JP2013204384A - Shovel, shovel control system, and information terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shovel for shortening a time of period from the time when an operator arrives at a work place where a shovel is on standby to the time when the shovel starts to be operated.SOLUTION: An motor is driven with power supplied from a power storage device. A radio communication device communicates with an information terminal . A control device warms up the power storage device when receiving a warm-up start command signal through the radio communication device.

Description

  The present invention relates to an excavator that drives an electric motor with a power storage device, an excavator management system, and an information terminal used for excavator management.

  In recent years, work machines such as excavators have been required to have performance such as fuel saving, low pollution, and low noise in consideration of the global environment. In order to satisfy these requirements, hybrid excavators using a motor generator connected to an internal combustion engine have appeared. The motor generator is driven by the electric power stored in the power storage device when performing the assist operation. When the power generation operation is performed, it is driven by the power generated by the internal combustion engine. The power storage device is charged with the generated power.

  The internal resistance of the power storage device depends on temperature, and the internal resistance increases at low temperatures. When normal discharge is performed in a state where the internal resistance is high, a voltage drop due to the internal resistance occurs, and the voltage between the terminals of the power storage device rapidly decreases. Conversely, when normal charging is performed in a state where the internal resistance is high, a voltage drop due to the internal resistance is superimposed on the electromotive force of the power storage device, and the voltage between the terminals of the power storage device increases rapidly. For this reason, control of charging / discharging becomes difficult.

  Patent Document 1 discloses a hybrid construction machine that can efficiently warm a power storage device.

International Publication No. 2010/079794

The work machine cannot be operated until the internal resistance sufficiently decreases after the warm-up of the power storage device is started.
An object of the present invention is to provide a shovel that can shorten the time from when an operator arrives at a work place where the shovel is waiting until the shovel is operated. Another object of the present invention is to provide an excavator management system and an information terminal for management.

According to one aspect of the invention,
A power storage device;
An electric motor driven by electric power supplied from the power storage device;
A wireless communication device for communicating with an information terminal;
When a warm-up start command signal is received through the wireless communication device, an excavator having a control device that performs a warm-up operation of the power storage device is provided.

According to another aspect of the invention,
A power storage device;
An electric motor driven by electric power supplied from the power storage device;
A wireless communication device;
When receiving a warm-up start command signal through the wireless communication device, an excavator having a control device that performs a warm-up operation of the power storage device,
There is provided an excavator management system including an information terminal that communicates with the excavator through the wireless communication device and transmits the warm-up start command signal to the excavator based on an input from an operator.

According to yet another aspect of the invention,
A wireless communication device for communicating with the excavator;
An input device for an operator to input;
A control device,
The control device is provided with an information terminal for sending a warm-up start command signal to the excavator through the wireless communication device when an operator instructs the warm-up start through the input device.

  The operator can start the warm-up operation of the power storage device of the excavator from a remote place. For this reason, it is possible to shorten the time from when the operator arrives at the work place where the excavator is waiting until when the excavator is operated.

FIG. 1 is a schematic diagram of an excavator and an information terminal according to an embodiment. FIG. 2 is a block diagram of an excavator according to the embodiment. FIG. 3 is a block diagram of a power storage circuit of the excavator according to the embodiment. FIG. 4A is a graph illustrating an example of a temporal change in voltage between terminals when the power storage device is discharged, and FIG. 4B is an equivalent circuit diagram of the power storage device. 5A, FIG. 5B, and FIG. 5C respectively show the time change of the charge / discharge current, the time change of the charge state of the power storage device, and the time change of the temperature of the power storage device during the warm-up operation period of the power storage device of the shovel according to the embodiment. It is a graph to show. FIG. 6 is a graph illustrating a signal transmission / reception sequence between the excavator and the information terminal according to the embodiment. 7A to 7F are plan views of the information terminal on which the excavator information is displayed. FIG. 8 is a plan view of the information terminal on which the position of the excavator is displayed. FIG. 9 is a block diagram of an excavator power storage circuit according to a modification of the embodiment.

