Electric work machine

Abstract

The present invention achieves both extension of running time and workability.　This electric work machine (1) comprises: a machine body (2); an actuating apparatus (3) that includes a travel device (4) and / or a work device (5) provided to the machine body (2); an electric actuator (51) that generates power for operating the actuating apparatus (3); and a plurality of batteries (52) that are mounted to the machine body (2) and are capable of supplying power to the electric actuator (51). The plurality of batteries (52) include one or more first batteries (52A) fixed to the machine body (2), and one or more second batteries (52B) that are different from the first batteries (52A) and that are detachably mounted to the machine body (2).

Description

Electric working machine

[0001] The present invention relates to an electric working machine.

[0002] The battery-powered hydraulic excavator disclosed in Patent Document 1 includes a vehicle body and a battery that is detachable from the vehicle body and serves as a power source. The battery has one or more cartridge-type battery packs.

[0003] Japanese Patent Laid-Open Publication "JP-A-2024-124101"

[0004] In the battery-powered hydraulic excavator of Patent Document 1, the operating time can be extended by replacing a battery pack with a reduced remaining capacity with a fully charged battery pack.

[0005] However, detachable battery packs may require a relatively large mounting space for the discharge capacity, and depending on the battery storage space, it may not be possible to mount a sufficient number of battery packs with a large discharge capacity on the vehicle body (machine body) for the work.

[0006] The present invention has been made to solve such problems of the prior art, and an object thereof is to provide an electric working machine capable of achieving both an extended operating time and workability.

[0007] An electric working machine according to an aspect of the present invention includes a machine body, operating equipment including a traveling device and / or a working device provided on the machine body, an electric actuator that generates power for operating the operating equipment, and a plurality of batteries mounted on the machine body and capable of supplying power to the electric actuator. The plurality of batteries include one or more first batteries fixed to the machine body and one or more second batteries that are different from the first batteries and are detachably mounted on the machine body.

[0008] According to the above electric working machine, it is possible to achieve both an extended operating time and workability.

[0009] This is a schematic side view showing an electric work machine. This is a block diagram illustrating the electric work machine in the first embodiment. This is a perspective view showing multiple batteries. This is an example of an electrical system diagram of the electric work machine in the first embodiment. This is a diagram illustrating the first change control in the first embodiment. This is a diagram illustrating the limit control in the first embodiment. This is a diagram illustrating the second change control in the first embodiment. This is a diagram illustrating the third change control in the first embodiment. This is a block diagram illustrating an electric work machine equipped with an engine. This is a block diagram illustrating the electric work machine in the second embodiment. This is an electrical system diagram of the electric work machine in the second embodiment. This is a diagram illustrating the fourth change control in the second embodiment. This is a diagram illustrating the fourth change control in a modified example of the second embodiment.

[0010] One embodiment of the present invention will be described below with reference to the drawings.

[0011] [First Embodiment] <About the Electric Work Machine 1> Figure 1 is a schematic side view showing an electric work machine 1 according to one embodiment of the present invention. Figure 2 is a block diagram illustrating the electric work machine 1 in the first embodiment. Figure 1 shows a backhoe operating as the electric work machine 1, powered by electricity supplied from a battery 52. ​​In the following description, the electric work machine 1 will be described using a backhoe as an example, but the electric work machine 1 is not limited to a backhoe and may be a construction work vehicle such as a compact track loader, or an agricultural work vehicle such as a combine harvester or rice transplanter.

[0012] In the following explanation, the direction indicated by arrow X1 in the drawing is forward, the direction indicated by arrow X2 is backward, the direction indicated by arrow Y1 is to the left, the direction indicated by arrow Y2 is to the right, the direction indicated by arrow Z1 is upward, and the direction indicated by arrow Z2 is downward.

[0013] As shown in Figure 1, the electric work machine 1 comprises a machine body 2 (turntable) and operating equipment 3. The machine body 2 supports various devices and equipment of the electric work machine 1. For example, the machine body 2 is equipped with a driver's seat 11 where the operator sits, and a protective mechanism 12 to protect the driver's seat 11. Operating devices 13 for operating the electric work machine 1 are provided around the driver's seat 11.

[0014] The operating device 13 includes hardware-type operating members such as levers and switches. The operating members may directly operate each device and equipment provided by the electric work machine 1, or they may output operating signals to a control device 54, etc., described later, and indirectly operate each device and equipment via the control device 54, etc. Furthermore, the operating members are not limited to hardware-type operating members and may also include software-type operating members displayed on a display device 14, such as a liquid crystal display or an organic EL display, provided by the electric work machine 1.

[0015] The operating device 3 is a device that is installed on the machine body 2 and is capable of being operated. The operating device 3 includes a traveling device 4 and / or a working device 5 installed on the machine body 2.

[0016] The traveling device 4 is a device that moves the machine body 2 when it is activated. The traveling device 4 supports the machine body 2 so that it can rotate around the pivot axis C. The traveling device 4 has a traveling frame 21 (track frame) and a traveling mechanism 22. The traveling frame 21 is a structure to which the traveling mechanism 22 is attached around the periphery and which supports the machine body 2 on top. The traveling frame 21 supports the machine body 2 around the pivot axis C via a pivot bearing 23.

[0017] The running mechanism 22 is a mechanism that, when activated, imparts thrust to the machine body 2. The running mechanism 22 is, for example, a crawler-type running mechanism. The running mechanism 22 is provided on the left and right sides of the running frame 21, respectively. Note that the running mechanism 22 is not limited to a crawler-type running mechanism, but may also be a tire-type running mechanism, and its structure is not particularly limited.

[0018] The working device 5 is a device that performs work by being activated. The working device 5 has a boom 32, an arm 33, and a working tool 34. The boom 32 and the arm 33 are members that support the working tool 34. The base end of the boom 32 is pivotally attached to a swing bracket 31 so as to be rotatable around a horizontal axis. The swing bracket 31 is provided so as to be rotatable around a vertical axis relative to the machine body 2. The arm 33 is pivotally attached to the tip end of the boom 32 so as to be rotatable around a horizontal axis. The arm 33 supports the working tool 34 at its tip end.

[0019] The work tool 34 is a device for performing work. The work tool 34 is pivotally attached to the tip of the arm 33 so as to be rotatable around a horizontal axis. Examples of work tools 34 include buckets, breakers, crushers, angle brooms, earth augers, pallet forks, sweepers, mowers, and snow blowers. The work tool 34 may also be a replaceable attachment.

[0020] Furthermore, the work device 5 may include a dozer device 35. The dozer device 35 is pivotally attached to the traveling device 4 so as to be rotatable around a horizontal axis.

[0021] The aforementioned operating device 3 is merely an example and is not particularly limited. Furthermore, the electric work machine 1 moves using the traveling device 4, rotates the machine body 2 around the pivot axis C, and performs work using the work device 5. In other words, the machine body 2, which is supported by the traveling device 4 around the pivot axis C, can also be considered the work device 5 or a part thereof.

[0022] As shown in Figure 2, the electric work machine 1 is equipped with an electric actuator 51. The electric actuator 51 generates power to operate the actuator 3. The electric actuator 51 is a drive source that operates using electricity supplied from a battery 52, which will be described later. The electric actuator 51 operates the actuator 3 directly or indirectly with the power it generates. Examples of the electric actuator 51 include an electric motor and an electric cylinder. Hereinafter, we will explain using the case where the electric actuator 51 is an electric motor and the electric motor indirectly operates the actuator 3 as an example.

[0023] As shown in Figure 2, the electric work machine 1 is equipped with a hydraulic oil tank 41, a hydraulic pump 42, a control valve 43, and hydraulic equipment 45. The hydraulic pump 42 is operated by the power generated by the electric actuator 51 to draw hydraulic oil stored in the hydraulic oil tank 41 and discharge the hydraulic oil to the control valve 43.

[0024] The control valve 43 controls (adjusts) the flow rate of the hydraulic fluid that operates the hydraulic equipment 45. For example, the control valve 43 controls the flow rate of the hydraulic fluid output from the hydraulic pump 42 to the hydraulic equipment 45.

[0025] The control valve 43 has one or more control valves 44 corresponding to the hydraulic equipment 45. The control valves 44 adjust the flow rate of hydraulic fluid that operates the hydraulic equipment 45 by changing the position of the spool in response to the operation of the operating device 13. The position of the spool of the control valves 44 is changed by pilot oil supplied from an operating valve that is directly operated by an operating member 13a included in the operating device 13, or by pilot oil supplied from a solenoid valve that is electrically operated by the operation of the operating member 13a.

[0026] The hydraulic equipment 45 is a hydraulic actuator driven by supplied hydraulic fluid. Examples of hydraulic actuators include hydraulic motors and hydraulic cylinders. In this embodiment, the electric work machine 1 includes, as hydraulic equipment 45, a travel motor 45a that drives the travel mechanism 22, a slewing motor 45b that rotates the machine body 2 around the slewing axis C, a swing cylinder 45c that rotates the swing bracket 31 around the vertical axis, a boom cylinder 45d that rotates the boom 32 around the horizontal axis, an arm cylinder 45e that rotates the arm 33 around the horizontal axis, a work tool cylinder 45f that rotates the work tool 34 around the horizontal axis, and a dozer cylinder 45g that rotates the dozer around the horizontal axis. The travel motor 45a and the slewing motor 45b are hydraulic motors. The swing cylinder 45c, boom cylinder 45d, arm cylinder 45e, work tool cylinder 45f, and dozer cylinder 45g are hydraulic cylinders.

