Electric construction machinery

Abstract

The present invention provides an electric construction machine which can avoid exceeding the allowable power that can be output by a power receiving device of a commercial power source as an external power source when multiple electric construction machines are operated simultaneously, and distribute the power supplied to each machine body without operation deviation corresponding to the respective required power of the multiple electric construction machines, so as to operate efficiently within the allowable power. Thus, a controller (53) calculates its own required power (Pd1) for driving multiple hydraulic actuators (13A) and (19) based on operation signals of multiple operating devices (35) and (37), and calculates the allowable power as a power limit value that can be used by an electric motor (31) based on its own required power, the required power of other electric construction machines received via a communication device (46), and the allowable power of a power receiving device (80) of the commercial power source, and controls the electric motor (31) in such a way that the power consumption does not exceed the allowable power.

Description

Technical Field

[0001] The present invention relates to an electric construction machine such as a hydraulic excavator, and more particularly to an electric construction machine that uses an electric motor driven by electric power supplied from an external power supply device as a power source to drive a hydraulic pump. Background Art

[0002] Construction machines represented by hydraulic excavators often use a diesel engine as a power source, and work is performed by operating a hydraulic actuator using hydraulic oil delivered from a hydraulic pump connected to the diesel engine.

[0003] Compared with engines powered by other fuels such as gasoline, the exhaust gas of a diesel engine generally contains a large amount of particulate matter (PM) and nitrogen oxides (NOx), which poses a problem.

[0004] Therefore, in order to gradually reduce the above substances contained in the exhaust gas of diesel engines, legal regulations are rapidly developing around the world.

[0005] Based on this background, it is possible that a large number of construction machines operated at work sites in the future will be shifted to electric construction machines that use electricity as a power source and do not generate exhaust gas.

[0006] In this context, a technique related to a charging device is described in Patent Document 1, which calculates a threshold value of an output current and controls the charging power supplied to a battery-mounted electric construction machine so that the power supplied during charging does not exceed the permissible power specified based on the power contract with the power utility organization. The charging device is provided with a mechanism for inputting the set power specification (equivalent to the contract power in this specification) to a power receiving mechanism (equivalent to a power receiving device of a commercial power source in this specification).

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2010-206978 Summary of the invention

[0010] Meanwhile, some electric construction machines such as hydraulic excavators operate by driving an electric motor and activating a hydraulic pump using electric power supplied from a switchboard installed at a work site to a vehicle body via a feeder cable.

[0011] When a plurality of such electric construction machines are operated at a work site, a switchboard is installed in the operating range of each electric construction machine, and each switchboard is supplied with power from a commercial power supply receiving device (external power supply) installed near the work site (inside a construction site, etc.).

[0012] Usually, commercial power receiving equipment is installed at the construction site, etc., and the power from the commercial power supply of the power utility is transformed and supplied to the distribution boards at various locations in the construction site. If the power consumption at the construction site increases and the power supplied from the receiving equipment exceeds the contracted power with the power utility, there may be an overcharge or load cut.

[0013] Therefore, when operating multiple electric construction machines at a work site using the same power receiving equipment, it is necessary to set up a mechanism that limits the total value of the power supplied to each electric construction machine via the distribution board to below the allowable power value so that the total value does not exceed the contracted power, thereby efficiently distributing the power to multiple electric construction machines.

[0014] Patent Document 1 is a technique for charging a battery-mounted electric construction machine, but a plurality of electric construction machines can be operated by replacing the charging device with a switchboard. In view of such a configuration, Patent Document 1 has the following problems.

[0015] The output current threshold of Patent Document 1 is set only so that the power supplied to one electric construction machine does not exceed the permissible power of the power receiving device (power receiving mechanism), and does not take into account the limit value corresponding to the required power of each electric construction machine when multiple electric construction machines are in operation. The electric construction machines have different load states such as body specifications, work content, state of the work site, and operation rate per unit work time, and thus the power required for each body is also different.

[0016] Therefore, if appropriate power supply restriction corresponding to the power required by the machine is not performed, problems may occur, such as deviation in the working speed of each machine, causing a high-load machine to stop.

[0017] The present invention is made in view of the above-mentioned problems of the prior art, and its purpose is to provide an electric construction machine that can avoid exceeding the allowable power that can be output by the power receiving equipment of the commercial power supply as the external power supply when multiple electric construction machines are operating at the same time, and at the same time distribute the supply power to each body without operating deviation corresponding to the respective required power of the multiple electric construction machines, so as to operate efficiently within the allowable power.

[0018] In order to achieve the above-mentioned purpose, the electric engineering machinery of the present invention comprises: an electric motor; a hydraulic pump driven by the electric motor; a plurality of hydraulic actuators driven by the hydraulic oil discharged from the hydraulic pump; a plurality of directional switching valves for controlling the flow of the hydraulic oil supplied from the hydraulic pump to the plurality of hydraulic actuators; and a plurality of operating devices for instructing the actions of the plurality of hydraulic actuators and generating operating signals for switching the plurality of directional switching valves, wherein the electric motor is driven by electricity from a power receiving device, and the electric engineering machinery comprises: a communication device for transmitting and receiving data between other electric engineering machinery that share the power receiving device; and a controller , which calculates its own required power for driving the multiple hydraulic actuators based on the operation signals of the multiple operating devices, sends the own required power to the other electric engineering machinery via the communication device, and receives the required power calculated in the other electric engineering machinery via the communication device, the controller calculates the allowable power that can be used by the electric motor based on the own required power, the required power of the other electric engineering machinery received via the communication device, and the allowable power of the power receiving device, and controls the electric motor in a way that the power consumption of the electric motor does not exceed the allowable power.

[0019] In this way, in the controller, its own required power is calculated and sent to other electric construction machines via the communication device, and the required power calculated in other electric construction machines is received via the communication device. The allowable power that can be used by the electric motor is calculated based on its own required power, the required power of other electric construction machines, and the allowable power of the power receiving equipment, and the electric motor is controlled in a manner that the power consumption of the electric motor does not exceed the allowable power. As a result, when multiple electric construction machines are operating at the same time, it is possible to avoid exceeding the allowable power that can be output by the power receiving equipment of the commercial power supply, and at the same time, the power supply is distributed to each body without operating deviation corresponding to the respective required power of the multiple electric construction machines, so that the operation is efficient within the allowable power.

[0020] Effects of the Invention

[0021] According to the present invention, when a plurality of electric construction machines are operating simultaneously, it is possible to avoid exceeding the allowable power that can be output by the power receiving equipment of the commercial power supply serving as the external power supply, and at the same time, distribute the supplied power to each machine body without operating deviation in accordance with the respective required power of the plurality of electric construction machines, so that the machines can operate efficiently within the allowable power. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a side view showing the overall structure of an electric hydraulic excavator according to one embodiment of the present invention.

