Work vehicle

Abstract

To provide a work vehicle capable of causing an operator to recognize reduction in battery residual amount before the battery residual amount is used up and enabling charging or replacement of a battery without trouble.SOLUTION: This work vehicle comprises: a vehicle body capable of travelling; a work device installed on the vehicle body; a main battery 70 that supplies power to a pump drive motor 53 for operating the work device; an operation device that operates the work device; and a controller 60 that controls the pump drive motor 53 in response to the operation of the operation device. The controller 60 includes a restriction release switch 65 that monitors a residual amount of the main battery 70, restricts the operation of the pump drive motor 53 when the monitored amount of the main battery 70 drops equal to or below a prescribed value, and releases the restriction imposed by the controller 60.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a work vehicle equipped with a battery that supplies power to operate work devices provided on the vehicle body. [Background technology]

[0002] Conventionally, there have been work vehicles equipped with a travelable vehicle body and working devices suitable for various tasks. For example, Patent Document 1 describes an aerial work vehicle having a scissor link mechanism attached to the upper part of a travelable vehicle body having tires and wheels, and a work platform supported by this scissor link mechanism. Inside the travelable vehicle described above, there are a battery, an inverter that converts DC power from the battery into AC power, and two travel motors that are driven by the AC power supplied from the inverter and independently drive a pair of left and right drive wheels. Also provided inside the travelable vehicle are a hydraulic pump and an electric motor that drives this hydraulic pump. The electric motor is driven by the battery described above, and pressurized oil discharged from the hydraulic pump operates the scissor link mechanism to raise and lower the work platform and steer the steering wheels. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-035419 Summary of the Invention [Problem to be solved by the invention]

[0004] Some of the work vehicles that run on battery power, such as those described above, display the remaining battery charge on a monitor or the like attached to the operating device, allowing the worker to grasp the remaining battery charge and, if the remaining battery charge drops to a predetermined value, to quickly charge the battery or replace it with a new one. However, simply displaying the remaining battery charge raises the risk that the worker will overlook the display and run out of battery power, causing the work equipment or the like to stop in the middle of operation.

[0005] The present invention has been made in consideration of such problems, and aims to provide a work vehicle that allows the worker to recognize that the battery charge is low before it is completely used up, and allows the battery to be charged or replaced without any problems. [Means for solving the problem]

[0006] In order to solve the above problems, the work vehicle of the present invention is a work vehicle that includes a drivable vehicle body, a work device (for example, a pump drive motor that drives the articulating boom 10 and hydraulic pump in the embodiments) provided on the vehicle body, and a main battery that supplies power to the work device, and is also equipped with an operating device (for example, an upper operating device 41 in the embodiments) that operates the work device, an operation control unit (for example, controller 60 in the embodiments) that controls the operation of the work device in response to operation of the operating device, a remaining charge monitoring unit (for example, controller 60 in the embodiments) that monitors the remaining charge of the main battery, an operation restriction unit (for example, controller 60 in the embodiments) that restricts the operation of the work device when the remaining charge of the main battery monitored by the remaining charge monitoring unit falls below a predetermined value, and a restriction release unit (for example, controller 60 in the embodiments) that releases the operation restriction on the work device whose operation has been restricted by the operation restriction unit.

[0007] In a work vehicle having the above configuration, it is preferable that the restriction release unit is provided with a momentary restriction release switch that releases the restriction imposed by the operation restriction unit, and that the restriction imposed by the operation restriction unit is released while the restriction release switch is operated.

[0008] Furthermore, the work vehicle according to the present invention is a work vehicle comprising a drivable vehicle body, a work device (for example, a pump drive motor that drives the articulating boom 10 and hydraulic pump in the embodiments) provided on the vehicle body, and a main battery and an auxiliary battery that supply power to the work device, and is also provided with an operating device (for example, upper operating device 41 in the embodiments) that operates the work device, an operation control unit (for example, controller 60 in the embodiments) that controls the operation of the work device in response to operation of the operating device, a remaining charge monitoring unit (for example, controller 60 in the embodiments) that monitors the remaining charge of the main battery, and a switching device (for example, contactor 64, contactor 82, inverter 63 and controller 60 in the embodiments) that switches the battery that supplies power to the work device from the main battery to the auxiliary battery when the remaining charge of the main battery monitored by the remaining charge monitoring unit falls below a predetermined value.

