JP2013234474A - Electric construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric construction machine capable of increasing the degree of freedom in mounting a motor control device for operating an electric motor (feed control) while reducing cost.SOLUTION: An electric motor 9 for driving a hydraulic pump 11 is fed via a feeder cable 21. A motor control device 23 for performing feed control of the electric motor 9 includes a safety circuit 29 provided in the middle of the feeder cable 21 for protecting the electric motor 9 from electrical abnormality, a starting/stopping circuit 30 provided in the middle of the feeder cable 21 for starting/stopping the electric motor 9, a signal output circuit 31 for outputting a signal output from the safety circuit 29 to a controller 39, and a starting/stopping control circuit 34 for switching over the starting/stopping circuit 30 on the basis of the signal and the like from a key switch 35. The safety circuit 29 and the starting/stopping circuit 30 are stored in a power box 24, and the signal output circuit 31 and the starting/stopping control circuit 34 are stored in a control box 25.

Description

  The present invention relates to an electric construction machine including an electric motor as a drive source such as an electric hydraulic excavator.

  In general, electric construction machines, such as electric excavators, are notable as exhaust gas problems, and in addition, they are attracting attention as low-vibration, low-noise construction machines when performing excavation work in urban areas. Has been.

  Such an electric construction machine includes a self-propelled vehicle body, an electric motor that rotates when power is supplied from an external power source via a power supply cable, a hydraulic pump that is driven by the electric motor, and a hydraulic pump. A hydraulic actuator that is driven by the discharged pressure oil and a motor control device (control panel) that performs operation (power feeding control) of the electric motor are roughly configured (see, for example, Patent Document 1).

  Here, for example, the motor control device is provided in the middle of the power supply cable to protect the electric motor from an electrical abnormality, and is provided in series with the safety circuit in the middle of the power supply cable to start and stop the electric motor. The system includes a start / stop circuit, a signal output circuit that outputs a signal output from the safety circuit to an external device, and a start / stop control circuit that switches the start / stop circuit based on an external signal.

  In addition, the motor control device is not required at a portion where the fuel tank is attached if the vehicle is equipped with an engine on the front side of the machine room that houses the electric motor in the upper swing body constituting the vehicle body. It is arranged in place of the fuel tank. In this case, for example, the motor control device has a configuration in which necessary circuits such as a safety circuit, a start / stop circuit, a signal output circuit, a start / stop control circuit, and various devices are collectively housed in a single storage box as a single control panel. It has become.

JP 2011-219917 A

  By the way, in the case of a configuration in which the motor control device is housed together in a single storage box as a single control panel, the specification is determined according to the vehicle case, the vehicle type, the specifications (performance, output) of the mounted electric motor, and the like. It is necessary to manufacture a matching control panel. That is, it is necessary to manufacture a control panel having a different internal configuration for each specification, which may increase the cost of the motor control device.

  Also, since the necessary circuits such as safety circuit, start / stop circuit, signal output circuit, start / stop control circuit are integrated into one control panel, the size of the entire control panel (the entire storage box) is increased, and the motor control device is installed. The degree of freedom and layout may be limited.

  In this case, depending on the mounting position of the motor control device, in order to ensure reliability of water ingress and heat, an extra sealing material or heat shield is necessary, which may lead to an increase in cost. is there. Furthermore, depending on the mounting position of the motor control device, the handling of the power supply cable may be troublesome or the length of the power supply cable may be excessively long.

  The present invention has been made in view of the above-described problems of the prior art, and is an electric construction machine capable of improving the degree of freedom of mounting a motor control device that performs the operation (power feeding control) of the electric motor and reducing the cost. The purpose is to provide.

  An electric construction machine according to the present invention includes a vehicle body, an electric motor that rotates when power is supplied from a battery power source or an external power source mounted on the vehicle body via a power supply cable, and a hydraulic pump that is driven by the electric motor. A hydraulic actuator driven by pressure oil discharged from the hydraulic pump, and a motor control device for operating the electric motor, the motor control device provided in the middle of the power supply cable from the electrical abnormality A safety circuit that protects the electric motor, a start / stop circuit that is provided in series with the safety circuit in the middle of the power supply cable to start and stop the electric motor, and a signal output from the safety circuit is output to an external device And a start / stop control circuit for switching the start / stop circuit based on an external signal.

  In order to solve the above-described problem, the invention adopts the features of the configuration of claim 1 in that the motor control device includes a power box that houses the safety circuit and the start / stop circuit, and the signal output circuit. And a control box that houses the start / stop control circuit, and the power box and the control box are arranged at different positions on the vehicle body.

  According to a second aspect of the present invention, the vehicle body includes a support frame on which a support shaft structure is formed and on which the electric motor and the hydraulic pump are mounted; A counterweight, a partition wall disposed in front of the electric motor and extending in the left and right directions of the vehicle body, and a machine room for housing the electric motor and the hydraulic pump between the counterweight and the partition wall. The power cover and the control box are both arranged in the machine room.

  According to a third aspect of the present invention, the power box and the control box are positioned in the machine room and attached to the partition wall or the electric motor.

  According to a fourth aspect of the present invention, the vehicle body includes a support frame on which a support shaft structure is formed and on which the electric motor and the hydraulic pump are mounted; A counterweight, a partition wall disposed in front of the electric motor and extending in the left and right directions of the vehicle body, and a machine room for housing the electric motor and the hydraulic pump between the counterweight and the partition wall. The power box is located in the machine room and attached to the electric motor, and the control box is arranged outside the machine room.

  According to a fifth aspect of the present invention, the safety circuit includes a first safety circuit provided with a breaker that cuts off the power supply cable when an electrical abnormality including a short circuit or leakage occurs, and an overload current in the power supply cable. And a second safety circuit provided with a thermal relay that cuts off the power supply cable when a power failure occurs, and the power box includes a connection terminal to which an external cable leading to the external power source is connected and the first safety circuit. A first power box that houses a safety circuit, and a second power box that houses the second safety circuit and the start / stop circuit, wherein the first power box of the power box is The configuration is such that it is arranged outside the machine room.

  According to the first aspect of the present invention, a motor control device includes a power box that houses a safety circuit and a start / stop circuit through which a relatively high voltage is conducted, a signal output circuit and a start / stop control circuit through which a relatively low voltage is conducted. The power box and the control box are arranged at different positions. For this reason, compared with the structure which accommodates the circuit required for one accommodation box collectively, a power box and a control box can each be comprised small. In this case, for example, even in a small vehicle body that cannot be mounted with a configuration that accommodates the necessary circuits in a single storage box, each is mounted by disposing a small power box and a control box at different positions. It becomes possible to do. Thereby, the freedom degree of mounting of a motor control apparatus and layout property can be improved.

