Electric work machine

Abstract

To provide an electric work machine that can easily change system output.SOLUTION: An electric work machine has a vehicle body. The vehicle body comprises a battery 112, an electric motor, and an inverter that supplies power from the battery 112 to the electric motor. The electric work machine has hub boxes 151A11, 151A12 connected to the battery 112 and a hub box 151B1 connected to the hub boxes 151A11, 151A12 and the inverter. Connectors 151S, 152N, 152S are respectively provided at output parts of the hub boxes 151A11, 151A12 to the hub box 151B1, input parts of the hub box 151B1 from the hub boxes 151A11, 151A12, and an output part of the hub box 151B1 to the inverter. The hub boxes 151A11, 151A12 and the hub box 151B1, and the hub box 151B1 and the inverter are connected by cables 154, etc. via the connectors 151S, 152N, 152S.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an electric working machine, and more particularly to an electric working machine provided with a power relay device that relays power when supplying power from a battery to an inverter.

Background Art

[0002] Recently, from the viewpoint of environmental consideration, electric working machines that operate by electric power have been increasingly used. As a driving method of an electric working machine, there is a type that obtains part of the electric power used from the electric power supplied from a battery mounted on the machine body. In this case, a direct current from the battery is converted into an alternating current by an inverter, and thereby an electric motor is operated to operate the electric working machine. And at this time, a power relay device that relays power may be used to transmit power from the battery to the inverter.

[0003] Patent Document 1 discloses a configuration in which a main battery, a sub-battery that receives, stores, and outputs surplus power from the main battery, an inverter having an output section that converts a direct current into an alternating current, and a relay that is interposed between the main battery and the sub-battery, sends surplus power from the main battery to the sub-battery, prevents reverse current, and sends the stored power of the sub-battery to the inverter when necessary, are provided in the main body of a construction machine.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When performing operations such as excavation and traveling with an electric working machine, normally the operation is performed under a load assumed at the rated output, but there may be a situation where an operation under a heavy load that cannot be handled at the rated output is required. In an electric working machine that operates by electric power, it is conceivable to cope with work under heavy load by temporarily setting the system output above the rated value by changing the number of mounted batteries that serve as the power source. However, when the system output is changed by increasing or decreasing the number of mounted batteries, the center of gravity position of the vehicle body changes due to the change in the vehicle body weight caused by the increase or decrease in the number of batteries, and the vehicle body stability is impaired, which may affect the work. In addition, when changing the output, there is also a possibility that the wiring connected to the battery may be changed. However, the work of changing the wiring according to the work is complicated, and there is also a risk of electric shock when the operator touches the terminals of the battery. The present invention has been made in view of such problems, and an object thereof is to provide an electric working machine capable of easily changing the system output.

Means for Solving the Problems

[0006] To solve the above problems, the present invention is an electric working machine having a vehicle body, the vehicle body including a battery, an electric motor, and an inverter that supplies electric power from the battery to the electric motor, the electric working machine having a first power relay device connected to the battery, and a second power relay device connected to the first power relay device and the inverter, wherein connectors are provided at an output portion of the first power relay device to the second power relay device, an input portion of the second power relay device from the first power relay device, and an output portion of the second power relay device to the inverter, and the connection between the first power relay device and the second power relay device, and the connection between the second power relay device and the inverter are connected by a cable via the connectors. In this case, a plurality of power relay devices for supplying electric power from the battery to the inverter are provided, and an electric working machine capable of easily changing the system output can be provided by replacing a power relay device not directly connected to the battery with one having other wiring.

