JP2010206978A - Charging device for battery-driven construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform effective and efficient power supply within a range not exceeding the maximum demand power set as a power specification, in charging the battery of a battery-driven construction machine. <P>SOLUTION: A battery 30 for driving an actuator is mounted on a battery-driven hydraulic excavator 1, and electric power from a charging device 32 connected to a power receiving mechanism 41 from a commercial power supply 40 is supplied to the battery 30. The charging device 32 includes an input panel 42 into which data is input regarding the power specification set in the power receiving mechanism 41. Current threshold calculation units 46A, 46B constituting an output current calculating means 44 calculate the threshold of the output current based on the data of the power specification thus input. The output current of the charging device 32 is controlled by the main power transistor 49 so as not to exceed the threshold of the output current stored in the control circuit 48 constituting the current limiting means 47. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a construction machine such as a hydraulic excavator, and is a battery-driven construction machine configured to drive a plurality of actuators using a battery as a drive source. The present invention relates to a charging device.

  In a hydraulic excavator as an example of a construction machine, an upper swing body is installed on a lower traveling body having left and right crawler belts via a swing device so that the upper swing body can swing. The upper swing body includes a boom, an arm and a bucket, and is provided with working means for performing work such as excavation of earth and sand. The upper swing body is also provided with a cab where an operator who operates the machine is boarded.

  The lower traveling body is driven by a traveling motor, and a turning motor is attached to the turning device. The working means are each driven by a hydraulic cylinder such as a boom cylinder, an arm cylinder, and a bucket cylinder. Therefore, the motor and the hydraulic cylinder constitute an actuator of the machine, and the operation of the vehicle, the turning of the upper turning body, and the work by the working means are executed by operating each actuator. Here, as the plurality of actuators, an electric motor or a hydraulic motor can be used as the motor. On the other hand, it is a hydraulic cylinder that drives the working means. Therefore, the hydraulic excavator is provided with a hydraulic pump. Thus, since it has a hydraulic pump, a travel motor and a turning motor can be comprised from an electric motor, and can also be comprised by a hydraulic motor.

  As a power source of a construction machine, an engine-driven type using an engine as a prime mover has been widely used. However, from the viewpoints of exhaust gas regulations in recent years, demands for noise reduction, and the like, an electrically driven type has been developed and put into practical use. In the case of the electric drive type, there is an external power supply type that requires a power supply to the outside, but in this method, the vehicle and the external power supply must always be connected with a power cord, and workability is poor There is.

  From the above, a battery-driven construction machine using a battery mounted on a vehicle and using the battery as a drive source is being put into practical use. However, since construction machines operate for a long time under high load conditions, the drive battery has a large capacity. To cover all power with the battery, it is placed on the upper revolving structure of the construction machine. You will have to use a battery that cannot be sized. Therefore, for environmental measures such as exhaust gas and noise, it is desirable to use a completely electric type that uses only the battery as the drive source. However, due to restrictions on the installation space of the battery, the battery and engine are used together for practical use. Preceded by hybrid construction machines. Here, the construction machine is also equipped with a battery as a power source for control, and this control battery is stored using a generator installed in the construction machine. In this case, the battery is used as a driving source for driving the actuator by being charged with the supply of electric power from a commercial power source.

  As described above, a battery mounted on a construction machine is charged by being connected to a charging device, and the charging device is supplied with electric power from a commercial power source provided by an electric power company. Here, in the field of civil engineering and construction work, various electric machinery and equipment are used, and power is supplied to various facilities. Therefore, a power receiving mechanism is constructed as a system, and a power receiving contract is concluded with an electric power company individually. Will do. Therefore, when a power receiving mechanism system is constructed, a charging device for supplying power to the battery is also incorporated into the power receiving mechanism. By connecting the cable from the charging device to the battery-driven construction machine, the battery is connected to the battery. Electric power is supplied and charging is performed. As an example of the charging device, as disclosed in Patent Document 1, for example, AC power from a commercial power source is converted into DC power and supplied to the battery. Therefore, in a battery-driven construction machine, power is supplied to the battery during a time period when work is not performed, such as at night, by a plug-in method from a charging device.

