JP5054661B2 - Electric drive work machine - Google Patents

Description

  The present invention relates to an electrically driven work machine that drives a hydraulic pump that is a pressure oil supply source to a hydraulic actuator using an in-vehicle battery or an electric motor that uses an external power source as a driving power source, and in particular, durability of a cubicle at high altitudes. And a means for improving reliability.

  In an electrically driven work machine that uses an electric motor as a drive source of a hydraulic pump, a cubicle that is an electric motor starting device composed of a combination of an electric device and an electronic device such as an inverter, a relay and a fuse is installed (for example, a patent) Reference 1).

As described in Patent Document 1, the mounting density of electric devices and electronic devices housed in a cubicle is increasing with the demand for downsizing and the improvement of mounting technology. Development of technology to prevent the occurrence of the accompanying defects is indispensable. Patent Document 1 discloses a technique for forcibly cooling air by taking outside air into the cubicle in order to prevent a temperature rise in the cubicle accompanying an increase in mounting density.
JP-A-62-281706

  By the way, since the motor drive power supplied to the cubicle is a high voltage of, for example, 6600 V, when the mounting density of the electrical equipment and electronic equipment housed in the cubicle increases, not only the temperature inside the cubicle rises but also the high voltage cutoff. Decrease in voltage resistance between the main circuit conductors of the machine or between the main circuit conductor and the ground becomes a problem. A normal electric drive work machine is designed to withstand voltage, assuming that it is used at an altitude of 1000 m or less, and an electric drive work machine used at an altitude of 1000 m or more has a dilute atmosphere and has a withstand voltage. Since the voltage drops, a cubicle whose rated voltage is one rank higher is installed.

  However, if a cubicle with a rated voltage one rank higher is used in this way, the cubicle becomes larger and more expensive, making it difficult to mount on an electrically driven work machine, or making an electrically driven work machine expensive. Inconvenience occurs.

  The present invention has been made to solve such problems of the prior art, and its purpose is to enable a cubicle designed to be used at an altitude of 1000 m or less to be used at an altitude of 1000 m or higher. The purpose is to reduce the size and cost of the electrically driven work machine.

  In order to achieve the above object, according to the present invention, firstly, in an electrically driven work machine equipped with an electric motor that drives a hydraulic pump that is a power source of a hydraulic actuator, and a cubicle that is a starter of the electric motor. Detecting means for outputting an output signal corresponding to the atmospheric pressure in the cubicle, pressurizing means for increasing the atmospheric pressure in the cubicle, supplying and shutting off motor drive power to the cubicle, and starting and stopping of the pressurizing device And control means for instructing to supply and shut off the motor drive power to the cubicle via the control means, and the control means is provided in the cubicle based on the output signal of the detection means. It is determined whether or not the atmospheric pressure of the cubicle has reached a predetermined set value, and the atmospheric pressure in the cubicle has not reached the set value When a signal for supplying motor drive power to the cubicle is received from the instructing means in the determined state, the pressure is applied from the pressurizing means to the cubicle before the motor drive power supply to the cubicle is started. Air is supplied to increase the atmospheric pressure in the cubicle, and after determining that the atmospheric pressure in the cubicle has reached the set value, supply of motor drive power to the cubicle is started.

  According to such a configuration, since the pressurized air is supplied from the pressurizing device to the cubicle so that the atmospheric pressure in the cubicle can be increased, the atmospheric pressure in the cubicle can be increased to, for example, 1 atm when used at an altitude of 1000 m or higher. For example, a cubicle designed to be used at an altitude of 1000 m or less can be used at high altitudes. Therefore, there is no need to use a cubicle whose rated voltage is one rank higher, so that it is possible to reduce the size and cost of an electrically driven work machine used at an altitude of 1000 m or higher. In addition, when the supply of motor drive power to the cubicle is started, it is a condition that the atmospheric pressure in the cubicle has reached a predetermined set value before that. It is possible to stably perform work at an altitude of 1000 m or more without causing insulation failure in the device.

  Secondly, the present invention is configured such that, in the first electrically driven work machine, the pressurizing device is an electric compressor driven by a power supply device of a system different from the cubicle.