[0023] Figure 2This is a top view of the same electric hydraulic excavator.

[0024] Figure 3 This is a hydraulic circuit diagram showing the configuration of a hydraulic drive device included in an electric hydraulic excavator.

[0025] Figure 4 It is a block diagram showing the configuration of an electric system in one embodiment of the present invention.

[0026] Figure 5 This diagram shows the configuration of a switch together with related devices.

[0027] Figure 6 It is a diagram showing the structure of a storage battery device.

[0028] Figure 7 : This is a table showing the operating states and operating conditions of the electric hydraulic excavator of this embodiment.

[0029] Figure 8 This is a functional block diagram showing the processing functions of the controller when controlling the driving of the electric motor in the commercial power supply driving mode.

[0030] Fig. 9 This is a functional block diagram showing the processing functions of the required power calculation unit.

[0031] Fig.10 This is an overall configuration diagram related to the operation of a plurality of electric hydraulic excavators that are operated by electric power supplied from a power receiving device of the same commercial power source. DETAILED DESCRIPTION

[0032] An embodiment of the present invention will be described with reference to the drawings, taking an electric hydraulic excavator as an example as an applicable object of the present invention.

[0033] ~Composition~

[0034] Figure 1 is a side view showing the overall structure of an electric hydraulic excavator according to one embodiment of the present invention. Figure 2 In addition, in this specification, the electric hydraulic excavator is Figure 1 In the state shown, the front side of the driver when the driver is sitting in the driver's seat ( Figure 1 Center right side), rear side ( Figure 1 Center left), left side ( Figure 1 Towards the back of the paper), right side ( Figure 1 The front side (the side facing the paper) is simply referred to as the front side, back side, left side, and right side.

[0035] In these Figure 1 as well as Figure 2In the embodiment, the electric hydraulic excavator (in this embodiment, a small excavator with a driving mass of less than 6 tons) has: a crawler-type lower traveling body 1; an upper rotating body 2 rotatably arranged on the lower traveling body 1; a rotating frame 3 constituting a basic lower structure of the upper rotating body 2; a rotating column 4 rotatably arranged on the front side of the rotating frame 3 in the left and right directions; a multi-jointed working device 5 connected to the rotating column 4 so as to be rotatable in the up-down direction (able to pitch); a cabin-type cab 6 arranged on the rotating frame 3; and a battery device 7 (see below) arranged on the rear side of the rotating frame 3. Figures 4 to 6 ) is a driving battery unit mounting portion 8 for storing the driving battery unit.

[0036] The lower traveling body 1 has: a vehicle frame 9 that is substantially H-shaped when viewed from above; left and right driving wheels 10A, 10B that are rotatably supported near the rear ends of the left and right sides of the vehicle frame 9; left and right driven wheels (idling wheels) 11A, 11B that are rotatably supported near the front ends of the left and right sides of the vehicle frame 9; and left and right crawler tracks 12A, 12B that are wound around the left and right driving wheels 10A, 10B and the driven wheels 11A, 11B. In addition, the left traveling hydraulic motor 13A (described later) is used to rotate the left vehicle frame 9. Figure 3 The left drive wheel 10A (that is, the left crawler track 12A) is rotated by driving the right travel hydraulic motor 13B, and the right drive wheel 10B (that is, the right crawler track 12B) is rotated by driving the right travel hydraulic motor 13B.

[0037] A blade 14 for bulldozing is provided on the front side of the vehicle frame 9 so as to be movable up and down. The blade 14 is moved up and down by extension and retraction drive of a blade hydraulic cylinder (not shown).

[0038] A rotating wheel 15 is provided at the center of the vehicle frame 9 , and the rotating frame 3 is rotatably provided via the rotating wheel 15 . The rotating frame 3 (that is, the upper rotating body 2 ) is rotated by being driven by a rotating hydraulic motor (not shown).

[0039] The rotating column 4 is provided on the front side of the rotating frame 3 so as to be rotatable in the left-right direction, and is rotated in the left-right direction by the extension and contraction drive of the rotating hydraulic cylinder (not shown). Thereby, the working device 5 rotates in the left-right direction.

[0040] The working device 5 includes a boom 16 connected to the rotating column 4 so as to be rotatable in the vertical direction, an arm 17 connected to the boom 16 so as to be rotatable in the vertical direction, and a bucket 18 connected to the arm 17 so as to be rotatable in the vertical direction. The boom 16, the arm 17, and the bucket 18 are vertically rotated by a boom hydraulic cylinder 19, an arm hydraulic cylinder 20, and a bucket hydraulic cylinder 21. The bucket 18 can be replaced with an attachment (not shown) assembled with, for example, a spare hydraulic actuator.

[0041] A driver's seat (seat) 22 is provided in the cab 6 for the driver to sit on. In front of the driver's seat 22, a left travel operating lever 23A (see below) is provided, which can be operated by hand or foot and instructs the operation of the left and right travel hydraulic motors 13A and 13B (that is, the left and right crawler tracks 12A and 12B) respectively by operating in the forward and backward directions. Figure 3 ) and a right travel operating lever (not shown). A standby operating pedal (not shown) is provided at the foot portion further to the left of the left travel operating lever 23A, which instructs the operation of the standby hydraulic actuator (that is, the attachment) by operating it in the left-right direction. A rotation operating pedal (not shown) is provided at the foot portion further to the right of the right travel operating lever, which instructs the operation of the rotation hydraulic cylinder (that is, the rotation column 4) by operating it in the left-right direction.

[0042] On the left side of the operator's seat 22, there is provided a cross-operated arm and rotation control lever 24A which instructs the movement of the arm hydraulic cylinder 20 (that is, the arm 17) by operating in the forward and backward directions and instructs the movement of the rotation hydraulic motor (that is, the upper rotating body 2) by operating in the left and right directions. On the right side of the operator's seat 22, there is provided a cross-operated arm and bucket control lever 24B which instructs the movement of the boom hydraulic cylinder 19 (that is, the boom 16) by operating in the forward and backward directions and instructs the movement of the bucket hydraulic cylinder 21 (that is, the bucket 18) by operating in the left and right directions. In addition, on the right side of the operator's seat 22, there is provided a blade control lever (not shown) which instructs the movement of the blade hydraulic cylinder (that is, the blade 14) by operating in the forward and backward directions.