  In FIG. 1, the schematic of the shovel management system by an Example is shown. The information terminal 11 transmits and receives signals to / from at least one hybrid excavator 10. Each of the excavators 10 includes a lower traveling body 71, an upper swing body 70, a boom 82, an arm 87, and a bucket 88. The upper turning body 70 is supported by the lower traveling body 71 by a turning bearing 73 so as to be turnable. The boom 82 swings up and down by a hydraulically driven boom cylinder 89. The arm 87 swings in the front-rear direction by an arm cylinder 90 that is hydraulically driven. The bucket 88 swings with respect to the arm 87 by a bucket cylinder 91 that is hydraulically driven.

  Each excavator 10 is equipped with a wireless communication device 13 and a power storage device 23. As the power storage device 23, for example, an electric double layer capacitor, a lead storage battery, a lithium ion secondary battery, a lithium ion capacitor, or the like is used. The information terminal 11 is equipped with an input device 12 and a wireless communication device 19. As the input device 12, for example, a touch panel or the like is used. As a wireless communication method, for example, a general communication method of a wireless LAN can be adopted.

FIG. 2 is a block diagram of a hybrid excavator according to the embodiment. In FIG. 2, the mechanical power system is represented by a double line, the high-pressure hydraulic line is represented by a thick solid line, the electric control system is represented by a thin solid line, and the pilot line is represented by a broken line.

  The drive shaft of the engine 74 is connected to the input shaft of the torque transmission mechanism 81. As the engine 74, an engine that generates a driving force by a fuel other than electricity, for example, an internal combustion engine such as a diesel engine is used. The engine 74 is always driven during operation of the work machine.

  The drive shaft of the motor generator 83 is connected to the other input shaft of the torque transmission mechanism 81. The motor generator 83 can perform both the electric (assist) operation and the power generation operation. As the motor generator 83, for example, an internal magnet embedded (IPM) motor in which magnets are embedded in the rotor is used.

  The torque transmission mechanism 81 has two input shafts and one output shaft. The output shaft is connected to the drive shaft of the main pump 75.

  When the load applied to the engine 74 is large, the motor generator 83 performs an assist operation, and the driving force of the motor generator 83 is transmitted to the main pump 75 via the torque transmission mechanism 81. Thereby, the load applied to the engine 74 is reduced. On the other hand, when the load applied to the engine 74 is small, the driving force of the engine 74 is transmitted to the motor generator 83 via the torque transmission mechanism 81, so that the motor generator 83 is in a power generation operation.

  The control device 130 includes a central processing unit (CPU) 130A and an internal memory 130B. The CPU 130A executes a drive control program stored in the internal memory 130B. The control device 130 communicates with the information terminal 11 (FIG. 1) by controlling the wireless communication device 13.

  The current position detection device 14 detects the current position of the excavator and inputs current position information to the control device 130. As the current position detection device 14, for example, a terminal for the global positioning system (GPS) is used. The current position information of the excavator is transmitted to the information terminal 11 (FIG. 1) via the wireless communication device 13.

  The main pump 75 supplies hydraulic pressure to the control valve 117 via the high pressure hydraulic line 116. The control valve 117 distributes hydraulic pressure to the hydraulic motors 101A and 101B, the boom cylinder 89, the arm cylinder 90, and the bucket cylinder 91 according to a command from the driver. The hydraulic motors 101A and 101B drive two left and right crawlers provided in the lower traveling body 71 shown in FIG.

  A motor generator 83 is connected to the storage circuit 80 via an inverter 84. A turning electric motor 76 is connected to the storage circuit 80 via an inverter 85. Inverters 84 and 85 and power storage circuit 80 are controlled by control device 130.

  The inverter 84 controls the operation of the motor generator 83 based on a command from the control device 130. Switching between the assist operation and the power generation operation of the motor generator 83 is performed by the inverter 84.

  During the period in which the motor generator 83 is being assisted, necessary power is supplied from the power storage circuit 80 to the motor generator 83 through the inverter 84. During the period in which the motor generator 83 is generating, the electric power generated by the motor generator 83 is supplied to the storage circuit 80 through the inverter 84.