[0027] The hydraulic equipment 45 (hydraulic actuator) provided by the electric work machine 1 is merely an example and is not limited to it.

[0028] Furthermore, if the electric actuator 51 directly operates the operating device 3, the hydraulic actuators described above can be replaced with the electric actuator 51. In such a case, each motor and each cylinder can be replaced with an electric motor or electric cylinder, etc. For example, the travel motor 45a and the slewing motor 45b can be replaced with electric motors. The swing cylinder 45c, boom cylinder 45d, arm cylinder 45e, work tool cylinder 45f, and dozer cylinder 45g can be replaced with electric cylinders.

[0029] As shown in Figure 2, the electric work machine 1 is equipped with multiple batteries 52. The multiple batteries 52 are mounted on the machine body 2 and are capable of supplying power to the electric actuator 51. Figure 3 is a perspective view showing the multiple batteries 52. As shown in Figure 3, the electric work machine 1 is equipped with a support structure 16 provided on the machine body 2, and each battery 52 is supported by the support structure 16.

[0030] The multiple batteries 52 are secondary batteries (storage batteries) such as lithium-ion batteries that can store and discharge (output) the stored power. Each battery 52 has multiple cells inside, and these multiple cells are electrically connected in series and / or parallel. Each battery 52 has a connector 52a for outputting power. This connector 52a is connected to a connector 61a of a power path 61 (electrical circuit) which will be described later, and the battery 52 can supply power to the electric actuator 51 via the power path 61.

[0031] The multiple batteries 52 include one or more first batteries 52A and one or more second batteries 52B. The first battery 52A is a battery 52 fixed to the aircraft body 2. Therefore, the first battery 52A is a fixed (stationary) battery 52. ​​For example, in the example shown in Figure 3, the first battery 52A is fixed to the support structure 16 via fasteners 17 such as fastening members (e.g., bolts).

[0032] Unlike the first battery 52A, the second battery 52B is a battery 52 that can be detachably mounted on the aircraft body 2. Therefore, the second battery 52B is a detachable (replaceable) battery 52. ​​The second battery 52B may be smaller in weight and / or volume than the first battery 52A. The discharge capacity of the second battery 52B may be less than that of the first battery 52A.

[0033] In the example shown in Figure 3, the second battery 52B is provided with a gripping portion 52b (handle) for the operator to grasp. The second battery 52B also has a sliding portion 52c that can slide relative to a sliding rail 16a provided on the support structure 16. This allows the operator to easily attach and detach the second battery 52B to the support structure 16 by opening the bonnet of the machine body 2 or the opening / closing door provided on the bonnet and moving the second battery 52B along the sliding rail 16a. In addition, the operator can transport the second battery 52B more easily than the first battery 52A.

[0034] In the example shown in Figure 3, the second battery 52B is fixed to the aircraft body 2 (support structure 16) by a fixing member (holder member) 18. The fixing member 18 can be switched between a fixed state in which the second battery 52B is fixed to the support structure 16 and a released state in which the fixing is released. For example, the fixing member 18 can be fitted into a hole formed in the support structure 16 and attached to the support structure 16, and can restrict the sliding movement of the second battery 52B (fixed state). In the example shown in Figure 3, since the second battery 52B is slidable in the front-rear direction, the fixing member 18 is fitted into a hole formed in the support structure 16 that penetrates vertically. Therefore, the restriction on the movement of the second battery 52B can be released by removing the fixing member 18 from the hole (released state).

[0035] The fixing member 18 described above is merely an example and is not limited to the above configuration. For example, the fixing member 18 may be electrically controlled and switch between a fixed state and a released state.

[0036] As explained above, the second battery 52B can be easily attached to and detached from the machine body 2 (support structure 16) compared to the first battery 52A. Therefore, when the remaining capacity of the second battery 52B mounted on the machine body 2 becomes low, the operator can easily replace it with a fully charged second battery 52B. However, since the second battery 52B has a gripping part 52b, a sliding part 52c, etc., and a fixing member 18 etc. is attached to the support structure 16, it requires more mounting space relative to its discharge capacity than the first battery 52A.

[0037] Furthermore, if the first battery 52A deteriorates and its discharge capacity decreases, the operator may remove the fixing device 17 and replace the first battery 52A. The first battery 52A may be fixed to the machine body 2 in a way that prevents removal.

[0038] Furthermore, although the example shown in Figure 3 illustrates a case where multiple batteries 52 include one first battery 52A and three second batteries 52B, the number of first batteries 52A and the number of second batteries 52B included in the multiple batteries 52 are not limited to the above example. The number of first batteries 52A may be greater than the number of second batteries 52B. Also, the number of second batteries 52B may be greater than the number of first batteries 52A. Moreover, the number of first batteries 52A and the number of second batteries 52B may be the same.

[0039] As shown in Figure 2, the electric work machine 1 may also be equipped with a low-voltage battery 53 in addition to the multiple batteries 52. The low-voltage battery 53 is a storage battery with a lower voltage than the multiple batteries 52. The low-voltage battery 53 supplies power to the electrical equipment E1 installed in the electric work machine 1. The electrical equipment E1 is a device separate from the electric actuator 51, and examples include a control device 54 (described later), a cooling fan, an air conditioner, various lamps, etc.

[0040] <Regarding the electrical system of the electric work machine 1> Next, the electrical system of the electric work machine 1 will be explained in detail. Figure 4 is an example of an electrical system diagram of the electric work machine 1 in the first embodiment. As shown in Figures 2 and 4, the electric work machine 1 is equipped with a control device 54. The electric work machine 1 is also equipped with a storage device 55.

[0041] The control device 54 includes one or more processors. The control device 54 is a controller of the electric working machine 1 and performs various controls related to the electric working machine 1. The control device 54 is communicably connected to each device and each apparatus mounted on the electric working machine 1 through an in-vehicle network such as CAN, ISO BUS, LIN, FlexRay, etc.

[0042] The control device 54 includes one or more memories, various analog circuits, various digital circuits, etc. The one or more memories store (memorize) software programs and various data to be executed by the one or more processors. The control device 54 can read a software program from the one or more memories by the one or more processors and execute various processes based on the software program. Note that the control device 54 may also execute various processes based on a predetermined logic circuit by the one or more processors.

[0043] The processor is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), etc.

[0044] Note that the control device 54 may execute various processes by a plurality of physically separated processors cooperating with each other, and its configuration is not limited to the above-described configuration. In such a case, the plurality of processors are respectively mounted on one or more computers physically separated from the electric working machine 1, and these processors are communicably connected by a network such as an in-vehicle network, a LAN, a WAN, and the Internet.

[0045] Further, the software program may be stored in a storage device 55 communicably connected to the control device 54 or an external server device connected via the above network, and may be configured to be installed from these into the above memory.

[0046] The storage device 55 stores various information and data related to the electric working machine 1 in a readable and writable manner. The storage device 55 includes a non-volatile memory such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The storage device 55 is communicably connected to the control device 54, and the control device 54 can acquire various information and data stored in the storage device 55.

[0047] The control device 54 may acquire information on each device and each component provided in the electric working machine 1 and control these devices and components based on the information. For example, the control device 54 may acquire the states of the plurality of batteries 52 and control each device and component according to the remaining capacity. The control device 54 can perform control of discharging (discharge control) in which the battery 52 supplies power (discharges) to each part provided in the electric working machine 1 according to the acquired remaining capacity. Also, the control device 54 can perform control of charging (charge control) of the battery 52 according to the acquired remaining capacity.

[0048] The control device 54 can switch between a discharge mode for performing discharge control and a charge mode for performing charge control. The discharge mode is a mode in which power is supplied from the plurality of batteries 52 to the electric actuator 51. The charge mode is a mode in which the plurality of batteries 52 are charged. For example, the control device 54 switches to the discharge mode or the charge mode according to the operation of the mode operation member 13b included in the operation device 13 or the connection of a charging cable to the charging port 74 described later.

[0049] The electric working machine 1 includes a battery monitoring device 56 (BMU: battery management unit). The battery monitoring devices 56 are provided in the corresponding batteries 52, respectively. Note that the battery monitoring devices 56 may be built in the corresponding batteries 52, respectively, or may be installed outside the batteries 52.

[0050] The battery monitoring device 56 controls the corresponding battery 52. ​​The battery monitoring device 56 controls the opening and closing of internal relays located inside the battery 52 to control the start and stop of power supply from the battery 52. ​​The battery monitoring device 56 also detects (monitors) the status of each corresponding battery 52. ​​The battery monitoring device 56 detects the temperature, voltage, current, or terminal voltage of the internal cells of the battery 52.

[0051] Furthermore, the battery monitoring device 56 detects the remaining capacity (charge rate) of the battery 52 by a voltage measurement method, for example, based on the terminal voltage of the cells inside the battery 52. ​​In this embodiment, the battery monitoring device 56 detects the remaining capacity of the battery 52 as a percentage.