  In addition, the safety circuit and start / stop circuit housed in the power box differ in the value of the current flowing through the circuit, etc., depending on the vehicle case, the vehicle type, the specifications (performance, output) of the mounted electric motor, etc. It is necessary to configure using components and circuits that match the current value. For this reason, in the safety circuit and the start / stop circuit, the component configuration, circuit configuration, outer diameter size, and the like change according to the specifications of the electric motor to be mounted, and the size of the power box may change accordingly. . On the other hand, the signal output circuit and the start / stop control circuit accommodated in the control box should be the same as the circuit that performs the same operation even if the vehicle case, the vehicle type, the specification of the electric motor mounted, etc. are different. Can do. As a result, it is possible to reduce the cost of the motor control device by sharing the signal output circuit, the start / stop control circuit, and the control box, and mass production.

  According to the second aspect of the present invention, since both the power box and the control box are arranged in the machine room, the power box and the feeding cable through which high voltage and high current flow can be isolated in the machine room. Thereby, an operator or a worker can be made difficult to approach the power box or the power feeding cable, and electrical safety can be improved. Moreover, since the power box and the electric motor can be arranged close to each other, the wiring between the power box and the electric motor can be shortened, and the wiring work including the wiring operation can be facilitated. it can. Moreover, by providing the power box with a connection terminal to which an external cable leading to an external power source is connected, it is not necessary to provide a connection terminal and a terminal box for housing it separately from the power box, and the cost is reduced by reducing the number of parts. Can be achieved.

  Further, since the machine room houses the electric motor, the machine room is waterproofed to prevent water from entering the machine room. Thus, the machine room is waterproofed so that the power box and the control box are waterproofed. Even if the processing is omitted or simplified, these waterproof properties can be secured. Thereby, cost reduction by reduction of the sealing material used for waterproofing processing, etc. can be aimed at. Moreover, the cooling of the power box and the control box can be performed using cooling air for cooling an electric motor, a heat exchanger, and the like housed in the machine room, for example. Thereby, it is also possible to ensure cooling performance.

  According to invention of Claim 3, it is set as the structure which attaches a power box and a control box to a partition or an electric motor in a machine room. In this case, when the power box and the control box are attached to the partition wall, the power box and the control box can be attached to the partition wall with sufficient support strength. On the other hand, in the configuration in which the power box and the control box are attached to the electric motor, the power box and the control box can be attached to the electric motor with sufficient support strength, and the electric motor, the power box, and the control box are integrated. Can be handled as one assembly (can be assembled). Further, it is not necessary to provide a connection cable between the power box and the electric motor, and it is not necessary to provide a connection terminal for connecting the connection cable and a terminal box for accommodating the connection cable. Wiring work can be facilitated and costs can be reduced. Further, if the electric motor is supported by vibration isolation with respect to the vehicle body, the vibration isolation performance of the power box and the control box attached thereto can be ensured.

  According to the invention of claim 4, since the power box is attached to the electric motor in the machine room and the control box is arranged outside the machine room, the power box is isolated, the wiring work is facilitated, and the waterproof process is omitted. It is possible to ensure flexibility in the layout of the control box while ensuring simplification, ensuring cooling, assembling, and vibration proofing.

  According to the invention of claim 5, the power box includes a first power box that houses a connection terminal to which an external cable leading to an external power source is connected and a first safety circuit provided with a breaker, and a thermal relay. The second safety circuit and the second power box that accommodates the start / stop circuit provided are divided and arranged. In this case, the external cable can be easily attached to the first power box arranged outside the machine room, and the connection work of the external cable can be facilitated.

1 is a front view showing an electric hydraulic excavator according to a first embodiment. It is an enlarged plan view showing an electric hydraulic excavator with a part of the working device omitted. It is an enlarged plan view of the same position as FIG. 2 showing the electric excavator with a part of the exterior cover removed. It is an expanded sectional view seen from the arrow IV-IV direction in FIG. 1 which shows an electric hydraulic excavator by omitting the working device. It is an expanded sectional view seen from the arrow VV direction in FIG. 4 which shows a support frame, a counterweight, an exterior cover, a partition, an external cable, a power box, an electric motor, etc. It is a perspective view which shows a partition, a power box, a control box, an external cable, etc. It is a circuit configuration diagram including an external power source, a safety circuit, a start / stop circuit, a signal output circuit, a start / stop control circuit, an electric motor, and the like. It is a front view which shows the electric hydraulic shovel by 2nd Embodiment. It is an enlarged plan view showing an electric hydraulic excavator with a part of the working device omitted. FIG. 10 is an enlarged plan view of the same position as in FIG. 9 showing the electric excavator with a part of the exterior cover removed. It is an expanded sectional view seen from an arrow XI-XI direction in Drawing 8 which omits a working device and shows an electric hydraulic excavator. It is an expanded sectional view seen from the arrow XII-XII direction in FIG. 11 which shows a support frame, a counterweight, an exterior cover, a partition, an external cable, a power box, an electric motor, and the like. It is a circuit configuration diagram including an external power source, a safety circuit, a start / stop circuit, a signal output circuit, a start / stop control circuit, an electric motor, and the like. It is the enlarged plan view seen from the same direction as Drawing 10 showing the electric hydraulic excavator by a 3rd embodiment in the state where a part of exterior cover was removed. It is an expanded sectional view seen from the same direction as Drawing 11 which shows an electric hydraulic excavator omitting a work device. It is a front view which shows the electric hydraulic excavator by 4th Embodiment. It is an enlarged plan view showing an electric hydraulic excavator with a part of the working device omitted. FIG. 18 is an enlarged plan view of the same position as FIG. 17 showing the electric excavator with a part of the exterior cover removed. It is an expanded sectional view seen from the arrow XIX-XIX direction in FIG. 16 which shows an electric hydraulic excavator by omitting the working device. It is an expanded sectional view seen from the arrow XX-XX direction in FIG. 19 which shows a support frame, a counterweight, an exterior cover, a partition, an external cable, a first power box, a second power box, an electric motor, and the like. It is a circuit configuration diagram including an external power source, a first safety circuit, a second safety circuit, a start / stop circuit, a signal output circuit, a start / stop control circuit, an electric motor, and the like.

  Hereinafter, an embodiment of an electric construction machine according to the present invention will be described in detail with reference to the accompanying drawings, taking as an example the case of applying to an electric hydraulic excavator fed from an external power source.

  1 to 7 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes an electric excavator. The excavator 1 is mounted on a lower traveling body 2 via a crawler-type lower traveling body 2 capable of self-propelling and a revolving wheel 3 so as to be capable of turning. The upper swing body 4 and the work device 5 provided on the front end side of the upper swing body 4 are roughly configured. The vehicle body of the hydraulic excavator 1 is composed of a lower traveling body 2 and an upper swing body 4, and an electric motor 9 described later is mounted on the upper swing body 4 as a power source.

  Here, the hydraulic excavator 1 is configured as a small turning machine in which the upper turning body 4 is substantially within the vehicle width of the lower traveling body 2. That is, as shown in FIGS. 2 and 3, the upper swing body 4 has a substantially circular shape so that at least the rear side is substantially within the vehicle width of the lower travel body 2, and is formed compact as a whole.