  The turning electric motor 76 is AC driven by an inverter 85 and can perform both a power running operation and a regenerative operation. As the turning electric motor 76, for example, an IPM motor is used. During the power running operation of the turning electric motor 76, electric power is supplied from the power storage circuit 80 to the turning electric motor 76 via the inverter 85. The turning electric motor 76 turns the upper turning body 70 (FIG. 1) via the speed reducer 124. During the regenerative operation, the rotational motion of the upper swing body 70 is transmitted to the turning electric motor 76 via the speed reducer 124, so that the turning electric motor 76 generates regenerative electric power. The generated regenerative power is supplied to the storage circuit 80 via the inverter 85. Thereby, the power storage device in the power storage circuit 80 is charged.

  The resolver 122 detects the position of the rotation shaft of the turning electric motor 76 in the rotation direction. The detection result is input to the control device 130. By detecting the position of the rotating shaft in the rotation direction before and after the operation of the turning electric motor 76, the turning angle and the turning direction are derived.

  A mechanical brake 123 is connected to the rotating shaft of the turning electric motor 76 and generates a mechanical braking force. The braking state and the release state of the mechanical brake 123 are switched by an electromagnetic switch under the control of the control device 130.

  The pilot pump 115 generates a pilot pressure necessary for the hydraulic operation system. The generated pilot pressure is supplied to the operating device 126 via the pilot line 125. The operation device 126 includes a lever and a pedal and is operated by a driver. The operating device 126 converts the primary side hydraulic pressure supplied from the pilot line 125 into a secondary side hydraulic pressure in accordance with the operation of the driver. The secondary hydraulic pressure is transmitted to the control valve 117 via the hydraulic line 127 and to the pressure sensor 129 via the other hydraulic line 128.

  The detection result of the pressure detected by the pressure sensor 129 is input to the control device 130. Thereby, the control apparatus 130 can detect the operation state of the lower traveling body 71, the boom 82, the arm 87, the bucket 88 (FIG. 1), and the turning electric motor 76.

  FIG. 3 shows a block diagram of the power storage circuit 80. The power storage circuit 80 includes a power storage device 23 and a step-up / down converter 24. The step-up / down converter 24 is connected to the inverters 84 and 85 via the bus line 61. The bus line 61 includes a smoothing capacitor and the like. The step-up / down converter 24 is controlled by the control device 130 and controls charging / discharging of the power storage device 23. At the time of discharging, the voltage between the terminals of the power storage device 23 is boosted, and power is supplied from the power storage device 23 to the bus line 61. At the time of charging, the electric power stored in the bus line 61 is supplied to the power storage device 23. By controlling the buck-boost converter 24 to charge / discharge the power storage device 23, the power storage device 23 can be heated.

  The temperature sensor 28 measures the temperature of the power storage device 23. The measurement result is input to the control device 130.

  With reference to FIG. 4A and FIG. 4B, the effect which warms up the electrical storage apparatus 23 before the operation of a shovel is demonstrated.

FIG. 4A shows an example of the time variation of the voltage between the terminals of the power storage device 23. The horizontal axis represents elapsed time, the left vertical axis represents inter-terminal voltage, and the right vertical axis represents discharge current. When a secondary battery such as a lead storage battery, a lithium ion secondary battery, a lithium ion capacitor, or an electric double layer capacitor is used for the power storage device 23, the voltage between the terminals of the power storage device 23 is between the lower limit value V _LL and the upper limit value V _UL. The charge / discharge is controlled so as to fall within the range.

FIG. 4B shows an equivalent circuit diagram of the power storage device 23. The electromotive force of the power storage device 23 is represented by E ₀ and the internal resistance is represented by Ri. The voltmeter 29 measures the voltage across the terminals of the power storage device 23.

As shown in FIG. 4A, a discharge current having a current value I ₁ flows during a period from time t ₀ to t ₁ . When an electric double layer capacitor is used for the power storage device 23, a constant discharge current flows, whereby the voltage V between the terminals of the power storage device 23 decreases almost linearly. When a lead storage battery or the like is used for the power storage device 23, the voltage between the terminals depends on the state of charge. When discharge is stopped at time t _1, the voltage drop due to the internal resistance Ri is eliminated, the terminal voltage V rises to the open voltage. At time _{t 2,} to resume the operation.