[0007] Here, for example, the battery and the first power relay device are connected by a cable via terminals or connectors provided respectively thereon. In this case, the connection between the battery and the first power relay device can be facilitated. Also, for example, the output portion of the battery to the first power relay device is a terminal, and the input portion of the first power relay device from the battery is a connector. In this case, the connection between the battery and the first power relay device can be further facilitated. Furthermore, for example, a plurality of batteries are provided, the first power relay device is connected to each of the plurality of batteries, and the second power relay device changes the series-parallel connection of the plurality of batteries. In this case, an appropriate output change according to the operation can be easily performed. Still further, for example, a plurality of batteries are provided, the first power relay device is connected to each of the plurality of batteries, and the second power relay device changes the number of parallel connections of the plurality of batteries. In this case, when a battery that cannot be used due to a failure or the like occurs, the unusable battery can be disconnected. Also, for example, the second power relay device is provided at a position outside the first power relay device with respect to the center of the vehicle body. In this case, the second power relay device can be easily replaced. Furthermore, for example, it has a cover that is the exterior of the vehicle body, an access port for maintenance is provided in the cover, and the second power relay device is provided at a position closer to the access port than the first power relay device. In this case, the second power relay device can be easily replaced using the access port. And, for example, it includes an insulation degradation sensor that monitors the insulation resistance between the vehicle body and the battery, and the insulation degradation sensor is provided in the second power relay device. In this case, even in a motorized construction machine that uses the system output increased or decreased, it is possible to easily detect a decrease in the insulation of the circuit when it occurs.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide a motorized working machine capable of easily changing the system output.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

[0010] Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail.

[0011] <Description of the Configuration of the Electric Shovel 100> FIG. 1 is a diagram showing the electric shovel 100 of the present embodiment. The electric shovel 100 shown in FIG. 1 is an example of an electric working machine having a vehicle body. However, the electric working machine to which the present embodiment is applied is not limited to the electric shovel 100, and may be a construction machine such as a wheel loader, a bulldozer, or a crane truck. Further, the electric working machine may be a truck for transporting gravel or the like. Furthermore, for example, the electric working machine may be an agricultural machine such as a felling machine, a sawing machine, a tractor, a forest work vehicle, or a logging machine.

[0012] The illustrated electric shovel 100 is supplied with power from the utility power source 400 through the power cable 200. Further, the electric shovel 100 is also supplied with power from the high-voltage battery 112. That is, the electric shovel 100 is configured to be able to use the power of the battery mounted on the machine while receiving power from the utility power source 400. However, in the present embodiment, the power supplied to the electric shovel 100 may not be used, and the power may be supplied only from the high-voltage battery 112.

[0013] The electric shovel 100 includes a high-voltage circuit 110, a vehicle control device 120, a hydraulic circuit 130, and an operation system 140. The illustrated electric shovel 100 controls the power supplied from the power cable 200 to the high-voltage circuit 110 by the vehicle control device 120 to drive the electric motor 118, which is a power source. The high-voltage circuit 110 includes an AC / DC converter 111 that receives power from the utility power supply 400 and converts the alternating-current power supplied from the power cable 200 into direct current, a high-voltage battery 112 which is an example of a battery and stores power, an inverter 117 which is an example of an inverter device that converts the direct-current power from the AC / DC converter 111 and the high-voltage battery 112 into alternating current, an electric motor 118 driven by the alternating-current power supplied from the inverter 117, and a hub box 150.

[0014] The hub box 150 relays the power from the high-voltage battery 112 and supplies it to the inverter 117. The detailed form of the hub box 150 will be described later.

[0015] The vehicle control device 120 changes the power received from the utility power supply 400 during the operation of the electric excavator 100. Then, the power received from the utility power supply 400 (the upper limit of the received power) is adjusted by the AC / DC converter 111. For example, the power received from the utility power supply 400 can be adjusted by adjusting the resistance value in the current limiting circuit of the AC / DC converter 111. The vehicle control device 120 includes a control arithmetic function unit 121, a data recording unit (memory) 122, and a communication function unit 123. The control arithmetic function unit 121 performs calculations for controlling the AC / DC converter 111, the high-voltage battery 112, and the inverter 117. The AC / DC converter 111, the high-voltage battery 112, and the inverter 117 are each provided with a control unit (controller) 111CO, 112CO, 117CO. The control units 111CO, 112CO, 117CO transmit data representing the states of the AC / DC converter 111, the high-voltage battery 112, and the inverter 117 to the control arithmetic function unit 121. Based on the transmitted data, the control arithmetic function unit 121 performs calculations and transmits control signals for controlling the AC / DC converter 111, the high-voltage battery 112, and the inverter 117 to the control units 111CO, 112CO, 117CO. When adjusting the power received from the utility power supply 400, the vehicle control device 120 sends a command, and the control unit 111CO of the AC / DC converter 111 receives the command. Then, the settings of the AC / DC converter 111 change, and thereby, the power received from the utility power supply 400 is changed. The data recording unit (memory) 122 records program data for the control arithmetic function unit 121 to perform calculations. The communication function unit 123 is a communication interface used when transmitting control signals to the control units 111CO, 112CO, 117CO.

