JP2009215855A - Working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly and effectively control a drive means installed on a working machine while power is supplied to the working machine, in prohibiting or limiting the use of the drive means. <P>SOLUTION: Inverters 30-33 connected to electric motors 20R, 20L, 21, and 26, respectively, are controlled according to signals from a control device 35. When the plug 38 of a power cable 38 is connected to a connector 40, the swing operation of the working machine is disabled, and the working machine is limited to travel at a speed lower than a normal speed, but the operation of each part of a working means 8 is not prohibited nor limited. A selector switch 26 is connected to the control device 35. When the selector switch 26 is turned ON, a crawler traveling means 2 of a carrier 3 is brought into a state in which the working machine can run at the normal speed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a work machine such as a construction machine or an industrial machine that operates using an electric motor as a main power source, and in particular, a work machine that can supply power from a power storage device provided in the work machine or from an external power source. It is about.

  A working machine such as a construction machine generally uses an engine as a power source. However, in recent years, the range of utilization of work machines has tended to expand. For example, hydraulic excavators as work machines have been used for civil engineering work such as excavation of earth and sand, but are also used for the treatment of industrial waste. It is used not only for open spaces such as outdoors, but also for working inside closed spaces such as warehouses and tunnels. In a closed space, the exhaust gas from the engine will be filled, and the working environment will be inferior due to the generation of severe noise. Even in an open space, as in civil engineering works in urban areas, there is a demand for significant regulations regarding exhaust gas, and demands for noise reduction tend to be strict.

  From the above, electric work machines using the power storage device as a power source are being put into practical use. In this electric work machine, when the power of the installed power storage device is consumed, power feeding or charging is performed. When charging at the work site, a power cable drawn from a fixed or portable external power supply is connected to the connector of the power storage device, and power is supplied to the power storage device via this power cable.

  Patent Document 1 shows an example of such an electric construction machine. In this known machine, a hydraulic pump is driven by a power storage device, that is, a battery, and the hydraulic oil from this hydraulic pump is supplied to each actuator to operate these actuators, thereby driving the working means and the lower part. The traveling by the traveling body and the turning of the upper revolving body installed on the lower traveling body are also possible. In addition, the operation of a part or all of the actuators is restricted when the remaining battery level becomes a predetermined level or less. For example, only the travel actuator can be operated, and the actuator for the working means is controlled to be stopped.

Here, although it is not impossible to install the battery on the lower traveling body, the hydraulic pump is provided on the upper swing body side, and the hydraulic actuator is also disposed on the upper swing body side except for the traveling motor. Therefore, the battery is generally arranged on the upper swing body side. Moreover, since the battery is heavy, for example, as shown in Patent Document 2, the battery can be used in place of the counterweight, and the upper swing body is more space for installing the battery than the lower traveling body. For example, it is preferable to install a battery in the upper swing body.
JP-A-11-107320 JP 07-309482 A

  By the way, when the remaining amount of the battery decreases, the battery is connected to an external power source to receive power. When the external power source is stationary, power is supplied by running the work machine to a predetermined location and connecting a power cable. On the other hand, when the external power supply is portable, the work machine may be moved closer to the external power supply placed at a predetermined position, or the external power supply may be moved closer to the work machine. In any case, even while the power cable is connected to the work machine, it is necessary to evacuate so as not to obstruct traffic. It is not desirable to completely prohibit

  In the above-described prior art, the operation of the actuator is restricted when the remaining battery level is below a predetermined level, but when the remaining battery level exceeds the set level due to the supply of power, this restriction is released and the work machine is You can move freely without restrictions. Therefore, the operator may perform work even though the power cable is connected to the work machine. Therefore, when the work machine is run, depending on the direction, a large pulling force may be applied to the power cable, and the power cable may be detached from the connector, thereby disconnecting the battery. Further, the power cable may be stepped on by the lower traveling body of the work machine to damage the power cable. In this case, there is a possibility of causing a situation such as electric leakage. Further, the connection position of the power cable is the upper swing body where the battery is installed. Therefore, if the upper revolving structure is swung while the power cable is connected, the action of the pulling force on the power cable and the possibility of detachment from the connector based thereon are further increased.