[0009] Furthermore, the work vehicle according to the present invention is a work vehicle comprising a travellable vehicle body, work equipment (for example, a pump drive motor that drives the articulating boom 10 and hydraulic pump in the embodiments) provided on the vehicle body, and a main battery and an auxiliary battery that supply power to the work equipment, and is also provided with an operating device (for example, an upper operating device 41 in the embodiments) that operates the work equipment, an operation control unit (for example, a controller 60 in the embodiments) that controls the operation of the work equipment in response to operation of the operating device, a remaining amount monitoring unit (for example, the controller 60 in the embodiments) that monitors the remaining amount of the main battery, an operation regulating unit (for example, the controller 60 in the embodiments) that regulates the operation of the work equipment when the remaining amount of the main battery monitored by the remaining amount monitoring unit falls below a predetermined value, and a switching device (for example, the controller 60, power system selector switch 68, and contactor 82 in the embodiments) that switches the battery that supplies power to the work equipment from the main battery to the auxiliary battery when the operation of the work equipment is regulated by the operation regulating unit.

[0010] In a work vehicle having any of the above configurations, it is preferable to provide an alarm device that notifies the user that the remaining charge of the main battery has fallen below a predetermined value when the remaining charge of the main battery monitored by the remaining charge monitoring unit falls below a predetermined value. [Effects of the Invention]

[0011] With the work vehicle of the present invention, operation of the work equipment is restricted when the remaining charge of the main battery falls below a predetermined value, so the worker can be made aware that the remaining charge of the main battery is low before the battery runs out of power and the work equipment or work vehicle becomes inoperable. In addition, since the work vehicle is equipped with a restriction release unit that releases the restriction even after operation of the work equipment has been restricted, the work equipment can be stored or the work vehicle can be evacuated to a safe location, and the main battery can be charged or replaced without hindrance.

[0012] Furthermore, with the work vehicle of the present invention, when the remaining charge of the main battery falls below a predetermined value, the battery that supplies power to the work equipment is switched from the main battery to the auxiliary battery. This means that the battery can be switched to the auxiliary battery before the remaining charge of the main battery is used up and the work equipment or work vehicle becomes inoperable, allowing the main battery to be charged or replaced without any problems.

[0013] Furthermore, with the work vehicle of the present invention, when the remaining charge of the main battery falls below a predetermined value, the operation of the work equipment is restricted, and then the battery supplying power to the work equipment is switched from the main battery to the auxiliary battery. This makes it possible to let the worker know that the remaining charge of the main battery is low and to switch to the auxiliary battery before the main battery runs out of power and the work equipment or work vehicle becomes inoperable, allowing the main battery to be charged or replaced without hindrance.

[0014] In addition, in a work vehicle having any of the above configurations, it is preferable to provide an alarm device that notifies the operator when the remaining charge of the main battery monitored by the remaining charge monitoring unit falls below a predetermined value. This configuration allows the operator to more clearly recognize that the remaining charge of the main battery has fallen below the predetermined value. [Brief explanation of the drawings]

[0015] [Figure 1] 1A and 1B are a plan view and a side view, respectively, showing a top surface and a side surface of an aerial work platform vehicle according to an embodiment of the present invention. [Figure 2] FIG. 2 is a side view for explaining the configuration of the articulated boom of the aerial work platform vehicle. [Figure 3] FIG. 2 is a block diagram showing the configuration of a power supply system of the aerial work vehicle. [Figure 4] FIG. 4 is a block diagram showing another configuration of the power supply system of the aerial work vehicle. [Figure 5] FIG. 4 is a block diagram showing another configuration of the power supply system of the aerial work vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0016] A preferred embodiment of the present invention will now be described with reference to the drawings. FIGS. 1 and 2 are diagrams showing the appearance of a vehicle for working at height 1 according to this embodiment. FIG. 1(a) is a plan view showing a retracted state of an articulating boom 10 provided as a working device on the vehicle for working at height 1, and FIG. 1(b) is a side view. FIG. 2 is a side view showing a state in which the boom and link members (described later) that make up the articulating boom 10 are substantially horizontal. Here, when describing with reference to FIG. 1(a), the front-rear and left-right directions follow the directions of the arrows shown in FIG. 1(a). The front-rear directions in FIGS. 1(b) and 2 are the same as the front-rear directions in FIG. 1(a).