  The lower traveling body 2 is provided with a traveling motor, and the upper revolving body 4 is provided with a turning motor (both not shown). The lower traveling body 2 performs traveling operations such as advancing and reversing by a traveling motor, and the upper swing body 4 is swung by a swing motor.

  The work device 5 includes a boom 5A, an arm 5B, a bucket (work tool) 5C, and the like. The boom 5A, the arm 5B, and the bucket 5C include a boom cylinder 5D, an arm cylinder 5E, a bucket cylinder (work tool cylinder) 5F, and the like. A hydraulic cylinder is installed. These cylinders 5D, 5E, and 5F constitute a hydraulic actuator that is driven by pressure oil discharged from a hydraulic pump 11 (to be described later) together with a hydraulic motor such as a traveling motor and a turning motor.

  Reference numeral 6 denotes a revolving frame as a support frame that forms a support structure of the upper revolving structure 4. The revolving frame 6 includes a cab 7, a counterweight 8, an electric motor 9, a hydraulic pump 11, a heat exchanger 14, An alternator 19, an in-vehicle battery 20 and the like are mounted. Here, as shown in FIGS. 3 and 4, the revolving frame 6 has a bottom plate 6A made of a thick steel plate or the like extending in the front and rear directions, and is erected on the bottom plate 6A and predetermined in the left and right directions. The left vertical plate 6B and the right vertical plate 6C extending in the front and rear directions with a spacing of the left side frame 6D and the right side frame 6E that are arranged on the outside of the vertical plates 6B and 6C with a spacing and extending in the front and rear directions. And a plurality of extended beams 6F that extend left and right from the bottom plate 6A and the respective vertical plates 6B and 6C and support the left and right side frames 6D and 6E at the front ends thereof.

  On the rear side of the left vertical plate 6B, an alternator mounting portion 6G for mounting an alternator 19 described later is provided. On the rear side of the left side frame 6D, a battery mounting portion 6H for mounting an in-vehicle battery 20 described later is provided. Between the rear side of the left vertical plate 6B and the rear side of the left side frame 6D, a heat exchanger mounting portion 6J on which a heat exchanger 14 described later is mounted is provided.

  Reference numeral 7 denotes a cab mounted on the left front side of the revolving frame 6. The cab 7 defines an operator cab in which an operator is boarded. Inside the cab 7 are disposed a driver's seat, a travel lever / pedal, an operation lever, a key switch 35, an emergency stop switch 36, a monitor device 40 (see FIG. 7), and the like.

  Reference numeral 8 is a counterweight attached to the rear end of the revolving frame 6, and the counterweight 8 is disposed in front of the vehicle body (upper revolving body 4) and rearward in the rear direction with respect to the electric motor 9 described later. A weight balance with the device 5 is obtained. As shown in FIGS. 2 and 3, the rear surface side of the counterweight 8 is formed in an arc shape so that the turning radius of the upper turning body 4 is small. A cable stand 22 to be described later is attached to the upper surface of the counterweight 8.

  Reference numeral 9 denotes an electric motor mounted on the turning frame 6 at the front side of the counterweight 8. The electric motor 9 is composed of, for example, a three-phase induction motor, and constitutes a drive source for a hydraulic pump 11 described later. In addition, the electric motor 9 is supported on the revolving frame 6 through vibration isolation members 9A such as vibration isolation rubber and vibration isolation mounts.

  The electric motor 9 rotates by being supplied with power from an external power supply 10 (see FIG. 7) such as a commercial power supply that supplies three-phase AC power of 400 V, for example, through a power supply cable 21 described later, and drives the hydraulic pump 11. Is. Operation control (power feeding control) of the electric motor 9 is performed by a motor control device 23 described later.

  Reference numeral 11 denotes a hydraulic pump mounted on the revolving frame 6 located on the right side which is one side of the left and right directions of the electric motor 9. The hydraulic pump 11 is composed of, for example, a variable displacement hydraulic pump, and constitutes a hydraulic pressure source together with a hydraulic oil tank 12 disposed on the right side of the front portion of the revolving frame 6. Here, the hydraulic pump 11 is attached to the right side of the electric motor 9 via a power transmission device 13 such as a coupling, and the rotational output of the electric motor 9 is transmitted by the power transmission device 13.

  The hydraulic pump 11 is driven by the electric motor 9 to discharge the hydraulic oil sucked from the hydraulic oil tank 12 as high-pressure pressure oil. The pressure oil discharged from the hydraulic pump 11 is supplied to various hydraulic actuators such as a traveling motor, a turning motor, a boom cylinder 5D, an arm cylinder 5E, and a bucket cylinder 5F mounted on the hydraulic excavator 1.

  Reference numeral 14 denotes a heat exchanger provided on the left side opposite to the hydraulic pump 11 with the electric motor 9 interposed therebetween. The heat exchanger 14 is mounted on the heat exchanger mounting portion 6J of the revolving frame 6 so as to face a cooling fan 15 described later. The heat exchanger 14 cools various fluids whose temperature has risen with cooling air F (see FIG. 4). For example, a hydraulic actuator (travel motor, swing motor, boom cylinder 5D, arm cylinder 5E, bucket cylinder 5F, etc.) ), An oil cooler that cools the return oil, a condenser that cools the refrigerant supplied from the indoor unit (not shown) in the cab 7, and the like.

  Reference numeral 15 denotes a cooling fan arranged on the left side (the same side as the heat exchanger 14) on the left and right sides of the electric motor 9 so as to face the heat exchanger 14. The cooling fan 15 is driven to rotate by using the electric motor 9 as a power source, thereby introducing outside air as cooling air F, and the cooling air F is supplied to the heat exchanger 14, the electric motor 9, and a motor control device 23 described later. Are supplied to the power box 24, the control box 25, and the like.

  Reference numeral 16 denotes a partition wall disposed on the front side of the electric motor 9 and attached to the revolving frame 6. The partition wall 16 extends in the left and right directions of the vehicle body (upper revolving body 4), and defines a machine room 18 that houses the electric motor 9 and the like together with the counterweight 8 and an exterior cover 17 described later. A power box 24 and a control box 25 of a motor control device 23, which will be described later, are attached to the partition wall 16 adjacent to each other in the left and right directions.

  Reference numeral 17 denotes an exterior cover provided on the revolving frame 6 from the rear side to the side of the cab 7. The exterior cover 17 defines a machine room 18 for accommodating the electric motor 9, the hydraulic pump 11, the heat exchanger 14, and the like between the counterweight 8 and the partition wall 16. Here, the exterior cover 17 includes an open / close cover 17A covering the upper side of the electric motor 9, a left side cover 17B provided with an air inlet 17B1, a right side cover 17C provided with an air outlet 17C1, and the electric motor 9. The under cover 17D and the like that cover the lower side are formed. A cable insertion hole 17A1 (FIG. 2) for drawing an external cable 21A of a power supply cable 21 (described later) into the machine room 18 at a portion corresponding to a power box 24 of a motor control device 23 (described later) on the front side of the opening / closing cover 17A. Reference) is provided.

