic controller according to an embodiment of the present invention.

2, the hydraulic controller 500 includes a hydraulic analog data input unit 510, a loading operation switch input unit 520, a hydraulic communication unit 530, a hydraulic control unit 540, a hydraulic error display unit 550, A motor drive waveform generating unit 560, and a hydraulic motor speed detecting unit 570.

The hydraulic analog data input unit 510 inputs the hydraulic motor current value, the heat sink temperature in the hydraulic controller, the remaining battery level, and the abnormality of the hydraulic motor FET to the hydraulic control unit 540.

The hydraulic analog data input unit 510 includes a hydraulic motor current detection unit 511, a hydraulic heat sink temperature detection unit 512, a hydraulic battery remaining amount detection unit 513, and a hydraulic motor FET check unit 514.

The hydraulic motor current detecting unit 511 detects the current of the hydraulic motor, the hydraulic heat sink temperature detecting unit 512 detects the heat sink temperature in the hydraulic controller, the hydraulic battery remaining amount detecting unit 513 detects the remaining amount of the battery, The FET check unit 514 checks whether or not the hydraulic motor FET is abnormal.

The unloading operation switch input unit 520 receives the on and off states of a lift switch for instructing to perform an operation of lifting the fork and turns on the tilt switch for instructing to perform the fork lifting operation ) · Enter off.

When the forward operation switch input unit 120 receives the input of the forward switch or the reverse switch, the load operation switch input unit 520 inputs the hydraulic motor for driving the power steering.

The hydraulic communication unit 530 communicates with the monitor, and communicates with the driving controller 100, and can be a serial communication or a CAN communication.

The hydraulic control unit 540 processes the data input from the hydraulic analog data input unit 510 and the loading operation switch input unit 520 to control the hydraulic motor. According to the hydraulic analog data, the current of the hydraulic motor, the temperature of the heat sink in the hydraulic controller, the residual amount of the hydraulic motor FET and the hydraulic battery are controlled to be optimal, and the forklift is operated forward or backward according to the operation of the unloading switch.

Meanwhile, the hydraulic control unit 540 may be implemented as a DSP (Digital Signal Processor).

The hydraulic error display unit 550 displays the error information input to the hydraulic pressure controller 540.

The hydraulic motor drive waveform generating unit 560 generates a control pulse for driving the hydraulic motor according to the control of the hydraulic control unit 540 and supplies the generated control pulse for driving the hydraulic motor to the hydraulic FET driving unit 700.

The hydraulic motor speed detection unit 570 detects the speed from the hydraulic motor and transmits the detected speed to the hydraulic pressure control unit 140.

The hydraulic power supply unit 600 supplies power to the hydraulic controller 500 and the hydraulic FET driver 700.

The hydraulic FET driving unit 700 receives power from the hydraulic power supply unit 600 and receives the control pulse for driving the hydraulic motor from the hydraulic motor driving waveform generating unit 560 and outputs the hydraulic motor FET according to the control pulse for driving the hydraulic motor. .

The hydraulic auxiliary power supply unit 800 supplies power to the hydraulic controller 500 when the power supply of the hydraulic power supply unit 600 is cut off so that the hydraulic controller 500 can operate normally.

3 is a flowchart illustrating a method of controlling an AC motor driven forklift according to an embodiment of the present invention.

3, when the key switch is turned on (S320), the forklift drive system is initialized (S330), and it is checked whether there is an abnormality in the traveling motor FET and the hydraulic motor FET. If the temperature of the heat sink in the traveling controller and the hydraulic pressure The temperature of the heat sink in the controller is checked, the remaining battery level is checked, and the abnormality of the magnet contact is checked (S340). Thereafter, when the forward switch is turned on (S350), the forward travel is controlled (A) when the forward switch is on, and the backward travel is controlled (S360) when the backward switch is on B), and performs hydraulic control (D) when both the forward switch and the reverse switch are off.

FIG. 4 is a flowchart illustrating a forklift forward driving operation of an AC motor drive system according to an embodiment of the present invention.