[0017] As shown in Figure 1, the aerial work vehicle 1 is composed of a travelling body 5 having steering wheels 3 and drive wheels 4, a swivel base 7 rotatably attached to the travelling body 5, and an articulating boom 10 attached to the swivel base 7. The steering wheels 3 attached to the travelling body 5 are arranged in pairs on both the left and right sides of the front of the travelling body and are rotatable and steerable in the left-right direction of the vehicle. The drive wheels 4 are arranged in pairs on both the left and right sides of the rear of the travelling body and are rotatable and are driven by a travel motor (not shown) connected to each drive wheel. The swivel base 7 is attached to the travelling body 5 so as to be rotatable horizontally and can be rotated by a swing motor (not shown).

[0018] The articulating boom 10 is mounted on a swivel base 7 and includes a lower link 11 pivotally connected to the rear side of the swivel base 7 so that it can be raised and lowered; an upper link 20 pivotally connected to the tip of the lower link 11 so that it can be raised and lowered; a boom 30 pivotally connected to the tip of the upper link 20 so that it can be raised and lowered; and a work platform 40 pivotally connected to the tip of the boom 30 so that it can swing up and down. As shown in FIG. 1(b), the lower link 11 is disposed on the right side of the swivel base 7, extends forward and backward, and includes a pair of lower link members 12 (see FIG. 2) spaced apart vertically. The base ends of the pair of lower link members 12 are pivotally connected to the swivel base 7, and the tip ends of the pair of lower link members 12 are pivotally connected to first brackets 13, so that the pair of lower link members 12 form a parallel link mechanism. The pair of lower link members 12 can be raised and lowered by a lower link cylinder 14 shown in FIG. 2.

[0019] As shown in FIG. 2 , the side shape of first bracket 13 is a generally obtuse triangle, with its apex facing the swivel bed 7. The lower hypotenuse is pivotally connected to the distal ends of a pair of lower link members 12, and the upper hypotenuse is pivotally connected to the proximal ends of a pair of upper link members 21 constituting upper link 20. The pair of upper link members 21 are spaced apart vertically, with each distal end pivotally connected to second bracket 22. The side shape of second bracket 22 is generally V-shaped, with its bent portion facing the swivel bed 7. Each distal end of upper link member 21 is pivotally connected to the bent portion and lower end of second bracket 22. Thus, the pair of upper link members 21 constitute a parallel link mechanism. An upper link cylinder 23 is straddled between the upper upper link member 21 of the pair of upper link members 21 and first bracket 13. The extension and contraction of upper link cylinder 23 allows the pair of upper link members 21 to be raised and lowered.

[0020] The base end of a boom 30 is pivotally connected to the upper end of the second bracket 22. The boom 30 extends forward of the swivel base 7 along the longitudinal direction of the upper link 20, and as shown in FIG. 1, is configured by combining a base boom end 30a and a tip boom end 30b in a telescopic manner from the base end side. A telescopic cylinder (not shown) is provided inside the base boom 30a, and the boom 30 can be extended or retracted by this telescopic cylinder. As shown in FIG. 2, a boom derrick cylinder 32 is provided between the boom 30 and the center of the second bracket 22, and the boom derrick cylinder 32 can be extended or retracted to raise or lower the boom 30 relative to the upper link 20. The boom 30 is attached to the swivel base 7 via the lower link 11 and the upper link 20. By extending or retracting either the lower link cylinder 14 or the upper link cylinder 23, the boom 30 can move up or down while maintaining its posture.

[0021] The aforementioned swing motor is a hydraulic motor that rotates using hydraulic pressure, and the aforementioned lower link cylinder 14, upper link cylinder 23, and the telescopic cylinder and boom derrick cylinder 32 installed inside the boom base end 30a are all hydraulic cylinders that extend and retract using hydraulic pressure. These hydraulic motors and hydraulic cylinders are collectively called hydraulic actuators.

