JP2000333364A - Power-supply device for electrically driven type working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the power-supplying device of an electrically driven type working machine that can always supply power stably, eliminates the need for charging operation, and prevents the power of a battery from running out, and performing operation with improved efficiency. SOLUTION: This power-supplying device is provided with a battery 25 and a fuel battery 26 as the supply source of power to an electric motor 24. Furthermore, the power-supplying device is provided with a load detector 33 for detecting the loaded state of actuators 14-16 and an operation device 28 and a power supply control device 27 for controlling power which is supplied from the battery 25 and the fuel battery 26, based on detection information from the load detector 33. Also, the power-supplying device is provided with a charging device 30 for charging the battery 25, using power which is outputted from the fuel battery 26 and an amount-of-charge detector 31 and an amount-of- discharge detector 32 for detecting the charged/discharged state of the battery 25, so that the operation device 28 controls the operation of the charging device 30, based on detection information from both the detectors 31 and 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for an electrically driven working machine having a structure in which an actuator is operated using the power of an electric motor.

[0002]

2. Description of the Related Art There are various types of electrically driven working machines, and for example, an electrically driven aerial work vehicle is known. This electric aerial work platform has a work platform for mounting the work vehicle at the tip of a boom mounted on the vehicle body, and hydraulic actuators (hydraulic cylinders and hydraulic motors) that raise, lower, extend, and turn the boom , Etc.) using the power of an electric motor (electric motor) driven by a battery. That is, the electric motor is driven by the electric power of the battery to operate the hydraulic pump, and the hydraulic actuator is operated by the hydraulic pressure discharged from the hydraulic pump.

[0003]

However, in the electric-powered working machine having such a configuration, when the battery discharge proceeds and falls below a specified value, the work has to be interrupted. In addition, when the worker does not notice that the discharge is progressing, the battery may be overdischarged and its life may be shortened. In addition, it is necessary to charge the battery after use, but the work machine cannot be used during the charging work, and the charging time is long when the battery has a large capacity. For,
In some cases, work efficiency deteriorated. Further, although the voltage of the battery decreases as the battery is discharged, in such a case, there is a disadvantage that stable power supply cannot be performed.

[0004] The present invention has been made in view of such a problem, and it is possible to always supply a stable power supply, and it is not necessary to perform a charging operation. It is an object of the present invention to provide a power supply device of an electric drive type working machine capable of performing the following.

[0005]

In order to achieve the above object, a power supply apparatus according to the present invention uses an electric motor (for example, a telescopic cylinder 14, an up-and-down cylinder 15, and a swing motor in the embodiment). 16)
In an electric drive type working machine (for example, the aerial work vehicle 10 in the embodiment) configured to operate a battery, a battery and a fuel cell are provided as a power supply source for an electric motor. For this reason, unlike the related art, it is possible to prevent a situation in which the operation of the battery is interrupted due to a shortage of the power of the battery, and it is possible to prevent a reduction in the life of the battery since the battery does not overdischarge. In addition, fuel cells have high energy conversion efficiency, low noise at the time of power generation, and are harmless by reaction products, and thus are environmentally superior and have many advantages.

In the above configuration, the load is supplied from the battery and the fuel cell based on information detected by the load detecting means (for example, the load detector 33 in the embodiment) for detecting the load state of the actuator. It is preferable to include a power supply control unit (for example, the arithmetic unit 28 and the power supply control unit 27 in the embodiment) that controls power. According to such a configuration, the disadvantage of the fuel cell, which can provide a stable output but has a slow response output to a load change, can be compensated for by the battery, and the output characteristics of the battery and the output characteristics of the fuel cell can be selectively used. Optimal power supply according to the load of the actuator can be performed.

[0007] In addition to the above configuration, a charging means (for example, the charging device 30 in the embodiment) for charging the battery using electric power output from the fuel cell, and a charging / discharging detecting means for detecting a charging / discharging state of the battery. (For example, the discharge amount detector 31 and the charge amount detection means 32 in the embodiment)
And a charging control unit (for example, the arithmetic unit 28 in the embodiment) for controlling the operation of the charging unit based on the detection information from the charging / discharging detection unit. According to such a configuration, it is possible to perform charging at any time when the electric motor is not driven by the battery, and it is not necessary to perform the charging operation of the battery as in the related art. improves. This also makes it possible to always supply stable power from the battery.