[0043] In addition, on the left side of the driver's seat 22 (in other words, the entrance of the cab 6), a door lock lever (not shown) is provided which can be operated to a lock release position (specifically, a lowered position that prevents the driver from getting on or off) and a lock position (specifically, an raised position that allows the driver to get on or off). In addition, on the right side of the driver's seat 22, a key switch 27, a dial 28, and a charging switch 29 (see below) are provided. Figure 4 ) etc. In addition, a monitor 30 is provided in front of the right side of the driver's seat 22.

[0044] Figure 3 1 is a hydraulic circuit diagram showing the structure of the hydraulic drive device of the above-mentioned electric hydraulic excavator. Figure 3 2 , the configurations related to the left travel hydraulic motor 13A and the boom hydraulic cylinder 19 are shown as representatives.

[0045] Figure 3In the embodiment, the hydraulic drive device comprises: an electric motor 31; a battery device 7 as a power source for the electric motor 31; an inverter 32 for controlling the power supplied to the electric motor 31 to drive the electric motor 31; a hydraulic pump 33 and a pilot pump 34 driven by the electric motor 31; the above-mentioned plurality of hydraulic actuators 13A, 19 ... (the illustration of hydraulic actuators other than the left travel hydraulic motor 13A and the boom hydraulic cylinder 19 is omitted) driven by the hydraulic oil discharged from the hydraulic pump 33; and control of the power supplied from the hydraulic pump 33 to the plurality of hydraulic actuators 13A, 19. A, 19... control the flow of hydraulic oil supplied by multiple directional switching valves 36, 38... (the illustration of directional switching valves other than the left travel directional switching valve 36 and the boom directional switching valve 38 is omitted); a plurality of hydraulic pilot-type operating devices 35, 37... (the illustration of operating devices other than the left travel operating device 35 and the bucket and boom operating device 37 is omitted) that instruct the action of multiple hydraulic actuators 13A, 19... and generate pilot pressure (operating signals) for switching the multiple directional switching valves 36, 38...

[0046] The left travel operating device 35 includes a left travel operating lever 23A, and controls the flow of hydraulic oil from the hydraulic pump 33 to the left travel hydraulic motor 13A according to the front-rear operation of the operating lever 23A. The bucket and boom operating device 37 includes a boom and bucket operating lever 24B, and controls the flow of hydraulic oil from the hydraulic pump 33 to the boom hydraulic cylinder 19 according to the front-rear operation of the operating lever 24B.

[0047] In the oil path between the hydraulic pilot type operating device 35 and the left travel direction switching valve 36, pressure sensors 26A and 26B are provided for detecting the pilot pressure (operation signal) generated by the plurality of pilot valves built into the operating device 35. Similarly, in the oil path between the operating device 37 and the boom direction switching valve 38, pressure sensors 26C and 26D are provided for detecting the pilot pressure (operation signal) generated by the plurality of pilot valves built into the operating device 37. The pressure sensors 26A and 26B and the detection signals of the pressure sensors 26A and 26B are input to the controller 53 (see the control circuit described later). Figure 4 ).

[0048] also, Figure 3 The configuration of the hydraulic drive device related to the right travel hydraulic motor 13B, the arm hydraulic cylinder 20, the bucket hydraulic cylinder 21, the swing hydraulic motor, the rotation hydraulic cylinder, and the blade hydraulic cylinder (not shown) is also substantially the same.

[0049] The left travel direction switching valve 36, the boom direction switching valve 38 and other direction switching valves not shown are of the central bypass type, and each has a central bypass passage located on the central bypass pipeline 39. The central bypass passage of each direction switching valve is connected in series with the central bypass pipeline 39. When the valve column of each direction switching valve is in the neutral position, the central bypass passage is connected. When the valve column of each direction switching valve is switched to the neutral position, the central bypass passage is connected. Figure 3 The central bypass line 39 is connected to the discharge line 40 of the hydraulic pump 33 at its upstream side, and to the tank line 41 at its downstream side.

[0050] In addition, a pressure sensor 25 for detecting the pressure of the discharge line 40 (discharge pressure of the hydraulic pump 33) is provided on the discharge line 40 of the hydraulic pump 33. The detection signal of the pressure sensor 25 is input to the controller 53 (see below). Figure 4 ).

[0051] The left travel direction switching valve 36 is switched by the pilot pressure from the operating device 35. The operating device 35 includes the above-mentioned left travel operating lever 23A and a pair of pilot valves (not shown) that generate pilot pressure using the discharge pressure of the pilot pump 34 as the source pressure according to the operation of the operating lever 23A in the front-rear direction. And, for example, if the operating lever 23A is operated forward from the neutral position, the pilot pressure generated by one pilot valve is switched to the left travel direction switching valve 36 according to the operation amount. Figure 3 The pressure receiving part on the right side of the middle is output, and the left travel direction switching valve 36 is switched to Figure 3 As a result, the left travel hydraulic motor 13A rotates forward, and the left drive wheel 10 and the crawler track 12 rotate forward. On the other hand, if the operating lever 23A is operated from the neutral position to the rear side, the pilot pressure generated by the other pilot valve according to the operation amount is applied to the left travel direction switching valve 36. Figure 3 The left side pressure receiving part outputs, and the left travel direction switching valve 36 is switched to Figure 3 As a result, the left travel hydraulic motor 13A rotates in the rear direction, and the left drive wheel 10 and the crawler belt 12 rotate in the rear direction.

[0052] The pilot pressure generated by the pilot valve of the operating device 35 increases in proportion to the operation amount, whereby the operation amount of the operating device 35 and the switching direction of the left travel direction switching valve 36 can be measured by the detection values ​​of the pressure sensors 26A and 26B.

[0053] The boom direction switching valve 38 is switched by the pilot pressure from the operating device 37. The operating device 37 includes the boom and bucket operating lever 24B, and a pair of pilot valves (not shown) that generate the pilot pressure using the discharge pressure of the pilot pump 34 as the source pressure according to the operation of the operating lever 24B in the front-back direction. And, for example, if the operating lever 24B is operated forward from the neutral position, the pilot pressure generated by one pilot valve is supplied to the boom direction switching valve 38 according to the operation amount. Figure 3 The pressure receiving part on the right side of the middle is output, and the boom direction switching valve 38 is switched to Figure 3 As a result, the boom hydraulic cylinder 19 is shortened and the boom 16 is lowered. On the other hand, if the operating lever 24B is operated to the rear side, for example, the pilot pressure generated by the other pilot valve according to the amount of operation is applied to the boom direction switching valve 38. Figure 3 The left side of the pressure receiving part outputs, thereby the boom direction switching valve 38 is switched to Figure 3 Thus, the boom hydraulic cylinder 19 is extended and the boom 16 is raised.