[0016] The hydraulic circuit 130 includes a hydraulic pump 131 that generates hydraulic pressure, a hydraulic oil tank 132 that stores hydraulic oil, a first direction control valve 133, and a second direction control valve 134. The hydraulic pump 131 is a variable displacement type hydraulic pump driven by an electric motor 118. This hydraulic pump 131 sucks hydraulic oil from the hydraulic oil tank 132 and supplies the hydraulic oil to the swing motor 14 and the hydraulic cylinder for the working device 16 of the hydraulic excavator 100 via the first direction control valve 133 and the second direction control valve 134 to operate the hydraulic excavator 100.

[0017] The operating system 140 is provided in the cab of the electric excavator 100 and is used when the operator operates the electric excavator 100. As the operating system 140, there are provided a work mode selection switch, a motor control dial (not shown) for setting the rotation speed of the electric motor 118, operation levers 141A and 141B, etc. The operation levers 141A and 141B correspond to the respective slewing motors 14 and the hydraulic cylinders 16 for the working device. For example, an electric lever that outputs an electrical operation signal (lever signal Lv) according to the operation amount is used.

[0018] <Description of the configuration of the hub box 150> Next, the configuration of the hub box 150 will be described in detail. Figs. 2(a) and (b) are diagrams showing a first example of the wiring between the high-voltage battery 112 and the hub box 150, and the wiring inside the hub box 150. In Fig. 2(a), four batteries 112A to 112D are shown as the high-voltage battery 112 on the left side in the figure. Also, from the center to the right side in the figure, the hub box 150 is shown as the hub boxes 151A11 and 151A12 of the hub box (A) and the hub box 152B1 of the hub box (B).

[0019] Between the batteries 112A to 112D and the hub boxes 151A11 and 151A12, they are connected by eight cables 153. In this case, the eight cables 153 are connected using the terminals 112T provided in two each for the batteries 112A to 112D and the connectors 151N provided in four each on one side (the left side in the figure) of the hub boxes 151A11 and 151A12. Note that in this case, the batteries 112A to 112D are connected to the cables 153 via the terminals 112T, but they may also be connected to the cables 153 via connectors (not shown) provided on the batteries 112A to 112D.

[0020] Between the hub boxes 151A11 and 151A12 and the hub box 152B1, they are connected by four cables 154. In this case, the four cables 154 are connected using connectors 151S provided in fours on the other side (the right side in the figure) of the hub boxes 151A11 and 151A12, and connectors 152N provided in fours on one side (the left side in the figure) of the hub box 152B1.

[0021] Although not shown in the figure, on the right side in the figure of the hub box 152B1, a cable connected to the inverter 117 side is connected. This cable is connected using two connectors 152S provided on the other side (the right side in the figure) of the hub box 152B1.

[0022] In this configuration, the power transmitted from the batteries 112A to 112D is transmitted in the order of the hub box 151A11 or the hub box 151A12, the hub box 152B1, and is transmitted toward the inverter 117.Y Therefore, the hub box 150 serves as a power relay device that relays the power from the batteries 112A to 112D and supplies it to the inverter 117.

