JP6190136B2 - External power control device for work machines - Google Patents

Description

  The present invention relates to an external power supply control device for a work machine including a work device that can be driven by electric power of an external power supply.

  As a conventional work machine, a traveling body, a working device provided on the traveling body, which performs a predetermined work, an electric motor that can be driven by electric power of an external power source, and a driving device that drives the working device, are provided on the traveling body. And a plurality of external power supply connection portions for connecting power cables for supplying power from an external power supply are known (see, for example, Patent Document 1).

  For example, when there is an obstacle behind the traveling body, the work machine connects a plurality of external power sources depending on the situation of the work place so that the power cable is connected to the external power source connecting portion located on the side surface of the traveling body. One external power supply connection part is selected from the part and the power cable is connected.

JP 2008-008009 A

  Generally, an external power source installed at a construction site has a plurality of power extraction units for extracting electric power, and multiple electric devices are driven simultaneously by extracting electric power from each of the electric power extraction units. Is possible. Each power extraction unit is set with the maximum power that can be extracted. For this reason, when an electric device that requires electric power equal to or greater than the maximum electric power is connected, when the load increases, the safety device operates to stop the supply of electric power, making it difficult to continue driving the electric device.

  An object of the present invention is to provide an external power supply control device for a work machine that can drive the work device with the required power without causing the supply of power to be stopped due to the operation of the safety device. There is.

In order to achieve the above object, the present invention includes a working device that performs a predetermined work and an electric motor that drives the working device, and is supplied from an external power source in a working machine that can drive the electric motor with electric power from an external power source. External power control device for a work machine that controls electric power to be supplied, and a plurality of external power connection portions to which cables for transmitting power from the external power supply are connected, and power supplied to the motor from the plurality of external power connection portions And a maximum current value setting means for setting a maximum current value that can be supplied to the motor from a plurality of external power supply connections, and the power control means is supplied to the motor by the maximum current value setting means. The maximum current value supplied to the motor from multiple external power supply connections when the motor drive is permitted and the motor drive is permitted on condition that the maximum current value setting is possible. That controls so as not to exceed the maximum current value set by the setting means.

  As a result, the electric motor can be driven by the electric power supplied from the plurality of electric power extraction units, and the electric power supplied from the plural electric power extraction units to the electric motor is controlled. In addition, the electric motor can be driven by the maximum power that can be supplied.

  According to the present invention, it is possible to limit the supply of electric power above a predetermined level and to drive the electric motor with the maximum electric power that can be supplied, so it is possible to improve the working efficiency of the working device. .

It is a side view of the mobile crane which shows one Embodiment of this invention. It is the schematic which shows a hydraulic pressure supply apparatus, a motive power apparatus, and a control system. It is a figure which shows an external power supply connection unit. It is a flowchart which shows a motor generator drive control process.

  1 to 4 show an embodiment of the present invention. The following embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications or changes can be made without departing from the scope of the invention. .

  As shown in FIG. 1, a mobile crane 1 as a work machine including an external power supply control device of the present invention includes a traveling vehicle 10 and a crane device 20.

  The vehicle 10 has wheels 11 and travels using an engine or an engine and a motor generator described later as a power source. Further, on both the left and right sides of the front side and the rear side of the vehicle 10, there are provided outriggers 12 for preventing the vehicle 10 from overturning during crane operation and for stably supporting the vehicle 10. The outrigger 12 can move outward in the width direction and can extend downward by a hydraulic jack cylinder. The outrigger 12 stably supports the vehicle 10 with respect to the ground by grounding the lower end.

  The crane apparatus 20 includes a swivel base 21 that is turnable on a horizontal plane at a substantially central portion in the front-rear direction of the vehicle 10, a boom 22 that is provided so as to be able to rise and fall with respect to the swivel base 21, and is extendable. The wire rope 23 suspended from the distal end side of the boom 22, the winch 24 for winding or unwinding the wire rope 23, and the front side of the swivel base 21 are related to the traveling of the vehicle 10 and the work by the crane device 20. And a cabin 25 for operation.