[0054] The pilot pressure generated by the pilot valve in the operating device 37 increases in proportion to the operation amount, whereby the operation amount of the operating device 37 and the switching direction of the boom direction switching valve 38 can be measured by the detection values ​​of the pressure sensors 26C and 26D.

[0055] A pilot relief valve (not shown) is provided on the discharge line 43 of the pilot pump 34 to keep the discharge pressure of the pilot pump 34 constant. In addition, a lock valve 45 is provided on the discharge line 43 of the pilot pump 34. The lock valve 45 is switched according to the operation of the door lock rod. Specifically, a lock switch 47 is provided, which is closed when the door lock rod is in the unlocked position (lowered position) and is opened when it is in the locked position (raised position) (see below). Figure 4 ). For example, if the lock switch 47 is turned off, the solenoid portion of the lock valve 45 is energized via the lock switch 47, and the lock valve 45 is switched to Figure 3 As a result, the discharge line 43 of the pilot pump 34 is connected, and the discharge pressure of the pilot pump 34 is introduced to the operating devices 35, 37, etc. On the other hand, if the lock switch 47 is turned on, the solenoid part of the lock valve 45 is not energized, and the lock valve 45 is closed by the force of the spring. Figure 3 The neutral position is at the upper middle side. As a result, the discharge line 43 of the pilot pump 34 is cut off. As a result, even if the operating devices 35, 37 and the like are operated, no pilot pressure is generated, and the hydraulic actuator does not operate.

[0056] Figure 4The electric power system in this embodiment has a power receiving device 80 (see Fig.10 ) connected to the distribution board 48 (hereinafter appropriately referred to as the commercial power distribution board) or the DC power rapid charger 49 to supply and charge the battery device 7, and to supply the power from the commercial power distribution board 48 or the battery device 7 to the electric motor 31 via the inverter 32 to operate the electric hydraulic excavator.

[0057] In order to perform the above functions, the electric system has a monitor 30 , a communication device 46 , and a controller 53 .

[0058] The controller 53 receives inputs of signals from the pressure sensor 25 , the pressure sensors 26A and 26B, and the pressure sensors 26A and 26B as described above, and receives inputs of signals from the key switch 27 , the dial 28 , the charging switch 29 , and the lock switch 47 .

[0059] The monitor 30 displays the operating state, the SOC indicating the remaining amount of the battery device 7, the current time, etc. through input from the controller 53. In addition, the monitor 30 has an input mechanism such as a switch that can be operated by the operator, and various information is sent to the controller 53 by operating the input mechanism, and necessary information can be set to the controller 53.

[0060] The controller 53 is also connected to the communication device 46. The communication device 46 is a short-range wireless communication module (wireless communication device), and serves as a communication mechanism between other electric hydraulic excavators (which are also equipped with the communication device 46) connected to the same network. The controller 53 receives data from other electric hydraulic excavators and sends data to other electric hydraulic excavators via the communication device 46.

[0061] The controller 53 is connected to a battery controller 59 in the battery device 7 to be described later, and monitors the battery status in the battery device 7 (see the controller 59 to be described later). Figure 6 ).

[0062] The inverter 32 controls the voltage applied to the electric motor 31 (more specifically, the frequency of the supply voltage) in response to a rotation speed control command from the controller 53 , thereby controlling the rotation speed of the electric motor 31 .

[0063] In addition, the controller 53 controls the relays 54A and 54B (see below) in the switch 51. Figure 5 ) is switched on and off to control the power supply.

[0064] Figure 5: This is a diagram showing the structure of the switch 51 together with related equipment. The AC power supplied from the commercial power distribution board 48 via the power receiving connector 52A is converted into DC by the rectifier 50 and supplied to the switch 51. The DC power supplied from the DC power supply rapid charger 49 via the power receiving connector 52B is directly supplied to the switch 51. The switch 51 has relays 54A and 54B, and the rectifier 50 is connected to the relay 54A, and the power receiving connector 52B is connected to the relay 54B. Here, the controller 53 supplies the power from the commercial power distribution board 48, that is, the DC power converted from the AC by the rectifier 50, to the high voltage circuit by turning on the relay 54A and turning on the relay 54B. Similarly, the DC power from the DC power supply rapid charger 49 is supplied to the high voltage circuit by turning on the relay 54A and turning on the relay 54B. In addition, the storage battery device 7 is connected to the high voltage circuit in the switch 51.

[0065] Figure 6 : is a diagram showing the structure of the battery device 7. The battery device 7 has a battery module 62 in which a plurality of battery groups 62A, 62B, ... are connected in series and a battery controller 59. The battery groups 62A, 62B, ... are monitored and controlled by a group controller (not shown) provided in the battery module 62. The battery controller 59 inputs state quantities such as the group voltage and group temperature detected by the group controller and periodically sends them to the controller 53.

[0066] In addition, a current sensor 63 is provided on the positive electrode side of the battery module 62. The current sensor 63 detects the input and output current values ​​of the battery device 7, and the input and output current values ​​are sent to the controller 53 via the battery controller 59. The controller 53 calculates the temperature, total voltage, SOC, and supply power of the battery device based on the information received from the battery controller 59. In addition, when the machine body is stopped or abnormal, the controller 53 sets the relay 64 to close to cut off the connection between the battery device 7 and the circuit. In addition, the calculated SOC of the battery device 7 is displayed on the monitor 30 through the display signal from the controller 53.

[0067] return Figure 4 The key switch 27 is composed of a lock cylinder and a key that can be inserted into the lock cylinder, and outputs a signal according to the rotational operation position of the key (closed position, open position or start position). The dial 28 indicates the target speed of the electric motor 31 and outputs a signal of the target speed corresponding to its rotational operation position. The charging switch 29 indicates whether the battery charging control is turned on or off, and outputs a signal according to its operation position (closed position or open position).

[0068] The electric hydraulic excavator of the present embodiment has two operating states: operation and charging.

[0069] Figure 7 : is a table showing the operating state and operating conditions of the electric hydraulic excavator of this embodiment. In this embodiment, the state in which power is supplied to the inverter 32 to rotate the electric motor 31 and the hydraulic pump 33 is called the operation mode. On the other hand, the state in which power is supplied to the battery device 7 and the electric motor 31 is stopped is called the charging mode. The charging mode and the operation mode are described below.

[0070] <Charging Mode>

[0071] The controller 53 performs battery charging control, for example, when it is determined that the key switch 27 is in the closed position by the voltage value of the signal from the key switch 27, that the charging switch 29 is operated to the open position by the voltage value of the signal from the charging switch 29, and that a cable from the commercial power distribution board 48 or the DC power rapid charger 49 is connected via the power receiving connectors 52A and 52B by the voltage value of the signal from the cable connection detection circuit (not shown).