JP 2008-86155 A

  The charge system based on the contract between the power receiving mechanism constructed at the civil engineering / construction site and the electric power company in the system is set based on the maximum power demand. Therefore, from the viewpoint of cost reduction, the maximum demand power is set in consideration of various conditions in each civil engineering / construction site, and the power consumption is limited so as not to exceed this maximum demand power. By making effective use of electric power, construction will be carried out smoothly.

  If the power capacity of the charging device is used to the maximum for charging the battery, the charging time can be shortened, but there is a possibility that the above-described maximum demand power will be exceeded. On the other hand, if the power capacity of the charging device is used in a state lower than the power capacity set according to the specification, the charging time will be prolonged correspondingly, and the charging efficiency will decrease. From the above, when charging the battery, it is necessary to perform efficient charging in a range not exceeding the maximum demand power set by the power specification. It is troublesome to change the output setting each time, and inconveniences caused by neglecting the setting change may not be eliminated.

  The present invention has been made in view of the above points, and the object of the present invention is a range that does not exceed the maximum demand power set as a power specification when charging a battery of a battery-driven construction machine. Thus, an effective and efficient power supply is to be performed.

  In order to achieve the above-described object, the present invention provides a charging device main body and a charging device main body that is drawn from the charging device main body and is detachably attached to the battery mounted on the construction machine. A battery-powered construction machine charging device including a cable to be connected, based on input means for inputting data related to power specifications set in the power receiving mechanism, and on the power specifications set by the input means Output current calculation means for calculating an output current threshold; and current limiting means including a control circuit for limiting the output current so as not to exceed the output current threshold based on an output signal from the output current calculation means; It is characterized by having a configuration including

  Here, when charging the battery from the charging device, AC current as a commercial power source is converted into DC current, and power corresponding to the power capacity of the battery is supplied. On the other hand, a power specification such as an electric method and maximum demand power is set in the power receiving mechanism, and the power supplied by this power specification is limited. When the battery is charged by the charging device, naturally, there is a limitation due to the power specification in the power receiving mechanism. In the contract with the electric power company, the maximum demand power is set and charged according to the actually consumed power capacity. Therefore, if the electric capacity to be used is large, the electric charge will increase accordingly. Therefore, it is necessary to charge the battery most efficiently within the limit of the power specification by the power receiving mechanism. For this purpose, data on the power specification by the power receiving mechanism is input to the charging device in advance. Then, based on this data, the threshold value of the output current is set, the output current at the time of charging is limited so as not to exceed this threshold value, and the battery is charged most efficiently within the range.

  If the power specification in the power receiving mechanism does not change, it is not necessary to input data about the power specification every time the battery is charged. Therefore, it is desirable to store this data in the control circuit of the current limiting means of the charging device. However, the power specifications of the power receiving mechanism may vary depending on the construction site. When the charging device is moved from one construction site to another, the power specifications are stored in the storage and storage means. -The stored data must be changed. Therefore, when the charging device is moved, the charging device erases the data related to the power specifications recorded and held in the power specification storage means so far and sets the data to require input again. When configured, inconvenience due to data change failure is avoided.

  In a battery-driven construction machine, the charging of the battery by the charging device can be controlled so as not to exceed the maximum demand power set as the power specification, and can be efficiently performed within the limited range.

1 is an overall configuration diagram illustrating a hydraulic excavator as an example of a battery-powered construction machine according to the present invention together with a battery charging device. FIG. FIG. 2 is a configuration explanatory diagram of a drive mechanism of the hydraulic excavator in FIG. 1. FIG. 4 is a configuration explanatory diagram of an output current control mechanism in a charging device. It is explanatory drawing which shows the structure of the data input means in the charging device of FIG.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 shows a hydraulic excavator as an example of a construction machine. Needless to say, the construction machine of the present invention is not limited to a hydraulic excavator.