[0022] As shown in Figure 1(b), a vertical post 33 is pivotally connected to the tip of the boom 30 so that it can swing up and down, and a work platform 40 is attached to this vertical post 33 so that it can swing left and right. The work platform 40 can be swiveled by a swing motor (not shown). An upper leveling cylinder 35 is pivotally connected to the bottom of the vertical post 33, and the upper leveling cylinder 35 extends and retracts in accordance with the boom 30 elevation angle (the angle between the boom 30 and the running body 5), keeping the work platform 40 always horizontal.

[0023] The work platform 40 is provided with an upper operating device 41 that controls the operation of the articulating boom 10, the traveling body 5, etc. The upper operating device 41 has a plurality of operating levers 41a as shown in FIG. 1(b). These operating levers 41a are tiltable, and tilting the operating levers 41a causes the lower link 11 and upper link 20 shown in FIG. 2 to be raised and lowered, the boom 30 to be raised and lowered or extended, and the work platform 40 to be swiveled. The swivel platform 7 is also provided with a lower operating device (not shown) that has the same functions as the upper operating device 41.

[0024] 1(a), when the articulating boom 10 is stored, the lower link 11 is inclined downward from the front to the rear of the running body 5, and the upper link 20 is inclined upward from the front to the rear of the running body 5. The boom 30 is stored in a state where it is approximately parallel to the lower link member 12 and inclined downward from the front to the rear of the running body 5.

[0025] Next, with reference to the block diagram of Figure 3, we will explain the power supply system that supplies electricity to the travel motor 50 that drives the drive wheels 4, and the pump drive motor 53 that drives the hydraulic pump that supplies hydraulic oil to hydraulic actuators such as the swing motor and the various hydraulic cylinders of the articulating boom 10. In the block diagram of Figure 3, the swing motor, lower link cylinder 14, upper link cylinder 23, and the telescopic cylinder and derrick cylinder 32 in the base boom end 30a are collectively shown as hydraulic actuator 51. The power supply system shown in Figure 3 is located inside the swivel base 7.

[0026] In FIG. 3, the main battery 70 is detachably connected to a power supply system provided inside the swivel platform 7 via a connector 61. The socket of the connector 61 is connected to the battery 70, and the plug of the connector 61 is connected to a converter 62 and a contactor 64 (described below). The converter 62 converts the output voltage of the main battery 70 into an operating voltage for the controller 60 and supplies power to the controller 60. The controller 60 operates using the power output from the converter 62 and controls various actuators provided on the aerial work platform 1 (such as the drive control of the various motors and the extension / retraction control of the hydraulic cylinder) in response to operation of the operating lever 41a of the upper operation device 41, as well as displays of various information for the worker. The controller 60 is electrically connected to the main battery 70 by wiring via a connector 67, calculates the remaining charge of the main battery based on the voltage value of the main battery 70, and monitors whether the calculated remaining charge has fallen below a predetermined value.

[0027] Specifically, a control valve 52 is provided corresponding to each hydraulic actuator 51, and when a hydraulic pump 54 is driven by a pump drive motor 53, the hydraulic pump 54 supplies hydraulic oil stored in a hydraulic oil tank T to the control valve 52. In addition, the controller 60 outputs a command signal to the control valve 52 in response to an operation signal output by operation of the upper operating device 41. As a result, each control valve 52 controls the supply direction and supply amount of hydraulic oil supplied from the hydraulic pump 54 to the corresponding hydraulic actuator 51. As a result, the hydraulic actuator 51 operates in response to the operation of the upper operating device 41.

[0028] The inverter 63 converts DC power supplied from the main battery 70 via the connector 61 into AC power and controls the amount of AC power (e.g., voltage) supplied to the travel motor 50 and the pump drive motor 53 in accordance with a control signal output from the controller 60. The controller 60 also outputs a control signal to the inverter 63 in response to the operation of the upper operation device 41. Although only one inverter 63 is shown in FIG. 3 , if there are multiple motors to which AC power is supplied, multiple inverters suitable for the specifications of each motor may be provided. The contactor 64 is disposed between the connector 61 and the inverter 63 and turns on / off the power supplied from the main battery 70 to the inverter 63 in accordance with the control of the controller 60. Specifically, a coil is provided inside the contactor 64, and when an activation signal is output from the controller 60 to the inverter 63, the inverter 63 outputs an excitation signal to the coil of the contactor 64. When the coil of the contactor 64 is excited by this excitation signal, the contact between the connector 61 and the inverter 63 is "closed" against the bias of an internal spring, and power is supplied from the main battery 70 to the inverter 63. Furthermore, when the start signal from the controller 60 is no longer output, the inverter 63 stops the excitation signal that it had been outputting to the coil of the contactor 64. As a result, the contact between the connector 61 and the inverter 63 is "disconnected" by the bias of the internal spring, and power supplied from the main battery 70 to the inverter 63 is cut off.