[0072] When the commercial power distribution board 48 is connected, the controller 53 controls the relay 54A in the switch 51 to be in a closed state and the relay 54B to be in an open state. In addition, when the DC power supply rapid charger 49 is connected, the controller 53 controls the relay 54A in the switch 51 to be in an open state and the relay 54B to be in a closed state. The DC power is supplied to the storage battery device 7 through the high voltage circuit from the relay 54A or the relay 54B in the closed state.

[0073] When commercial power distribution board 48 and rapid charger 49 are connected at the same time, relays 54A and 54B are controlled to be in an open state for safety.

[0074] When controller 53 determines that charging switch 29 is in the closed position based on the voltage value of the signal from charging switch 29 during charging of storage battery device 7, controller 53 stops charging by controlling relays 54A and 54B to open.

[0075] Alternatively, when the SOC of the storage battery device 7 calculated by the controller 53 exceeds a predetermined threshold value, it is determined that the storage battery is fully charged, and similarly, the relay 54A and the relay 54B are controlled to be in the open state to stop charging.

[0076] <Operation Mode>

[0077] <<Battery Operation Mode>>

[0078] The operation mode based on the storage battery device 7 will be described.

[0079] For example, when the controller 53 determines that the key switch 27 is operated to the start position based on the voltage value of the signal from the key switch 27, and that the charging switch 29 is operated to the closed position based on the voltage value of the signal from the charging switch 29, and that the cables from the commercial power distribution board 48 and the DC power rapid charger 49 are not connected through the power receiving connectors 52A and 52B by the voltage value of the signal from the cable connection detection circuit (not shown), the controller 53 starts driving the electric motor 31 based on the power from the battery device 7. Alternatively, when the voltage value of the signal from the lock switch 47 determines that the door lock rod is in the unlock position, the controller 53 starts driving the electric motor 31 based on the power from the battery device 7.

[0080] At this time, the controller 53 turns on the relays 54A and 54B in the switch 51 to control the circuit connection between the commercial power distribution board 48 and the DC power rapid charger 49 to be disconnected.

[0081] The controller 53 also outputs a target rotation speed command indicated by the dial 28 to the inverter 32. The inverter 32 controls the voltage applied to the electric motor 31 in accordance with the command so that the actual rotation speed of the electric motor 31 reaches the target rotation speed.

[0082] When the controller 53 determines that the key switch 27 is in the closed position based on the voltage value of the signal from the key switch 27 during driving of the electric motor 31, for example, it outputs a stop command to the inverter 32. The inverter 32 stops the electric motor 31 in response to the command.

[0083] Alternatively, when the SOC of the battery device 7 calculated by the controller 53 is lower than a predetermined threshold value, it is determined that the remaining amount of the battery is low, and the controller 53 outputs an instruction to limit the output to the inverter 32. The output limit has a level according to the SOC, and the inverter 32 controls the rotation speed of the electric motor 31 according to the instruction, and finally stops the electric motor 31 when the SOC is lower than the SOC threshold value determined to have a safety problem.

[0084] <<Commercial power operation mode>>

[0085] Next, an operation mode realized by the power supplied from the commercial power distribution board 48 will be described.

[0086] For example, when the controller 53 determines that the key switch 27 is operated to the start position based on the voltage value of the signal from the key switch 27, and that the charging switch 29 is operated to the closed position based on the voltage value of the signal from the charging switch 29, and that the cable from the commercial power distribution board 48 is connected but the cable from the DC power rapid charger 49 is not connected based on the voltage value of the signal from the cable connection detection circuit (not shown) via the power receiving connectors 52A and 52B, the controller 53 starts driving the electric motor 31 based on the power from the commercial power distribution board 48. Alternatively, when the controller 53 determines that the door lock rod is in the unlock position based on the voltage value of the signal from the lock switch 47, the controller 53 starts driving the electric motor 31 based on the power from the commercial power distribution board 48.

[0087] At this time, the controller 53 switches the relay 54A inside the switch 51 to a closed state, switches the relay 54B to an open state, connects the commercial power distribution board 48 to the high voltage circuit and supplies power, and controls the direction to cut off the circuit connection between the DC power supply rapid charger 49.

[0088] The controller 53 calculates a speed control command Nd based on the target speed indicated by the dial 28 and a motor required speed Ndr described later, and outputs the speed control command Nd to the inverter 32 , thereby controlling the voltage applied to the electric motor 31 and controlling the speed of the electric motor 31 .

[0089] When the controller 53 determines that the key switch 27 is in the closed position based on the voltage value of the signal from the key switch 27 during driving of the electric motor 31, for example, it outputs a stop command to the inverter 32. The inverter 32 stops the electric motor 31 in response to the command.

[0090] Figure 8 1 is a functional block diagram showing processing functions of the controller 53 when controlling the driving of the electric motor 31 in the commercial power supply driving mode.

[0091] As described above, the electric hydraulic excavator of this embodiment can receive power from the power receiving device 80 (see FIG. 1 ) of the commercial power supply via the switchboard 48. Fig.10) supplies power to the electric motor 31. Therefore, the electric hydraulic excavator of this embodiment has a commercial power supply drive control device, which has a communication device 46 for performing data transmission and reception with other electric construction machines that share a power receiving device, and a controller 53. The controller 53 has the following functions: based on the operation signal of the operation device 35, 37..., it calculates its own required power Pd1 for driving the plurality of hydraulic actuators 13A, 19..., and sends the self-required power Pd1 to other electric construction machines via the communication device 46, and receives the required power Pd2, Pd3, ..., Pdn calculated in other electric construction machines via the communication device 46.

[0092] The controller 53 also generates a signal based on its own required power Pd1, the required powers Pd2, Pd3, ..., Pdn of other electric construction machines received via the communication device 46, and the power receiving device 80 (see FIG. 1 ) of the commercial power supply. Fig.10 ) is used to calculate the allowable power Plim as the power limit value that can be used by the electric motor 31, and the electric motor 31 is controlled in such a way that the power consumption of the electric motor 31 does not exceed the allowable power Plim.

[0093] By controlling the electric motor 31 in this way, it is possible to avoid exceeding the allowable power that can be output by the power receiving device 80 of the commercial power supply serving as the external power supply when multiple electric construction machines are operating simultaneously. At the same time, the supply power can be allocated to each machine body without operating deviation in accordance with the required power Pd1, Pd2, Pd3, ... Pdn of each of the multiple electric construction machines, so that the machines can operate efficiently within the allowable power.

[0094] Figure 8 In order to execute the above functions, the controller 53 includes a required power calculation unit 70, an internal setting recording unit 71, an allowable power calculation unit 72, a minimum value selection unit 73, and a motor rotation speed calculation unit 75.