Referring to FIG. 4, when the steering hydraulic motor is turned on (S410) and the accelerator switch is turned on (S415), the seating switch is turned on (S420). When the accelerator switch is off, the on / off detection (C) of the forward switch and the reverse switch is performed again. On the other hand, if the seating switch is off, an error of the seating switch is displayed (S425), and the on / off detection C of the forward switch and the backward switch is performed again. Then, when the foot brake switch is on, a brake error is displayed (S435), and the on / off detection (C) of the forward switch and the reverse switch is performed again do. When the foot brake switch is off, the side brake switch is turned on (S440). When the side brake is on, the on / off detection (C) of the forward switch and the reverse switch is performed again. When the brake switch is off, the voltage of the accelerator is sensed (S445). If the voltage of the accelerator is within the setting range (S450), the traveling motor speed is controlled (S460), and if the voltage of the accelerator is outside the set range, an accelerator error is displayed (S455). When the accelerator switch is on, the on / off detection of the forward switch is detected (S470). When the accelerator switch is off, the on / off of the reverse switch is detected (S475). When the accelerator switch is ON and the forward switch is ON, the voltage of the accelerator is sensed again (S445). If the accelerator switch is OFF and the reverse switch is ON, the traveling motor is stopped and the backward travel control (B) is performed (S480). If the backward switch is OFF, the traveling motor is stopped (S485) and the process is terminated.

5 is a flow chart of a forklift reverse travel of an AC motor drive system according to an embodiment of the present invention.

5, the steering hydraulic motor is turned on (S510) and the accelerator switch is turned on (S515). If the accelerator is turned on, the on / off state of the seating switch is detected (S520) When the accelerator switch is off, the on / off detection (C) of the forward switch and the reverse switch is performed again. If the seating switch is on, the on / off of the foot brake switch is sensed (S530). If the seating switch is off, an error of the seating switch is displayed (S525). When the foot brake switch is on, a brake error is displayed (S535), and the on / off detection (C) of the forward switch and the reverse switch is performed again. If the foot brake switch is off, the on / off of the side brake switch is sensed (S540). When the side brake switch is on, a brake error is displayed (S535), and the on / off detection (C) of the forward switch and the reverse switch is performed again. When the side brake switch is off, the accelerator voltage is sensed (S545). If the voltage of the accelerator is within the setting range (S550), the traveling motor speed is controlled (S560). If the voltage of the accelerator is outside the set range, an error of the accelerator is displayed (S555). When the accelerator switch is on, the on / off state of the reverse switch is detected (S570). When the accelerator switch is off, the accelerator switch is turned on. On / off is detected (S575). When the accelerator switch is on and the reverse switch is on, the process returns to step 545 of sensing the voltage of the accelerator again. If the accelerator switch is turned off and the forward switch is turned on, the traveling motor is stopped and the forward travel control A is performed (S580). If the accelerator switch is off and the forward switch is off The traveling motor is stopped (S585).

FIG. 6 is a flowchart illustrating an AC motor-driven forklift unloading according to an embodiment of the present invention.

Referring to FIG. 6, the operation of the steering hydraulic motor is delayed in accordance with the preset delay time (S610), and the steering hydraulic motor is driven (S620). When the lift switch is on, the hydraulic motor is driven (S640) to control the position of the fork. If the lift switch is off, the on / off state of the lift switch is detected (S630) On-off detection (C). After the hydraulic motor is driven (S640), the on / off of the lift switch is sensed again (S650), and if the lift switch is off, the on / off of the tilt switch is sensed (S660). When the tilt switch is ON, the hydraulic motor is driven (S670) to control the fork to be in a closed state or a straight state, and the on / off state of the tilt switch is sensed again (S680). If the tilt switch is OFF, (C) on / off detection of the backward switch.