  Actuators 60 such as each jack cylinder, a turning motor for turning the swivel base 21, a raising cylinder for raising and lowering the boom 22, a telescopic cylinder for extending and retracting the boom 22, and a winch motor for rotating the winch 24, Operates with hydraulic oil. As shown in FIG. 2, the hydraulic oil that operates each actuator 60 is supplied by a hydraulic pressure supply device 30.

  As shown in FIG. 2, the hydraulic pressure supply device 30 includes a hydraulic pump 31 for generating hydraulic pressure, and a hydraulic oil circuit 32 for supplying hydraulic oil discharged from the hydraulic pump 31 to each actuator 60. ing.

  As shown in FIG. 2, the hydraulic pump 31 is provided in the vehicle 10, and generates power for driving the vehicle 10 and is driven by power extracted from a power device 40 for transmitting power to the wheels 11. The hydraulic pump 31 is, for example, a swash plate type axial plunger hydraulic pump, and is a variable displacement hydraulic pump capable of changing the angle of the swash plate.

  An actuator 60 (an undulating cylinder, a telescopic cylinder, a winch motor) provided in the crane device 20 is connected to the hydraulic oil circuit 32 via a rotary joint 33. The hydraulic oil circuit 32 is provided with a plurality of control valves (not shown), and the flow rate and flow direction of the hydraulic oil flowing into the actuators 60 are controlled by the control valves. Each control valve is operated by an operation input unit 51 (described later) such as an operation lever or an operation pedal in the cabin 25, and the flow rate of the hydraulic oil can be adjusted according to the operation amount of the operation input unit 51. Each control valve has switching means such as a solenoid and can be operated by a signal from a controller 50 described later.

  The power unit 40 includes a power source unit 41 for generating power, a torque converter 42 for converting the power output from the power source unit 41 to the wheel 11 side by converting torque, and the torque converter 42. A transmission 43 for changing the rotational speed and torque of the output power, a propeller shaft 44 for transmitting the power output from the transmission 43 to the wheels 11, an electric retarder 45 provided on the propeller shaft 44, It has.

  The power source unit 41 mainly functions as an electric motor by an engine 41a that is a power source for vehicle travel and the supplied power, and also functions as a generator by the power of the engine 41a or during deceleration during travel. A motor generator 41b that stores the electric power generated by the motor generator 41b, and a battery 41c that can supply power when the motor generator 41b functions as an electric motor, and controls the output of the battery 41c or A motor generator drive control unit 41d for controlling the operation and a clutch 41e capable of switching the connection and release of the connection between the output shaft of the engine 41a and the input / output shaft of the motor generator 41b.

  The motor generator 41b is provided between the engine 41a and the torque converter 42. The power of the engine 41a is transmitted to the torque converter 42 via the input / output shaft of the motor generator 41b by connecting the output shaft of the engine 41a and the input / output shaft of the motor generator 41b by the clutch 41e. The motor generator 41b can be driven as an electric motor by the power of an external power source installed at a place where crane work is performed or the power of the battery 41c. As the external power source, for example, a power source such as a three-phase AC 200V or a three-phase AC 400V is used.

  The motor generator drive control unit 41d includes an inverter, a boost converter, a motor control unit, a generator control unit, and the like. The motor generator drive control unit 41d controls the output of the battery 41c to supply power to the motor generator 41b, or switches the function of the motor generator 41b to a generator or an electric motor according to a signal from the controller 50 described later. To do. The motor generator drive control unit 41d can switch the power source to the battery 41c or an external power source when the motor generator 41b functions as an electric motor. The electric power of the external power supply is supplied to the motor generator drive control unit 41d via the external power supply connection unit 70. The external power supply connection units 70 are provided at four locations on the front surface, rear surface, and left and right side surfaces of the vehicle 10.

  As shown in FIG. 3, the external power supply connection unit 70 measures the amount of power supplied from the external power supply connection unit 71 and the external power supply connection unit 71 for connecting the power supply cable 41 f that transmits power from the external power supply. An watt-hour meter 72 for performing the operation, an emergency stop switch 73 as a safety device for stopping the drive of the crane device 20 in an emergency, and a leakage breaker 74 as a safety device. The external power connection unit 70 is assembled as one part when the mobile crane 1 is assembled.