[0095] The required power calculation unit 70 receives signals from the pressure sensors 26A and 26B that detect the pilot pressure generated by the pilot valve of the operating device 35, the pressure sensors 26C and 26D that detect the pilot pressure generated by the pilot valve of the operating device 37, and the pressure sensors that detect the pilot pressure generated by the pilot valves of other operating devices (not shown), and calculates the required power Pd1 for driving the hydraulic actuators 13A, 19, etc. based on the pilot pressures indicated by these signals. The required power Pd1 is sent to the allowable power calculation unit 72 and the minimum value selection unit 73. In addition, the required power Pd1 is also sent to the communication device 46 connected to the controller 53, and is sent to other electric hydraulic excavators via the communication device 46.

[0096] In addition, in this embodiment, the operating device is a hydraulic pilot type, and the operating signal is a pilot pressure. Alternatively, the operating device may be an electronic type, in which case the operating signal is an electronic signal, and the required power calculation unit 70 may directly use the electronic signal input to the controller 53 to calculate its own required power Pd1.

[0097] Furthermore, the required power calculation unit 70 may receive the detection signal of the pressure sensor 25 in addition to the operation signal, and calculate the self-required power Pd1 based on the operation signal and the delivery pressure of the hydraulic pump 33 .

[0098] The internal setting recording unit 71 inputs and records the setting information from the monitor 30. Here, the operator operates a switch provided on the monitor 30 to input the commercial power source predetermined based on the contract power between the operator and the power utility organization to the power receiving device 80 (see Fig.10 The monitor 30 outputs the allowable power to the internal setting recording unit 71. The internal setting recording unit 71 multiplies the allowable power by the power conversion coefficient to calculate the allowable power PSlim of the power receiving device 80, and records the allowable power PSlim as setting information. In addition, the operation of calculating the allowable power PSlim from the allowable power of the power receiving device 80 of the commercial power supply may be performed in the monitor 30.

[0099] The allowable power calculation unit 72 inputs the required power Pd1 calculated by the required power calculation unit 70, the allowable power PSlim of the power supply recorded in the internal setting recording unit 71, and the required powers Pd2, Pd3, ..., Pdn from other electric hydraulic excavators received by the communication device 46, and calculates the allowable power Plim of the electric motor 31 that can be used by its own body.

[0100] Here, other electric hydraulic excavators that transmit and receive data via the communication device 46 also have Figure 8 The controller 53 shown in the figure is a similar controller. In the required power calculation unit of these controllers, the required power Pd2, Pd3, ..., Pdn of each machine body is calculated. In this specification, in order to distinguish such required power Pd2, Pd3, ..., Pdn, sometimes Figure 8 The required power Pd1 calculated in the required power calculation unit 70 shown is appropriately referred to as self-required power.

[0101] Required power Pd1 calculated by required power calculation unit 70 and allowable power Plim calculated by allowable power calculation unit 72 are directed to minimum value selection unit 73, which selects the smaller value of allowable power Plim and required power Pd1 as target required power Pr.

[0102] The motor rotation speed calculation unit 75 inputs the target required power Pr and a signal from the pressure sensor 25 that detects the pressure P in the discharge line 40 of the hydraulic pump 33 , and calculates the motor required rotation speed Ndr based on the target required power Pr and the pressure P.

[0103] The target speed calculation table 74 receives the instruction signal corresponding to the rotational operation position from the dial 28 and calculates the target speed Nd0 of the electric motor 31 corresponding to the instruction signal of the dial 28. The target speed calculation table 74 is set with the characteristic of the target speed corresponding to the instruction signal (rotational operation position) of the dial 28.

[0104] The motor speed request Ndr of the motor speed calculation unit 75 and the target speed Nd0 calculated by the target speed calculation table 74 are input to the minimum value selection unit 76, and the minimum value selection unit 76 selects the smaller value between the motor speed request Ndr and the target speed Nd0 as the speed control command Nd.

[0105] The speed control command Nd is output to the inverter 32 , and the inverter 32 controls the voltage applied to the electric motor 31 according to the speed control command Nd, thereby controlling the speed of the electric motor 31 so that the actual speed of the electric motor 31 becomes the speed control command Nd.

[0106] Fig. 9 Requested power calculation unit 70 is a functional block diagram showing processing functions of request power calculation unit 70. Requested power calculation unit 70 includes tables 77A, 77B, 77C, and 77D and a maximum value selection unit 78.

[0107] Tables 77A, 77B, 77C, and 77D input signals from pressure sensors 26A, 26B, 26C, and 26D, respectively, and calculate required powers Pd_a, Pd_b, Pd_c, and Pd_d.

[0108] Tables 77A, 77B, 77C, and 77D set the characteristics of each required power corresponding to the operation amount of the operating lever of the operating device 35, 37 that determines the required workload of the hydraulic actuator 13A, 19, ... (pilot pressure Pi_a, Pi_b, Pi_c, Pi_d detected by the pressure sensors 26A, 26B, 26C, and 26D). By referring to the pilot pressures Pi_a, Pi_b, Pi_c, and Pi_d detected by the pressure sensors 26A, 26B, 26C, and 26D in Tables 77A, 77B, 77C, and 77D, the required powers Pd_a, Pd_b, Pd_c, and Pd_d corresponding to the operation amount of the operating lever are calculated. The characteristics of the required power set in Tables 77A, 77B, 77C, and 77D are predetermined for the specifications of each machine body.

[0109] The required powers Pd_a, Pd_b, Pd_c, and Pd_d calculated from the tables 77A, 77B, 77C, and 77D are directed to the maximum value selection unit 78, and the largest value among the required powers Pd_a, Pd_b, Pd_c, and Pd_d is selected and output as the required power Pd1.

[0110] In this way, the controller 53 calculates the self-required power Pd1 in the required power calculation unit 70 based on the pilot pressures Pi_a, Pi_b, Pi_c, and Pi_d detected by the plurality of pressure sensors 26A, 26B, 26C, and 26D.

[0111] Furthermore, the required power calculation unit 70 may include an adding unit instead of the maximum value selection unit 78 to add the required powers Pd_a, Pd_b, Pd_c, and Pd_d to calculate the required power Pd1.

[0112] The allowable power calculation unit 72 calculates the allowable power Plim using the following equation (1).