  In the figure, reference numeral 1 denotes a hydraulic excavator. The hydraulic excavator 1 includes a lower traveling body 3 having crawler type traveling means 2 on the left and right sides, and an upper revolving body 5 provided on the lower traveling body 3 via a swiveling device 4. The upper turning body 5 is provided with a cab 6 in which an operator is boarded and a machine room building 7 in which various machines and instruments are stored. In addition, a work machine 8 is mounted on the upper swing body 5, and this work machine 8 is for performing operations such as excavation of earth and sand, and as a boom 9, an arm 10 and a replaceable front attachment. Of buckets 11.

  A pair of left and right crawler type traveling means 2 has a crawler belt 14 wound around a sprocket 12 and an idler 13, and the sprocket 12 is driven to rotate by a motor 20. The turning device 4 turns the upper turning body 5 and is also driven by the motor 21. Furthermore, the work machine 8 is provided with a boom cylinder 22, an arm cylinder 23, and a bucket cylinder 24. By driving these cylinders 22 to 24, operations such as excavation of earth and sand are performed.

  FIG. 2 shows the configuration of the drive control mechanism of each drive means described above. The traveling motor 20, specifically the crawler traveling means 2, is provided on the left and right, and two traveling motors are provided as indicated by reference numerals 20 </ b> R and 20 </ b> L in FIG. 2. These travel motors 20R and 20L are electric motors. The turning motor 21 is also an electric motor. The cylinders 22 to 24 as drive means of the work machine 8 are hydraulic cylinders, and a hydraulic pump 25 is provided to supply pressure oil to the cylinders 22 to 24. The hydraulic pump 25 is an electric motor. 26 is driven. Accordingly, the motors 20R, 20L, and 21 and the cylinders 22 to 24 are actuators of the hydraulic excavator 1. In addition, inverters 27A to 27D are connected to the motors 20R, 20L, 21 and 26, respectively, and a battery 30 is provided in the machine room building 7 to supply power to the inverters 27A to 27D. 30 and the inverters 27A to 27D are electrically connected. Although only the battery 30 is provided, the engine may be installed together with the battery 30.

  Inverters 25 to 29 are controlled based on a signal from control device 31. Although not shown, the cab 6 is provided with operation levers for left and right traveling, turning, boom operation, arm operation, and bucket operation. The control device 31 is configured to take control of the inverters 25 to 29 based on the operation signals of these operation levers.

  In order to supply power to the battery 30, a charging device 32 is fixedly installed at a predetermined position. The charging device 32 is configured to pull out the cable 33b from the charging device housing 33a, and the cable 33b is detachably connected to the connection portion 15 provided in the upper swing body 5 of the excavator 1. ing. In this way, by connecting the cable 33b to the connection portion 15, power is supplied to the battery 30 and charging is performed. The switching unit 34 is connected to the connection unit 15, and the switching unit 34 is connected to the connection unit 15 and the state in which the battery 30 is connected to the inverters 27 </ b> A to 27 </ b> D based on the control signal from the control device 31. Control to switch to the state is performed. When the battery 30 is connected to the inverters 27A to 27D, power is supplied to the motors 20R, 20L, 21 and 26, and the excavator 1 becomes movable. Further, when the battery 30 is connected to the connection unit 15, the battery 30 is charged.

  The charging device 32 is supplied with power from the commercial power supply 40 via the power receiving mechanism 41. The power receiving mechanism 41 is used not only as the charging device 32 but also as a power source for various electric devices used at the work site. Here, a predetermined power specification is set in the power receiving mechanism 41 by a contract with an electric power company. The battery 30 has a much higher power consumption than other electric devices that receive power from the power receiving mechanism 41, and may have a power capacity that exceeds the power specifications set in the power receiving mechanism 41. is there. Therefore, necessary data of the power specification set in the power receiving mechanism 41 is input to the charging device 32, and the output current at the time of charging the battery 30 is the threshold value of the output current set in the power specification. It is set as the structure controlled so that it may not be exceeded.