  The present invention has been made in view of the above points. The object of the present invention is to prohibit or restrict the driving means provided in the work machine while power is supplied to the work machine. Therefore, it is possible to control this appropriately and effectively.

  In order to achieve the above-mentioned object, the present invention provides an upper swing body on a lower traveling body via a swinging means, and working means is mounted on the upper swinging body. Among the working means, a plurality of driving means including a turning means is configured as an electric driving means, and an electric storage device that supplies electric power to the electric driving means and a connector to which a power cable from an external power source is connected A working machine provided in a machine and configured to be able to operate the driving means while supplying power from the external power source to the power storage device, wherein the power cable is connected to the connector Detecting means for detecting the power cable, and when the detecting means detects that the power cable is connected to the connector, at least one of the electric driving means It is an its features that it has a structure and a control means for prohibiting or restricting the work.

  While the power cable is connected to the connector, it is not preferable to perform substantial work by the work machine, whether it is during power feeding or before power feeding is started or after power feeding is finished. However, for various reasons, it is desirable that certain types of driving means can be driven, although within a limited range. Here, since the power cable is connected to the upper swing body, when the upper swing body is swung, the power cable is likely to be detached. Further, as a work machine, for example, in a hydraulic excavator for excavating earth and sand, a turning operation is inevitably performed when excavation work is performed. Therefore, when the power cable is connected to the connector, at least the turning drive is set to be prohibited. This prevents work from being performed and prevents the power cable from being detached from the connector.

  In addition to the turning drive means of the upper turning body, the driving means includes a driving means for the lower running body and a driving means for each part constituting the working means. Of these, not all driving is a problem when the power cable is connected to the connector. On the other hand, since other machines and vehicles pass at the work site, it is desirable to suppress prohibited driving to a minimum. Even if the working means can be driven, there is almost no possibility of contact with the power cable. In addition, depending on the posture state of the working means, it may become an obstacle to the passage of other machines or vehicles. Therefore, in order to change the attitude of the working means, the control means does not restrict the operation of the working means.

  This may be allowed for travel drive, but depending on the travel direction, the power cable may be stepped on, and the power cable may be disconnected from the connector, so travel drive is prohibited or restricted. Is desirable. However, travel drive is not completely prohibited because it may interfere with the passage of other vehicles. Therefore, the traveling can be disabled, and more preferably, the traveling speed is limited to a low speed or a very low speed. On top of that, the work machine is moved to enable emergency evacuation for reasons such as allowing other vehicles to pass. For this reason, it can return to the state which can drive | work by switch operation. Further, the restriction on the maximum speed traveling may be constant, but may be two to a plurality of stages or continuously variable. In addition to the travel means described above, it is also possible to restrict the operation, and when restricting the operation of a plurality of means, it can be released collectively by operating the switch. An independent release switch may be provided. Furthermore, some means can be switched to two states, ie, restriction and restriction release, and other means can be set to change the restriction stepwise or continuously.

  In a state where the power cable is connected to the connector of the power storage device, a necessary operation among the operations of the construction machine is prohibited and the operation is restricted. This may cause the work machine to be inadvertently operated while the power cable is connected, disconnecting the power cable from the work machine, or stepping on the power cable placed on the ground to damage the power cable. It is possible to reliably prevent the occurrence of such a situation.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 shows a hydraulic excavator as an example of a work machine. In the figure, a state where electric power is supplied to the hydraulic excavator is shown. Needless to say, the work machine of the present invention is not limited to a hydraulic excavator.

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

  A pair of left and right crawler type traveling means 2 has a crawler belt 14 wound between a sprocket 12 and an idler 13, and the sprocket 12 is rotationally driven by a motor 20 as will be described later. The turning device 4 turns the upper turning body 5 and is also driven by the motor 21. Further, the working means 8 is provided with a boom cylinder 22, an arm cylinder 23, and a bucket cylinder 24. By operating these cylinders 22 to 24, these parts are operated to perform operations such as excavation of earth and sand. Executed.