  According to this configuration, since the power supply device that supplies the drive voltage to the pressurizing device and the power supply device that supplies the motor drive voltage to the cubicle are separated, the pressurization device is driven before the motor drive voltage is supplied to the cubicle. As a result, the inside of the cubicle can be pressurized, and the motor drive voltage can be supplied to the cubicle at an appropriate pressure, so that the dielectric breakdown of the cubicle can be prevented. In addition, since the electric compressor is used as the pressurizing device, it is possible to easily and stably control the atmospheric pressure in the cubicle as compared with the case where another pressurizing source such as an air cylinder is used.

  Thirdly, in the first electrically driven work machine according to the present invention, the detection means is an atmospheric pressure sensor that detects an atmospheric pressure in the cubicle.

  Since the atmospheric pressure sensor can detect the atmospheric pressure in the cubicle with high accuracy, if the atmospheric pressure sensor is provided as a means of detecting atmospheric pressure in the cubicle, the atmospheric pressure in the cubicle that can start supplying motor drive power to the cubicle is strictly regulated. Therefore, it is possible to reliably prevent the insulation failure of the electrical equipment and electronic equipment housed in the cubicle.

  Fourthly, according to the present invention, in the first electrically driven work machine, the detection means determines whether a relief valve that keeps the atmospheric pressure in the cubicle below a certain pressure, and whether the relief valve is operating. It consists of a switch to detect.

  When the relief valve is operating, the air pressure in the cubicle is higher than the relief valve set pressure. When the relief valve is not operating, the air pressure in the cubicle reaches the relief valve set pressure. Not. Therefore, it is possible to detect whether the pressure in the cubicle is higher than the set pressure of the relief valve by detecting whether the relief valve is operating or not by using a switch. Therefore, it is possible to regulate the atmospheric pressure in the cubicle capable of starting the supply of water and to reliably prevent the insulation failure of the electrical equipment and electronic equipment housed in the cubicle.

  The electrically driven work machine of the present invention receives an instruction signal from an instruction means for supplying motor drive power to the cubicle in a state where the control means determines that the air pressure in the cubicle has not reached a predetermined set value. If the air pressure in the cubicle has increased to a predetermined set value by supplying pressurized air from the pressurizing device to the cubicle before the motor drive power supply to the cubicle is started, the atmospheric pressure in the cubicle is increased. Since the motor drive power supply to the cubicle is started, if the atmospheric pressure in the cubicle is increased to, for example, 1 atm when used at an altitude of 1000 m or higher, the cubicle is designed to be used at an altitude of 1000 m or lower. Achieving miniaturization and cost reduction of electrically driven work machines that can be used at high altitudes above 1000m. It is possible. In addition, since the atmospheric pressure in the cubicle can be constantly maintained at a predetermined value or higher from the start of supply of motor drive power to the cubicle until the supply is stopped, insulation failure occurs in electrical and electronic equipment stored in the cubicle. There is no such thing, and work at an altitude of 1000 m or more can be performed stably.

  Hereinafter, a first embodiment of an electrically driven work machine according to the present invention will be described with reference to FIGS. 1 to 5 by taking an electric excavator as an example. 1 is a side view of the electric excavator according to the first embodiment, FIG. 2 is a side view showing the arrangement of the cubicle and the electric motor in the electric excavator according to the first embodiment, and FIG. 3 is the electric excavator according to the first embodiment. 4 is a rear view showing the arrangement of the cubicle and the electric motor, FIG. 4 is a block diagram showing a configuration of the control device according to the first embodiment, and FIG. 5 is a flowchart showing a procedure of processing executed by the control device according to the first embodiment. It is.