[0052] The method for detecting the remaining capacity of the battery 52 is not limited to the voltage measurement method, but may also be other methods such as the Coulomb counter method, the battery cell modeling method, or the impedance track method. Furthermore, a capacity detection unit for detecting the remaining capacity of the battery 52 may be provided separately from the battery monitoring device 56.

[0053] As a result, the control device 54 can obtain the remaining capacity of the battery 52 from the battery monitoring device 56 and control each device and equipment (for example, discharge control and charge control) according to the remaining capacity. The control device 54 may also control the display device 14 to display the remaining capacity on the display device 14.

[0054] As shown in Figures 2 and 4, the electric work machine 1 is equipped with a power path 61. The power path 61 is electrically connected to a plurality of batteries 52. The power path 61 is also electrically connected to the electric actuator 51, thereby electrically connecting the plurality of batteries 52 to the electric actuator 51.

[0055] In this embodiment, the electric work machine 1 includes a junction box 63 that houses at least a portion of the power path 61. The junction box 63 is electrically connected to other electrical components E2. For example, the junction box 63 is electrically connected to a plurality of batteries 52, an inverter 71, a DC / DC converter 72, and a charger 73.

[0056] As shown in Figures 2 and 4, the electric work machine 1 is equipped with an inverter 71. The inverter 71 converts the DC power input from the battery 52 via the junction box 63 into three-phase AC power and supplies the three-phase AC power to the electric actuator 51. The inverter 71 is controlled by a control device 54, and the frequency, voltage, and current of the power supplied to the electric actuator 51 can be arbitrarily adjusted. The control device 54 controls the inverter 71 in accordance with the operation of the rotary operating member 13c included in the operating device 13.

[0057] As shown in Figures 2 and 4, the electric work machine 1 is equipped with a DC / DC converter 72. The DC / DC converter 72 is a voltage converter that converts the voltage of the DC power input from the battery 52 via the junction box 63 to a different voltage. The DC / DC converter 72 is a step-down converter that converts the high voltage of the battery 52 to a predetermined low voltage corresponding to the electrical equipment E1 installed in the electric work machine 1. After voltage conversion, the DC / DC converter 72 supplies power to the low-voltage battery 53.

[0058] As shown in Figures 2 and 4, the electric work machine 1 is equipped with a charging port 74 (charging inlet) and a charger 73. A charging cable is connected to the charging port 74, and an external power source (commercial power supply, etc.) is connected via the charging cable. The charging port 74 has a connector into which the charging cable is fitted. The charging port 74 may also have a connection detection device 74a (connection detection sensor) that detects the connection of the charging cable. The connection detection device 74a is connected to the control device 54 in a communicative manner and inputs the detection result to the control device 54.

[0059] The charger 73 is electrically connected to the charging port 74 and the junction box 63. The charger 73 converts the three-phase AC power input from an external power source via the charging cable and charging port 74 into DC power and supplies the DC power to the junction box 63. The charger 73 has a rectifier that converts the three-phase AC power into DC power, and an electronic circuit that adjusts the current and voltage of the DC power supplied to the junction box 63. The electronic circuit is composed of, for example, switching elements, diodes, resistors, and electrolytic capacitors.

[0060] <About the Change Device 62> As shown in Figures 2 and 4, the electric work machine 1 is equipped with a change device 62. The change device 62 is provided in the power path 61 and can change the discharge battery that supplies power to the electric actuator 51 from among the multiple batteries 52. The change device 62 may also be provided in the power path 61 and can change the charging battery that performs charging from among the multiple batteries 52.

[0061] The change device 62 is controlled by the control device 54, which controls the change device 62 to change the charging battery and / or discharging battery. The change device 62 can change the discharging battery, for example, by changing the connection state between multiple batteries 52 and the electric actuator 51. The discharging battery is the battery 52 that is connected to the electric actuator 51 by the change device 62. In other words, a battery 52 whose connection to the electric actuator 51 is disconnected by the change device 62 is not a discharging battery and cannot supply power to the electric actuator 51.

[0062] The changing device 62 can change the battery being charged, for example, by changing the connection status between multiple batteries 52 and the charger 73. The battery being charged is the battery 52 that is connected to the charger 73 by the changing device 62. In other words, a battery 52 whose connection to the charger 73 is disconnected by the changing device 62 is not a battery being charged and cannot be charged by the charger 73.

[0063] In the following explanation, we will describe the case in which the modification device 62 changes the discharge battery and the recharge battery by changing the connection state of the power path 61, but the method by which the modification device 62 changes the recharge battery and the discharge battery is not particularly limited. For example, the modification device 62 may change the discharge battery and the recharge battery by boosting and / or lowering the output voltage of multiple batteries 52.

[0064] In this embodiment, the change device 62 has one or more external relays 63g provided in the junction box 63. As shown in Figure 4, the junction box 63 houses a part of the electrical circuit (discharge circuit) for carrying power discharged from multiple batteries 52, a part of the electrical circuit (charging circuit) for carrying power to charge the multiple batteries 52, and one or more external relays 63g.

[0065] As shown in Figure 4, the junction box 63 includes, as part of the discharge circuit, a plurality of primary circuits 63a (first circuits) connected to each of the plurality of batteries 52, a common circuit 63b (second circuit) electrically connected to the plurality of first circuits 63a, and a plurality of secondary circuits 63c (third circuits) electrically connected to the second circuit 63b and connected to each of the electrical components E2 (inverter 71 and DC / DC converter 72). The junction box 63 also includes, as part of the charging circuit, a plurality of primary circuits 63d (fourth circuits) connected to each of the plurality of batteries 52, a common circuit 63e (fifth circuit) electrically connected to the plurality of first circuits 63a, and a secondary circuit 63f (sixth circuit) electrically connected to the second circuit 63b and connected to the charger 73.

[0066] The external relay 63g is provided in the primary circuits (first circuit 63a, fourth circuit 63d) and can change the connected and disconnected states of the primary circuits 63a and 63d. The external relay 63g is a relay switch with an normally open (a) contact. Therefore, the external relay 63g normally keeps the primary circuits 63a and 63d open and closes them when activated. The external relay 63g is controlled by the control device 54 and switches between either the open or closed state.

[0067] The external relay 63g is provided in either the positive or negative terminal circuit of the primary circuits 63a and 63d. In the example shown in Figure 4, it is provided in the negative terminal circuit of the primary circuits 63a and 63d.

[0068] Therefore, when the external relay 63g of the first circuit 63a is in the open state, the connection between the battery 52 connected to the first circuit 63a on which the external relay 63g is provided and the second circuit 63b can be disconnected. On the other hand, when the external relay 63g of the first circuit 63a is in the closed state, the connection between the battery 52 connected to the first circuit 63a on which the external relay 63g is provided and the second circuit 63b can be made.

[0069] Furthermore, when the external relay 63g of the fourth circuit 63d is in the open state, the connection between the battery 52 connected to the fourth circuit 63d, on which the external relay 63g is provided, and the fifth circuit 63e can be disconnected. On the other hand, when the external relay 63g of the fourth circuit 63d is in the closed state, the connection between the battery 52 connected to the fourth circuit 63d, on which the external relay 63g is provided, and the fifth circuit 63e can be made.

[0070] With the above configuration, the changing device 62 can change the discharge battery and the rechargeable battery. In particular, in the example shown in Figure 4, the changing device 62 can change the rechargeable battery and the discharge battery independently.

[0071] Although the power path 61 and the modification device 62 have been described using Figure 4, the power path 61 and the modification device 62 are not limited to the example shown in Figure 4. For example, in the example shown in Figure 4, the first battery 52A and the second battery 52B are connected to different primary circuits 63a and 63d, respectively. However, if the battery 52 includes multiple first batteries 52A, these multiple first batteries 52A may be connected in parallel and connected to a common primary circuit. Also, if the battery 52 includes multiple first batteries 52A, these multiple first batteries 52A may be connected in series and connected to a common primary circuit.

[0072] Furthermore, if the battery 52 includes a plurality of second batteries 52B, these plurality of second batteries 52B may be connected in parallel and connected to a common primary circuit 63a, 63d. Also, if the battery 52 includes a plurality of second batteries 52B, these plurality of second batteries 52B may be connected in series and connected to a common primary circuit 63a, 63d. Furthermore, one or more first batteries 52A and one or more second batteries 52B may be connected in series or in parallel.

[0073] Furthermore, although the power path 61 has a discharge circuit and a charging circuit, the charging circuit may be omitted by connecting the charger 73 to the third circuit 63c.

[0074] <Regarding the change of the discharge battery in discharge mode> The control device 54 controls the change device 62 according to the remaining capacity of the acquired battery 52. ​​As a result, the control device 54 changes the discharge battery according to the remaining capacity of the battery 52 (first change control). For example, the control device 54 performs the first change control in discharge mode. The control device 54 may perform the first change control in response to the operation of the change operation member 13d included in the operation device 13, or it may perform the first change control according to other conditions (for example, the remaining capacity of the battery 52). The control device 54 preferentially selects the second battery 52B over the first battery 52A as the discharge battery.