  FIG. 2 shows the configuration of the operation control circuit of each driving means described above. The traveling motor 20, specifically the crawler traveling means 2, is provided on the left and right, and two traveling motors are provided as indicated by reference numerals 20 </ b> R and 20 </ b> L in FIG. 2. These travel motors 20R and 20L are electric motors. The turning motor 21 is also an electric motor. The cylinders 22 to 24 as the driving means of the working means 8 are hydraulic cylinders, and a hydraulic pump 25 is provided to supply pressure oil to the cylinders 22 to 24. The hydraulic pump 25 is an electric motor. 26 is driven. Therefore, the motors 20R, 20L and 21 and the cylinders 22 to 24 are actuators of the hydraulic excavator 1. In addition, inverters 30 to 33 are connected to the motors 20R, 20L, 21 and 26, respectively, and a power storage device 34 is provided in the machine room building 7 in order to supply power to the inverters 30 to 33. The power storage device 34 and the inverters 30 to 33 are electrically connected. Although only the power storage device 34 is provided, the engine may be installed together with the power storage device 34. Further, the motor can be constituted by a hydraulic motor driven by a hydraulic pump instead of an electric motor.

  Inverters 30 to 33 are controlled based on a signal from control device 35. The cab 6 is provided with operation levers 27 for left and right traveling, turning, boom operation, arm operation, and bucket operation, and the operator tilts these operation levers 27 in the cab 6. To be operated. And the operation signal of these each operation lever 27 is taken in into the control apparatus 35, and the output control of inverter 30-33 is performed.

  In order to supply power to the power storage device 34, a rectifier 36 is provided. The rectifier 36 is provided with a connector 40 that allows a plug 39 provided on the power cable 38 from the external power source 37 to be detachable. The rectifier 36 is electrically connected to a power switch 41, and the power switch 41 is charged from the drive power supply mode in which the power storage device 34 is connected to each of the inverters 30 to 33 and the external power supply 37. It is possible to switch between charging modes. Further, even when the power switch 41 is switched to the charging mode, the power storage device 34 and the inverters 30 to 33 are held in a conductive state.

  Further, the connector 42 is provided with a switch 42 as detection means. When the plug 38 of the power cable 38 is connected to the connector 40, the switch 42 is connected to the connector 42 by a pin 38a provided on the plug 38. It comes to turn on. And this signal is taken in into the control apparatus 35, and the output level at the time of the electric power supply from the electrical storage apparatus 34 to each inverter 30-33 by the power supply switch 41 is restrict | limited based on this detection signal. . Note that the switch 42 may not only simply control ON / OFF, but also change the output level stepwise or steplessly until the output level reaches the maximum.

  In the operation control circuit of each drive unit of the hydraulic excavator 1 configured as described above, a power storage device 34 is installed in the hydraulic excavator 1. The electric power from the power storage device 34 is used to drive the lower traveling body 3 and the upper drive body 5 to be swiveled by the swiveling device 4. Further, the boom cylinder 22, arm cylinder 23, and bucket cylinder 24 that constitute the working means 8 are provided. In operation, the boom 9, the arm 10 and the bucket 11 are driven to perform operations such as excavation of earth and sand. The traveling motors 20R and 20L are provided on the lower traveling body 3 side, but the boom cylinder 22, the arm cylinder 23, the bucket cylinder 24, and the turning motor 21 as actuators of the working means 8 are provided on the upper turning body 5 side. The power storage device 34 and its drive control circuit are installed in the upper swing body 5.

  If the work is continuously performed, power is consumed and the remaining amount of power stored in the power storage device 34 decreases. Therefore, the battery must be charged before the amount of power stored becomes zero. Here, the remaining amount of electricity stored in the electricity storage device 34 can be detected by incorporating a battery checker or the like. Therefore, based on this detection signal, when the remaining amount of power storage is reduced to a level that requires charging, the operator can be notified by an alarm or the like. Based on this warning, the operator performs charging operation of the power storage device 34 on the external power source 37.