Although a conventional lead battery may be used as the battery, it is possible to output power with higher efficiency by using a nickel-metal hydride battery. This nickel-metal hydride battery has a high energy density and good output efficiency, and is environmentally friendly because it does not use heavy metals. However, since it is expensive, its capacity cannot be increased so much. For this reason, the capacity scale has to be reduced to some extent, but by using the fuel cell together with the power supply device according to the present invention,
Such a decrease in the capacity scale can be sufficiently covered.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an aerial work vehicle 10 equipped with a power supply device according to the present invention. The aerial work vehicle 10 has a swivel 12 that can freely swing on a body 11 based on a truck, and a telescopic boom 13 is attached to the swivel 12 so as to be able to move up and down. The telescopic boom 13 includes a telescopic boom 13a, an intermediate boom 13b, and a distal boom 13c in a telescopic manner. The proximal boom 13a is pivotally connected to the swivel 12 to be able to move up and down. The telescopic boom 13 is expanded and contracted by a telescopic cylinder 14 (not shown in FIG. 2) disposed therein, and is raised and lowered by a raising and lowering cylinder 15 disposed between the swivel base 12 and the base end boom 13a. It is supposed to be.
The swivel table 12 is swung by a swivel motor 16 (not shown in FIG. 2) provided in the vehicle body 11.

A vertical post 1 is provided at the tip of the tip boom 13c.
The vertical post 17 is provided with a worktable 18 for an operator to sway horizontally. A leveling device (not shown) is provided in the vicinity of the vertical post 17 so that the worktable 18 is always kept horizontal regardless of whether the boom 13 is up or down. Also,
Outrigger jacks 19 are provided on the front, rear, left and right sides of the vehicle body 11 to extend during operation and support the vehicle body 11.

In the aerial work vehicle 10 constructed as described above, an operator on the work table 18 operates the upper operation device 21 disposed on the work table 18, or a worker on the ground operates the lower operation apparatus 21. By operating the device 22, the swivel of the swivel table 12, the undulation and expansion and contraction of the boom 13, the work table 1
8 can be performed.
Can be moved to a predetermined height.

FIG. 1 shows the configuration of a power supply device according to the present invention mounted on such an aerial work vehicle 10.
As shown in the figure, the above-described telescopic cylinder 14, the up-and-down cylinder 15, and the turning motor 16 (hereinafter, referred to as an actuator) are provided with a hydraulic pump 2 provided in the vehicle body 11.
The hydraulic pump 23 is driven by the power of an electric motor (electric motor) 24.

The electric motor 24 is driven by electric power from a battery 25 and a fuel cell 26 supplied via a power supply control device 27. The power supply control device 27 is a device that efficiently supplies the electric power output from the battery 25 and the electric power output from the fuel cell 26 to the electric motor 24, and operates based on a control signal from the arithmetic device 28. It has become. The operation of starting and stopping the power generation of the fuel cell 26 and the adjustment of the output power are performed by the arithmetic unit 2.
8 is controlled by an output control device 29 that operates based on a signal from the control unit 8.

The battery 25 is connected to a fuel cell 26 via a charging device 30 and can be charged by electric power supplied from the fuel cell 26. Battery 2
The amount of discharge (i.e., the amount of power supplied from the battery 25 to the electric motor 24) is determined by the discharge detector 31 and the amount of charge to the battery 25 (i.e., the fuel cell 26
The amount of electric power supplied to the power supply is detected by the charge amount detector 32, and the arithmetic unit 28
The operation of the charging device 30 is controlled based on the detection information from the charging devices 1 and 32. The two detectors 31, 32 are connected to the battery 25.
The power consumption is calculated by detecting a current flowing between the power supply control device 27 and the charging device 30 and the battery 25,
Thus, the amount of discharge and the amount of charge are obtained.

In the oil passage of the hydraulic oil supplied to the actuators 14 to 16, a load detector 3 for detecting the load on the actuators 14 to 16 based on the oil pressure acting on the oil passage.
The detection information is input to the arithmetic unit 28. The arithmetic unit 28 activates the power supply control unit 27 based on the detection information from the load detector 33, and the electric power corresponding to the loads of the actuators 14 to 16 is supplied to the electric motor 24.
The power supplied from the battery 25 and the fuel cell 26 is controlled so as to be supplied to the power supply.