[0113] Equation 1

[0114]

[0115] In the formula (1), the first term on the right side is the power supply allowable power PSlim set in the internal setting recording unit 71. In the second term on the right side, the denominator is the sum of the required powers Pd1, Pd2, Pd3, ..., Pdn of the electric hydraulic excavator operated by the power supplied from the power receiving device 80 of the same commercial power supply (total required power). The required powers Pd1, Pd2, Pd3, ..., Pdn are values ​​calculated in the required power calculation unit 70 of the controller 53 mounted on each body of the electric hydraulic excavator, and are included in the data received by the communication device 46 mounted on each body. In addition, the numerator is the self-required power Pd1 required by the electric hydraulic excavator of the present embodiment described above. Therefore, the second term represents the ratio of the power (self-required power) Pd1 required by the body to the total required power of the electric hydraulic excavator operated by the power receiving device 80 of the same commercial power supply.

[0116] The power supply allowable power PSlim that can be output from the allowable power of the power receiving device 80 of the commercial power supply is allocated according to the ratio of the required power of the electric hydraulic excavator using the power receiving device 80, and the result is the allowable power Plim.

[0117] In this way, the controller 53 calculates the ratio of its own required power Pd1 to the total required power between its own required power Pd1 and the required powers Pd2, Pd3, ..., Pdn of other electric construction machinery received via the communication device 46 in the allowable power calculation unit 72, and calculates the allowable power Plim based on the allowable power of the power receiving equipment 80 of the commercial power supply and the above ratio.

[0118] The controller 53 also presets the power supply allowable power PSlim calculated based on the allowable power of the power receiving device 80 of the commercial power supply in the internal setting recording unit 71, and calculates the allowable power Plim by multiplying the power supply allowable power PSlim by the ratio of the self-required power Pd1.

[0119] The motor rotation speed calculation unit 75 calculates the required rotation speed Ndr using the following equation (2).

[0120] Equation 2

[0121]

[0122] In addition, Nmin≤Ndr≤Nmax

[0123] In the right side of the formula (2), μm in the denominator of the third term is the mechanical efficiency of the hydraulic pump 33, and qm is the capacity of the hydraulic pump 33, that is, the amount of oil discharged per rotation of the hydraulic pump. In addition, the required rotation speed Ndr is limited to a minimum rotation speed Nmin and a maximum rotation speed Nmax determined by the specifications of the electric motor 31.

[0124] The numerator Pr of the third term in the equation (2) is the value selected by the minimum value selection unit 73 as the smaller value between the self-required power Pd1 and the allowable power Plim, and the power receiving device 80 (see Fig.10 ) is taken into account, and the required speed Ndr is calculated by the target required power Pr and the current pressure of the hydraulic pump 33, that is, the detection value P of the pressure sensor 25.

[0125] In this way, the controller 53 selects the smaller value between its own required power Pd1 and the allowable power Plim as the target required power Pr in the minimum value selection unit 73, and calculates the required speed Ndr of the electric motor 31 based on the target required power Pr in the motor speed calculation unit 75, and controls the speed of the electric motor 31 based on the required speed Ndr.

[0126] ~Work~

[0127] Fig.10This is an overall configuration diagram related to the operation of a plurality of electric hydraulic excavators that are operated by electric power supplied from a power receiving device 80 of the same commercial power source.

[0128] The power feeder cable A-71 is connected to a power receiving connector A-52A provided in the electric hydraulic excavator A, and electric power from a commercial power source is supplied from a switchboard A-48.

[0129] Similarly, the feeder cable B-71 is connected to the power receiving connector B-52A provided on the electric hydraulic excavator B, and the commercial power is supplied from the switchboard B-48. The feeder cable C-71 is connected to the power receiving connector C-52A provided on the electric hydraulic excavator C, and the commercial power is supplied from the switchboard C-48.

[0130] The switchboards A- 48 , B- 48 , and C- 48 are connected in parallel to a power receiving device 80 of a commercial power source, and the power of the commercial power source is supplied from the power receiving device 80 .

[0131] In addition, the communication device A-46 mounted on the electric hydraulic excavator A, the communication device B-46 mounted on the electric hydraulic excavator B, and the communication device C-46 mounted on the electric hydraulic excavator C form a wireless network, and mutually exchange information from the controller ( Figure 4 The data entered is recorded.

[0132] In addition, for simplicity, three electric hydraulic excavators A, B, and C are used for description.

[0133] It is assumed that any machine body is operated in the commercial power supply operation mode, that is, operated by the power supply from the power receiving device 80 of the same commercial power supply.

[0134] In addition, the power supply allowable power PSlim determined by taking into account the amount of conversion from the supplied power to the power of the electric hydraulic excavator is set in the internal setting recording unit 71 ( Figure 8 as recorded).

[0135] As described above, the power supply allowable power PSlim is calculated by inputting the contract power set by the operator for the power receiving device 80 of the commercial power supply into the monitor 30 provided in each machine body.

[0136] <When the total power required by the electric construction machinery does not exceed the allowable power>

[0137] The required power of the electric hydraulic excavator A is represented by Pd1, the required power of the electric hydraulic excavator B is represented by Pd2, and the required power of the electric hydraulic excavator C is represented by Pd3.

[0138] The required power Pd1 is transmitted as data to the electric hydraulic excavator B and the electric hydraulic excavator C via the communication device A- 46 .

[0139] Similarly, the requested power Pd2 is transmitted to the electric hydraulic excavator A and the electric hydraulic excavator C via the communication device B-46, and the requested power Pd3 is transmitted to the electric hydraulic excavator A and the electric hydraulic excavator B via the communication device C-46.

[0140] In the allowable power calculation unit 72 of the electric hydraulic excavator A, the allowable power Plim(A) is calculated by the following equation (3).

[0141] Equation 3

[0142]

[0143] Based on formula (3), when the sum of the power required by electric hydraulic excavator A, the power required by electric hydraulic excavator B, and the power required by electric hydraulic excavator C, that is, Pd1+Pd2+Pd3, is lower than the power supply allowable power PSlim, Plim(A)>Pd1. In this case, the target required power Pr as the output of the minimum value selection unit 73 is Pd1.

[0144] Similarly, the allowable power Plim(B) calculated by the electric hydraulic excavator B and the allowable power Plim(C) calculated by the electric hydraulic excavator C are calculated by the following formula (4).

[0145] Equation 4

[0146]

[0147] Similar to the case of the electric hydraulic excavator A, the output of the minimum value selection unit 73 of the electric hydraulic excavators B and C, namely the target required power Pr, becomes Pd2 and Pd3 respectively. Therefore, the motor required speed Ndr is determined by the required powers Pd1, Pd2, and Pd3 and is not limited by the allowable power Plim.

[0148] Therefore, the electric hydraulic excavator operated by the power supplied from the power receiving device 80 of the same commercial power source is not limited by the allowable power Plim and operates at a required rotation speed corresponding to the required power unless the total required power does not exceed the allowable power PSlim taking the allowable power into consideration.