100: traveling controller 110: traveling analog data input unit
120: a traveling operation switch input unit 130:
140: a travel controller 150: a magnet driver
160: running error display unit 170: running motor drive waveform generating unit
180: running motor speed detecting section 200: running power supply section
300: a traveling FET driving part 400: a traveling auxiliary power supply part
500: Hydraulic controller 510: Hydraulic analog data input part
520: unloading operation switch input unit 530: hydraulic communication unit
540: Hydraulic error display unit 550: Hydraulic motor drive waveform generating unit
560: Hydraulic motor speed detection unit 600: Hydraulic power supply unit
700: Hydraulic FET drive unit 800: Hydraulic auxiliary power supply unit

Claims (7)

A traveling operation switch input unit for sensing the state of the operation switch, and data and error detection data input through the traveling analog data input unit and the traveling operation switch input unit, A traveling motor drive waveform generator for supplying a control pulse for driving motor according to the control of the traveling controller, and a traveling communication unit for performing communication with the forklift, A traveling controller for driving the vehicle;
A hydraulic analog data input part for exchanging data by communication with the traveling controller and receiving data for checking the operation state of the forklift, a loading operation switch input part for sensing an operation signal of a lift and tilt switch, A hydraulic control unit for controlling data input from the hydraulic analog data input unit, the unloading operation switch input unit and the traveling controller to control the forklift and changing and setting parameter values used in the forklift; A hydraulic controller including a hydraulic motor drive waveform generator for supplying a control pulse for driving a hydraulic motor according to a control; And
A monitor data input unit for receiving overload of the traveling motor and the hydraulic motor and fuse check data, a key input unit for selecting a display mode and setting a parameter value, a monitor communication unit for exchanging data with a travel controller, And a display unit for processing data provided from the travel controller and displaying a character or figure to be displayed,
The travel control unit and the hydraulic control unit are implemented by a DSP (Digital Signal Processor)
The traveling controller includes a magnet driving part for driving the magnet contactor by the traveling control part, a traveling error display part for detecting a contact and operation error generated in the magnet contactor and displaying a driving motor FET error inputted from the traveling control part, A traveling motor drive waveform generator for generating a drive motor drive waveform when the contactor is driven, and a drive motor speed detector for detecting the speed of the drive motor during traveling of the forklift,
The hydraulic controller includes a hydraulic error display unit for displaying a hydraulic motor FET error input from the hydraulic control unit, a hydraulic motor drive waveform generation unit for generating a hydraulic motor drive waveform, and a hydraulic motor speed detection unit for detecting the speed of the hydraulic motor in unloading the forklift. Further comprising:
The magnet drive unit includes a main magnet contactor for supplying power to each accessory device of the forklift, a forward magnet contactor for supplying power to the traveling motor at the time of forward travel, a backward magnet contactor for supplying power to the traveling motor at the time of backward travel, A steering magnet contactor for causing the hydraulic motor to stop by a preset value when the motor is in a neutral state, a bypass magnetization contactor for applying a bypass on-duty when the power to the traveling motor is higher than a predetermined value, A bypass magnet contactor which is turned on to protect the FET when it is determined to be equal to or greater than a set value, and a field-contacting magnet contactor connected to the resistor when the speed of the traveling motor becomes lower than a predetermined speed Wherein the control unit is operable to control the operation of the forklift.
delete delete The method according to claim 1,
Wherein the running analog data input unit comprises: a traveling motor current detecting unit for detecting a current value consumed by the traveling motor at the time of traveling on a forklift;
A running motor speed detector for detecting the speed of the running motor at the time of forklift traveling;
A traveling heat sink temperature detector for detecting the temperature of the forklift heat sink;
A traveling battery residual quantity detector for detecting a remaining battery charge by checking a voltage of a forklift battery when the forklift is traveling;
A traveling motor FET check unit for checking a field effect transistor (FET) for driving the traveling motor; And
And an accelerator input detector for detecting a voltage input to an accelerator.
The method according to claim 1,
The hydraulic analog data input unit includes a hydraulic motor current detector for detecting a current value consumed by the hydraulic motor when the forklift is unloaded;
A hydraulic heat sink temperature detector for detecting the temperature of the heat sink during the unloading operation of the forklift;
A hydraulic battery residual quantity detector for detecting a remaining battery charge by checking a voltage of a forklift battery when unloading a forklift; And
And a hydraulic motor FET check unit for checking a field effect transistor (FET) for driving the hydraulic motor.
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