[0075] For example, the control device 54 uses the second battery 52B as the main battery to be discharged when the remaining capacity of the second battery 52B is equal to or greater than a predetermined threshold (first threshold). The control device 54 obtains the remaining capacity of the second battery 52B, and if the remaining capacity of the second battery 52B is equal to or greater than the first threshold, it controls the change device 62 to change the discharge battery to the second battery 52B.

[0076] On the other hand, the control device 54 uses the first battery 52A as an auxiliary battery to be discharged when the remaining capacity of the second battery 52B is below the first threshold. When the remaining capacity of the second battery 52B is below the first threshold, the control device 54 controls the change device 62 to change the discharge battery to the first battery 52A. The auxiliary battery is a battery (reserve battery) that assists in supplying power to the main battery.

[0077] The first threshold is a predefined value, for example, defined as 10%. The first threshold is a predetermined value stored in the storage device 55 and may be changeable by a predetermined input interface such as the operating device 13.

[0078] Figure 5 is a diagram illustrating the first change control in the first embodiment. The series of processes of the first change control shown in Figure 5 are executed by the processor based on a software program pre-stored in the memory of the control device 54. The control device 54 checks whether the current mode is discharge mode or charge mode (S11). The control device 54 checks the current mode according to the operation of the mode operation member 13b or the detection result of the connection detection device 74a. If the control device 54 determines that the current mode is charge mode (S11: No), it does not perform the first change control and terminates the series of processes.

[0079] If the control device 54 determines that the current mode is discharge mode (S11: Yes), it acquires an operation signal input from the change operation member 13d (S12). Based on the acquired operation signal from the change operation member 13d, the control device 54 determines whether or not the change operation member 13d has been operated (S13). If the control device 54 determines that the change operation member 13d has not been operated (S13: No), it does not perform the first change control and terminates the series of processes.

[0080] When the control device 54 determines that the change operation member 13d has been operated (S13: Yes), it executes the first change control (S14). The control device 54 obtains the remaining capacity of the multiple batteries 52 (S14a). The control device 54 determines whether there is a second battery 52B among the multiple batteries 52 whose remaining capacity is equal to or greater than the first threshold (S14b).

[0081] If the control device 54 determines that there is a second battery 52B whose remaining capacity is equal to or greater than the first threshold (S14b: Yes), it selects the second battery 52B with the smallest remaining capacity among the second batteries 52B as the discharge battery (S14c). If the control device 54 determines that there is no second battery 52B whose remaining capacity is equal to or greater than the first threshold (S14b: No), it determines whether there is a first battery 52A whose remaining capacity is equal to or greater than the first threshold (S14d).

[0082] If the control device 54 determines that there is a first battery 52A whose remaining capacity is equal to or greater than a first threshold (S14d: Yes), it selects the first battery 52A with the smallest remaining capacity among the first batteries 52A to be discharged (S14e). If the control device 54 determines that there is no first battery 52A whose remaining capacity is equal to or greater than a first threshold (S14d: No), it selects the battery 52 with the largest remaining capacity among the multiple batteries 52 to be discharged (S14f).

[0083] When the control device 54 selects a discharge battery (S14c, S14e, S14f), it controls the change device 62 to change the discharge battery (S14g). The control device 54 switches the external relay 63g of the first circuit 63a connected to the discharge battery to the closed state, and switches the external relay 63g of the first circuit 63a connected to the other battery 52 to the open state.

[0084] The flowchart of the first change control explained using Figure 5 is an example and is not limited to the flow described above. For example, in Figure 5, the control device 54 determines the discharge mode or charge mode and then selects the discharge battery, but it may also determine the discharge mode or charge mode after selecting the discharge battery. Also, although the case in steps S14c, S14e, and S14f is described in which the battery 52 with the least remaining capacity is selected as the discharge battery, it is not limited to this and may be configured to allow the selection of any battery 52.

[0085] In the first change control described above, the control device 54 prioritized selecting the second battery 52B over the first battery 52A as the discharge battery, but it may also prioritize selecting the first battery 52A over the second battery 52B.

[0086] At this time, the control device 54 uses the first battery 52A as the main battery to be discharged when the remaining capacity of the first battery 52A is equal to or greater than a first threshold. The control device 54 obtains the remaining capacity of the first battery 52A, and if the remaining capacity of the first battery 52A is equal to or greater than a first threshold, it controls the change device 62 to change the discharge battery to the first battery 52A.

[0087] On the other hand, the control device 54 uses the second battery 52B as an auxiliary battery to be discharged when the remaining capacity of the first battery 52A is below the first threshold. When the remaining capacity of the first battery 52A is below the first threshold, the control device 54 controls the change device 62 to change the discharge battery to the second battery 52B.

[0088] <Regarding output limiting of discharge battery> Furthermore, when the auxiliary battery is a discharge battery, the control device 54 may limit the output of the electric actuator 51 and / or the output voltage of the discharge battery compared to when the main battery is a discharge battery (limiting control). Note that when the first battery 52A and the second battery 52B are connected in parallel, the control device 54 performs limiting control only when the discharge battery is the auxiliary battery.

[0089] The control device 54, in limiting control, either directly limits the power output from the discharge battery or indirectly limits the power supplied from the discharge battery by limiting the operation of each electric actuator 51, etc., which are driven by the power output from the discharge battery. Of the first battery 52A and the second battery 52B, one of the batteries 52 is predefined as the main battery, and the other battery 52 is predefined as the auxiliary battery. The definitions of the main battery and the auxiliary battery are stored in the storage device 55.

[0090] For example, the limit control includes a control (first limit control) that limits the upper limit (maximum rotational speed) of the rotational speed of the electric actuator 51 (electric motor). In the first limit control, the control device 54 corrects the instruction signal output to the inverter 71 regardless of the operation signal output from the rotational operation member 13c, and limits the rotational speed of the electric actuator 51 to less than the maximum rotational speed.

[0091] Furthermore, the limiting control may include a control (second limiting control) that limits the operation of the operating equipment 3 (traveling device 4 and / or working device 5). For example, in the second limiting control, the control device 54 limits the operation of the traveling device 4 among the operating equipment 3. As shown in Figure 2, if each control valve 44 of the control valve 43 is operated by pilot oil from the operating valve, it is sufficient to limit the pilot oil supplied to the operating valve corresponding to the working device 5.

[0092] For example, an electromagnetic proportional valve (unload valve) is provided in the oil passage (pilot oil passage) connecting the operating valve and the control valve 44, and the control device 54 controls the unload valve to switch from a position that supplies pilot oil to the operating valve (supply position) to a position that cuts off the supply (unload position, cut-off position). Also, when each control valve 44 is operated by pilot oil from the electromagnetic valve, the control device 54 can limit the operation of the control valve 44 by correcting the instruction current output to the electromagnetic valve, regardless of the operation signal output from the operating member 13a.

[0093] In the second limiting control, the control device 54 may stop the operation of the operating device 3, or it may limit the operation by limiting the operating speed or operating range.

[0094] Furthermore, the limiting control may include control that limits the power supplied to the electrical equipment E1 (third limiting control). In the third limiting control, the control device 54 performs control that limits the heating or cooling output of the air conditioning system to below a predetermined level. For example, in the third limiting control, the control device 54 limits the heating or cooling output of the air conditioning system to below a predetermined level by limiting the heating and / or cooling output (at least one of heating and / or cooling) or by cutting off the power supply to the air conditioning system.

[0095] In the third limit control, the control device 54 may limit the rotation speed of the cooling device's fan motor to below a predetermined upper limit. The cooling device is, for example, a radiator that exchanges heat with cooling water to cool the electric actuator 51 or the battery 52. ​​In the third limit control, the control device 54 may lower the upper limit of the fan motor's rotation speed or limit the fan motor's rotation speed to zero by cutting off the power supply to the fan motor, compared to the case where the third limit control is not performed.

[0096] The control device 54 may, in the third limit control, limit the output of the lamp to less than a predetermined level. In the third limit control, the control device 54 limits the power supplied to the lamp from the low-voltage battery 53, thereby reducing the illuminance of the lamp or turning it off.

[0097] Figure 6 is a diagram illustrating the limit control of the first embodiment. First, the control device 54 checks whether the current mode is discharge mode or charge mode (S21). If the control device 54 determines that the current mode is charge mode (S21: No), it does not perform limit control and terminates the series of processes.

[0098] When the control device 54 determines that the current mode is discharge mode (S21: Yes), it determines whether the current discharged battery is an auxiliary battery or not (S22). For example, when the control device 54 selects a discharged battery in the first change control, it stores in memory which battery 52 that discharged battery is. As a result, the control device 54 can determine whether the discharged battery is an auxiliary battery or not by referring to the battery 52 information stored in memory.

[0099] If the control device 54 determines that the discharge battery is an auxiliary battery (S22: Yes), it executes a predetermined restriction control (S23). The control device 54 executes at least one of the restriction contents of the first to third restriction controls. On the other hand, if the control device 54 determines that the discharge battery is not an auxiliary battery (S22: No), it does not execute the restriction control and terminates the series of processes.