  For this purpose, the charging device 32 includes the output current control mechanism shown in FIG. This output current control mechanism is provided with an input panel 42 as input means and a display unit 43 for displaying input data. As shown in FIG. 4, the input panel 42 is provided with a numeric keypad for inputting a numerical value from 0 to 9, a set button and an erase button, and the display unit 43 is set according to the specification. The maximum value of voltage, the maximum value of power capacity, and the number of phases as an electric system are displayed. On the other hand, a selection button is provided on the display unit 43, and the selection button includes a voltage setting button, a power capacity setting button, and a phase number setting button. In addition, a numerical value display section for displaying numerical values along with these selection buttons is provided. Therefore, for example, when the voltage setting button is pressed, a numerical value is input with the numeric keypad, and the setting key is pressed, the voltage value set in the power specification is input. Each of these keys and buttons is input using a touch panel.

  An output current calculation unit 44 is connected to the input panel 42, and the output current calculation unit 44 includes a classification circuit 45 and a plurality of current threshold calculation units. Data relating to the voltage value, the power capacity value, and the number of phases as the electrical system input by the input panel 42 are taken into the sorting circuit 45 of the output current calculation means 44. In the classification circuit 45, the threshold value of the output current is obtained by calculation for each number of phases. In this case, there are two types, a single-phase method and a three-phase method. 46A and 46B, the maximum value of the output current of each of the single-phase system and the three-phase system, that is, the current threshold value is calculated.

  The current limiting means 47 is connected to the output current calculating means 44, and the data relating to the current threshold values calculated by the current threshold calculating sections 46 A and 46 B in the output current calculating means 44 is the control circuit 48 constituting the current limiting means 47. Will be entered. The commercial power source 40 is connected to the main power transistor 49 of the charging device 32 via the power receiving mechanism 41, and the power from the commercial power source 40 is a threshold value output from the control circuit 48 by the switching operation by the main power transistor 49. Thus, the electric power that is the output current controlled so as not to exceed is supplied to the battery 30.

  When the charging of the battery 30 is completed and the cable 33b is detached from the connecting portion 15, the excavator 1 can be operated. Here, the control circuit 48 is provided with storage means. Therefore, as long as the construction work site does not change, the data relating to the current threshold described above is stored and retained in the storage means of the control circuit 48, and it is necessary to re-enter the data every time charging is performed. Disappears.

  However, since the power specifications in the power receiving mechanism 41 are not uniform depending on the construction work site where the hydraulic excavator 1 operates, when carrying out from one construction work site and moving to another construction work site, Need to rewrite the data. For this reason, the charging device 32 is kept in an ON state as long as it is installed at a predetermined position so as to hold the above-described data, so that it can be carried out from the construction work site. When it is moved, the movement is detected, and the data relating to the maximum output current stored and held in each unit constituting the output current calculation unit 44, more specifically, the current threshold value calculation units 46A and 46B is erased. It is composed. For this purpose, a data erasing switch 35 is provided on the bottom surface of the charging device 32. The switch 35 is operated by the weight of the charging device 32, and is always in an ON state. When the charging device 32 is pulled up from a predetermined position using a crane or the like, the switch 35 is turned off, and the stored data is erased in the current threshold value calculation units 46A and 46B of the output current calculation means 44. It is configured.

  The present embodiment is configured as described above, and the hydraulic excavator 1 has a battery 30 mounted thereon. The electric power from the battery 30 causes the lower traveling body 3 to travel and the swiveling device 4 to perform the upper operation. The turning body 5 is turned, and the work machine 8 is further driven to perform work such as excavation of earth and sand. If such an operation is continued, power is consumed and the remaining amount of electricity stored in the battery 30 decreases. Therefore, the battery must be charged before the amount of electricity stored becomes zero. The remaining amount of electricity stored in the battery 30 can be detected by incorporating a battery checker or the like. Therefore, based on this detection signal, when the remaining amount of power storage is reduced to a level that requires charging, the operator can be notified by an alarm or the like. The operator performs the charging operation of the battery 30 based on this warning.

  Here, in order to efficiently charge the battery 30 in a short time, it is desirable to set the output current from the charging device 32 to a maximum value based on the power capacity of the battery. However, the charging device 32 is connected to the commercial power supply 40 via the power receiving mechanism 41, and a predetermined power specification is set in the power receiving mechanism 41, and the maximum power capacity is limited. Therefore, the charging device 32 is restricted by the power specification of the power receiving mechanism 41, and data related to the power specification is input to the charging device 32 in advance.