[0029] The restriction release switch 65 is a momentary switch provided on the upper operation device 41 shown in Figures 1 and 2, and will be described in detail later. This switch is used to release the restriction when the drive of the traveling motor 50 or the pump drive motor 53 is restricted. The restriction release switch 65 may be a push button switch or a toggle switch as long as it is a momentary switch. The restriction notification device 66 is also provided on the upper operation device 41, like the restriction release switch 65, and is a device that notifies the worker on the work platform 40 that the drive of the traveling motor 50 or the pump drive motor 53 has been restricted. This restriction notification device 66 may be a lamp that lights up when restriction is applied, a display device that displays a message indicating that restriction has occurred, a buzzer that generates a warning sound, or an audio output device that outputs a warning message by voice.

[0030] In the power supply system shown in FIG. 3 , when the main switch of the traveling vehicle 5 is off and the traveling vehicle 5 is in an inoperative state, the contacts of the contactor 64 are "disconnected." When the main switch of the traveling vehicle 5 is turned on and the traveling vehicle 5 is in an operational state, DC power from the main battery 70 is output to the converter 62 via the connector 61, and the converter 62 converts it to an operating voltage for the controller 60 and supplies it to the controller 60. When the operating voltage is supplied to the controller 60, the controller 60 outputs an activation signal to the inverter 63. In response to this, the inverter 63 outputs an excitation signal to the coil of the contactor 64. This causes the contacts of the contactor 64 to be "connected," and DC power from the main battery 70 is supplied to the inverter 63 via the connector 61. The inverter 63 converts the supplied DC power into AC power and supplies it to the traveling motor 50 and the pump drive motor 53. As a result, power is supplied to the traveling motor and the pump drive motor of the traveling vehicle 5, enabling the traveling vehicle 5 to travel and the articulating boom 10 to operate.

[0031] Thereafter, the controller 60 controls the drive of the travel motor and the extension and retraction of each hydraulic cylinder of the articulating boom 10 in accordance with the operation of the upper operating device 41. The controller 60 also constantly monitors the remaining battery charge of the main battery 70, and when the remaining battery charge drops to a specified value, the controller 60 activates the restriction alarm device 66 to notify the operator that the remaining battery charge has dropped to the specified value. The controller 60 determines the remaining battery charge of the main battery 70 based on the output voltage of the main battery 70. The specified value of the remaining battery charge is set so that the articulating boom 10 can be operated until it reaches the stowed state regardless of the position of the articulating boom 10, and the traveling body 5 can be moved a specified distance.

[0032] At the same time, the controller 60 outputs a stop signal to the inverter 63, which stops the supply of AC power from the inverter 63 to the traveling motor 50 and the pump drive motor 53, restricting the traveling of the traveling body 5 and the operation of the articulating boom 10. The operator can know that the remaining battery charge of the main battery 70 is low by the notification from the restriction notification device 66 and the restriction on the traveling of the traveling body 5 or the operation of the articulating boom 10.

[0033] In this state, if it is necessary to store the articulating boom 10 or move the aerial work platform 1 to a location where it will not get in the way, for example, the worker turns on the restriction release switch 65. This causes the controller 60 to again output a start signal to the inverter 63 while the restriction release switch 65 is on. As a result, it becomes possible for the inverter 63 to supply AC power to the traveling motor 50 and the pump drive motor 53, and the controller 60 controls the articulating boom 10 and the traveling body 5 in accordance with operation from the upper operation device 41. If the restriction release switch 65 is turned off at this time, the controller 60 outputs a stop signal to the inverter 63, and as a result, the operation of the articulating boom 10 and the traveling body 5 is again restricted.