  Here, when the external power source 37 is a stationary type, the excavator 1 is caused to travel to a place where the external power source 37 is installed. When the external power source 37 is portable, the external power source 37 can be moved to a place where the excavator 1 is located. In any case, by connecting the plug 39 provided at the tip of the power cable 38 connected to the external power source 37 to the connector 40 of the rectifier 36, the charging operation in the power storage device 34 is started. The power storage device 34 and devices such as a rectifier 36 provided to supply power to the power storage device 34 are provided in the machine room building 7 of the upper swing body 5, and as shown in FIG. The plug 39 of the power cable 38 is connected to the connector 40 of the rectifier 36 installed on the upper swing body 5.

  Even while the charging operation is being performed, electric power can be supplied from the power storage device 34 to the inverters 30 to 33, and thus the motors 20R, 20L, 21 and 26 can be driven. Accordingly, although the excavator 1 can be driven, it is not preferable to perform the operation with the excavator 1 while the plug 39 of the power cable 38 is connected to the connector 40 of the rectifier 36 including during the charging operation. Therefore, the operation is restricted so that the work cannot be performed. However, inconvenience arises when the excavator 1 is not moved at all. That is, the external power source 37 is installed at a work site where various construction machines including other hydraulic excavators are active and vehicles such as dump trucks also pass. It is necessary to perform some kind of operation so that it does not happen.

  When the plug 39 is connected to the connector 40, the switch 42 constituting the detection means is turned on, and this signal, that is, the cable connection detection signal is taken into the control device 35, so that power is supplied to the power storage device 34. Is detected. The control device 35 receives operation signals of the operation levers 27, performs output control by the inverters 30 to 33, travels the lower traveling body 3, and turns the upper portion by the turning device 4. The body 5 is turned and the working means 8 is driven. Therefore, in the control device 35, when the detection signal during cable connection is not input, naturally, the driving of the movable parts described above is not limited. However, when the cable connection detection signal is input to the control device 35, some of the movable parts are prohibited from being driven, and other parts of the drive are restricted.

  First, excavation work of earth and sand in the hydraulic excavator 1 is prohibited. Here, the earth and sand excavation work is performed by driving the working means 8 including the boom 9, the arm 10 and the bucket 11. However, the excavated earth and sand needs to be moved to another place such as being loaded on a dump truck. Accordingly, although the vehicle may travel, the turning operation is essential. When the upper swing body 5 can be turned, a pulling force is always applied to the power cable 38 connected to the upper swing body 5, and the upper swing body 5 is detached from the connector 40. Therefore, the turning operation is not performed while the cable is connected. That is, while the cable connection detection signal is being input to the control device 35, even if the operation lever 27 for turning operation is operated, power is not supplied to the motor 21, which is the actuator, and accordingly turning. No action is taken.

  When the posture of the working means 8 may be in an unstable state, and there is a possibility that the entire hydraulic excavator 1 or the working means 8 may come into contact with other vehicles that come and go to the work site, It is necessary to move the excavator 1. If the traveling by the lower traveling body 3 and the operation of the working means 8 are allowed, the emergency avoiding operation can be executed, and the turning operation of the upper revolving body 5 is not essential for the emergency avoiding operation. Therefore, even if the cable connection detection signal is output, power is supplied to the motors 26 driving the motors 20R and 20L and the hydraulic pump 25 by operating the operation lever 27, and the crawler type traveling means 2 of the lower traveling body 3 is used. Driving and driving of the working means 8 are possible.

  However, the traveling by the lower traveling body 3 may cause the power cable 38 to be stepped on and damaged by the crawler belt 14 depending on the direction, and the power cable 38 may be detached from the connector 40 depending on the traveling distance. Accordingly, there is a restriction on traveling by the lower traveling body 3. This restriction may be temporarily prohibited, and the restriction may be released by performing a special operation. However, because of the nature of the emergency avoidance operation, the entire excavator 1 may be moved slightly. In addition, since the amount of movement may be small, even if the traveling is low speed to very low speed, it does not cause much trouble. Therefore, the traveling by the lower traveling body 3 can be driven after the speed is reduced, that is, after the speed is limited.