  That is, the maximum voltage, the maximum power capacity, and the number of phases are input from the input panel 42 and the display unit 43 by a touch panel method, and data based on the specifications is obtained by inputting numerical values for these and operating the setting buttons. Entered. Each data input in this way is taken into the output current calculation means 44, and is classified into data of the maximum voltage and maximum power capacity for each number of phases by the classification circuit 45, respectively. The current threshold value is calculated at 46B, and these data are taken into the control circuit 48 of the current limiting means 47 and stored.

  Here, the current threshold value calculation unit 46A calculates a current threshold value for a single phase, and the current threshold value calculation unit 46B calculates a current threshold value for a three-phase case. Therefore, the current threshold calculation unit 46A calculates current threshold = maximum power capacity / maximum voltage, and the current threshold calculation unit 46B calculates current threshold = maximum power capacity / √3 / maximum voltage.

  In this way, the control circuit 48 stores data relating to the current threshold value for each number of phases. In order to charge the battery 30 of the excavator 1, the excavator 1 is moved to a position close to the charging device 32. By running and connecting the cable 33b to the connecting portion 15, charging of the battery 30 is started. At the time of this charging, the main power transistor 49 of the current limiting means 47 is activated, and the supplied power is limited by the current threshold by the switching operation. Therefore, according to the power specification set in the power receiving mechanism 41. The battery 30 is charged most efficiently within a range not exceeding the maximum demand power.

  When the charging to the battery 30 is completed, the cable 33b is detached from the connection unit 15. At this time, the above-described various data stored in the charging device 32 are held as they are. Therefore, the same control as described above is performed during repeated charging.

  By the way, the power specifications of the power receiving mechanism 41 are individually set based on the respective scales, construction schedules, and the like depending on the respective construction work sites. Therefore, when the charging device 32 is installed on another construction work site. Needs to match the power specifications set in the power receiving mechanism 41 at the construction site. In principle, the charging device 32 does not move from one place to another, but when it is carried into another place, the charging apparatus 32 is lifted and transported using a crane or the like. The charging device housing 33a of the charging device 32 is provided with a switch 35 in the control circuit 48 in order to hold data relating to the stored current threshold value. When the switch 35 is in the ON state, The above-described data is retained, but is erased when the switch 35 is turned off. Therefore, when the charging device housing 33a of the charging device 32 is lifted by the crane, the switch 35 is turned off, and therefore the data stored in the control circuit 48 is erased and input again. It will be necessary.

  Therefore, it is desirable that the charging device 38 is set so as not to be in an operating state unless data is input. As a result, every time the construction site is changed, data can be written that can be adapted to the new power specifications of the new site without hesitation. Therefore, when the single charging device 32 is reused for a plurality of construction sites having different power specifications, the charging device 32 exhibits the maximum charging capability within the range of the power specification of the power receiving mechanism 41. .

DESCRIPTION OF SYMBOLS 1 Hydraulic excavator 15 Connection part 30 Battery 33b Cable 35 Switch 40 Commercial power supply 41 Power receiving mechanism 42 Input panel 43 Display part 44 Output current calculation means 45 Classification circuit 46A, 46B Current threshold value calculation part 47 Current limitation means 48 Control circuit 49 Main power transistor

Claims (3)

A battery-driven construction machine comprising a charging device body and a cable that is drawn from the charging device body and is detachably connected to the battery in order to supply power from a power receiving mechanism to a battery mounted on the construction machine Charging device,
Input means for inputting data relating to the power specifications set in the power receiving mechanism;
Based on the power specification set by the input means, output current calculation means for calculating a threshold value of the output current;
A battery-driven construction comprising: a current limiting means including a control circuit that limits the output current based on an output signal from the output current calculating means so as not to exceed a threshold of the output current Mechanical charging device. 2. The battery-powered construction machine charging apparatus according to claim 1, wherein the control circuit of the current limiting means includes means for storing and holding data relating to the power specification input by the input means. 3. The apparatus according to claim 2, further comprising means for erasing data relating to the power specification stored and held in the power specification storage means when the charging device main body is moved from the installation position. Battery-powered construction machine charging equipment.

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