  As shown in FIGS. 1 to 4, the electric excavator 1 according to the first embodiment includes a lower traveling body 3 provided with a traveling crawler belt 2, and an upper turning provided on the lower traveling body 3 via a turning wheel 4. A body 5, a boom 6 having one end pivotably connected to the front portion of the upper swing body 5, an arm 7 having one end pivotally coupled to the tip of the boom 6, and a tip of the arm 7 A bucket 8 whose one end is pivotally coupled to the upper part, a boom cylinder 9 for rotating the boom 6 in a plane perpendicular to the upper swinging body 5, and a surface for vertically extending the arm 7 to the boom 6. An arm cylinder 10 that rotates inside, a bucket cylinder 11 that rotates the bucket 8 in a plane perpendicular to the arm 7, and a key switch that is provided at a front portion of the upper swing body 5 and that is operated by the driver, for example. Instruction means 21 (see FIG. 4) for starting the motor such as A driver's cab 12 equipped with various operation levers, an excavator drive electric motors 13 and 14 provided at a rear portion of the upper swing body 5, and a cubicle 15 as an activation device for the excavator drive electric motors 13 and 14; , An electric compressor 16 for supplying pressurized air into the cubicle 15, a relief valve 17 provided at the upper part of the cubicle 15, an atmospheric pressure sensor 18 as a means for detecting atmospheric pressure in the cubicle 15, and a motor drive to the cubicle 15 It is mainly comprised from the control apparatus 19 (refer FIG. 4) which controls supply and interruption | blocking of a power supply, and starting and a stop of the electric compressor 16. FIG. Reference numeral 20 in the drawing denotes a power cable for connecting an external power source (not shown) and the cubicle 15. The power cable 20 is appropriately attached to and detached from the electric excavator 1.

  The electric excavator 1 of this example is activated when the driver operates the instruction means 21 provided in the driver's cab 12, and each part is driven by operating an operation lever or the like (not shown). Work is performed. That is, by driving the traveling crawler belt 2, the electric excavator 1 travels forward or backward, and by driving the turning wheel 4, the upper swing body 5 is swung relative to the lower travel body 3, and the boom cylinder 9, arm cylinder The boom 6, the arm 7, and the bucket 8 are appropriately driven by 10 and the bucket cylinder 11 to perform necessary work such as excavation and loading.

  The excavator driving electric motors 13 and 14 drive a hydraulic pump that supplies pressure oil to a hydraulic actuator such as a traveling motor (not shown) that drives the swivel wheel 4, the boom cylinder 9, the arm cylinder 10, the bucket cylinder 11, and the traveling crawler belt 2. It is driven by a motor drive power supplied from an external power supply (not shown) via a power cable 20 or a motor drive power supplied from a battery (not shown) mounted on the vehicle.

  The cubicle 15 is a starting device for the excavator driving electric motors 13 and 14, and is necessary for starting the excavator driving electric motors 13 and 14 such as an inverter, a relay and a fuse inside a box-shaped housing. Various electrical and electronic devices are housed. In addition, the power supply unit of the cubicle 15 is provided with a power switch (not shown) for intermittently supplying the motor driving power to the cubicle 15 according to a command from the control device 19. As shown in FIG. 3, the cubicle 15 is installed on the upper swing body 5 via a vibration isolating rubber 22. Thereby, the vibration which acts on the cubicle 15 with operation | movement of the electric shovel 1 can be relieved, and the earthquake resistance of the cubicle 15 can be improved.

  The electric compressor 16 supplies pressurized air into the cubicle 15, and the electric motor 16 a is driven by a power supply device different from the cubicle 15 to generate pressurized air. The power supply unit of the power supply motor 16 a is provided with a power switch (not shown) that intermittently supplies the motor drive power to the electric motor 16 a according to a command from the control device 19. The electric compressor 16 is also installed on the upper swing body 5 through a vibration-proof rubber (not shown) in order to improve the earthquake resistance.

  The relief valve 17 maintains the atmospheric pressure in the cubicle 15 at a predetermined constant pressure. When the electric excavator 1 is used at a high altitude of 1000 m or more, the set pressure is, for example, 1 atm (101325 Pa) or more. It is set to a predetermined value. As a result, the cubicle 15 designed to be used at an altitude of 1000 m or less can be used even in an altitude of 1000 m or higher, and the cubicle 15 and thus the electric excavator 1 can be reduced in size and cost. .

  The atmospheric pressure sensor 18 detects the atmospheric pressure in the cubicle 15, and is installed in a casing constituting the cubicle 15. The installation position of the atmospheric pressure sensor 18 can be arbitrarily selected, but it is desirable to install it at a position where the airflow is as gentle as possible in order to obtain a stable output.