  As shown in FIG. 4, when the cooling fan 15 is driven to rotate in accordance with the rotation of the electric motor 9, the outside air is supplied as cooling air F from the left side cover 17 </ b> B on the upstream side in the flow direction of the cooling air F. Flows in. Then, the cooling air F flowing into the machine room 18 cools the heat exchanger 14, the electric motor 9, the power box 24 and the control box 25 of the motor control device 23 described later, and the like on the downstream side. It flows out from the right side cover 17C. In this case, the cooling air F is guided from the left side to the right side in the machine room 18 by the exterior cover 17, the partition wall 16, and the counterweight 8 that define the machine room 18. 14, the electric motor 9, the power box 24, the control box 25, etc. can be cooled efficiently.

  Reference numeral 19 denotes an alternator that generates electric power by being driven by the electric motor 9, and the alternator 19 supplies the generated electricity to an in-vehicle battery 20 to be described later. Here, the alternator 19 is mounted on the alternator mounting portion 6G of the revolving frame 6. The alternator 19 is rotationally driven by the rotation of the electric motor 9 being transmitted through the endless belt 19A, thereby generating electric power.

  Reference numeral 20 denotes an in-vehicle battery that stores electrical energy. The in-vehicle battery 20 is mounted on the battery mounting portion 6H of the turning frame 6. The in-vehicle battery 20 stores electric energy, and various electric devices (not shown) such as a motor control device 23, a controller 39, a monitor device 40, various lighting fixtures, electromagnetic valves, and electronic components mounted on the hydraulic excavator 1 described later. ). The in-vehicle battery 20 supplies, for example, 24V DC power to various electric devices including the motor control device 23 and the like, and is configured by connecting, for example, two 12V DC batteries in series.

  Reference numeral 21 denotes a power feeding cable that electrically connects the external power source 10 and the electric motor 9 via a motor control device 23 (power box 24 thereof) described later. The power supply cable 21 includes an external cable 21A disposed between the external power source 10 and the power box 24 of the motor control device 23, and a motor connection cable disposed between the power box 24 and a motor terminal box 37 described later. 21B etc. are comprised. Here, the external cable 21A is supported by a cable stand 22 described later, and is connected to the connection terminal 28 (see FIG. 7) of the power box 24 through the cable insertion hole 17A1 of the exterior cover 17 (opening / closing cover 17A).

  Reference numeral 22 denotes a cable stand attached to the counterweight 8, and the cable stand 22 supports the external cable 21 </ b> A of the feeding cable 21. Here, the cable stand 22 extends upward and downward, and has a support 22A that is fixed to the counterweight 8. The support 22A can swing in the horizontal direction (left and right) with the support 22A as a swing center. And a support bar 22B provided on the main body. And the holding member 22C which hold | grips the intermediate part of the external cable 21A is provided in the upper end part of support | pillar 22A, and the front-end | tip part of the support horizontal bar 22B, respectively. As indicated by a virtual line (two-dot chain line) in FIG. 2, the cable stand 22 is excessive in the power supply cable 21 due to the support horizontal bar 22 </ b> B swinging around the support 22 </ b> A according to the movement of the excavator 1. The external cable 21 </ b> A is prevented from being caught in the excavator 1 while suppressing the application of a large force.

  Next, the motor control device 23 that operates the electric motor 9 will be described.

  That is, reference numeral 23 denotes a motor control device serving as a control panel for controlling power supply to the electric motor 9, and the motor control device 23 includes a power box 24, a control box 25, a safety circuit 29, a start / stop circuit 30, which will be described later, The signal output circuit 31 and the start / stop control circuit 34 are configured. Here, the motor control device 23 is configured to have two storage boxes, a power box 24 and a control box 25, as storage boxes for storing necessary circuits, electrical components, electrical equipment, and the like. Specifically, the motor control device 23 accommodates a safety circuit 29 and a start / stop circuit 30 in which a relatively high voltage (for example, three-phase AC power of 400 V) is conducted from the external power supply 10 via the power supply cable 21. The configuration is divided into a box 24 and a control box 25 that houses a signal output circuit 31 and a start / stop control circuit 34 in which a relatively low voltage (for example, DC power of 24 V) is conducted from the in-vehicle battery 20.

  And the power box 24 and the control box 25 are arrange | positioned in the vehicle body (upper turning body 4) in the separate position (each as a separate storage box). Specifically, the power box 24 and the control box 25 are both in the vicinity of the electric motor 9 in the machine room 18, that is, between the hydraulic pump 11 and the heat exchanger 14 (the hydraulic pump in the direction of the flow of the cooling air F). 11 and upstream of the heat exchanger 14 and downstream of the heat exchanger 14. In this case, the power box 24 and the control box 25 are located in the machine room 18 and are attached to the partition wall 16 adjacent to each other in the left and right directions.

  As shown in FIG. 6, each of the power box 24 and the control box 25 is formed as a substantially rectangular parallelepiped hollow box body, each of which has a bottomed rectangular tube-shaped main body portion 24A, 25A, and the main body portion. It is comprised by the square-plate-shaped lid bodies 24B and 25B which block | close the opening of 24A and 25A. In this case, if the waterproofing of the machine room 18 is ensured, the waterproofing process between the main body portions 24A and 25A and the lid bodies 24B and 25B can be omitted or simplified.

  The power box 24 and the control box 25 are attached to the partition wall 16 via shelf-like brackets 26 and 27, respectively. The power box 24 is provided with a connection terminal (connector connector) 28 (see FIG. 7) to which an external cable 21A leading to the external power supply 10 is connected. Accordingly, the external cable 21A is electrically connected to the safety circuit 29 and the start / stop circuit 30 accommodated in the power box 24 via the connection terminal 28.

  Reference numeral 29 denotes a safety circuit accommodated in the power box 24. The safety circuit 29 is provided in the middle of the power supply cable 21 and protects the electric motor 9 from electrical abnormalities such as a short circuit, leakage, and current increase due to overload. For this reason, the safety circuit 29 has a breaker 29A that cuts off the power supply cable 21 when an electrical abnormality including a short circuit or leakage occurs, and the power supply cable 21 is cut off when an overload current is generated in the power supply cable 21. A thermal relay 29B or the like is provided. The safety circuit 29 protects the electric motor 9 and the motor control device 23 from an electrical abnormality, that is, an overload state, an undervoltage state, an overvoltage state, a ground fault, a short circuit, etc., and is provided with a breaker 29A and a thermal relay 29B. However, the present invention is not limited to this, and various protective devices and protective circuits can be used.