[0023] The configuration of the hub box 150 shown in Fig. 2(a) can also be described as follows. The hub boxes 151A11 and 151A are function as a first power relay device connected to the batteries 112A to 112D. The hub box 152B1 functions as a second power relay device connected to the hub boxes 151A11 and 151A12, which are the first power relay devices, and the inverter 117. Connectors are provided at the output part of the hub boxes 151A11 and 151A12 to the hub box 152B1, the input part of the hub box 152B1 from the hub boxes 151A11 and 151A12, and the output part of the hub box 152B1 to the inverter 117, respectively. These connectors are the connector 151S, the connector 152N, and the connector 152S, respectively. The connection between the hub boxes 151A11, 151A12 and the hub box 152B1, and the connection between the hub box 152B1 and the inverter 117 are connected by cables via connectors. That is, the connection between the hub boxes 151A11, 151A12 and the hub box 152B1 is connected by a cable 154 via connectors 151S, 152N. Also, the connection between the hub box 152B1 and the inverter 117 is connected by a connector 152S and the cable connected to the inverter 117 side described above. The batteries 112A~112D and the hub boxes 151A11, 151A12 are connected by a cable 153 via terminals or connectors provided respectively. However, in Fig. 2(a), the output parts of the batteries 112A~112D to the hub boxes 151A11, 151A12 are terminals 112T, and the input parts of the hub boxes 151A11, 151A12 from the batteries 112A~112D are connectors 151N.

[0024] Fig. 2(b) shows the case where the hub box 152B1 is replaced with the hub box 152B2 as compared with Fig. 2(a). The hub box 152B2 has the same number and positions of the connectors 152N as the hub box 152B1, but the internal wiring states are different. The hub boxes 152B1, B2 are detachable, and it is possible to replace the hub box 152B1 with the hub box 152B2. Also, conversely, it is possible to replace the hub box 152B2 with the hub box 152B1. That is, among the hub boxes 150, the hub boxes 151A11, 151A12 have fixed wiring states, but the hub boxes 152B1, 152B2 can be replaced with those having different wiring states by replacement.

[0025] And in Fig. 2(a), for the four batteries 112A~112D, it is possible to make a wiring in which they are in two series and two parallel. Thereby, the voltage of two batteries is output from the hub box 150 to the inverter 117. On the other hand, in Fig. 2(b), the four batteries 112A to 112D can be wired in four series (4 series and 1 parallel). As a result, the voltage of four batteries is output from the hub box 150 to the inverter 117.

[0026] That is, in the forms of Figs. 2(a) and 2(b), the hub boxes 151A11 and 151A12 are connected to each of the plurality of batteries 112A to 112D, and the hub boxes 152B1 and 152B2 can change the series-parallel connection of the plurality of batteries 112A to 112D. Also, in this form, by replacing the hub box 152B1 with one having a different wiring state, the series-parallel connection of the batteries 112A to 112D can be changed. In this case, the hub boxes 151A11 and 151A12 play a role of collecting the voltage required to operate the power shovel 100. The hub boxes 151A11 and 151A12 are installed to obtain the voltage required to operate the power shovel 100 at the rated output. Also, the hub boxes 152B1 and 152B2 play a role of varying the voltage collected by the hub boxes 151A11 and 151A12. That is, when operating the power shovel 100 at the rated output during normal work, the wiring state using the hub box 152B1 in Fig. 2(a) is adopted. On the other hand, when work under a heavy load that cannot be handled at the rated output of the power shovel 100 is required, the hub box 152B1 in Fig. 2(a) is replaced with the hub box 152B2, and the wiring state using the hub box 152B2 shown in Fig. 2(b) is adopted. As a result, without changing the number of mounted batteries, it is possible to easily change between the case of operating the power shovel 100 at the normal rated output and the case of operating it at a heavy load output that cannot be handled at the rated output, simply by exchanging the hub box 152B1 and the hub box 152B2, which serve as the second power relay device.