[0100] Note that the flowchart of the limit control described using Figure 6 is just one example and is not limited to the flow described above. For example, the control device 54 may perform limit control when the battery 52 includes multiple auxiliary batteries and at least one of the auxiliary batteries is a discharged battery. For example, the control device 54 may be configured to perform limit control when the number of auxiliary batteries whose remaining capacity is equal to or greater than a first threshold is less than or equal to a predetermined number (e.g., one).

[0101] <Regarding the change of the charging battery in charging mode> The control device 54 controls the change device 62 according to the remaining capacity of the battery 52 and changes the charging battery (second change control). For example, the control device 54 performs the second change control in charging mode. The control device 54 preferentially selects the first battery 52A as the charging battery over the second battery 52B.

[0102] The control device 54 obtains the remaining capacity of the first battery 52A, and if the remaining capacity of the first battery 52A is less than a predetermined threshold (second threshold), it controls the change device 62 to change the charging battery to the first battery 52A. On the other hand, if the remaining capacity of the first battery 52A is equal to or greater than the second threshold, the control device 54 controls the change device 62 to change the charging battery to the second battery 52B. The second threshold is a predetermined value, for example, defined as 80%. The second threshold is a predetermined value stored in the storage device 55 and may be changeable by a predetermined input interface such as the operating device 13.

[0103] Figure 7 is a diagram illustrating the second change control in the first embodiment. The series of processes of the second change control shown in Figure 7 are executed by the processor based on a software program pre-stored in the memory of the control device 54. The control device 54 checks whether the current mode is discharge mode or charge mode (S31). If the control device 54 determines that the current mode is discharge mode (S31: No), it does not perform the second change control and terminates the series of processes.

[0104] When the control device 54 determines that the current mode is charging mode (S31: Yes), it executes a second change control (S32). The control device 54 obtains the remaining capacity of the multiple batteries 52 (S32a). The control device 54 determines whether there is a first battery 52A among the multiple batteries 52 whose remaining capacity is less than the second threshold (S32b).

[0105] If the control device 54 determines that there is a first battery 52A whose remaining capacity is less than the second threshold (S32b: Yes), it selects the first battery 52A with the largest remaining capacity among the first batteries 52A as the charging battery (S32c). If the control device 54 determines that there is no first battery 52A whose remaining capacity is less than the second threshold (S32b: No), it determines whether there is a second battery 52B whose remaining capacity is less than the second threshold (S32d).

[0106] If the control device 54 determines that there is a second battery 52B whose remaining capacity is less than the second threshold (S32d: Yes), it selects the second battery 52B with the largest remaining capacity among the second batteries 52B as the charging battery (S32e). If the control device 54 determines that there is no second battery 52B whose remaining capacity is less than the second threshold (S32d: No), it terminates the second change control.

[0107] When the control device 54 selects a rechargeable battery (S32c, S32e), it controls the change device 62 to change the rechargeable battery (S32f). The control device 54 switches the external relay 63g of the fourth circuit 63d connected to the rechargeable battery to the closed state, and switches the external relay 63g of the fourth circuit 63d connected to the other battery 52 to the open state.

[0108] The flowchart of the second change control explained using Figure 7 is an example and is not limited to the flow described above. For example, in Figure 7, the control device 54 determines the charging mode or discharging mode and then selects the charging battery, but it may also determine the charging mode or discharging mode after selecting the charging battery. Also, although the case in steps S32c and S32e was explained in which the battery 52 with the largest remaining capacity is selected as the charging battery, it is not limited to this and may be configured to allow the selection of any battery 52.

[0109] Furthermore, although Figure 7 describes a case where charging control is terminated when the remaining capacity of all batteries 52 exceeds the second threshold, the second change control may be continued by selecting a battery to charge again until the remaining capacity of the batteries 52 is fully charged.

[0110] In the second change control described above, the control device 54 prioritized selecting the first battery 52A over the second battery 52B as the charging battery, regardless of the definitions of the main battery and auxiliary battery. However, it may also prioritize selecting the second battery 52B over the first battery 52A. In this case, the control device 54 obtains the remaining capacity of the second battery 52B, and if the remaining capacity of the second battery 52B is less than a predetermined second threshold, it controls the change device 62 to change the charging battery to the second battery 52B. On the other hand, if the remaining capacity of the second battery 52B is equal to or greater than the second threshold, the control device 54 controls the change device 62 to change the charging battery to the first battery 52A.

[0111] Furthermore, the control device 54 may prioritize selecting the auxiliary battery over the main battery as the rechargeable battery. In this case, the control device 54 obtains the remaining capacity of the auxiliary battery, and if the remaining capacity of the auxiliary battery is less than a predetermined second threshold, it controls the change device 62 to change the rechargeable battery to the auxiliary battery. On the other hand, if the remaining capacity of the auxiliary battery is equal to or greater than the second threshold, the control device 54 controls the change device 62 to change the rechargeable battery to the main battery.

[0112] Furthermore, the control device 54 may prioritize selecting the main battery over the auxiliary battery as the charging battery. In this case, the control device 54 obtains the remaining capacity of the main battery, and if the remaining capacity of the main battery is less than a predetermined second threshold, it controls the change device 62 to change the charging battery to the main battery. On the other hand, if the remaining capacity of the main battery is equal to or greater than the second threshold, the control device 54 controls the change device 62 to change the charging battery to the auxiliary battery.

[0113] <Regarding charging the battery 52 with electricity generated by the generator 57> As shown in Figures 2 and 4, the electric work machine 1 may be equipped with a generator 57. When charging is performed using electricity generated by the generator 57, the control device 54 controls the power change device 62 to supply the electricity to a predetermined battery 52.

[0114] For example, the generator 57 is capable of generating regenerative power. The generator 57 generates power using, for example, the regenerative energy of the actuator 3. As a result, the battery 52 can be charged by the regenerative power. In such a case, the generator 57 generates power using the inertial energy (kinetic energy) when the actuator 3 stops after being operated. As a result, the generator 57 can generate regenerative power through the operation of the actuator 3. The generator 57 is an alternator.

[0115] In this embodiment, the generator 57 is provided on the machine body 2 or the traveling device 4. The generator 57 generates electricity using the inertial energy generated when the machine body 2 rotates around the rotation axis C and comes to a stop.

[0116] As shown in Figure 4, the generator 57 is connected to the charger 73 via a power path 61 (charging circuit). A generator relay 63h (alternator relay) is provided between the generator 57 and the charger 73 in the power path 61. The alternator relay 63h can change the connection between the generator 57 and the charger 73 between an connected state and an disconnected state. The alternator relay 63h is a relay switch with an normally open contact. Therefore, the alternator relay 63h normally keeps the connection circuit open and closes the connection circuit when it is activated. The alternator relay 63h is controlled by the control device 54 and switches to the closed state when the operating device 3 stops. The control device 54 acquires the operation of the operating device 3 from the operation signal of the operating member 13a and various sensors provided on the operating device 3, and switches to the closed state when the operating device 3 stops and to the open state at other times when the operating device 3 is not stopped.

[0117] The generator 57 may generate electricity using the inertial energy when the operating device 3 stops, or it may be installed in another device included in the operating device 3 and generate electricity using the kinetic energy from that device. For example, the generator 57 may be installed in the traveling device 4 and generate electricity using the kinetic energy from the traveling device 4 when the electric work machine 1 stops while traveling. The generator 57 may be installed in the work device 5 and generate electricity using the kinetic energy from the work device 5 when the work device 5, which performs a rotational operation, stops.

[0118] Furthermore, although the above explanation described the case in which regenerative power is generated by the generator 57, if the operating device 3 is directly driven by the power generated by the electric actuator 51, the generator 57 is not required. For example, if the electric actuator 51 is an electric motor, the electric motor is a motor-generator that performs both an output operation to generate power and a power generation operation to generate electricity as a generator. In other words, the electric actuator 51 also functions as the generator 57.

[0119] The regenerative power may be supplied to the discharge battery, or, as in the example shown in Figure 4, if the change device 62 can independently change between the charging battery and the discharge battery, it may be supplied to a battery 52 (charging battery) other than the discharge battery.

[0120] For example, when regenerative power is generated by the operation of the actuator 3, the control device 54 controls the change device 62 to change the charging battery to the first battery 52A and supplies regenerative power to the first battery 52A. The control device 54 switches the charging battery according to the remaining capacity of the battery 52 and supplies regenerative power to the charging battery (third change control).

[0121] The control device 54 obtains the remaining capacity of the first battery 52A, and if the remaining capacity of the first battery 52A is less than a predetermined threshold (second threshold), it controls the change device 62 to switch the rechargeable battery to the first battery 52A. On the other hand, if the remaining capacity of the first battery 52A is equal to or greater than the second threshold, the control device 54 controls the change device 62 to switch the rechargeable battery to the second battery 52B.

[0122] Figure 8 is a diagram illustrating the third change control in the first embodiment. The series of processes of the third change control shown in Figure 8 are executed by the processor based on a software program pre-stored in the memory of the control device 54. The control device 54 checks whether the current mode is discharge mode or charge mode (S41). If the control device 54 determines that the current mode is charge mode (S41: No), it does not perform the third change control and terminates the series of processes.