  Reference numeral 30 denotes a start / stop circuit accommodated in the power box 24. The start / stop circuit 30 is provided in series with the safety circuit 29 in the middle of the power supply cable 21 to start and stop the electric motor 9. For this purpose, the start / stop circuit 30 is configured using a star delta circuit 30A. Here, when the electric motor 9 is started, the star delta circuit 30A switches the connection with a coil (not shown) in the electric motor 9 from the star connection to the delta connection after a predetermined time has elapsed. The electromagnetic switch (not shown) is comprised.

  That is, the electric motor 9 has a low impedance and a large current immediately after starting and before the rotation speed reaches a predetermined rotation speed, that is, before reaching the rotation speed according to the frequency (50 Hz, 60 Hz) of the supplied power. Flowing. Therefore, the star delta circuit 30A uses a star connection with high impedance and controllable current before reaching the rotation speed, and after reaching the rotation speed, switches to a delta connection with low impedance and earning current. . The start / stop circuit 30 performs at least the start and stop of the electric motor 9, and is not limited to the star delta circuit 30A. For example, a reactor circuit, an inverter circuit, or the like can be used.

  Reference numeral 31 denotes a signal output circuit accommodated in the control box 25. The signal output circuit 31 is connected to the safety circuit 29 and outputs a signal output from the safety circuit 29 to an external device, specifically, a controller 39 described later. For this purpose, the input side of the signal output circuit 31 is connected to the safety circuit 29 via a connection cable 32 disposed between the power box 24 and the control box 25, and the output side of the signal output circuit 31 is The controller 39 is connected to the controller 39 via another connection cable 33 provided between the control box 25 and the controller 39 and the like.

  When the safety circuit 29 is activated due to an electrical abnormality, for example, when the thermal relay 29B is cut off due to an increase in current due to an overload of the electric motor 9, the signal output circuit 31 receives a signal to that effect as an input signal. Is entered as The signal output circuit 31 converts the input signal into an output signal to the controller 39 and outputs the signal to the controller 39. The controller 39 outputs a signal indicating that a warning display, a warning display, a warning sound or the like is emitted to the monitor device 40, which will be described later, as necessary. Further, the controller 39 stores information indicating that the safety circuit 29 has been activated in the memory 39A as device malfunction information as needed, and manages its history.

  Reference numeral 34 denotes a start / stop control circuit accommodated in the control box 25. The start / stop control circuit 34 is connected to the start / stop circuit 30 and is supplied with an external signal, specifically, a signal from the key switch 35 that is turned on by the operator when the excavator 1 is started, and is turned on by the operator in an emergency. On the basis of a signal from the emergency stop switch 36, a signal from a controller 39, which will be described later, and the like, switching control of the start / stop circuit 30 (open / close control of the electromagnetic switch of the star delta circuit 30A) is performed.

  Specifically, for example, when an ON signal from the key switch 35 is input to the start / stop control circuit 34, the start / stop control circuit 34 electromagnetically opens and closes the star delta circuit 30A to start the electric motor 9 in a star delta system. An open / close signal for realizing star connection and delta connection is output to the device. On the other hand, for example, when an OFF signal from the key switch 35 or an ON signal from the emergency stop switch 36 is input to the start / stop control circuit 34, the start / stop control circuit 34 to the star delta circuit 30 </ b> A is stopped to stop the electric motor 9. An open signal indicating that the power supply to the electric motor 9 is cut off is output to the electromagnetic switch.

  For this purpose, the input side of the start / stop control circuit 34 is connected to the start / stop circuit 30 via the connection cable 32 and the key switch 35, emergency stop switch 36, controller 39, etc. via another connection cable 33. Connected with. The output side of the start / stop control circuit 34 is connected to the start / stop circuit 30 via the connection cable 32 and is connected to the controller 39 via another connection cable 33.

  Reference numeral 37 denotes a motor terminal box attached to the electric motor 9. A connection terminal (connector connector) 38 (see FIG. 7) is provided in the motor terminal box 37. A motor connection cable 21 </ b> B disposed between the power box 24 and the electric motor 9 is connected to the connection terminal 38. Thus, the safety circuit 29, the start / stop circuit 30 and the electric motor 9 in the power box 24 attached to the partition wall 16 are electrically connected.

  Reference numeral 39 denotes a controller (control unit) composed of a microcomputer or the like. The controller 39 is disposed, for example, in the cab 7 and is connected to the signal output circuit 31 and the like of the control box 25 via a connection cable 33. That is, the controller 39 has an input side connected to the signal output circuit 31 and the start / stop control circuit 34, and an output side connected to the start / stop control circuit 34 and a monitor device 40 described later. When the signal indicating that the safety circuit 29 is activated is input via the signal output circuit 31 when the safety circuit 29 is activated, the controller 39 issues an alarm such as an alarm display or an alarm sound to the monitor device 40 described later. Output a signal. The controller 39 has a memory 39A composed of ROM, RAM, etc., and information (signal) indicating that the safety circuit 29 from the signal output circuit 31, for example, is operated is stored as device malfunction information in the memory 39A. Is done.

  40 is a monitor device provided in the vicinity of the driver's seat in the cab 7, and the monitor device 40 is connected to the controller 39, and based on signals from the controller 39, the operator is provided with driving information, caution information, Alarm information and the like are notified. For this purpose, the monitor device 40 includes a monitor 40A that displays driving information, caution information, and the like, a speaker 40B that emits an alarm sound, and the like.

  The electric excavator 1 according to the present embodiment has the above-described configuration, and the operation thereof will be described next.

  When the operator gets on the cab 7 and turns on the key switch 35, the electric motor 9 is rotated by the electric power from the external power supply 10. Specifically, when the key switch 35 is turned on, the start / stop circuit 30 is switched based on a signal from the start / stop control circuit 34, and the electric motor 9 is started by the star delta method. The electric motor 9 rotates at a rotation speed corresponding to the frequency (50 Hz, 60 Hz) of the supplied power, and the hydraulic pump 11 is driven by the rotation of the electric motor 9.

  In this state, when the operator seated in the driver's seat of the cab 7 operates the travel lever / pedal, the lower traveling body 2 can be self-propelled and the excavator 1 can be moved. Further, when the operator operates the operation lever, excavation work such as earth and sand can be performed by the work device 5 while turning the upper turning body 4.

  Further, during operation, when the safety circuit 29 is activated due to an electrical abnormality such as an overload current, a signal to that effect is input from the safety circuit 29 to the controller 39 via the signal output circuit 31. The controller 39 outputs, to the monitor device 40, a signal indicating that a caution display, alarm display, alarm sound, or the like indicating that the safety circuit 29 has been activated. Thereby, the device malfunction information that the safety circuit 29 has been activated can be notified to the operator.

  By the way, in the case of a configuration in which the motor control device 23 that controls power supply to the electric motor 9 is accommodated in one accommodation box as one control panel, the degree of mounting and layout are limited, and the cost is increased. It may lead to On the other hand, according to the present embodiment, the motor control device 23 includes a power box 24 that houses the safety circuit 29 and the start / stop circuit 30 in which a relatively high voltage is conducted, and a signal in which a relatively low voltage is conducted. The output box 31 and the start / stop control circuit 34 are divided into control boxes 25 that house them, and the power box 24 and the control box 25 are arranged at different positions.