[0027] In addition, since the hub boxes 151A11 and 151A12, which are the first power relay devices, and the hub boxes 152B1 and 152B2, which are the second power relay devices, are connected by the connector 151S and the connector 152N, it is easy to remove and reconnect the cable 154. Therefore, the work of changing the wiring can be made simple. That is, since the hub boxes 151A11 and 151A12, which are the first power relay devices, and the hub boxes 152B1 and 152B2, which are the second power relay devices, are connected by the connector 151S and the connector 152N, it is not necessary to open the hub boxes 151A11 and 151A12 or the hub boxes 152B1 and 152B2, or to change the terminal connection of the cable 154 using tools, and it becomes easy to remove and reconnect the cable 154. Furthermore, when changing the system output, the operator only needs to remove and reconnect the cable 154 connected by the connector and replace the hub boxes 152B1 and 152B2, which are the second power relay devices. Therefore, the operator does not touch the terminals 112T of the batteries 112A to 112D. Therefore, electric shock by the batteries 112A to 112D can be prevented. And for each of the four cables 154, even when the hub box 152B1 is replaced with the hub box 152B2, the connectors 151S and 152N to be connected use those provided in the same number and at the same positions. Therefore, it is possible to prevent the cable 154 from being connected to the wrong connector, and it is excellent in safety. Note that the same applies to the cable connecting the hub boxes 152B1 and 152B2 to the inverter 117 side.

[0028] Figs. 3(a) and (b) are diagrams showing a second example of the wiring between the high-voltage battery 112 and the hub box 150 and the wiring inside the hub box 150. Comparing Figs. 3(a) and (b) with Figs. 2(a) and (b), in Figs. 3(a) and (b), the two hub boxes 151A11 and 151A12 are combined into one and become the hub box 151A, which is different, and the rest is the same.

[0029] FIG. 4(a) is a diagram showing a third example of the wiring between the high-voltage battery 112 and the hub box 150 and the wiring inside the hub box 150. This third example is obtained by making the normal rated output of the electric shovel 100 larger than that shown in FIG. 2(a). Comparing FIG. 4(a) with FIG. 2(a), the high-voltage battery 112 has increased from four batteries 112A to 112D to six batteries 112A to 112F. Correspondingly, the number of hub boxes has increased from two (151A11 and 151A12) to three (151A21 to 151A23). And the hub box 152B3 has a wiring configuration of two series and three parallel for the six batteries 112A to 112F. Further, the cable 153 has increased from eight to twelve, and the cable 154 has increased from four to six.

[0030] FIG. 4(b) is a diagram showing a fourth example of the wiring between the high-voltage battery 112 and the hub box 150 and the wiring inside the hub box 150. This fourth example is obtained by making the normal rated output of the electric shovel 100 even larger than that of the third example. Comparing FIG. 4(b) with FIG. 2(a), the high-voltage battery 112 has increased from four batteries 112A to 112D to eight batteries 112A to 112F. Correspondingly, the number of hub boxes has increased from two (151A11 and 151A12) to four (151A31 to 151A34). And the hub box 152B4 has a wiring configuration of two series and four parallel for the eight batteries 112A to 112F. Further, the cable 153 has increased from eight to sixteen, and the cable 154 has increased from four to eight.

[0031] In Fig. 4(a), for the six batteries 112A to 112F, the wiring is in a configuration of two in series and three in parallel. As a result, the voltage equivalent to that of two batteries is output from the hub box 150 to the inverter 117. Also, in Fig. 4(b), for the eight batteries 112A to 112H, the wiring is in a configuration of two in series and four in parallel. Thus, the voltage equivalent to that of two batteries is output from the hub box 150 to the inverter 117. Even in the cases of Figs. 4(a) and (b), by replacing the hub box 152B3 or the hub box 152B4 with ones having different wiring states, the series-parallel connection of the batteries 112A to 112D can be changed. In the case of Fig. 4(a), by replacing the hub box 152B3, for example, the wiring can be made to be six in series (six in series and one in parallel). Also, in the case of Fig. 4(b), by replacing the hub box 152B4, for example, the wiring can be made to be four in series and two in parallel or eight in series (eight in series and one in parallel).

[0032] Fig. 5(a) is a diagram showing a fifth example of the wiring between the high-voltage battery 112 and the hub box 150, and the wiring inside the hub box 150. The fifth example is different from the third example in that the three hub boxes 151A21 to A23 are combined into one hub box 151A2, and the rest is the same. Fig. 5(b) is a diagram showing a sixth example of the wiring between the high-voltage battery 112 and the hub box 150, and the wiring inside the hub box 150. The sixth example is different from the fourth example in that in Fig. 5(b), the four hub boxes 151A31 to A34 are combined into one hub box 151A3, and the rest is the same.