[0123] When the control device 54 determines that the current mode is discharge mode (S41: Yes), it executes the third change control (S42). The control device 54 obtains the remaining capacity of the multiple batteries 52 (S42a). The control device 54 determines whether there is a first battery 52A among the multiple batteries 52 whose remaining capacity is less than the second threshold (S42b).

[0124] If the control device 54 determines that there is a first battery 52A whose remaining capacity is less than the second threshold (S42b: Yes), it selects the first battery 52A with the largest remaining capacity among the first batteries 52A as the charging battery (S42c). If the control device 54 determines that there is no first battery 52A whose remaining capacity is less than the second threshold (S42b: No), it determines whether there is a second battery 52B whose remaining capacity is less than the second threshold (S42d).

[0125] If the control device 54 determines that there is a second battery 52B whose remaining capacity is less than the second threshold (S42d: Yes), it selects the second battery 52B with the largest remaining capacity among the second batteries 52B as the charging battery (S42e). If the control device 54 determines that there is no second battery 52B whose remaining capacity is less than the second threshold (S42d: No), it terminates the third change control.

[0126] When the control device 54 selects a rechargeable battery (S42c, S42e), it controls the change device 62 to change the rechargeable battery (S42f). The control device 54 switches the external relay 63g of the fourth circuit 63d connected to the rechargeable battery to the closed state, and switches the external relay 63g of the fourth circuit 63d connected to the other battery 52 to the open state.

[0127] The flowchart for the third change control described using Figure 8 is an example and is not limited to the flow described above. For example, in Figure 8, the control device 54 determines the charging mode or discharging mode and then selects the charging battery, but it may also determine the charging mode or discharging mode after selecting the charging battery. Also, although the case in steps S42c and S42e was described in which the battery 52 with the largest remaining capacity is selected as the charging battery, it is not limited to this and may be configured to allow the selection of any battery 52.

[0128] Furthermore, although Figure 8 describes a case where the series of processes ends when the remaining capacity of all batteries 52 exceeds the second threshold, the third change control may be continued by selecting a battery to charge again until the remaining capacity of the batteries 52 is fully charged.

[0129] In the third change control described above, the control device 54 prioritized selecting the first battery 52A over the second battery 52B as the battery 52 that supplies regenerative power, regardless of the definition of the main battery and auxiliary battery. However, it may also prioritize selecting the second battery 52B over the first battery 52A. In this case, the control device 54 obtains the remaining capacity of the second battery 52B, and if the remaining capacity of the second battery 52B is less than a predetermined second threshold, it controls the change device 62 to change the charging battery to the second battery 52B. On the other hand, if the remaining capacity of the second battery 52B is equal to or greater than the second threshold, the control device 54 controls the change device 62 to change the charging battery to the first battery 52A.

[0130] Furthermore, the control device 54 may prioritize selecting the auxiliary battery over the main battery. In this case, the control device 54 obtains the remaining capacity of the auxiliary battery, and if the remaining capacity of the auxiliary battery is less than a predetermined second threshold, it controls the change device 62 to change the rechargeable battery to the auxiliary battery. On the other hand, if the remaining capacity of the auxiliary battery is equal to or greater than the second threshold, the control device 54 controls the change device 62 to change the rechargeable battery to the main battery.

[0131] Furthermore, the control device 54 may prioritize selecting the main battery over the auxiliary battery. In this case, the control device 54 obtains the remaining capacity of the main battery, and if the remaining capacity of the main battery is less than a predetermined second threshold, it controls the change device 62 to switch the rechargeable battery to the main battery. On the other hand, if the remaining capacity of the main battery is equal to or greater than the second threshold, the control device 54 controls the change device 62 to switch the rechargeable battery to the auxiliary battery.

[0132] The electric work implement 1 may be a so-called hybrid type electric work implement. In this case, the electric work implement 1 is equipped with an engine 81, and the generator 57 generates electricity using the driving force of the engine 81 (see Figure 9). The engine 81 can be an internal combustion engine such as a diesel engine or a gasoline engine.

[0133] Furthermore, examples of hybrid systems for the electric work machine 1 include parallel, series, and split configurations. In this case, the electric actuator 51 may also function as a motor-generator, serving as both the motor and generator 57. When charging is performed using the power generated by the generator 57, the control device 54 controls the change device 62 to change the charging battery to the first battery 52A.

[0134] [Second Embodiment] In the first embodiment, the electric work machine 1 was described in which the changing device 62 changes the discharge battery and / or the recharge battery. However, the electric work machine 1 of the second embodiment differs in that the changing device 62 changes the connection method between multiple batteries 52 between series and parallel. Hereinafter, the electric work machine 1 of the second embodiment will be described focusing on the configuration that differs from the first embodiment described above, and the same reference numerals will be used for configurations common to the first embodiment and detailed explanations will be omitted.

[0135] Figure 10 is a block diagram illustrating the electric work machine 1 in the second embodiment. Figure 11 is an electrical system diagram of the electric work machine 1 in the second embodiment. In the example shown in Figure 11, the plurality of batteries 52 include two first batteries 52A and two second batteries 52B.

[0136] <Regarding the change in the connection method of the first battery 52A and the second battery 52B> As shown in Figure 11, the change device 62 of the second embodiment is provided in the power path 61 and can change the connection method of the first battery 52A and the second battery 52B between series and parallel. As shown in Figure 10, the electric work machine 1 is equipped with an operating tool 13e (connection operating member) that accepts operation to change the connection method, and the change device 62 changes the connection method according to the operation of the connection operating member 13e. The connection operating member 13e is included in the operating device 13. The connection operating member 13e accepts a first operation to change the connection method to series and a second operation to change the connection method to parallel, depending on the switching of the operating position, the number of operations, etc.

[0137] The changing device 62 is controlled by the control device 54, which controls the changing device 62 to change the connection method between series and parallel (fourth changing control). The changing device 62 can change the connection method by, for example, changing the connection method of one or more first batteries 52A and one or more second batteries 52B.

[0138] In this embodiment, the change device 62 has one or more external relays 64e provided in the junction box 63. As shown in Figure 11, the junction box 63 houses an electrical circuit in the power path 61 that connects multiple batteries 52 to other electrical components E2 (inverter 71, DC / DC converter 72, and charger 73).

[0139] Specifically, the junction box 63 includes a primary circuit 64a (seventh circuit) connected to the first battery 52A, a primary circuit 64b (eighth circuit) connected to the second battery 52B, a connection circuit 64c (ninth circuit) electrically connected to the seventh circuit 64a and the eighth circuit 64b, a secondary circuit 64d (tenth circuit) electrically connected to the ninth circuit 64c and connected to each of the electrical components E2 (inverter 71, DC / DC converter 72, and charger 73), and an external relay 64e. The ninth circuit 64c includes the positive terminal side circuits of the seventh circuit 64a and the eighth circuit 64b, and a positive terminal side connection circuit 64c1 electrically connected to the positive terminal side circuit of the tenth circuit 64d. The ninth circuit 64c includes the negative electrode side circuit of either the seventh circuit 64a or the eighth circuit 64b, as well as the positive electrode side circuit and the negative electrode side circuit of the other, and a negative electrode side connection circuit 64c2 that is electrically connected to the negative electrode side circuit of the tenth circuit 64d.

[0140] The external relay 64e is provided in the ninth circuit 64c and can change the connection state and disconnection state of the ninth circuit 64c. The external relay 64e includes a first external relay 64e1 provided in the positive side connection circuit 64c1 and capable of changing the connection state and disconnection state of the positive side connection circuit 64c1, and a second external relay 64e2 provided in the negative side connection circuit 64c2 and capable of changing the connection state and disconnection state of the negative side connection circuit 64c2.

[0141] The first external relay 64e1 is a relay switch with an normally open (a) contact. For example, the first external relay 64e1 normally keeps the positive terminal connection circuit 64c1 open (see Figure 11), and closes the positive terminal connection circuit 64c1 when activated.

[0142] The second external relay 64e2 is a relay switch with a c-contact. In its normal state, the second external relay 64e2 electrically connects the negative terminals of the seventh circuit 64a and the eighth circuit 64b to the negative terminal of the tenth circuit 64d, and sets it to a first state in which it disconnects the negative terminal of either the seventh circuit 64a or the eighth circuit 64b from the positive terminal of the other (see Figure 11). On the other hand, when the second external relay 64e2 is activated, it electrically connects the negative terminal of either the seventh circuit 64a or the eighth circuit 64b from the positive terminal of the other, and sets it to a second state in which it disconnects the negative terminals of the seventh circuit 64a and the eighth circuit 64b to each other.

[0143] Therefore, when the first external relay 64e1 is in the open state and the second external relay 64e2 is in the second state, the connection method with the first battery 52A and the second battery 52B can be changed to series. When the first external relay 64e1 is in the closed state and the second external relay 64e2 is in the first state, the connection method with the first battery 52A and the second battery 52B can be changed to parallel (see Figure 11).