  For this reason, compared with the structure which accommodates the circuit required for one accommodation box collectively, the power box 24 and the control box 25 can each be comprised small. In this case, for example, a small power box 24 and a control box 25 are arranged at different positions even on a small vehicle body that cannot be mounted with a configuration in which necessary circuits are accommodated together in one storage box. Can be installed. Thereby, the freedom degree of mounting of the motor control apparatus 23 and layout property can be improved.

  In addition, the safety circuit 29 and the start / stop circuit 30 accommodated in the power box 24 have a current value or the like flowing through the circuit according to the vehicle type, the vehicle type, the specifications (performance, output) of the electric motor 9 mounted, and the like. Since they are different, it is necessary to configure them using components and circuits that match the current values. For this reason, in the safety circuit 29 and the start / stop circuit 30, the component configuration, circuit configuration, outer diameter size, and the like change according to the specifications of the electric motor 9 mounted, and the size of the power box 24 also changes accordingly. there is a possibility. On the other hand, the signal output circuit 31 and the start / stop control circuit 34 accommodated in the control box 25 are the same as the circuits that perform the same operation even if the vehicle case, the vehicle type, the specification of the mounted electric motor 9 and the like are different. Things can be used. Thereby, the cost of the motor control device 23 can be reduced by sharing the signal output circuit 31, the start / stop control circuit 34, and the control box 25, and mass production.

  According to the present embodiment, since both the power box 24 and the control box 25 are arranged in the machine room 18, the power box 24 and the power supply cable 21 through which high voltage and high current flow are placed in the machine room 18. Can be isolated. Thereby, an operator or a worker can be made difficult to approach the power box 24 or the power supply cable 21, and electrical safety can be improved.

  Further, since the power box 24 and the electric motor 9 can be arranged close to each other, the wiring between the power box 24 and the electric motor 9 can be shortened, and the wiring work including the wiring operation is facilitated. Can also be planned. In addition, by providing the power box 24 with the connection terminal 28 to which the external cable 21A leading to the external power supply 10 is connected, it is not necessary to provide a connection terminal and a terminal box for housing it separately from the power box 24. The cost can be reduced by reducing the cost.

  Further, since the machine room 18 accommodates the electric motor 9, the machine room 18 is waterproofed to prevent water from entering the machine room 18. Even if the waterproofing process of the control box 24 and the control box 25 is omitted or simplified, the waterproofness can be ensured. Thereby, cost reduction by reduction of the sealing material used for waterproofing processing, etc. can be aimed at.

  Moreover, the cooling of the power box 24 and the control box 25 can also be performed using cooling air F for cooling the electric motor 9, the heat exchanger 14, and the like housed in the machine room 18, for example. Thereby, it is also possible to ensure cooling performance. In this case, the power box 24 and the control box 25 are both between the hydraulic pump 11 and the heat exchanger 14, that is, upstream of the hydraulic pump 11 in the flow direction of the cooling air F and downstream of the heat exchanger 14. Arranged on the side. For this reason, the power box 24 and the control box 25 can be cooled by the cooling air F that does not receive heat from the hydraulic pump 11, and the heat load on the power box 24 and the control box 25 (particularly the power box 24) is reduced. be able to. In addition, although illustration is abbreviate | omitted, in order to improve the cooling property of the power box 24, you may provide a thin-plate-like radiation fin in the outer surface of the power box 24. FIG. Further, in order to improve the cooling performance of the control box 25, a thin plate-like heat radiation fin may be provided on the outer surface of the control box 25.

  According to the present embodiment, since the power box 24 and the control box 25 are attached to the partition wall 16 in the machine room 18, the power box 24 and the control box 25 are attached to the partition wall 16 with sufficient support strength. Can do.

  Next, FIGS. 8 to 13 show a second embodiment of the present invention. The feature of this embodiment is that the power box and the control box are attached to the electric motor. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, reference numeral 41 denotes an electric motor, and the electric motor 41 is supported on the revolving frame 6 via a vibration isolating member 41A such as a vibration isolating rubber and a vibration isolating mount. Here, on the upper side of the electric motor 41, mounting bases 41B and 41C to which a power box 45 and a control box 46, which will be described later, are respectively attached, are provided adjacent to each other in the left and right directions.

  Reference numeral 42 denotes an exterior cover. The exterior cover 42 includes an open / close cover 42A provided with a cable insertion hole 42A1, a left side cover 42B provided with an air inlet 42B1, and a right side provided with an air outlet 42C1. The cover 42C and the under cover 42D that covers the lower side of the electric motor 41 are configured. Here, the cable insertion hole 42A1 of the opening / closing cover 42A is provided at the rear side of the opening / closing cover 42A, that is, at a position as far as possible from the cab 7 near the counterweight 8. In other words, in this embodiment, if the excavator is equipped with an engine, the tail pipe insertion hole into which the exhaust tail pipe for discharging the exhaust gas of the engine is inserted is used as the cable insertion hole 42A1. Yes.

  Reference numeral 43 denotes a power supply cable for electrically connecting the external power supply 10 and the electric motor 41. The power supply cable 43 is an external cable 43A disposed between the external power supply 10 and a power box 45 described later. It is comprised including. Here, in the present embodiment, the motor connection cable 21B and the motor terminal box 37 provided in the above-described first embodiment are provided in accordance with a configuration in which a power box 45 described later is attached to the electric motor 41. The connection terminal 38 (see FIGS. 5 and 7) can be omitted. As a result, the cost can be reduced by shortening the wiring, omitting it, reducing the number of parts, and facilitating the wiring work.

  Reference numeral 44 denotes a motor control device that controls power supply to the electric motor 41, and the motor control device 44 is configured to have two storage boxes, a power box 45 and a control box 46. The power box 45 and the control box 46 are located in the machine room 18 and attached to the upper portion of the electric motor 41. That is, the power box 45 and the control box 46 are attached to the mounting bases 41B and 41C of the electric motor 41 via brackets (not shown). In this case, a connection cable 47 is disposed between the power box 45 and the control box 46, and another connection cable 48 is disposed between the control box 46 and the controller 39 or the like.

  In the present embodiment, operation control (power feeding control) of the electric motor 41 is performed using the motor control device 44 as described above, and its basic operation is exceptionally different from that according to the first embodiment described above. There is no difference.

  In particular, in the case of the present embodiment, since the power box 45 and the control box 46 are mounted on the electric motor 41 in the machine room 18, the power box 45 and the control box 46 are sufficiently supported by the electric motor 41. Can be installed with strength. In this case, the electric motor 41, the power box 45, and the control box 46 can be handled as one assembly (can be assembled), and assemblability can be improved.