[0033] Figs. 6(a) to (c) are diagrams showing a seventh example of the wiring between the high-voltage battery 112 and the hub box 150, and the wiring inside the hub box 150. Among these, Fig. 6(a) is the same as the case shown in Fig. 2(a). Here, it is assumed that at least one of the batteries 112C and 112D has stopped operating due to a failure or the like. In this case, the operation of disconnecting the batteries 112C and 112D is performed.

[0034] FIG. 6(b) is a first example showing the case of disconnecting the batteries 112C and 112D. Here, the case where the batteries 112C and 112D are disconnected by removing the two lower cables 154 shown in FIG. 6(a) and the wiring becomes two series and one parallel is shown. This cable 154 is a cable connected to the hub box 151A12 and the hub box 152B1 via connectors and can be easily detached and attached.

[0035] Also, FIG. 6(c) is a second example showing the case of disconnecting the batteries 112C and 112D. Here, by replacing the hub box 152B1 with the hub box 152B5, the case where the batteries 112C and 112D are disconnected and the wiring is changed from two series and two parallel to two series and one parallel is shown. In this form, the hub boxes 151A11 and 151A12 are connected to each of the plurality of batteries 112A to 112D, and the hub boxes 152B1 and 152B5 can be said to change the number of parallel connections of the plurality of 112A to 112D. Also, in this form, it can be said that the number of connected batteries 112A to 112D is changed by replacing the hub box 152B1 with one having a different wiring state. Thus, even when it is desired to disconnect a battery that cannot be used when a battery failure or the like occurs, it is only necessary to remove and reconnect the cable 154 connected by the connector and replace the hub boxes 152B1 and 152B5 which are the second power relay devices, so the operation can be made simple. Furthermore, since the operator only needs to remove and reconnect the cable 154 connected by the connector and replace the hub boxes 152B1 and 152B5 which are the second power relay devices, the operator does not touch the terminals 112T of the batteries 112A to 112D. Therefore, electric shock by the batteries 112A to 112D can be prevented.

[0036] Further, FIG. 7 is a third example showing a case where the batteries 112C and 112D are disconnected. In this case, a hub box 152B6 provided with two circuit breakers 152K inside the hub box 152B1 is used, and by turning off the circuit breakers 152K, the same wiring as the hub box 152B5 in FIG. 6(c) can be achieved. Thereby, the batteries 112C and 112D can be disconnected and the wiring can be made into a two-series and one-parallel configuration.

[0037] <Explanation of the position where the hub box 150 is provided> FIGS. 8(a) to (d) and FIGS. 9(a) and (b) are diagrams showing the positions where the hub box 150 is provided in the electric shovel 100. In the figures, CAB is the operator's cab. Also, LIB is a lithium-ion battery, which is the battery described above. Further, C / W is the counterweight. Also, in the figures, the X direction is the direction from the rear to the front of the body of the electric shovel 100. The Y direction is the direction from the right to the left of the body of the electric shovel 100. The Z direction is the direction from the bottom to the top of the body of the electric shovel 100. Among these, FIGS. 8(a) to (d) are diagrams showing the positions where the hub box 150 is provided when the electric shovel 100 is viewed from above. Also, FIGS. 9(a) and (b) are diagrams showing the positions where the hub box 150 is provided when the electric shovel 100 is viewed from the side. Here, BOX_A is the hub boxes 151A1 to 151A3, 151A11 to 151A12, 151A21 to 151A23, 151A31 to 151A34 which are the first power relay devices described above. When not distinguishing the hub boxes 151A1 to 151A3, 151A11 to 151A12, 151A21 to 151A23, 151A31 to 151A34, they may simply be referred to as the hub box 151 hereinafter. Also, BOX_B is the hub boxes 152B1 to 152B6 which are the second power relay devices described above. When not distinguishing the hub boxes 152B1 to 152B6, they may simply be referred to as the hub box 152 hereinafter.