[0034] In the power supply system configured as described above, when the remaining battery charge of the main battery 70 drops to a specified value, the operator is notified of this and the travel of the traveling body 5 and the operation of the articulating boom 10 are restricted, so the operator can clearly recognize that the main battery 70 needs to be charged. Furthermore, even after the travel of the traveling body 5 and the operation of the articulating boom 10 are restricted, the traveling of the traveling body 5 and the operation of the articulating boom 10 can be enabled again by turning on the restriction release switch 65, so that the aerial work platform 1 can be retracted and the articulating boom 10 can be stored, for example.

[0035] Next, a modified example of the power supply system shown in FIG. 3 will be described with reference to the block diagram shown in FIG. 4. In the block diagram shown in FIG. 4, the same components as those in the block diagram shown in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted. The block diagram shown in FIG. 4 differs from the block diagram shown in FIG. 3 in that a power supply system changeover switch 68 is provided and connected to the controller 60 instead of the restriction release switch 65, a connector 69 is provided between the contactor 64 and the inverter 63, and an auxiliary battery 80 is added, and a connector 81 for connecting to the connector 69 and a contactor 82 for turning on / off between the auxiliary battery 80 and the connector 81 are provided. Note that a signal line for outputting an excitation signal to the coil of the contactor 82 is connected to the inverter 63.

[0036] The power supply system selector switch 68 is a switch that specifies whether the battery to be used is the main battery 70 or the auxiliary battery 80, with the main battery 70 usually being specified. The socket of the connector 69 is connected to the contacts of the contactor 64, and the plug of the connector 69 is connected to the inverter 63, which will be described next. The connector 81 is a socket that can be fitted with the plug of the connector 69.

[0037] In the power supply system shown in the block diagram of Fig. 4, the restriction notification device 66 issues a notification when the remaining battery charge of the main battery 70 drops to a specified value, and the control up to the point where the operation of the articulating boom 10 and the travel of the traveling body 5 are restricted is the same as that of the power supply system shown in Fig. 3. Therefore, the following describes the control when the power supplied to the inverter 63 is switched from the main battery 70 to the auxiliary battery 80 after the operation of the articulating boom 10 and the travel of the traveling body 5 are restricted.

[0038] First, when the operator recognizes that the remaining battery charge of the main battery 70 has dropped to a specified value due to an alarm from the restriction alarm device 66 or due to restrictions on the operation of the articulating boom 10 or the travel of the traveling body 5 being imposed (a stop signal being output from the controller 60 to the inverter 63), the operator unplugs the connector 69 and connects it to the socket of the connector 81 in order to switch the power supplied to the inverter 63 to the auxiliary battery 80 (see the dashed line in FIG. 4). Then, the power supply system selector switch 68 is switched from the main battery 70 side to the auxiliary battery 80 side.

[0039] As a result, when the remaining battery charge of the main battery 70 drops to a specified value and the power supply system selector switch 68 is turned on, the controller 60 outputs a start signal to the inverter 63 and designates the contactor 82 as the contactor that outputs an excitation signal. In response to this, the inverter 63 outputs an excitation signal to the coil of the contactor 82, and as a result, the contacts of the contactor 82 are "closed" and DC power from the auxiliary battery 80 is supplied to the inverter 63 via the connector 81. As a result, the inverter 63 converts the DC power to AC power and can supply it to the traveling motor 50 and the pump drive motor 53, enabling the traveling body 5 to travel and the articulating boom 10 to operate in accordance with control signals from the controller 60.

[0040] In the above-described power supply system, the contactor 82 is provided between the auxiliary battery 80 and the connector 81. However, the contactor 82 may be omitted and the auxiliary battery 80 may be directly connected to the connector 81. In such a configuration, the power supply system selector switch 68 can be omitted. In addition, in the above-described power supply system, the connector 69 is provided between the contactor 64 and the inverter 63. When switching from the main battery 70 to the auxiliary battery 80, the plug of the connector 69 is connected to the socket of the connector 81. However, the connector 69 may be omitted and the plug of the connector 61 may be connected to the socket of the connector 81. In such a configuration, when switching from the main battery 70 to the auxiliary battery 80, the power supply to the controller 60 is temporarily cut off. Therefore, it is preferable that the controller 60 be able to determine whether the connected battery is the main battery 70 or the auxiliary battery 80. For example, the controller 60 may store information in a non-volatile memory or the like that indicates that the remaining battery charge of the main battery 70 has dropped to a specified value. When a battery is connected again, if the remaining battery charge of the battery exceeds the specified value, the connected battery may be determined to be the auxiliary battery 80.