[0149] <When the total power required by electric construction machinery exceeds the allowable power>

[0150] In the allowable power calculation unit 72 in the electric hydraulic excavator A, when the sum of the required power Pd1 of the electric hydraulic excavator A, the required power Pd2 of the electric hydraulic excavator B, and the required power Pd3 of the electric hydraulic excavator C, that is, Pd1+Pd2+Pd3, exceeds the power supply allowable power PSlim, Plim<Pd1 is obtained. Therefore, the output of the minimum value selection unit 73, that is, the target required power Pr, becomes Plim(A).

[0151] Similarly, in the electric hydraulic excavator B and the electric hydraulic excavator C, the output of the minimum value selection unit 73, that is, the target required power Pr, becomes Plim(B) and Plim(C), respectively, and therefore the motor required speed Ndr is determined by the allowable power Plim(A), Plim(B), and Plim(C), and is not limited by the allowable power Plim.

[0152] At this time, the total allowable power of the electric hydraulic excavators A, B, and C is calculated as the result of the following equation (5).

[0153] Equation 5

[0154] Plim(A)+Plim(B)+Plim(C)=PSlim…(5)

[0155] Therefore, the total allowable power of each electric hydraulic excavator is limited to the power supply allowable power PSlim, thereby preventing the total power supplied to each machine from exceeding the allowable power of the power receiving device 80 of the commercial power supply.

[0156] ~Effect~

[0157] As described above, according to the present embodiment, when a plurality of electric construction machines are operating simultaneously, it is possible to avoid exceeding the allowable power that can be output by the power receiving equipment of the commercial power supply serving as the external power supply, and at the same time, the supply power can be allocated to each machine body without operating deviation in accordance with the respective required powers Pd1, Pd2, Pd3, ... Pdn of the plurality of electric construction machines, so that the machines can operate efficiently within the allowable power.

[0158] Furthermore, in the above-described embodiment, the electric construction machine is described as a crawler hydraulic excavator, but the electric construction machine may be a construction machine other than a hydraulic excavator, for example, a wheel hydraulic excavator, a wheel loader, or other construction machine.

[0159] Description of Reference Numerals

[0160] 1 Lower running body

[0161] 2 Upper rotating body

[0162] 5 Operating equipment

[0163] 7 Battery device

[0164] 13A, 13B Travel hydraulic motor

[0165] 16 Boom

[0166] 17 Stick

[0167] 18 Bucket

[0168] 19 Hydraulic cylinder for boom

[0169] 20 Hydraulic cylinder for bucket arm

[0170] 21 Bucket hydraulic cylinder

[0171] 23A Travel lever

[0172] 24B Boom and bucket operating lever

[0173] 25. Pressure Sensor

[0174] 26A, 26B, 26C, 26D Pressure Sensors

[0175] 27 Key switch

[0176] 28 Dial

[0177] 29 Charging switch

[0178] 30 Monitor

[0179] 31 Electric Motor

[0180] 32 Inverter

[0181] 33 Hydraulic pump

[0182] 34 pilot pump

[0183] 35 Left driving operating device

[0184] 37 Bucket and boom operating devices

[0185] 36 Direction switching valve for left travel

[0186] 38 Boom Directional Switching Valve

[0187] 46 Communication devices

[0188] 47 Lock switch

[0189] 48 Commercial power distribution board

[0190] 49 DC Power Rapid Charger

[0191] 50 Rectifier

[0192] 51 Switcher

[0193] 52A, 52B power receiving connector

[0194] 53 Controller

[0195] 70 Required power calculation unit

[0196] 71 Internal setting record

[0197] 72 Allowable power calculation unit

[0198] 73 Minimum value selection unit

[0199] 74 Target speed calculation table

[0200] 75 Motor speed calculation unit

[0201] 76 Minimum value selection unit

[0202] Table 77A, 77B, 77C, 77D

[0203] 78 Maximum value selection unit

[0204] 80 Powered Device

[0205] A, B, C Electric hydraulic excavator (electric construction machinery)

[0206] PSlim Power Supply Allowable Power

[0207] Plim Permissible power

[0208] Pd1 (self) required power

[0209] Pr target required power

[0210] Ndr Motor required speed

[0211] Nd Speed ​​control command

Claims

1. An electric engineering machine, comprising: an electric motor; a hydraulic pump driven by the electric motor; a plurality of hydraulic actuators driven by hydraulic oil discharged from the hydraulic pump; a plurality of directional switching valves for controlling the flow of hydraulic oil supplied from the hydraulic pump to the plurality of hydraulic actuators; a plurality of operating devices for instructing the actions of the plurality of hydraulic actuators and generating operating signals for switching the plurality of directional switching valves; and a battery device for supplying power to the electric motor, The electric construction machine comprises: A battery operation mode in which the electric motor is driven by electric power supplied from the battery device; and A commercial power operation mode in which the electric motor is driven by power supplied from a power receiving device, The electric construction machine is characterized by having: A communication device for transmitting and receiving data between other electric construction machines that share the power receiving device; and a controller that calculates its own required power for driving the plurality of hydraulic actuators based on the operation signals of the plurality of operating devices, The controller is configured as follows: In the battery operation mode, the electric motor is controlled based on the remaining amount of the battery device, When in the commercial power supply operation mode, the self-required power is transmitted to the other electric construction machinery via the communication device, and the required power calculated in the other electric construction machinery is received via the communication device, and the allowable power that can be used by the electric motor is calculated based on the self-required power, the required power of the other electric construction machinery received via the communication device, and the allowable power of the power receiving device, and the electric motor is controlled in such a way that the power consumption of the electric motor does not exceed the allowable power.

2. The electric construction machine according to claim 1, characterized in that: The controller calculates a ratio of the own required power to a total required power of the own required power and required power of the other electric construction machines received via the communication device, and calculates the allowable power based on the allowable power of the power receiving device and the ratio.

3. The electric construction machine according to claim 2, characterized in that: The controller predetermines a power source allowable power calculated based on the allowable power of the power receiving device, and calculates the allowable power by multiplying the power source allowable power by the ratio of the self-required power.

4. The electric construction machine according to claim 1, characterized in that: The controller selects a smaller value between the self-required power and the allowable power as a target required power, calculates a required rotation speed of the electric motor based on the target required power, and controls the rotation speed of the electric motor based on the required rotation speed.

5. The electric construction machine according to claim 1, characterized in that: The plurality of operating devices are hydraulic pilot type that generate pilot pressure as the operating signal, The electric construction machine further includes a plurality of pressure sensors for detecting a plurality of pilot pressures generated by the plurality of operating devices. The controller calculates the self-required power based on the plurality of pilot pressures detected by the plurality of pressure sensors.

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