If the time from time t ₁ to t ₂ is longer, for example, the period from time t ₁ to t ₂ is, when corresponding to a period from the time of the work until end day of work start, the temperature of the power storage device 23 is outside air temperature It decreases until it becomes almost equal. For example, when the outside air temperature is about 0 ° C., the increase in the internal resistance Ri becomes significant. When a discharge current having a current value I ₁ is supplied at time t ₂ , a voltage drop of Ri × I ₁ occurs due to the internal resistance Ri. Internal resistance Ri, since larger than the internal resistance Ri of the point of time t _1, the voltage between terminals is greatly reduced. Depending on the outside air temperature and the current state of charge, the voltage between the terminals may be lower than the lower limit value V _LL of the allowable voltage range. When the inter-terminal voltage falls below the lower limit value V _LL of the allowable voltage range, control of the power storage device 23, the motor generator 83, the turning electric motor 76, etc. becomes unstable.

The magnitude of the discharge current that flows at time t ₂ is set to I ₂ that is smaller than I ₁ . At this time, the voltage drop Ri × I ₂ is smaller than the voltage drop Ri × I ₁ . By setting the magnitude I ₂ of the discharge current so that the terminal voltage does not fall below the lower limit value V _LL of the allowable voltage range, the control stability of the power storage device 23 can be maintained.

When charging the power storage device 23, a voltage drop due to the internal resistance Ri is superimposed on the electromotive force E _0. For this reason, when charging is performed in a state where the internal resistance Ri is large, the voltage between the terminals of the power storage device 23 rapidly increases. In order to avoid an excessive increase in the inter-terminal voltage, it is preferable to set the charging current to a value smaller than the charging current during normal operation. By flowing a small charge / discharge current, the power storage device 23 can be heated by heat generated from the internal resistance Ri of the power storage device 23 without causing instability of the operation of the power storage device 23 or the like. By controlling the buck-boost converter 24, the magnitudes of the charging current and the discharging current can be controlled.

When the temperature of the power storage device 23 rises and the internal resistance Ri decreases, a large discharge current can flow under the condition that the inter-terminal voltage does not fall below the lower limit value V _LL of the allowable voltage range. Similarly, a large charging current can be passed under the condition that the voltage between the terminals does not exceed the upper limit value V _UL of the allowable voltage range.

  FIG. 5A shows an example of the change over time of the charge / discharge current during the warm-up operation. The discharge current is positive and the charge current is negative. The magnitude of the charging current and the discharging current is, for example, Ia. As an example, discharging and charging are switched every 10 seconds. Switching between charging and discharging is performed by the control device 130 (FIG. 3) controlling the inverter 84 (FIG. 2) and the buck-boost converter 24 (FIG. 3). The discharged power is temporarily stored in the bus line 20. Electric power for charging is obtained by causing the motor generator 83 to generate electricity.

  The magnitude Ia of the discharge current and the charge current is set so that the voltage drop due to the internal resistance is sufficiently small. For example, a threshold value for the discharge current and a threshold value for the charging current are determined in advance. The control device 130 performs charge / discharge control so that the discharge current does not exceed the discharge current threshold and the charge current does not exceed the charge current threshold.

FIG. 5B shows a change over time in the state of charge (SOC) of the power storage device 23. The charging state decreases during the discharging period, and the charging state increases during the charging period.

  FIG. 5C shows the change over time of the temperature of the power storage device 23. As the power storage device 23 is charged and discharged, the temperature of the power storage device 23 rises. Control device 130 (FIG. 3) periodically monitors the temperature of power storage device 23. When the temperature of power storage device 23 reaches determination threshold value Tth, the control device stops the warm-up operation.

  Generally, a secondary battery such as a lead-acid battery has a cycle life that varies depending on the temperature of the electrolytic solution, and thus is preferably used in an appropriate temperature range. By performing the warm-up operation of the power storage device 23 before the excavator is operated, deterioration of the cycle life of the power storage device 23 can be suppressed.

  FIG. 6 shows a signal transmission / reception sequence between the excavator 10 and the information terminal 11. 7A to 7F show examples of charts displayed on the information terminal 11.

  When the application software of the information terminal 11 is activated, a button for “inquiry” is displayed on the screen of the information terminal 11 as shown in FIG. 7A. When the operator touches the “inquiry” button, the information terminal 11 sends a current status inquiry signal to a plurality of excavators (FIG. 6). The excavator machine number to be inquired is registered in the information terminal 11 in advance. The case where the excavators of machine numbers # 1 to # 3 are registered in the information terminal 11 will be described. FIG. 6 shows a case where there is a response from the shovels having the machine numbers # 1 and # 3 and no response from the shovel having the machine number # 2.