  As shown in FIG. 4, the control device 19 includes an atmospheric pressure signal SD <b> 1 output from the atmospheric pressure sensor 18, and an instruction signal output from the instruction means 21 operated by the driver for starting, starting, and stopping the electric excavator 1. An input section 19a for inputting SD2, a power switch switching signal SC1 for turning on / off a power switch provided in the power supply section of the cubicle 15 to intermittently supply the motor drive power to the cubicle 15, and a power supply section of the electric compressor 16 The cubicle 15 is turned on and off according to the atmospheric pressure in the cubicle 15 detected by the atmospheric pressure sensor 18, and an output unit 19 b that outputs a compressor control signal SC 2 that controls the start and stop of the electric motor 16 a by turning on and off the power switch. By the determination / control unit 19c for controlling the supply of the motor drive power to the motor and the determination / control unit 19c Mainly from a ROM 19d that stores a set value SH of the atmospheric pressure in the cubicle 15 that is a reference for the supply of motor drive power to the vehicle 15, and a RAM 19e that stores a program for processing executed by the determination / control unit 19c. It is configured. The set value SH is set to an appropriate value capable of working in an altitude of 1000 m or higher, for example, 1 atm (101325 Pa).

  The determination / control unit 19c compares the atmospheric pressure in the cubicle 15 detected by the atmospheric pressure sensor 18 with the set value SH stored in the ROM 19d according to the program stored in the RAM 19e, and the atmospheric pressure in the cubicle 15 is stored in the ROM 19d. If the set value SH has not been reached, the motor drive power supply process to the cubicle 15 is not performed, and the atmospheric pressure in the cubicle 15 has reached the set value SH stored in the ROM 19d, and the cubicle 15 is supplied to the cubicle 15. The motor drive power supply process is performed.

  Hereinafter, the flow of processing executed by the control device 19 provided in the electrically driven work machine according to the first embodiment will be described with reference to FIG.

  When the electric excavator 1 is in the drive stop state, when the driver turns the instruction means 21 installed in the driver's cab from the OFF state to the ON state (step S1), an auxiliary power source is supplied from the power supply for the control device (not shown) to the control device 19. When the voltage is supplied, the control device 19 enters an operating state, and the determination / control unit 19c receives the atmospheric pressure signal SD1 output from the atmospheric pressure sensor 18, and the instruction signal SD2 from the instruction means 21 to the determination / control unit 19c. Capture is possible (step S2).

  When the instruction means 21 is switched to the start state from this state (step S3), the instruction signal SD2 output from the instruction means 21 is taken into the determination / control section 19c via the input section 19a (step S4). In response, the determination / control unit 19c compares the atmospheric pressure signal SD1 with the set value SH stored in the ROM 19d, and determines whether the atmospheric pressure signal SD1 has reached the set value SH (step S5). In step S5, when the determination / control unit 19c determines that the atmospheric pressure signal SD1 has reached the set value SH (Yes), the process proceeds to step S6 and is illustrated from the determination / control unit 19c via the output unit 19b. An ON signal is output to the power switch not to be operated, and motor driving power is supplied to the cubicle 15 from an external power source or an in-vehicle battery. As a result, the excavator driving electric motors 13 and 14 are activated, the electric excavator 1 travels by driving the traveling crawler belt 2, the upper revolving body 5 turns by driving the swivel wheel 4, and the boom 6 and arm 7. In addition, various operations can be performed by driving the bucket 8.

  On the other hand, when the determination / control unit 19c determines in step S5 that the atmospheric pressure signal SD1 has not reached the set value SH (No), the process proceeds to step S7, where the determination / control unit 19c outputs the output unit. The compressor control signal SC2 is output to the electric compressor 16 via 19b. Thereby, the electric motor 16a attached to the electric compressor 16 is started, and the atmospheric pressure in the cubicle 15 is increased. At this time, since the excavator drive electric motors 13 and 14 are not activated even when the instruction means 21 is in the start state, the driver returns the instruction means 21 to the ON state (step S8). Thereafter, the process returns to step S3, and the procedure from step S3 is repeated after the driver waits until the instruction means 21 is operated again to the start state.