  Further, it is not necessary to provide a connection cable (the motor connection cable 21B of the first embodiment) between the power box 45 and the electric motor 41, and a connection terminal (first terminal) for connecting the connection cable. This eliminates the need to provide the connection terminal 38) and the terminal box (the motor terminal box 37 of the first embodiment) for housing the same, and also from this aspect, the wiring work is facilitated and the cost is reduced. Can be planned.

  Furthermore, since the electric motor 41 is supported by the revolving frame 6 via the vibration isolating member 41A, the power box 45 and the control box 46 attached thereto can be combined to ensure the vibration isolating performance. .

  Next, FIG. 14 and FIG. 15 show a third embodiment of the present invention. The feature of this embodiment is that the power box is attached to the electric motor of the machine room and the control box is arranged outside the machine room. In the present embodiment, the same components as those in the first and second embodiments described above are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, reference numeral 51 denotes an electric motor, and the electric motor 51 is supported on the revolving frame 6 via a vibration isolating member 51A such as a vibration isolating rubber and a vibration isolating mount. Here, on the upper side of the electric motor 51, a mounting base 51B to which a power box 53 to be described later is attached is provided.

  Reference numeral 52 denotes a motor control device that controls power supply to the electric motor 51, and the motor control device 52 is configured to have two storage boxes, a power box 53 and a control box 54. The power box 53 is located in the machine room 18 and attached to the upper portion of the electric motor 51. That is, the power box 53 is attached to the mounting base 51B of the electric motor 51 via a bracket (not shown).

  On the other hand, the control box 54 is outside the machine room 18, more specifically, on the revolving frame 6, on the front side of the machine room 18 (partition wall 16) and on the right side of the hydraulic oil tank 12, in other words, the engine is mounted. If it is a hydraulic excavator to be used, it is arranged at a portion where a fuel tank is attached. In this case, a connection cable 55 is disposed between the power box 53 and the control box 54, and another connection cable 56 is disposed between the control box 54 and the controller 39 or the like. The control box 54 may be arranged in the cab 7, for example, instead of the right side of the hydraulic oil tank 12.

  In the present embodiment, operation control (power feeding control) of the electric motor 51 is performed using the motor control device 52 as described above, and the basic operation thereof is according to the first and second embodiments described above. There is no special difference.

  In particular, in the case of the present embodiment, since the power box 53 is attached to the electric motor 51 in the machine room 18, the power box 53 is isolated and wired as in the second example of the above-described embodiment. , The omission or simplification of the waterproofing process, the securing of cooling performance, the assembly, and the vibration proofing performance can be secured. At the same time, since the control box 54 is arranged outside the machine room 18, the degree of freedom in the layout of the control box 54 can be ensured.

  Next, FIGS. 16 to 21 show a fourth embodiment of the present invention. A feature of the present embodiment is that the power box includes a first power box that houses the connection terminal and the first safety circuit, and a second power box that houses the second safety circuit and the start / stop circuit. The configuration has the following. In the present embodiment, the same components as those in the first to third embodiments described above are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, reference numeral 61 denotes an electric motor, and the electric motor 61 is supported on the revolving frame 6 via a vibration isolating member 61A such as a vibration isolating rubber and a vibration isolating mount. Here, on the upper side of the electric motor 61, a mounting base 61B to which a second power box 66 described later is attached is provided.

  62 denotes a power supply cable for electrically connecting the external power supply 10 and the electric motor 61. The power supply cable 62 is an external power supply disposed between the external power supply 10 and a first power box 65 described later. The cable 62 </ b> A includes a power box connection cable 62 </ b> B disposed between the first power box 65 and the second power box 66.

  Reference numeral 63 denotes a cable stand attached to the counterweight 8. The cable stand 63 supports an external cable 62A of the power feeding cable 62 and a first power box 65 to be described later. Here, the cable stand 63 is roughly constituted by a column 63A and a supporting horizontal bar 63B that swings around the column 63A. A gripping member 63C that grips an intermediate portion of the external cable 62A is provided at the upper end of the support 63A and the tip of the support horizontal bar 63B. A first power box 65, which will be described later, is attached to the column 63A via a box attachment portion 63D, which is positioned below the support horizontal bar 63B.

  Reference numeral 64 denotes a motor control device that controls power supply to the electric motor 61, and the motor control device 64 includes a first power box 65, a second power box 66, and a control box 67. The first power box 65 is attached to the outside of the machine room 18, specifically, to the support 63 </ b> A of the cable stand 63. On the other hand, the second power box 66 is located in the machine room 18, more specifically, in the machine room 18, and is attached to the upper part (mounting base 61B) of the electric motor 61 via a bracket (not shown). It has been.

  In this case, the first power box 65 accommodates a connection terminal 68 to which an external cable 62A leading to the external power supply 10 is connected and a first safety circuit 72 to be described later. On the other hand, the second power box 66 accommodates a second safety circuit 73 to be described later and a start / stop circuit 30 similar to those of the first to third embodiments described above.

  Further, the control box 67 operates in the same manner as in the third example of the above-described embodiment, outside the machine room 18, more specifically, on the swivel frame 6, on the front side of the machine room 18 (partition wall 16). If it is a hydraulic excavator on which the engine is mounted, it is arranged at a site where the fuel tank is attached.

  In this case, a first connection cable 69 (shown only in FIG. 21) is disposed between the first power box 65 and the control box 67. A second connection cable 70 is disposed between the second power box 66 and the control box 67. A third connection cable 71 is disposed between the control box 67 and the controller 39 or the like.

  Reference numeral 72 denotes a first safety circuit housed in the first power box 65. The first safety circuit 72 is provided in the middle of the power supply cable 62 and constitutes a safety circuit that protects the electric motor 61 from an electrical abnormality together with a second safety circuit 73 described later. For this purpose, the first safety circuit 72 is provided with a breaker 72A for cutting off the power supply cable 62 when an electrical abnormality including a short circuit or leakage occurs.

  Reference numeral 73 denotes a second safety circuit housed in the second power box 66. The second safety circuit 73 is also provided in the middle of the power supply cable 62 and constitutes a safety circuit that protects the electric motor 61 from an electrical abnormality together with the first safety circuit 72. For this purpose, the second safety circuit 73 is provided with a thermal relay 73A and the like for cutting off the power supply cable 62 when an overload current is generated in the power supply cable 62.

  In this embodiment, operation control (power feeding control) of the electric motor 61 is performed using the motor control device 64 as described above, and the basic operation thereof is according to the above-described first to third embodiments. There is no special difference.

  Particularly, in the case of the present embodiment, the first power box 65 and the second power box 66 are provided. That is, the power boxes 65 and 66 include a first power box 65 that houses a connection terminal 68 to which an external cable 62A communicating with the external power source 10 is connected, and a first safety circuit 72 provided with a breaker 72A. The second safety circuit 73 provided with the relay 73A and the second power box 66 that accommodates the start / stop circuit 30 are divided and arranged on the vehicle body (upper rotating body 4). In this case, the external cable 62A can be easily attached to the first power box 65 disposed on the cable stand 63 outside the machine room 18, and the connection work of the external cable 62A can be facilitated.