  Then, if the operator is aware that the cable is being connected, the operation is performed so as to limit the traveling direction and the traveling distance. Therefore, when the changeover switch 28 is provided in the cab 6 and the changeover switch 28 is operated to be in the ON state, the speed limit described above is canceled so that the vehicle can run at a normal speed. This enables a quick emergency avoidance operation. In addition, the fact that the switch 28 has been operated means that the operator recognizes that the cable is being connected, so that the vehicle is carefully driven, and the power cable 38 is disconnected or the crawler belt 14 is used. There is no trampling.

  Even if the working means 8 provided in the upper swing body 5 is operated, there is almost no possibility of contacting with the power cable 38. As is clear from FIG. 1, the working means 8 protrudes greatly from the upper swing body 5. In the posture state of FIG. 1, the working means 8 is folded upward. However, when the excavator 1 stops, it is not necessarily in this posture state, and may have various postures. There is. Therefore, when performing the emergency avoidance operation, it is necessary to move the boom 9, the arm 10, and the bucket 11 of the working means 8 to change the posture so as not to come into contact with other vehicles or the like. In addition, in order to perform an emergency avoidance operation, when the traveling drive by the lower traveling body 3 is performed, in order to avoid collision with other objects and to balance the posture, the driving of the working means 8 is limited. Is not provided. And as already explained, if turning is prohibited, work such as excavation of earth and sand cannot be performed even if the working means 8 is operated. Therefore, a situation where the work is performed while the cable is connected does not occur.

  Therefore, the control device 35 performs control based on the flowchart shown in FIG. That is, when the starter key is turned on, it is always determined whether or not the plug 39 provided on the power cable 38 of the external power source 37 is connected to the connector 40 (step 1). If the plug 39 is not connected, Each drive unit is normally operated without limitation (step 2). On the other hand, when it is detected that the plug 39 is connected, that is, when a cable connection detection signal is output, it is determined whether or not the changeover switch 28 is turned on (step 3). If the result of this determination is that the changeover switch 28 is not in the ON state, the turning operation is prohibited and the traveling operation is speed limited (step 4). On the other hand, when it is detected that the changeover switch 28 is turned on, only the turning operation is prohibited, and the traveling operation becomes an unrestricted movable state (step 5). In step 4, turning and running are prohibited, turning is prohibited in step 5, and traveling can be set to limit the speed.

FIG. 1 shows a hydraulic excavator as an example of a work machine, and is an external view of a state where electric power is supplied to the hydraulic excavator. It is a block diagram which shows the structure of the drive device of a hydraulic shovel. It is a flowchart figure which shows the control procedure of a control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic excavator 2 Crawler type traveling means 8 Working means 20R, 20L, 21, 26 Electric motor 27 Operation lever 28 Changeover switch 30-33 Inverter 34 Power storage device 35 Control device 36 Rectifier 37 External power supply 38 Power cable 39 Plug 40 Connector 41 Power supply Switch 42 switch

Claims (5)

An upper swing body is provided on the lower traveling body via a swinging means, and working means is attached to the upper swing body, and a plurality of drive means including the swinging means among the traveling means, the swinging means, and the working means of the lower traveling body. And a power storage device for supplying electric power to the electric drive means, and a connector to which a power cable from an external power source is connected to the work machine, and the electric power is stored from the external power source. In a working machine that is capable of operating the drive means while supplying to the apparatus,
Detecting means for detecting that the power cable is connected to the connector;
And a control unit that prohibits or restricts the operation of at least one of the electric drive units when the detection unit detects that the power cable is connected to the connector. A working machine characterized by 2. The work machine according to claim 1, wherein the control unit prohibits driving of the turning unit when the detection unit detects that the power cable is connected to the connector. 3. . 3. The work machine according to claim 1, wherein the work means can be driven even when power is supplied from the external power source by the control means. When the detecting means detects that the power cable is connected to the connector, the restriction means enables the lower traveling body to travel, but restricts the traveling speed to a low speed or a fine speed. The work machine according to any one of claims 1 to 3, wherein 5. The work machine according to claim 4, wherein the restriction of the traveling means by the restriction means can be released by a switch after the restriction is performed.

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