[0041] Furthermore, in consideration of the case where the operation of the articulating boom 10 is restricted while an operator is on the work platform 40, for example, a restriction release switch 65 shown in the power supply system in FIG. 3 may be provided. In this case, the controller 60 outputs a start signal to the inverter 63 again while the restriction release switch 65 is turned on. As a result, AC power can be supplied from the inverter 63 to the traveling motor 50 and the pump drive motor 53, and the controller 60 can control the articulating boom 10 in response to operation from the upper operating device 41.

[0042] Furthermore, in the power supply system shown in Figures 3 and 4, the controller 60 immediately outputs a stop signal when the remaining battery charge of the main battery 70 drops to a specified value. However, for example, if the remaining battery charge drops to a specified value while the articulating boom 10 is in operation or while the traveling body 5 is traveling, the controller 60 may gradually slow down the operation of the articulating boom 10 or the traveling body 5 until it is completely stopped, without relying on the operation of the upper operating device 41, and then output a stop signal.

[0043] Next, a modified example of the power supply system shown in Fig. 4 will be described with reference to the block diagram shown in Fig. 5. In the block diagram shown in Fig. 5, the same components as those in the block diagram shown in Fig. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted. The block diagram shown in Fig. 5 differs from the block diagram shown in Fig. 4 in that connector 69 and connector 81 are omitted, and the outputs of contactor 64 and contactor 82 are directly connected to inverter 63.

[0044] The operation of the power supply system shown in Figure 5 will now be described. First, when the main switch of the vehicle 5 is off and the vehicle is in an inoperative state, the contacts of the contactors 64 and 82 are both "disconnected." When the main switch of the vehicle 5 is turned on and the vehicle is in an operational state, DC power from the main battery 70 is output to the converter 62 via the connector 61, converted by the converter 62 to an operating voltage for the controller 60, and supplied to the controller 60. When the operating voltage is supplied to the controller 60, the controller 60 outputs an activation signal to the inverter 63 and designates the contactor 64 as the contactor that will output an excitation signal. In response to this, the inverter 63 outputs an excitation signal to the coil of the contactor 64, and as a result, the contacts of the contactor 64 are "connected," and DC power from the main battery 70 is supplied to the inverter 63 via the connector 61. This allows the inverter 63 to convert DC power into AC power and supply it to the travel motor 50 and the pump drive motor 53, making it possible for the travelling body 5 to travel and the articulating boom 10 to operate in accordance with control signals from the controller 60.

[0045] When the remaining battery charge eventually drops to a specified value, the controller 60 activates the restriction notification device 66 to notify the operator that the remaining battery charge has dropped to the specified value. The controller 60 also outputs a stop signal to the inverter 63, which stops the supply of AC power from the inverter 63 to the traveling motor 50 and the pump drive motor 53, thereby restricting the traveling of the traveling body 5 and the operation of the articulating boom 10.

[0046] If the operator becomes aware of the low remaining battery charge in the main battery 70 due to a notification from the restriction notification device 66 or due to restrictions on the travel of the traveling body 5 or the operation of the articulating boom 10 and switches the power supply system selector switch 68 from the main battery 70 to the auxiliary battery 80, the controller 60 outputs a start signal to the inverter 63 and designates the contactor 82 as the contactor that outputs an excitation signal. In response to this, the inverter 63 outputs an excitation signal to the coil of the contactor 82, and as a result, the contacts of the contactor 82 are "closed" and DC power from the auxiliary battery 80 is supplied to the inverter 63. As a result, the inverter 63 converts the DC power to AC power which can be supplied to the traveling motor 50 and the pump drive motor 53, and the controller 60 can control the travel of the traveling body 5 and the articulating boom 10 in response to operations from the upper operation device 41.