  As shown in FIG. 7B, buttons corresponding to a plurality of excavators are displayed. “Usable” is displayed on the buttons of the excavators with the machine numbers # 1 and # 3, and “Unusable” is displayed on the buttons of the excavator with the machine numbers # 2. Further, a “map display” button for displaying the position of the excavator is displayed. When the operator touches the “map display” button, a map (FIG. 8) showing the current positions of the operator and the excavator is displayed. The operator can confirm the current position of the usable excavator. The operator selects one excavator from the available excavators and touches the button (FIGS. 7B and 8) of the selected excavator. As an example, a case where the excavator having the machine number # 1 is selected will be described.

  As shown in FIG. 7C, the information terminal 11 displays the current state of the excavator with the machine number # 1. This state is included in the response signal from the shovel. FIG. 7C shows that the warm-up operation is not performed, the lock is not performed, the failure diagnosis is in operation, and the state of charge is 78%. Further, the machine body identification number is 41FB15P, the manager is Taro Sumitomo, the operating state is stopped, the battery temperature is 0 ° C., and the outside air temperature is 0 ° C.

  When the operator recognizes that the battery temperature is 0 ° C., the operator determines that the battery (power storage device 23) needs to be warmed up. As shown in FIG. 7D, the operator touches the “ON” button for warming up displayed on the information terminal 11 in order to warm up the power storage device 23.

  As shown in FIG. 6, the information terminal 11 transmits a warm-up start command signal to the excavator with the machine number # 1. When receiving the warm-up start command signal, the excavator with the machine number # 1 transmits a response signal to the information terminal 11 and starts the warm-up operation. Specifically, the control device 130 (FIGS. 2 and 3) operates the engine 74 (FIG. 2) and controls the inverter 84 and the step-up / down converter 24 (FIG. 3) to discharge the power storage device 23. Repeat charging and charging alternately. At this time, control device 130 monitors the temperature of power storage device 23 measured by temperature sensor 28 at a constant cycle, for example, a 10-second cycle.

  During the warm-up operation, the excavator transmits temperature information of the power storage device 23 to the information terminal 11 at a constant cycle, for example, a 10-second cycle. When the information terminal 11 receives the temperature information from the shovel, the information terminal 11 displays the temperature of the power storage device. FIG. 7E shows an example of a chart displayed on the information terminal 11 when the battery temperature rises to 10 ° C. It can be seen that the warm-up is in the “ON” state and the battery temperature is 10 ° C. Furthermore, the remaining time until the warm-up is completed is displayed. The remaining time can be predicted from the change in battery temperature over time. The remaining time may be predicted by the shovel control device 130 or by the application software of the information terminal 11.

  Control device 130 compares the current temperature of power storage device 23 with a determination threshold, and determines that the warm-up is complete when the current temperature is equal to or higher than the determination threshold. The determination threshold is set to an appropriate value based on the internal resistance of power storage device 23 and the temperature dependence of the lifetime. When the warm-up is completed, the control device 130 stops the warm-up operation and transmits a warm-up completion notification signal to the information terminal 11.

  As illustrated in FIG. 7F, when the information terminal 11 receives the warm-up completion notification signal, the information terminal 11 displays the warm-up completion. For example, “complete” is displayed in the warm-up remaining time column. At this time, the battery temperature is, for example, 25 ° C., and the warm-up is “OFF”. When the warm-up completion signal is received, the operator may be notified of the warm-up completion by a notification sound or the like.

  In the embodiment, an operator who is away from the excavator can start the warm-up operation of the power storage device 23 (FIG. 3) with respect to the excavator. For this reason, it is possible to shorten the waiting time from when the operator arrives at the work site until the excavator is activated. Alternatively, the excavator can be operated immediately after the operator arrives at the work site.

  In the said Example, although the electrical storage apparatus 23 was warmed up by repeating charging / discharging of the electrical storage apparatus 23, you may warm up by another method.