  In the above embodiment, no means for notifying the driver of the atmospheric pressure in the cubicle 15 is provided, but the notifying means is provided in the cab 12 or the like, and the determination / control unit in step S7 in FIG. After starting the electric motor 16a by the output of the compressor control signal SC2 from 19c, it is possible to notify the driver that the atmospheric pressure in the cubicle 15 has not reached the set value SH through the notification means. In this way, it is possible to prevent the driver from operating the instruction means 21 in a state where the atmospheric pressure in the cubicle 15 has not reached the set value SH, so that the operation of the electric shovel 1 can be made more efficient, It is possible to eliminate the driver's anxiety that the electric excavator 1 has failed.

  When the instruction means 21 is switched from the ON state to the OFF state when the electric excavator 1 is stopped, the determination / control unit 19c receives this, and the power switch and the electric compressor 16 provided in the cubicle 15 are switched from the output unit 19b to the electric compressor 16. An OFF signal is output to the power switch provided to cut off the supply of motor drive power from the external power supply or vehicle battery to the cubicle 15, and supply of motor drive power to the electric compressor 16 from a separate power supply unit Cut off. Thereby, the electric shovel 1 is in a stopped state.

  As described above, the atmospheric pressure in the cubicle 15 is detected by the atmospheric pressure sensor 18, and the motor drive power can be supplied to the cubicle 15 only when the atmospheric pressure in the cubicle 15 is equal to or higher than a predetermined set pressure SH. Then, since the motor drive power can be supplied to the cubicle 15 only when the atmospheric pressure in the cubicle 15 becomes, for example, 1 atm or more when the work machine is used at a high altitude of 1000 m or higher, the altitude is 1000 m. The cubicle 15 designed to be used below can be used at high altitudes. Therefore, there is no need to use a cubicle whose rated voltage is one rank higher, so that it is possible to reduce the size and cost of an electrically driven work machine used at an altitude of 1000 m or higher and to be stored in the cubicle 15. Insulation failure of electrical and electronic equipment can be prevented, and work at an altitude of 1000 m or higher can be performed stably.

  Next, a second embodiment of the electrically driven work machine according to the present invention will be described with reference to FIGS. 6 is a rear view showing the arrangement of the cubicle and the electric motor in the electric excavator according to the second embodiment, FIG. 7 is a block diagram showing the configuration of the control device according to the second embodiment, and FIG. 8 is according to the second embodiment. It is a flowchart which shows the procedure of the process performed by a control apparatus.

  As shown in FIG. 6, the electrically driven work machine of the present example determines whether or not the relief valve 17 is operating as a means for detecting the atmospheric pressure in the cubicle 15 instead of the atmospheric pressure sensor 18 in the first embodiment. It is characterized by using a switch 30 for detection. The switch signal SD3 output from the switch 30 is input to the input unit 19a of the control device 19, as shown in FIG. Others are the same as those of the electrically driven work machine according to the first embodiment, and therefore, the corresponding parts are denoted by the same reference numerals and description thereof is omitted.

  Hereinafter, the flow of processing executed by the control device 19 provided in the electrically driven work machine according to the second embodiment will be described with reference to FIG.

  When the electric excavator 1 is in the drive stop state, when the driver turns the instruction means 21 installed in the driver's cab from the OFF state to the ON state (step S1), an auxiliary power source is supplied from the power supply for the control device (not shown) to the control device 19. When the voltage is supplied, the control device 19 enters an operating state, and the determination / control unit 19c receives the switch signal SD3 output from the switch 30, and the instruction unit 21 captures the instruction signal SD2 to the determination / control unit 19c. (Step S2).

  When the instruction means 21 is switched to the start state from this state (step S3), the instruction signal SD2 output from the instruction means 21 is taken into the determination / control section 19c via the input section 19a (step S4). The determination / control unit 19c receives this signal, and the switch signal SD3 is a signal indicating the operating state of the relief valve 17 (in this example, an ON signal), or the relief valve 17 is not operating. (In this example, an OFF signal) is determined (step S5). When the determination / control unit 19c determines in step S5 that the switch signal SD3 is a signal indicating the operating state of the relief valve 17 (Yes), the process proceeds to step S6, and the output from the determination / control unit 19c to the output unit 19b. Then, an ON signal is output to a power switch (not shown), and motor driving power is supplied to the cubicle 15 from an external power source or an in-vehicle battery. On the other hand, when the determination / control unit 19c determines in step S5 that the switch signal SD3 is a signal indicating the non-operating state of the relief valve 17 (No), the process proceeds to step S7. The compressor control signal SC2 is output from the unit 19c to the electric compressor 16 via the output unit 19b. Thereby, the electric motor 16a attached to the electric compressor 16 is started, and the atmospheric pressure in the cubicle 15 is increased. The following procedure is the same as that of the electrically driven work machine according to the first embodiment.