[0047] In the power supply system described above, when switching the power supplied to the inverter 63 from the main battery 70 to the auxiliary battery 80, an operator operates the power supply system selector switch 68. However, instead, when the controller 60 determines that the remaining battery charge of the main battery 70 has dropped to a specified value, the controller 60 may change the designation of the contactor that outputs the excitation signal from the contactor 64 to the contactor 82, so that the inverter 63 stops outputting the excitation signal to the contactor 64 and then outputs the excitation signal to the contactor 82. In this case, the power supply system selector switch 68 can be omitted.

[0048] Furthermore, in the power system shown in Figures 3 to 5, when restricting the travel of the traveling body 5 or the operation of the articulating boom 10, a stop signal is output from the controller 60 to the inverter 63, which causes the inverter 63 to stop supplying power to the traveling motor 50 and the pump drive motor 63. However, when the inverter 63 receives a stop signal from the controller 60, the inverter 63 may stop the excitation signal it has been outputting to the coil of the contactor 64, thereby "disconnecting" the contacts of the contactor 64, thereby cutting off the power supply to the traveling motor 50 and the pump drive motor 63.

[0049] In the above embodiment, the vehicle for aerial work is driven by tires and wheels, but it may also be driven by crawlers. The vehicle body may be a truck, and the working device may be battery-powered but propelled by an engine. Furthermore, the working device is not limited to an articulating boom, but may be a work platform supported by a normal boom or a scissor link mechanism, or other working device such as a press device on a garbage truck or a crane on a crane truck. Furthermore, the restriction notification device 66 may be omitted from the power supply system shown in FIGS. 3 to 5. [Explanation of symbols]

[0050] 1. Aerial work platform 5 Running body 7 Swivel 10 Refraction Boom 14 Lower link cylinder 23 Up-Pan Cylinder 32 Elevating cylinder 40 Workbench 41 Upper control device 40 Workbench 50 Travel motor 51 Hydraulic Actuator 52 Control valve 53 Pump drive motor 54 Hydraulic pump 60 Controller 61, 67, 69, 81 Connectors 63 Inverter 64, 82 Contactor 70 Main Battery 80 Auxiliary Battery

Claims

1. A work vehicle comprising: a travellable vehicle body; a work implement provided on the vehicle body; and a main battery that supplies power to the work implement, an operating device for operating the working device; an operation control unit that controls the operation of the working device in response to an operation of the operating device; a remaining charge monitoring unit that monitors the remaining charge of the main battery; an operation restriction unit that restricts operation of the working device when the remaining charge of the main battery monitored by the remaining charge monitoring unit falls below a predetermined value; a restriction release unit that releases the restriction on operation of the working device whose operation has been restricted by the operation restriction unit.

2. the restriction release unit includes a momentary restriction release switch that releases the restriction imposed by the operation restriction unit, 2. The work vehicle according to claim 1, wherein the restriction by the operation restriction unit is released while the restriction release switch is operated.

3. A work vehicle comprising a travellable vehicle body, a work implement provided on the vehicle body, and a main battery and an auxiliary battery that supply power to the work implement, an operating device for operating the working device; an operation control unit that controls the operation of the working device in response to an operation of the operating device; a remaining charge monitoring unit that monitors the remaining charge of the main battery; a switching device that switches the battery supplying power to the work device from the main battery to the auxiliary battery when the remaining charge of the main battery monitored by the remaining charge monitoring unit falls below a predetermined value.

4. A work vehicle comprising a travellable vehicle body, a work implement provided on the vehicle body, and a main battery and an auxiliary battery that supply power to the work implement, an operating device for operating the working device; an operation control unit that controls the operation of the working device in response to an operation of the operating device; a remaining charge monitoring unit that monitors the remaining charge of the main battery; an operation restriction unit that restricts operation of the working device when the remaining charge of the main battery monitored by the remaining charge monitoring unit falls below a predetermined value; a switching device that switches the battery supplying power to the working device from the main battery to the auxiliary battery when the operation of the working device is restricted by the operation restriction unit.

5. A work vehicle as described in any one of claims 1 to 4, characterized in that it is provided with an alarm device that, when the remaining charge of the main battery monitored by the remaining charge monitoring unit falls below a predetermined value, notifies the user that the remaining charge of the main battery has fallen below a predetermined value.

Images