Here, the arithmetic unit 28 usually has the fuel cell 2
The motor 24 is controlled so as to be driven by the electric power supplied from the actuator 6.
When it is detected that the load fluctuations of 4 to 16 have increased, the electric motor 24
Is controlled to be driven. This is the fuel cell 26
This is because the response of the power output to the fluctuation of the load is slow, and it is necessary to supply the current for the delay by the battery 25 temporarily.

As described above, in this power supply device, the power supplied from the battery 25 and the fuel cell 26 is controlled based on the detection information from the load detector 33, so that the power supply device is stable. The disadvantage of the fuel cell 26, which can output power but has a slow response output to a load change, can be compensated for by the battery 26. The output characteristics of the battery 25 and the output characteristics of the fuel cell 26 can be selectively used to load the actuators 14 to 16 separately. It is possible to perform the optimal power supply according to the conditions. The actuator 14
As means for detecting the loads of (1) to (16), means for detecting the load state of the electric motor 24 may be used.

When the electric power output from the battery 25 is not used for driving the electric motor 24, the arithmetic unit 28 charges the battery 25 with the amount of electric power corresponding to the amount of discharge detected by the discharge amount detector 31. Charging device 30
Activate The charging control of the battery 25 (control of the charging current and the charging time during charging) is performed based on the discharging amount of the battery 25 and the charging amount detected by the charging amount detector 32. Is small, the charging current is controlled so that the battery is charged with a large current at the beginning and a small current at the end if the amount of discharge is large. The reason for changing the charging current in this way is that it is necessary to keep the current density per surface area of the electrode active material of the battery 25 constant. The means for detecting the charge / discharge state of the battery 25 includes the above-described discharge amount detection means 31 and charge amount detection means 32,
May be used to detect the electromotive force. In this case, it is preferable that the control of the charging current and the charging time when charging the battery 25 be performed in accordance with the magnitude of the electromotive force that changes (recovers) with the charging.

As described above, according to the power supply device of the present invention, the battery 25 serves as a power supply source to the electric motor 24.
The fuel cell 26 and the fuel cell 26 are provided in parallel, thereby preventing a situation in which the operation of the battery 25 is interrupted due to a shortage of power as in the related art, and the battery 25 is not overdischarged because the battery 25 is not overdischarged. The life can be prevented from being shortened. Further, the fuel cell 26 has high energy conversion efficiency, low noise at the time of power generation, and is harmless to the products generated by the reaction, and thus is environmentally excellent, and has many advantages. Further, since the charging is performed as needed when the electric motor 24 is not driven by the battery 25, the work of charging the battery 25 does not need to be performed as in the related art, so that the workability is improved. This also makes it possible to always supply stable power from the battery 25.

Further, as in the above configuration, the power output from the fuel cell 26 may not be directly supplied to the electric motor 24, but may be used exclusively for charging the power lost by discharging the battery 25. Even in such a configuration, the effect that the battery 25 and the fuel cell 26 are provided side by side as a power supply source for the electric motor 24 is the same as in the above configuration.

As the battery 25, a lead battery may be used as in the prior art. However, by using a nickel-metal hydride battery, power can be output with higher efficiency. This nickel-metal hydride battery has a high energy density and good output efficiency, and is environmentally friendly because it does not use heavy metals. However, since it is expensive, its capacity cannot be increased so much. For this reason, the capacity scale has to be reduced to a certain extent, but such a decrease in the capacity scale can be sufficiently covered by using the fuel cell 26 together with the power supply apparatus according to the present invention. it can. It is also effective to use a lithium-ion battery, a supercapacitor or the like in addition to the nickel-metal hydride battery.