[0038] As shown in FIGS. 8 and 9, the hub box 152 is provided at a position outside the vehicle body center O compared to the hub box 151. Further, the hub box 152 is provided close to the access port 160 provided in the vehicle body. The power shovel 100 has a cover that serves as an exterior of the vehicle body, and an access port 160 is provided in the cover as an opening for maintenance. A door, a lid, etc. are attached to the access port 160, and in a normal state, it is closed by these, but during maintenance, etc., by opening these, access to the inside of the power shovel 100 can be achieved. That is, from the viewpoint of ease of attachment and detachment, the hub box 152 is preferably provided at a position outside the vehicle body center O compared to the hub box 151 and at a position close to the access port 160.

[0039] In the case of FIG. 8(a), the access port 160 is provided at the center of the right side surface of the vehicle body, and the hub box 152 is provided adjacent to the access port 160. On the other hand, the hub box 151 is provided inside the vehicle body compared to the hub box 151, and the hub box 152 is provided at a position outside the hub box 151 with respect to the vehicle body center O. Further, the hub box 152 is provided at a position closer to the access port 160 than the hub box 151.

[0040] In the case of FIG. 8(b), the access port 160 is provided at the front of the right side surface of the vehicle body, and the hub box 152 is provided adjacent to the access port 160. On the other hand, the hub box 151 is provided behind the vehicle body compared to the hub box 152, and the hub box 152 is provided at a position outside the hub box 151 with respect to the vehicle body center O. Further, the hub box 152 is provided at a position closer to the access port 160 than the hub box 151.

[0041] In the case of Fig. 8(c), the access port 160 is provided at the center of the left side surface of the vehicle body, and a hub box 152 is provided adjacent to the access port 160. On the other hand, the hub box 151 is provided at a position closer to the right side than the left side of the vehicle body, and the hub box 152 is provided at a position outside the hub box 151 with respect to the center O of the vehicle body. Also, the hub box 152 is provided at a position closer to the access port 160 than the hub box 151.

[0042] In the case of Fig. 8(d), the access port 160 is provided at the rear part of the right side surface of the vehicle body, and a hub box 152 is provided adjacent to the access port 160. On the other hand, the hub box 151 is provided at the central position in the front-rear direction of the vehicle body, and the hub box 152 is provided at a position outside the hub box 151 with respect to the center O of the vehicle body. Also, the hub box 152 is provided at a position closer to the access port 160 than the hub box 151.

[0043] In the case of Fig. 9(a), the access port 160 is provided at the rear part of the upper surface of the vehicle body, and a hub box 152 is provided adjacent to the access port 160. On the other hand, the hub box 151 is provided at the central position in the up-down direction of the vehicle body, and the hub box 152 is provided at a position outside the hub box 151 with respect to the center O of the vehicle body. Also, the hub box 152 is provided at a position closer to the access port 160 than the hub box 151.

[0044] In the case of Fig. 9(b), the access port 160 is provided at the rear part of the lower surface of the vehicle body, and a hub box 152 is provided adjacent to the access port 160. On the other hand, the hub box 151 is provided at the central position in the up-down direction of the vehicle body, and the hub box 152 is provided at a position outside the hub box 151 with respect to the center O of the vehicle body. Also, the hub box 152 is provided at a position closer to the access port 160 than the hub box 151.

[0045] <Description of insulation degradation sensor> The hub box 152 preferably includes an insulation degradation sensor. The insulation degradation sensor is a sensor that monitors the insulation resistance between the vehicle body and the high-voltage battery 112, and has a function of outputting a warning signal when the insulation resistance deteriorates.

[0046] FIGS. 10(a) and (b) are diagrams showing the positions where the insulation degradation sensor 152Z is disposed. Among these, FIG. 10(a) shows an example in which the insulation degradation sensor 152Z is attached to the hub box 152B1 shown in FIG. 2(a). Further, FIG. 10(b) shows an example in which the insulation degradation sensor 152Z is attached to the hub box 152B2 shown in FIG. 2(b). In both cases, the insulation degradation sensor 152Z is provided so as to be connected to the transmission lines 152L1 and 152L2 supplied to the inverter 117.