  In each of the embodiments described above, power is supplied to the electric motors 9, 41, 51, 61 from the external power source 10 such as a commercial power source outside the excavator 1 via the power supply cables 21, 43, 62. The case has been described as an example. However, the present invention is not limited to this. For example, a large-capacity battery power source (storage battery) such as a lithium ion battery is mounted on the vehicle body, and the battery power source mounted on the vehicle body is connected to the electric motor via a power supply cable. It is good also as a structure which supplies electric power. In this case, for example, an inverter circuit can be used as a start / stop circuit for starting and stopping the electric motor in order to change the DC battery voltage to an AC voltage and supply power to the electric motor.

  In the third and fourth embodiments described above, the control boxes 54 and 67 are placed on the revolving frame 6 in front of the machine room 18 (partition wall 16) and on the right side of the hydraulic oil tank 12 (hydraulic pressure on which the engine is mounted). In the case of an excavator, the case where it is configured to be disposed at a portion where the fuel tank is attached) has been described as an example. However, the present invention is not limited to this. For example, the control box may be arranged in another part outside the machine room, such as in the cab where the operator is boarded, in the vicinity of the cab, or in the utility room provided on the front side of the vehicle body. Good. Similarly, the power box can be disposed outside the machine room.

  In each of the above-described embodiments, the breakers 29A and 72A and the thermal relays 29B and 73A are used as the safety circuits 29, 72, and 73 that protect the electric motors 9, 41, 51, and 61 from an electrical abnormality. The case has been described as an example. However, the present invention is not limited to this. For example, the safety circuit can protect the electric motor and the motor control device from electrical abnormalities such as an overload state, an undervoltage state, an overvoltage state, a ground fault, and a short circuit. Various protective devices and protective circuits that can be used can be used.

  In each of the above-described embodiments, the case where the star delta circuit 30A is used as the start / stop circuit 30 for starting and stopping the electric motors 9, 41, 51, 61 has been described as an example. However, the present invention is not limited to this, and various devices and circuits that can start and stop at least the electric motor, such as a reactor circuit and an inverter circuit, can be used as the start / stop circuit.

  In each of the above-described embodiments, the feeding cables 21, 43, 62 are drawn into the upper swing body 4 via the cable stands 22, 63 as cable support members attached to the counterweight 8 of the upper swing body 4. The case has been described as an example. However, the present invention is not limited to this. For example, a cable support member such as a cable stand or a cable reel is attached to the lower traveling body, and a slip ring is provided between the lower traveling body and the upper swing body so that the lower traveling body It is good also as a structure which draws in an electric power feeding cable in an upper revolving body via a cable support member and a slip ring from the body side.

  When the power feeding cable is pulled in from the lower traveling body side, the power box of the motor control device includes the first power box and the second power box as in the fourth embodiment described above. It can be set as a structure, and it can be set as the structure which arrange | positions a 1st power box on the lower traveling body side, and arrange | positions a 2nd power box on the upper revolving body side. According to this configuration, the external cable can be easily attached to the first power box arranged outside the machine room, and the connection work of the external cable can be facilitated.

  In each embodiment mentioned above, crawler type hydraulic excavator 1 is illustrated as an electric construction machine. However, the present invention is not limited to this, and can be widely applied to other construction machines such as a wheel-type hydraulic excavator and a wheel loader. Furthermore, the present invention can be applied to work machines that perform various operations including industrial machines such as forklifts and lift trucks and agricultural machines such as tractors.

1 Hydraulic excavator (Electric construction machine)
2 Lower traveling body (car body)
4 Upper swing body (car body)
5D boom cylinder (hydraulic actuator)
5E Arm cylinder (hydraulic actuator)
5F Bucket cylinder (hydraulic actuator)
6 Rotating frame (support frame)
8 Counterweight 9, 41, 51, 61 Electric motor 10 External power supply 11 Hydraulic pump 16 Bulkhead 17 Exterior cover 18 Machine room 21, 43, 62 Power supply cable 21A, 43A, 62A External cable 23, 44, 52, 64 Motor controller 24, 45, 53, 65, 66 Power box 25, 46, 54, 67 Control box 29, 72, 73 Safety circuit 29A, 72A Breaker 29B, 73A Thermal relay 30 Start / stop circuit 31 Signal output circuit 34 Start / stop control circuit

Claims (5)

A vehicle body, an electric motor that rotates when power is supplied from a battery power source or an external power source mounted on the vehicle body via a power supply cable, a hydraulic pump that is driven by the electric motor, and pressure oil that is discharged from the hydraulic pump A hydraulic actuator driven by the motor, and a motor control device that operates the electric motor,
The motor control device is provided in the middle of the power supply cable to protect the electric motor from an electrical abnormality, and is provided in series with the safety circuit in the middle of the power supply cable to start and stop the electric motor. A start / stop circuit to perform, a signal output circuit for outputting a signal output from the safety circuit to an external device, and a start / stop control circuit for switching the start / stop circuit based on an external signal. In electric construction machinery,
The motor control device includes two storage boxes, a power box that stores the safety circuit and the start / stop circuit, and a control box that stores the signal output circuit and the start / stop control circuit. An electric construction machine characterized in that the power box and the control box are arranged at different positions. The vehicle body includes a support frame that forms a support shaft structure and on which the electric motor and the hydraulic pump are mounted, a counterweight that is disposed on the rear side in front and rear of the electric motor, and that balances the weight. A partition that is disposed in front of the motor and extends in the left and right directions of the vehicle body, and an exterior cover that defines a machine room for housing the electric motor and the hydraulic pump between the counterweight and the partition. And
The electric construction machine according to claim 1, wherein both the power box and the control box are arranged in the machine room.   3. The electric construction machine according to claim 2, wherein the power box and the control box are arranged in the machine room and attached to the partition wall or the electric motor. The vehicle body includes a support frame that forms a support shaft structure and on which the electric motor and the hydraulic pump are mounted, a counterweight that is disposed on the rear side in front and rear of the electric motor, and that balances the weight. A partition that is disposed in front of the motor and extends in the left and right directions of the vehicle body, and an exterior cover that defines a machine room for housing the electric motor and the hydraulic pump between the counterweight and the partition. And
The electric construction machine according to claim 1, wherein the power box is located in the machine room and attached to the electric motor, and the control box is arranged outside the machine room. The safety circuit includes a first safety circuit provided with a breaker that cuts off the power supply cable when an electrical abnormality including a short circuit or leakage occurs, and the power supply when an overload current is generated in the power supply cable. It consists of a second safety circuit with a thermal relay that cuts off the cable,
The power box accommodates a first power box that accommodates a connection terminal to which an external cable leading to the external power source is connected and the first safety circuit, and a second safety circuit and the start / stop circuit. A second power box that
The electric construction machine according to claim 2, 3 or 4, wherein the first power box among the power boxes is arranged outside the machine room.

Images