  Each external power supply connection unit 71 is connected to the motor generator drive control unit 41d via a power combining circuit (not shown) for combining a plurality of input powers. For this reason, the motor generator drive control unit 41d can be supplied with electric power larger than the electric power that can be supplied from one external power supply connection unit 71.

  A PTO (power take-off) mechanism 46 capable of taking out the power transmitted to the transmission 43 is provided on the output side of the torque converter 42, and the hydraulic pump 31 can be connected via the PTO mechanism 46. The PTO mechanism 46 is capable of switching between connection and release of the connection between the output shaft of the engine 41a and the input / output shaft of the torque converter 42 with respect to the hydraulic pump 31.

  The mobile crane 1 also has a controller 50 for controlling the hydraulic pressure supply device 30 and the power device 40 when the vehicle 10 is traveling or when the crane device 20 is working.

  The controller 50 has a CPU, ROM, RAM, and the like. When the controller 50 receives an input signal from a device connected to the input side, the CPU reads a program stored in the ROM based on the input signal, and stores a state detected by the input signal in the RAM. The output signal is transmitted to a device connected to the output side.

  The controller 50 is used to operate a control valve (not shown) corresponding to each actuator 60, a hydraulic pump 31, a power source unit 41, the vehicle 10 such as an operation lever and an accelerator pedal, and the crane device 20. An operation input unit 51, a setting input unit 52 for performing various settings such as traveling of the vehicle 10 and driving of the crane device 20, and a liquid crystal provided in the cabin 25 for displaying settings and operating states by the operator. A display device 53 composed of a panel or the like and an external power supply connection unit 70 are connected. Here, a signal line for transmitting a signal between the vehicle 10 and the crane device 20 is connected via a slip ring provided in the rotary joint 33.

  A signal relating to a voltage supplied to the external power supply connection portion 71 of each external power supply connection unit 70 is input to the controller 50. The controller 50 also receives a signal related to the amount of power supplied from each external power supply connection unit 71, and records the amount of power data in a data storage device such as a HDD (Hard Disk Drive) or an SSD (Solid State Drive). To do. Further, the controller 50 outputs a signal for controlling the display of the display device 53.

  In the mobile crane 1 as the work machine configured as described above, when the crane device 20 performs the work, the hydraulic pump 31 is driven by any of the power of the engine 41a, the power of the battery 41c, and the power of the external power source. Can be driven. For this reason, the crane apparatus 20 is hydraulically driven by the engine working mode for driving the hydraulic pump 31 by the power of the engine 41a, the battery working mode for driving the hydraulic pump 31 by the power of the battery 41c, or by the power of the external power source. It is driven by an external power supply operation mode for driving the pump 31. The worker sets any one of the engine work mode, the battery work mode, and the external power supply work mode by operating the setting input unit 52 before starting the work.

  In the engine working mode, the transmission 43 is in a neutral state, the engine 41a and the motor generator 41b are connected by the clutch 41e, and the output shaft of the engine 41a and the motor generator 41b are input to the hydraulic pump 31 by the PTO mechanism 46. The output shaft is connected.

  In the engine work mode, the rotation speed of the engine 41a is adjusted by an accelerator operation with respect to the operator's operation input unit 51, and is driven at a work idling rotation speed in a state where there is no accelerator operation with respect to the user's operation input unit 51. In the standby state between work in the engine work mode, the motor generator 41b is driven by the power of the engine 41a driven at the work idling speed, and the generated electric power is supplied to the battery 41c via the motor generator drive control unit 41d. To charge. Further, in the engine working mode, the battery 41c can be charged by the power of the external power source.

  In the battery work mode and the external power supply work mode, the transmission 43 is in a neutral state, and the clutch 41e is in a state in which the connection between the engine 41a and the motor generator 41b is released. In the battery work mode and the external power supply work mode, the PTO mechanism 46 is connected to the hydraulic pump 31 with the input / output shaft of the motor generator 41b.