  FIG. 9 shows a block diagram of a power storage circuit of an excavator that performs warm-up by another method. Hereinafter, differences from the above embodiment will be described, and description of the same configuration will be omitted. In the modification of the embodiment shown in FIG. 9, a heater 25 is disposed in the vicinity of the power storage device 23. The heater 25 is connected to the output terminal of the power storage device 23 via the switch 26.

When performing the warm-up operation of the power storage device 23, the control device 130 causes the switch 26 to conduct so that the discharge current of the power storage device 23 flows through the heater 25. The buck-boost converter 24 is not controlled. That is, power is not transmitted and received between the power storage device 23 and the bus line 61. The magnitude of the discharge current is adjusted by the resistance value of the heater 25. The discharge current is set to a sufficiently small value so that the voltage between the terminals does not fall below the lower limit value V _LL of the allowable range even if a voltage drop occurs due to the internal resistance Ri (FIG. 4B) of the power storage device 23. The power storage device 23 is heated by the heat generated from the internal resistance Ri and the heat generated from the heater 25.

  Note that the power storage device 23 may be heated by various methods other than repeated charge / discharge and heating by a heater.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

DESCRIPTION OF SYMBOLS 10 Excavator 11 Information terminal 12 Input device 13 Wireless communication device 14 Current position detection device 19 Wireless communication device 23 Power storage device 24 Buck-boost converter 25 Heater 26 Switch 28 Temperature sensor 29 Voltmeter 61 Bus line 70 Upper turning body 71 Lower traveling body 73 Slewing bearing 74 engine 75 main pump 76 slewing motor 80 power storage circuit 81 torque transmission mechanism 82 boom 83 motor generators 84, 85 power converter (inverter)
87 Arm 88 Bucket 89 Boom cylinder 90 Arm cylinder 91 Bucket cylinder 101A, 101B Hydraulic motor 115 Pilot pump 116 Hydraulic line 117 Control valve 122 Resolver 123 Mechanical brake 124 Reducer 125 Pilot line 126 Operating device 127, 128 Hydraulic line 130 Control device 130A Central processing unit (CPU)
130B internal memory

Claims (10)

A power storage device;
An electric motor driven by electric power supplied from the power storage device;
A wireless communication device for communicating with an information terminal;
A shovel having a control device that performs a warm-up operation of the power storage device when a warm-up start command signal is received through the wireless communication device.   The excavator according to claim 1, wherein when the warm-up operation of the power storage device is completed, the control device sends a warm-up completion notification signal to the information terminal through the wireless communication device. And a temperature sensor for measuring the temperature of the power storage device,
The excavator according to claim 1 or 2, wherein the control device transmits information on the temperature of the power storage device measured by the temperature sensor to the information terminal through the wireless communication device. In addition, it has a current position detection device,
The excavator according to any one of claims 1 to 3, wherein the control device transmits information on a current position detected by the current position detection device to the information terminal through the wireless communication device. In addition, it has an engine driven by fuel,
The electric motor also operates as a generator by being driven by the engine,
5. The control device according to claim 1, wherein the control device performs the warm-up operation by repeating charging of the power storage device by electric power generated by the electric motor and discharging from the power storage device. 6. Excavator.   The excavator according to claim 5, wherein the control device charges and discharges the power storage device under a condition that a charging current and a discharging current do not exceed a predetermined threshold. A power storage device;
An electric motor driven by electric power supplied from the power storage device;
A wireless communication device;
When receiving a warm-up start command signal through the wireless communication device, an excavator having a control device that performs a warm-up operation of the power storage device,
An excavator management system comprising: an information terminal that communicates with the excavator through the wireless communication device and transmits the warm-up start command signal to the excavator based on an input from an operator. The information terminal
The excavator management system according to claim 7, wherein the temperature of the power storage device is displayed based on the temperature information of the power storage device received from the excavator. When the warm-up operation of the power storage device is completed, the control device sends a warm-up completion notification signal to the information terminal through the wireless communication device,
The excavator management system according to claim 7 or 8, wherein when the information terminal receives the warm-up completion notification signal, the information terminal notifies the operator of the completion of warm-up. A wireless communication device for communicating with the excavator;
An input device for an operator to input;
A control device,
The control device is an information terminal that sends a warm-up start command signal to the excavator through the wireless communication device when an operator instructs the start of warm-up through the input device.

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