[0144] With the above configuration, the modification device 62 can change the connection method of the first battery 52A and the second battery 52B between series and parallel. Although the power path 61 and the modification device 62 have been described using Figure 11, the power path 61 and the modification device 62 are not limited to the example shown in Figure 11. For example, in the example shown in Figure 11, the two first batteries 52A are connected in parallel by the seventh circuit 64a, but they may be connected by different circuits or in series. Needless to say, the same applies to the second battery 52B.

[0145] Figure 12 is a diagram illustrating the fourth change control in the second embodiment. The control device 54 acquires an operation signal input from the connecting operation member 13e (S51). Based on the acquired operation signal from the connecting operation member 13e, the control device 54 determines whether or not the connecting operation member 13e has been operated (S52). If the control device 54 determines that the connecting operation member 13e has not been operated (S52: No), it does not perform the fourth change control and terminates the series of processes.

[0146] When the control device 54 determines that the connection operating member 13e has been operated (S52: Yes), it executes the fourth change control (S53). Based on the operation signal, the control device 54 determines whether the connection operating member 13e has been operated in the first or second operation (S53a).

[0147] When the control device 54 determines that the connection operating member 13e has been operated for the first time (S53a: Yes), it controls the changing device 62 to change the connection method of the first battery 52A and the second battery 52B to a series connection (S53b). The control device 54 opens the first external relay 64e1 and sets the second external relay 64e2 to a second state, thereby changing the connection method of the first battery 52A and the second battery 52B to a series connection.

[0148] On the other hand, when the control device 54 determines that the connection operating member 13e has been operated a second time (S53a: Yes), it controls the change device 62 to change the connection method of the first battery 52A and the second battery 52B to parallel (S53c). The control device 54 closes the first external relay 64e1 and sets the second external relay 64e2 to the first state, thereby changing the connection method of the first battery 52A and the second battery 52B to parallel.

[0149] Note that the flowchart of the fourth change control explained using Figure 12 is just one example and is not limited to the flow described above. For example, the control device 54 may omit the processing in step S52.

[0150] <Regarding variations of the fourth change control> In the above description, the case in which the change device 62 changes the connection method in response to the operation of the connection operating member 13e was described, but the change device 62 may change the connection method regardless of the operation of the connection operating member 13e. For example, the change device 62 may change the connection method according to the mode of the control device 54. The control device 54 controls the change device 62 to make the connection method different for the discharge mode and the charge mode. In this embodiment, the control device 54 changes the connection method to series in the discharge mode and changes the connection method to parallel in the charge mode.

[0151] Figure 13 illustrates the fourth mode change control in a modified example of the second embodiment. The control device 54 checks whether or not the mode will be changed (S61). The control device 54 checks whether or not to change the mode according to the operation of the mode operation member 13b or the detection result of the connection detection device 74a. If the control device 54 determines that the mode will not be changed (S61: No), it does not perform the fourth mode change control and terminates the series of processes.

[0152] When the control device 54 determines that it wants to change the mode (S61: Yes), it executes the fourth mode change control (S62). The control device 54 determines whether to change to discharge mode or charge mode (S62a). The control device 54 determines which mode to change to based on the operation of the mode operation member 13b and the detection result of the connection detection device 74a.

[0153] When the control device 54 determines that it is time to switch to discharge mode (S62a: Yes), it controls the change device 62 to change the connection method of the first battery 52A and the second battery 52B to series (S62b). Also, when the control device 54 changes the connection method to series (S62b), it switches from charge mode to discharge mode (S62c).

[0154] On the other hand, when the control device 54 determines to change to charging mode (S62a: No), it controls the changing device 62 to change the connection method of the first battery 52A and the second battery 52B to parallel (S62d). Also, when the control device 54 changes the connection method to parallel (S62d), it changes from discharge mode to charging mode (S62e).

[0155] Note that the flowchart for the fourth change control explained using Figure 13 is just one example and is not limited to the flow described above.

[0156] Furthermore, the control device 54 may change the connection method to parallel in the discharge mode and to series in the charge mode.

[0157] Furthermore, the control device 54 may use different connection methods depending on the type of work tool 34. For example, the control device 54 may control the changing device 62 and use different connection methods depending on whether or not the work tool 34 has a drive mechanism driven by power from the electric actuator 51. For example, work tools 34 that do not have a drive mechanism, such as buckets and pallet forks, are called "non-driven work tools." On the other hand, work that is driven directly or indirectly by power from the electric actuator 51, such as breakers, crushers, angle brooms, earth augers, sweepers, mowers, and snow blowers, is called "driven work tools."

[0158] The control device 54 controls the change device 62 to change the connection method to series when the work tool 34 is a driven work tool, and to change the connection method to parallel in charging mode when the work tool 34 is a non-driven work tool. For example, the control device 54 recognizes which work tool 34 is attached based on the operation of the attachment selection member 13f included in the operating device 13. Alternatively, a transmitter (e.g., a beacon) that transmits individual identification information to identify the work tool 34 may be attached to each work tool 34, and a receiver (beacon scanner) may be attached to the machine body 2 or the work device 5, and the control device 54 may recognize which work tool 34 is attached based on the identification information received by the receiver from the beacon.

[0159] The control device 54 may also control the modification device 62 to change the connection method depending on the work performed by the work tool 34. For example, if the work tool 34 is performing work that requires a relatively large amount of power, the control device 54 will control the modification device 62 to change the connection method to series according to the work tool 34. If the work tool 34 is performing work that requires a relatively small amount of power, the control device 54 will control the modification device 62 to change the connection method to parallel according to the work tool 34. Examples of work tools 34 that perform work that requires a relatively large amount of power include breakers, crushers, angle brooms, and earth augers. Examples of work tools 34 that perform work that requires a relatively small amount of power include buckets, grapples, and thumbs.

[0160] (Other variations) In the embodiment described above, a case was described in which multiple batteries 52 are directly mounted on the aircraft body 2. However, the multiple batteries 52 only need to be capable of supplying power to the electric actuator 51. For this reason, the multiple batteries 52 do not have to be directly mounted on the aircraft body 2. For example, the multiple batteries 52 may be mounted on a cargo bed connected to the aircraft body 2 or on another vehicle.

[0161] Furthermore, in the above-described embodiment, the case in which the change device 62 is composed of relays 63g and 64e (external relays) provided in the junction box 63 was explained, but the relays constituting the change device 62 may be internal relays provided inside the battery 52.

[0162] Furthermore, although the above-described embodiment explained the case in which the modification device 62 is composed of relays 63g and 64e, the modification device 62 is not limited to the above example, and can be configured to change the connection relationship between each battery 52 using prior art. For example, the modification device 62 may have a boost converter, and the discharge battery and / or recharge battery may be changed by changing the output voltage of each battery 52 using the converter.

[0163] Using Figure 4 of the first embodiment as an example, a modified example can be illustrated in which a converter is provided in place of each relay 63g. For example, by controlling a converter connected to a discharge battery and making the output voltage from that converter higher than the output voltage from a converter connected to another battery 52, switching of the discharge battery can be achieved.

[0164] Furthermore, although the above-described embodiment explains the case in which the electric work machine 1 is operated by an operating device 13 provided on the machine body 2, the invention is not limited to this, and the electric work machine 1 may be operated by a remote control device located at a remote location, or it may operate autonomously based on information about the electric work machine 1 and the surrounding environment.

[0165] A preferred embodiment of the present invention provides an electric work machine 1 as described in the following items.

[0166] (Item 1) An electric work machine 1 comprising a machine body 2, an operating device 3 including a traveling device 4 and / or a working device 5 provided on the machine body 2, an electric actuator 51 that generates power to operate the operating device 3, and a plurality of batteries 52 mounted on the machine body 2 and capable of supplying power to the electric actuator 51, wherein the plurality of batteries 52 include one or more first batteries 52A fixed to the machine body 2, and one or more second batteries 52B that are detachably mounted on the machine body 2, unlike the first batteries 52A.

[0167] According to the electric work machine 1 described in item 1, the multiple batteries 52 include a fixed first battery 52A that requires relatively little mounting space and a removable second battery 52B. Therefore, the electric work machine 1 can be equipped with a sufficient number and size of battery packs 52 with a discharge capacity sufficient for the operation of the actuator 3. Furthermore, by replacing the second battery 52B according to its remaining capacity, the operating time of the electric work machine 1 can be extended. This makes it possible to achieve both extended operating time and work efficiency.

[0168] (Item 2) The electric work machine 1 according to Item 1, comprising: a power path 61 that electrically connects the plurality of batteries 52 and the electric actuator 51; a changing device 62 provided in the power path 61 that can change the discharge battery among the plurality of batteries 52 that supplies power to the electric actuator 51; and a control device 54 that controls the changing device 62 to change the discharge battery.

[0169] According to the electric work machine 1 related to item 2, the control device 54 controls the change device 62 to change the discharge battery, thereby appropriately changing the power supply from multiple batteries 52 to the electric actuator 51.

[0170] (Item 3) The electric work machine 1 according to Item 2, wherein the control device 54 uses the second battery 52B as the main battery to be discharged when the remaining capacity of the second battery 52B is above a predetermined threshold, and uses the first battery 52A as the auxiliary battery to be discharged when the remaining capacity of the second battery 52B is below the threshold.