[0047] As shown in these examples, it is preferable that the insulation degradation sensor 152Z is provided in the hub box 152 rather than the hub box 151. As the specification of the insulation degradation sensor 152Z, it is necessary to use one that matches the voltage to be used. That is, it is necessary to use the insulation degradation sensor 152Z that matches the voltage output to the inverter 117. In the case of Fig. 10(a), it is 2 series and 2 parallel, and the voltage used here is the voltage of two batteries output to the inverter 117 as described above. Also, in the case of Fig. 10(b), it is 4 series, and the voltage used here is the voltage of four batteries output to the inverter 117 as described above. And since the hub box 152 has a circuit configuration for changing this voltage, if the insulation degradation sensor 152Z that matches the voltage used in each case is attached to the hub box 152, when the hub box 152 is replaced, so to speak, an appropriate insulation degradation sensor 152Z is automatically attached. In this case, the insulation degradation sensor 152Z attached to the hub box 152B2 is selected to have a higher voltage specification than the insulation degradation sensor 152Z attached to the hub box 152B1. In Fig. 10(a), as the insulation degradation sensor 152Z, one corresponding to the M (Middle) voltage is used, and in Fig. 10(b), it shows that as the insulation degradation sensor 152Z with a higher voltage specification than this, one corresponding to the Hi voltage is used.

[0048] As described above, the present embodiment has been explained, but the technical scope of the present invention is not limited to the scope described in the above embodiment. It is obvious from the description of the claims that those obtained by making various changes or improvements to the above embodiment are also included in the technical scope of the present invention.

Explanation of reference numerals

[0049] 100…Electric excavator, 110…High-voltage circuit, 111…AC / DC converter, 112…High-voltage battery, 112A~112H…Battery, 112T…Terminal, 151N, 151S, 152N, 152S…Connector, 117…Inverter, 120…Vehicle control device, 151A1~151A3, 151A11~151A12, 151A21~151A23, 151A31~151A34…Hub box (first power relay device), 152B1~152B6…Hub box (second power relay device), 152Z…Insulation deterioration sensor, 153, 154…Cable, 160…Access port

Claims

1. It has a vehicle body, wherein the vehicle body is an electric working machine including a battery, an electric motor, and an inverter that supplies power from the battery to the electric motor, having a first power relay device connected to the battery and a second power relay device connected between the first power relay device and the inverter, wherein connectors are respectively provided at an output portion of the first power relay device to the second power relay device, an input portion of the second power relay device from the first power relay device, and an output portion of the second power relay device to the inverter, and the connection between the first power relay device and the second power relay device and the connection between the second power relay device and the inverter are connected by a cable via the connectors, characterizing the electric working machine.

2. In the electric working machine according to Claim 1, the battery and the first power relay device are connected by a cable via terminals or connectors provided respectively thereon, characterizing the electric working machine.

3. In the electric working machine according to Claim 2, an output portion of the battery to the first power relay device is a terminal, and an input portion of the first power relay device from the battery is a connector, characterizing the electric working machine.

4. In the electric working machine according to Claim 1, a plurality of the batteries are provided, the first power relay device is connected to each of the plurality of batteries, and the second power relay device changes a series-parallel connection of the plurality of batteries, characterizing the electric working machine.

5. In the electric working machine according to Claim 1, a plurality of the batteries are provided, the first power relay device is connected to each of the plurality of batteries, and the second power relay device changes the number of parallel connections of the plurality of batteries, characterizing the electric working machine.

6. In the electric working machine according to Claim 1, the second power relay device is provided at a position outside the first power relay device with respect to the center of the vehicle body, characterizing the electric working machine.

7. In the electric working machine according to Claim 1, it has a cover serving as an exterior of the vehicle body, the cover is provided with an access port for maintenance, and the second power relay device is provided at a position closer to the access port than the first power relay device. An electric working machine characterized by the above.

8. In the electric working machine according to Claim 1, an insulation degradation sensor for monitoring the insulation resistance between the vehicle body and the battery is provided, and the insulation degradation sensor is provided in the second power relay device. An electric working machine characterized by the above.

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