The embodiment of the power supply device according to the present invention has been described above. However, the present invention is not limited to the above configuration, and various modifications are possible. For example, the actuators 14 to 16 need not be driven via hydraulic pressure, and may be driven only by electric force.
Further, the detection of the discharge amount of the battery 25 is not limited to the detection by the discharge amount detector 31. As an example, the discharge hydraulic pressure of the hydraulic pump 23 is detected by a pressure sensor or the like, and the drive current of the electric motor 24 is calculated from the drive torque of the electric motor 24 obtained in accordance with the discharge oil pressure. There is also a method of calculating the discharge amount of the battery 25 from the operating time of the battery 25. The target to which the power supply device is used is not limited to the aerial work vehicle as described above, and can be widely used for an electrically driven work machine configured to operate an actuator using the power of an electric motor. .

[0023]

As described above, in the power supply device for an electric drive type working machine according to the present invention, a battery and a fuel cell are provided as a power supply source for an electric motor, so that a conventional power supply is provided. In addition, a situation in which the operation of the battery is interrupted due to insufficient power of the battery is prevented, and the battery is not overdischarged. In addition, fuel cells have high energy conversion efficiency, low noise during power generation, and are harmless to the products of the reaction.

In the above configuration, the load detecting means for detecting the load state of the actuator and the power supply controlling means for controlling the power supplied from the battery and the fuel cell based on the detection information from the load detecting means are provided. According to such a configuration, it is possible to compensate for the disadvantage of the fuel cell, which can provide stable output while having a slow response output with respect to a load change, by the battery. It is possible to perform optimal power supply according to the load of the actuator by properly using the output characteristics of the actuator.

Further, in addition to the above configuration, a charging means for charging the battery using the power output from the fuel cell, a charging / discharging detecting means for detecting a charging / discharging state of the battery, and detection information from the charging / discharging detecting means. It is preferable to include a charge control unit (for example, the arithmetic unit 28 in the embodiment) that controls the operation of the charging unit based on the above. According to such a configuration, when the motor is not driven by the battery, It is possible to charge the battery at any time, and it is not necessary to perform the charging work of the battery as in the related art, so that the workability is improved. This also makes it possible to always supply stable power from the battery. Further, by using a nickel hydrogen battery as the battery, it is possible to output power with higher efficiency.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a power supply device according to the present invention.

FIG. 2 is a perspective view showing an aerial work vehicle provided with the power supply device.

[Explanation of symbols]

 Reference Signs List 10 aerial work vehicle (electrically driven work machine) 14 telescopic cylinder (actuator) 15 undulating cylinder (actuator) 16 turning motor (actuator) 24 electric motor 25 battery 26 fuel cell 27 power supply control device (power supply control means) 28 arithmetic Device (power supply control means, charge control means) 29 output control means 30 charging device (charge means) 31 discharge amount detector (charge / discharge detection means) 32 charge amount detector (charge / discharge detection means) 33 load detector (load) Detection means)

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroaki Seki 414-1 Higashimine Sukawa, Shinji-mura, Tone-gun, Gunma Pref. No. 10 Aichi Corporation Ageo Works (72) Inventor Hiroshi Noguchi 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Shoichi Yoshida 2 Keihanhondori, Moriguchi-shi, Osaka 5-5-5 Sanyo Electric Co., Ltd. (72) Inventor Ken Kanai 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. 3F333 AA08 AB04 CA09 FA32 FD06 FE04 FE09 5G003 AA05 BA01 CA06 CA14 DA04 DA13 DA18 5G065 BA09 DA01 EA02 GA09 HA01 HA09 HA16 LA01 LA02 LA03

Claims (4)

[Claims] 1. A power supply device for an electric drive type working machine configured to operate an actuator using the power of a motor, wherein a battery and a fuel cell are provided together as a power supply source for the motor. A power supply device for an electrically driven working machine. 2. A load detecting means for detecting a load state of the actuator, and a power supply controlling means for controlling electric power supplied from the battery and the fuel cell based on detection information from the load detecting means. The power supply device for an electric drive type working machine according to claim 1, further comprising: 3. A charging unit for charging the battery using power output from the fuel cell; a charging / discharging detecting unit for detecting a charging / discharging state of the battery; and detection information from the charging / discharging detecting unit. 3. A power supply device for an electric drive type working machine according to claim 1, further comprising: charge control means for controlling the operation of the charging means based on the control information. 4. The power supply device for an electrically driven working machine according to claim 1, wherein said battery is a nickel hydrogen battery.