  When the relief valve 17 is in operation, the air pressure in the cubicle 15 is equal to or higher than the set pressure of the relief valve 17, and when the relief valve 17 is not in operation, the air pressure in the cubicle 15 is The set pressure of 17 has not been reached. Accordingly, whether or not the relief valve 17 is operating is detected by the switch 30, and supply of motor drive power to the cubicle 15 is started only when the atmospheric pressure in the cubicle 15 is equal to or higher than the set pressure of the relief valve 17. By doing so, it is possible to reliably prevent the insulation failure of the electrical equipment and electronic equipment housed in the cubicle 15 even at high altitudes.

  In each of the above embodiments, an electric excavator has been described as an example. However, the gist of the present invention is not limited to this, and can be applied to any other electric work machine.

  Moreover, in the said embodiment, although the electric compressor 16 was used as a pressurization means which raises the atmospheric pressure in the cubicle 15, the summary of this invention is not limited to this, Other pressurization apparatuses, such as an air cylinder, are used. It can also be used.

It is a side view of the electric shovel which concerns on 1st Embodiment. It is a side view which shows the arrangement | positioning of the cubicle and electric motor in the electric shovel which concern on 1st Embodiment. It is a rear view which shows the arrangement | positioning of the cubicle and electric motor in the electric shovel which concern on 1st Embodiment. It is a block diagram which shows the structure of the control apparatus which concerns on 1st Embodiment. It is a flowchart which shows the procedure of the process performed by the control apparatus which concerns on 1st Embodiment. It is a rear view which shows arrangement | positioning of the cubicle and electric motor in the electric shovel which concern on 2nd Embodiment. It is a block diagram which shows the structure of the control apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the procedure of the process performed by the control apparatus which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric excavator 2 Running crawler track 3 Lower traveling body 4 Turning wheel 5 Upper turning body 6 Boom 7 Arm 8 Bucket 9 Boom cylinder 10 Arm cylinder 11 Bucket cylinder 21 Instruction means 12 Driver's cab 13, 14 Excavator drive electric motor 15 Cubicle 16 Electric Compressor (pressurizing means)
17 Relief valve 18 Barometric pressure sensor (detection means)
19 control device 20 power cable 30 switch (detection means)

Claims (4)

In an electrically driven work machine equipped with an electric motor that drives a hydraulic pump that is a power source of a hydraulic actuator, and a cubicle that is a starter of the electric motor,
Detection means for outputting an output signal corresponding to the atmospheric pressure in the cubicle, pressurizing means for increasing the atmospheric pressure in the cubicle, supply and interruption of motor drive power to the cubicle, and activation and deactivation of the pressure device Control means for controlling, and instruction means for instructing supply and cutoff of motor drive power to the cubicle through the control means,
The control means determines whether or not the atmospheric pressure in the cubicle has reached a predetermined set value based on the output signal of the detection means, and if the atmospheric pressure in the cubicle has not reached the set value When a signal for supplying motor drive power to the cubicle is received from the instructing means in the determined state, the pressure is applied from the pressurizing means to the cubicle before the motor drive power supply to the cubicle is started. An electric drive work characterized in that air is supplied to increase the atmospheric pressure in the cubicle and supply of motor drive power to the cubicle is started after determining that the atmospheric pressure in the cubicle has reached the set value. machine.   2. The electrically driven work machine according to claim 1, wherein the pressurizing unit is an electric compressor driven by a power supply device of a system different from the cubicle.   The electrically driven work machine according to claim 1, wherein the detection unit is an atmospheric pressure sensor that detects an atmospheric pressure in the cubicle.   2. The electricity according to claim 1, wherein the detection unit includes a relief valve that maintains an atmospheric pressure in the cubicle below a predetermined pressure, and a switch that detects whether the relief valve is operating or not. Driven work machine.

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