  In the external power supply work mode, the power extraction unit provided on the distribution board of the external power supply installed at the place where the crane work is performed and the external power supply connection unit 71 are connected by the power cable 41f. At this time, when the distribution board has a plurality of power extraction units, the power extraction unit and the external power supply connection unit 71 are connected by a plurality of power cables 41f. In the external power supply work mode, the operator sets a maximum supplyable current value, which is the maximum current value that can be supplied by the external power supply, using the setting input unit 52 as a condition for enabling the crane work. In the external power supply work mode, the controller 50 drives the motor generator 41b in a range where the current does not exceed the maximum current value set by the worker. Further, in the standby state between work in the external power supply work mode, the battery 41c can be charged by the power of the external power supply.

  In the external power supply work mode, the controller 50 performs a motor generator drive control process as shown in FIG.

(Step S1)
In step S1, the CPU determines whether or not an external power supply work mode is set. If it is determined that the external power supply work mode is set, the process proceeds to step S2, and if it is determined that the external power supply work mode is not set, the motor generator drive control process is terminated.

(Step S2)
If it is determined in step S1 that the external power supply work mode is set, in step S2, the CPU determines whether or not the maximum supplyable current value of the motor generator 41b is set. If it is determined that the maximum supplyable current value is set, the process proceeds to step S3. If it is determined that the maximum supplyable current value is not set, the process proceeds to step S5.

(Step S3)
When it is determined in step S2 that the maximum supplyable current value is set, in step S3, the CPU determines whether or not the motor generator 41b is driven. If it is determined that the motor generator 41b is driven, the process proceeds to step S4. If it is determined that the motor generator 41b is not driven, the motor generator drive control process is terminated.

(Step S4)
When it is determined in step S3 that the motor generator 41b is driven, in step S4, the CPU performs output restriction control to limit the output of the motor generator 41b so that the current does not exceed the maximum suppliable current value. The generator drive control process is terminated.

  Specifically, during a crane operation, when the load acting on the crane device 20 increases, the rotational speed of the motor generator 41b decreases and the flowing current increases. In the output restriction control, the voltage and current of power supplied to the motor generator 41b are adjusted so that the current at this time does not exceed the maximum supplyable current, and the output of the motor generator 41b is restricted.

(Step S5)
When it is determined in step S2 that the maximum supplyable current value is not set, in step S5, the CPU restricts the drive of the motor generator 41b to restrict the drive of the crane device 20, and the process proceeds to step S6.

  Specifically, when the maximum supplyable current value is not set, the motor generator 41b is not driven even if the operation input unit 51 is operated.

(Step S6)
In step S6, the CPU displays on the display device 53 that the driving of the crane device 20 is restricted, and ends the motor generator drive control process.

Thus, according to the external power supply control device for a work machine of the present embodiment, a plurality of external power supply connection portions 71 are provided in the vehicle 10, and the motor is controlled by controlling the power supplied from the plurality of external power supply connection portions 71. The generator 41b is driven.
As a result, it is possible to limit the supply of electric power above a predetermined level and to drive the motor generator 41b with the maximum electric power that can be supplied, so that the work efficiency of the crane apparatus 20 can be improved. .

Further, the electric power supplied from the plurality of external power supply connection portions 71 is combined and supplied to the motor generator 41b.
As a result, the motor generator 41b can be driven with a power larger than the maximum power that can be supplied from one external power supply connection portion 71. Therefore, even when the power that can be extracted from the power extraction portion of the external power supply is small. Since it becomes possible to drive the motor generator 41b with necessary electric power, it becomes possible to improve the work efficiency of crane work.

In addition, the motor generator 41b is controlled so that the power supplied from the plurality of external power supply connection portions 71 to the motor generator 41b is equal to or lower than a predetermined power.
As a result, when the power that can be taken out from the external power source is limited, the motor generator 41b can be driven by the power within the limited range, so that the crane device being driven by the operation of the safety device of the external power source 20 can be prevented, and safety and work efficiency can be improved. In addition, it is possible to prevent damage to the vehicle 10 and other electric devices of the crane apparatus 20 due to the supply of electric power exceeding a predetermined level from an external power source.