[0171] According to the electric work machine 1 described in item 3, the power of the second battery 52B can be preferentially consumed and driven compared to the power of the first battery 52A. Therefore, by preferentially consuming the power of the detachable second battery 52B and replacing the second battery 52B when its remaining capacity becomes low, the operating time of the electric work machine 1 can be further extended.

[0172] (Item 4) The electric work machine 1 according to Item 2, wherein the control device 54 uses the first battery 52A as the main battery to be discharged when the remaining capacity of the first battery 52A is above a predetermined threshold, and uses the second battery 52B as the auxiliary battery to be discharged when the remaining capacity of the first battery 52A is below the threshold.

[0173] According to the electric work machine 1 described in item 4, the power of the first battery 52A can be preferentially consumed to power the work machine compared to the power of the second battery 52B. Therefore, since the detachable second battery 52B consumes less power than the fixed first battery 52A, the frequency of replacing the second battery 52B can be reduced. This prevents frequent replacement of the second battery 52B and avoids interruptions to the operation of the electric work machine 1.

[0174] (Item 5) The control device 54 limits the output of the electric actuator 51 and / or the output voltage of the discharge battery when the auxiliary battery is the discharge battery, compared to when the main battery is the discharge battery, as described in Item 3 or 4 of the electric work machine 1.

[0175] According to the electric work machine 1 described in item 5, power consumption while being driven by the auxiliary battery can be suppressed. For example, when the power of the main battery is relatively low and the work machine is being driven by the power of the auxiliary battery, it is possible to suppress the sudden stopping of the electric work machine 1 when the power of the auxiliary battery becomes zero.

[0176] (Item 6) An electric work machine 1 according to any one of items 1 to 5, comprising: a power path 61 electrically connected to the plurality of batteries 52; a changing device 62 provided in the power path 61 that can change the rechargeable battery among the plurality of batteries 52 that is to be charged; and a control device 54 that controls the changing device 62 to change the rechargeable battery.

[0177] According to the electric work machine 1 related to item 6, the control device 54 controls the change device 62 to change the charging battery, thereby enabling proper charging of multiple batteries 52.

[0178] (Item 7) The electric work machine 1 according to Item 6, which is equipped with a generator 57, and when the control device 54 is charging using the power generated by the generator 57, controls the changing device 62 to change the charging battery to the first battery 52A.

[0179] According to the electric work machine 1 described in item 7, the generator 57 prioritizes charging the first battery 52A over the second battery 52B with the electricity it generates, thereby suppressing the power consumption of the first battery 52A. As a result, the electric work machine 1 can be driven using the power of the first battery 52A for a relatively long period of time.

[0180] (Item 8) The generator 57 is the electric work machine 1 described in Item 7, which generates electricity using the regenerative energy of the operating device 3.

[0181] According to the electric work machine 1 described in item 8, the first battery 52A is charged preferentially over the second battery 52B by so-called regenerative power, thereby suppressing the power consumption of the first battery 52A. For this reason, the electric work machine 1 can be driven using the power of the first battery 52A for a relatively long period of time.

[0182] (Item 9) The electric work machine 1 according to Item 7, which is equipped with an engine 81 and the generator 57 generates electricity using the driving force of the engine 81.

[0183] According to the electric work machine 1 described in item 9, the first battery 52A is charged preferentially over the second battery 52B using the driving force generated by the engine 81, thereby suppressing the power consumption of the first battery 52A. For this reason, the electric work machine 1 can be driven using the power of the first battery 52A for a relatively long period of time.

[0184] (Item 10) The electric work machine 1 according to Item 1, comprising a power path 61 electrically connected to the plurality of batteries 52, and a changing device 62 provided in the power path 61 that can change the connection method of the first battery 52A and the second battery 52B between series and parallel.

[0185] According to the electric work machine 1 related to item 10, the connection method of the first battery 52A and the second battery 52B can be changed between series and parallel, so that discharge from multiple batteries 52 and charging of multiple batteries 52 can be performed appropriately.

[0186] (Item 11) The electric work machine 1 according to Item 10, which is equipped with an operating tool 13e that accepts the operation of changing the connection method, and the changing device 62 changes the connection method in accordance with the operation of the operating tool 13e.

[0187] According to the electric work machine 1 described in item 11, the operator can arbitrarily change between a state where the connection method is in series and the output of the electric actuator 51 is prioritized over the operating time, and a state where the connection method is in parallel and the operating time is prioritized over the output of the electric actuator 51, by operating the operating tool 13e. Therefore, it is possible to further achieve both an extension of the operating time of the electric work machine 1 and work efficiency.

[0188] (Item 12) The electric work machine 1 according to Item 10 or 11, which includes a control device 54 that controls the changing device 62 and causes the connection method to differ between a discharge mode in which power is supplied from the plurality of batteries 52 to the electric actuator 51 and a charging mode in which the plurality of batteries 52 are charged.

[0189] According to the electric work machine 1 related to item 12, by changing the connection method, power can be supplied to the electric actuator 51 and the battery 52 can be charged appropriately.

[0190] (Item 13) The electric work machine 1 according to Item 12, wherein the control device 54 changes the connection method to series in the discharge mode and changes the connection method to parallel in the charging mode.

[0191] According to the electric work machine 1 related to item 13, in discharge mode, the output of the electric actuator 51 can be prioritized, and in charging mode, the remaining capacity of each battery 52 can be charged relatively evenly.

[0192] (Item 14) The electric work machine 1 according to Item 1, wherein the first battery 52A and the second battery 52B are connected in series.

[0193] According to the electric work machine 1 related to item 14, the output of the electric actuator 51 can be improved by connecting a fixed first battery 52A and a detachable second battery 52B in series.

[0194] (Item 15) The electric work machine 1 according to Item 1, wherein the first battery 52A and the second battery 52B are connected in parallel.

[0195] According to the electric work machine 1 described in item 15, the operating time of the electric work machine 1 can be extended by connecting a fixed first battery 52A and a detachable second battery 52B in series.

[0196] Having described the present invention above, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope of equivalents of the claims are intended to be included.

[0197] 1: Electric work machine 2: Machine body (turntable) 3: Actuator 4: Traveling device 5: Work device 13e: Operating device (connecting operating member) 51: Electric actuator 52: Battery 52A: First battery 52B: Second battery 54: Control device 61: Power path 62: Change device

Claims

1. An electric work machine comprising: a machine body; an operating device including a traveling device and / or a working device provided on the machine body; an electric actuator that generates power to operate the operating device; and a plurality of batteries mounted on the machine body and capable of supplying power to the electric actuator, wherein the plurality of batteries include one or more first batteries fixed to the machine body and one or more second batteries that, unlike the first batteries, are detachably mounted on the machine body.

2. The electric work machine according to claim 1, comprising: a power path electrically connecting the plurality of batteries and the electric actuator; a changing device provided in the power path that can change the discharge battery among the plurality of batteries that supplies power to the electric actuator; and a control device that controls the changing device to change the discharge battery.

3. The electric work machine according to claim 2, wherein the control device uses the second battery as the main battery which is discharged when the remaining capacity of the second battery is equal to or greater than a predetermined threshold, and uses the first battery as the auxiliary battery which is discharged when the remaining capacity of the second battery is less than the threshold.

4. The electric work machine according to claim 2, wherein the control device uses the first battery as the main battery which is discharged when the remaining capacity of the first battery is equal to or greater than a predetermined threshold, and uses the second battery as the auxiliary battery which is discharged when the remaining capacity of the first battery is less than the threshold.

5. The electric work machine according to claim 3 or 4, wherein the control device limits the output of the electric actuator and / or the output voltage of the discharge battery when the auxiliary battery is the discharge battery, compared to when the main battery is the discharge battery.

6. The electric work machine according to claim 1, further comprising: a power path electrically connected to the plurality of batteries; a changing device provided in the power path that can change the rechargeable battery among the plurality of batteries that is to be charged; and a control device that controls the changing device to change the rechargeable battery.

7. The electric work machine according to claim 6, wherein the control device, when charging is performed using the power generated by the generator, controls the changing device to change the charging battery to the first battery.

8. The electric work machine according to claim 7, wherein the generator generates electricity using the regenerative energy of the operating device.

9. The electric work machine according to claim 7, comprising an engine, wherein the generator generates electricity using the driving force of the engine.

10. The electric work machine according to claim 1, comprising: a power path electrically connected to the plurality of batteries; and a changing device provided in the power path that can change the connection method between the first battery and the second battery between series and parallel.

11. The electric work machine according to claim 10, comprising an operating tool for receiving an operation to change the connection method, wherein the changing device changes the connection method in accordance with the operation of the operating tool.

12. The electric work machine according to claim 10, further comprising a control device that controls the changing device and causes the connection method to differ between a discharge mode, which supplies power from the plurality of batteries to the electric actuator, and a charging mode, which charges the plurality of batteries.

13. The electric work machine according to claim 12, wherein the control device changes the connection method to series in the discharge mode and changes the connection method to parallel in the charging mode.

14. The electric work machine according to claim 1, wherein the first battery and the second battery are connected in series.

15. The electric work machine according to claim 1, wherein the first battery and the second battery are connected in parallel.

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