The external power supply connecting portion 71 is formed integrally with an emergency stop switch 73 and a leakage breaker 74 that are used when the motor generator 41b is driven by the power of the external power supply.
As a result, when the mobile crane 1 is assembled, the external power connection 71, the emergency stop switch 73, and the earth leakage breaker 74 can be assembled as one component, so that the work efficiency of the assembly work can be improved. It becomes.

  In the above-described embodiment, the mobile crane 1 including the crane device 20 that can be driven by the power of the external power source is shown as a work machine, but the present invention is not limited to this. The present invention can be applied to a work machine such as an aerial work vehicle or an excavator as long as it has a work device that can be driven by power from an external power source.

  In the above embodiment, the crane apparatus 20 is driven by the power of one or both of the engine 41a and the motor generator 41b. However, the present invention is not limited to this. For example, the crane apparatus 20 may be driven only by the power of an electric motor that can be driven by electric power from an external power source.

  In the above embodiment, the maximum current value that can be supplied by the operator is shown. However, the present invention is not limited to this. For example, when the external power supply has a function of transmitting a signal related to the maximum suppliable current value, it is based on the signal transmitted from the external power supply without setting the maximum suppliable current value by the operator. The maximum supplyable current value may be set. In this case, since it is not necessary for the operator to set the maximum current value that can be supplied, the work efficiency can be improved.

  Moreover, although the said embodiment showed what provided the external power supply connection unit 70 in the front surface of the vehicle 10, the rear surface, and both right-and-left both sides, it is not restricted to this. For example, a plurality of external power connection units 70 may be arranged on the side surface of the vehicle 10.

  In the above embodiment, the vehicle 10 is provided with the four external power connection portions 71. However, at least two or more may be used.

  In the above embodiment, the external power supply connection portion 71 is provided in the vehicle 10. However, the external power supply connection portion 71 may be provided in the crane device 20.

  In the above embodiment, one external power supply connection unit 71 is provided for one external power supply connection unit 70, but a plurality of external power supply connection units 71 are provided in one external power supply connection unit 70. May be.

  In the above embodiment, the external power supply connection unit 70, the watt hour meter 72, the emergency stop switch 73, and the earth leakage breaker 74 are integrally provided as the external power supply connection unit 70, but the present invention is not limited to this. Absent. The external power supply connection unit 70 may be configured such that the external power supply connection unit 71 and at least a safety device such as an emergency stop switch and a leakage breaker 74 are integrally formed.

  DESCRIPTION OF SYMBOLS 1 ... Mobile crane, 10 ... Vehicle, 20 ... Crane apparatus, 30 ... Hydraulic supply device, 31 ... Hydraulic pump, 40 ... Power device, 41 ... Power source unit, 41b ... Motor generator, 41d ... Motor generator drive control part, 41f ... power cable, 50 ... controller, 51 ... operation input unit, 52 ... setting input unit, 60 ... actuator, 70 ... external power supply connection unit, 71 ... external power supply connection unit, 73 ... emergency stop switch, 74 ... earth leakage breaker .

Claims (3)

External power control of a work machine that controls power supplied from an external power source in a work machine that includes a work device that performs a predetermined work and an electric motor that drives the work device and that can drive the electric motor with electric power from an external power source A device,
A plurality of external power supply connections to which cables for transmitting power from the external power supply are connected;
Power control means for controlling the power supplied to the motor from a plurality of external power supply connections;
A maximum current value setting means for setting a maximum current value that can be supplied to the electric motor from a plurality of external power supply connections , and
The power control means
The drive of the motor is permitted on condition that the maximum current value that can be supplied to the motor by the maximum current value setting means is set.
When the drive of the electric motor is permitted, control is performed so that the maximum current value supplied to the electric motor from a plurality of external power supply connection portions is equal to or less than the maximum current value set by the maximum current value setting means. Machine external power supply control device. 2. The external power supply control device for a work machine according to claim 1, wherein the electric power control unit combines electric power from a plurality of external power supply connection portions and supplies the combined electric power to the electric motor. The external power supply control device for a work machine according to claim 1, wherein the external power supply connection unit is configured integrally with a safety device used when the electric motor is driven by electric power of the external power supply.

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