Electric power tool

Abstract

This electric work machine (1) comprises a body (2), a battery unit (30) installed in the body, an electric motor (9) driven by electric power from the battery unit, a hydraulic apparatus operated by motive power from the electric motor, a working device (20, 10) operated by the hydraulic pressure of hydraulic oil supplied from the hydraulic apparatus, a control device (7) for controlling the driving of the electric motor, a switching member (5c, 58) capable of switching between a first position where operation of the working device is permitted and a second position where operation of the working device is not permitted, and an oil temperature detection device (44) for detecting the temperature (T) of the hydraulic oil, the control device (7) controlling the rotation speed (R) of the electric motor to a prescribed first rotation speed (R1) equivalent to a stopped state of the electric motor when, during the driving of the electric motor, the switching member is switched to the second position and the temperature of the hydraulic oil is in a prescribed acceptable temperature range that is neither a low-temperature state nor a high-temperature state.

Description

Technical Field

[0001] The present invention relates to a power-operated work machine driven by the power of an electric motor.

Background Art

[0002] For example, Patent Document 1 discloses a power-operated work machine driven by the power of an electric motor. The power-operated work machine disclosed in Patent Document 1 includes an electric motor driven by electric power output from a battery unit, a hydraulic pump driven by the electric motor to discharge hydraulic oil, a hydraulic device driven by the hydraulic oil discharged by the hydraulic pump, a work device operated by the hydraulic device, an operation device for operating the hydraulic device, a control device for controlling the rotation speed of the electric motor, and the like. When the output current value from the battery unit is equal to or greater than a predetermined value, the control device sets the rotation speed of the electric motor according to the operation of the operation device, and when the output current value from the battery unit is less than the predetermined value, the control device sets the rotation speed of the electric motor to a predetermined idling rotation speed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the electric motor is rotationally driven when the operator is not operating the power-operated work machine, power is wasted, and the work efficiency of the power-operated work machine is reduced.

[0005] The present invention has been made to solve the above problems of the prior art, and an object thereof is to reduce wasteful power consumption in a power-operated work machine and improve work efficiency.

Means for Solving the Problems

[0006] An electric working machine according to one aspect of the present invention includes a machine body, a battery unit mounted on the machine body, an electric motor driven by electric power from the battery unit, a hydraulic device operated by power from the electric motor, a working device operated by the hydraulic pressure of hydraulic oil supplied from the hydraulic device, a control device for controlling the drive of the electric motor, a switching member that can be switched to either a first position that permits the operation of the working device or a second position that does not permit the operation of the working device, and an oil temperature detection device for detecting the temperature of the hydraulic oil. The control device is configured to: During the drive of the electric motor, when the switching member is switched to the second position and the temperature of the hydraulic oil is within a predetermined allowable temperature range that is neither a low temperature state nor a high temperature state, control the rotational speed of the electric motor to a predetermined first rotational speed corresponding to the stopped state of the electric motor During the driving of the electric motor, if the switching member is switched to the second position and the temperature of the hydraulic oil is not within the allowable temperature range, the rotational speed of the electric motor is controlled to a predetermined idling rotational speed that is greater than the first rotational speed and less than or equal to the lower limit of the rotational speed when the work device performs work. to do.

[0007] The control device, during the drive of the electric motor, when the switching member is switched to the second position ta case, If the temperature of the hydraulic oil is lower than the lower limit of the allowable temperature range, the rotational speed of the electric motor is controlled to match a predetermined third rotational speed. If the temperature of the hydraulic oil is higher than the upper limit of the allowable temperature range, The rotational speed of the electric motor may be controlled to be greater than the first rotational speed a predetermined second rotational speed that is less than the third rotational speed to do.

[0008] The electric working machine includes a work detection device that detects the presence or absence of the operation of the work device based on the hydraulic pressure of the hydraulic oil. The second rotational speed is set to a rotational speed at which the work detection device can generate the hydraulic pressure of the hydraulic oil at which the presence or absence of the operation of the work device can be detected. may also be.

[0009] The electric working machine in 、 During the driving of the electric motor, when the switching member is in the first position and the work device has not operated for a predetermined time or more, if the temperature of the hydraulic oil is lower than the lower limit of the allowable temperature range, the rotational speed of the electric motor is controlled to match the third rotational speed. If the temperature of the hydraulic oil is equal to or higher than the lower limit of the allowable temperature range, the rotational speed of the electric motor is controlled to the second rotational speed. may also be.

[0010] An electric working machine according to an aspect of the present invention includes a machine body, a battery unit mounted on the machine body, an electric motor driven by electric power from the battery unit, a hydraulic device operated by the power from the electric motor, a work device operated by the hydraulic pressure of the hydraulic oil supplied from the hydraulic device, a control device that controls the driving of the electric motor, a switching member that can be switched to either a first position that permits the operation of the work device or a second position that does not permit the operation of the work device, and an oil temperature detection device that detects the temperature of the hydraulic oil. The control device is configured to: During the drive of the electric motor, when the switching member is in the first position and the working device has not operated for a predetermined time or more, if the temperature of the hydraulic oil is lower than the allowable temperature range lower limit of , control the rotational speed of the electric motor to a predetermined... that is greater than a predetermined first rotational speed corresponding to the stopped state of the electric motor and less than or equal to the lower limit of the rotational speed when the work device performs work match the third rotational speed, and if the temperature of the hydraulic oil is equal to or higher than the allowable temperature range lower limit of , control the rotational speed of the electric motor to a predetermined... that is greater than the first rotational speed and less than the third rotational speed the second rotational speed to do .

[0011] The electric working machine includes an instruction member that is operated to instruct the rotational speed of the electric motor, and the control device may set the rotational speed of the electric motor that can be instructed by the operation of the instruction member according to the temperature of the hydraulic oil.

[0012] The electric working machine includes a selection member that selects either a first mode or a second mode in which power consumption is lower than that of the first mode, and when the temperature of the hydraulic oil is within the allowable temperature range, the control device determines the rotational speed of the electric motor by operating the instruction member when the second mode is selected by the selection member finger of The upper limit value of the demonstration range may be set to be smaller than the upper limit value of the instruction range when the first mode is selected by the selection member.

[0013] When the temperature of the hydraulic oil is lower than a predetermined first temperature that is lower than the allowable temperature range, no matter whether the first mode or the second mode is selected by the selection member, the control device sets the upper limit value of the instruction range of the rotational speed of the electric motor by operating the instruction member to a value smaller than a predetermined maximum rotational speed, and the maximum rotational speed may be the upper limit value of the rotational speed that can be instructed by the instruction member when the temperature of the hydraulic oil is within the allowable temperature range and the first mode is selected.

[0014] When the temperature of the hydraulic oil is higher than a predetermined second temperature that is higher than the allowable temperature range, no matter whether the first mode or the second mode is selected by the selection member, the rotational speed that can be instructed by the instruction member is set to the a predetermined... greater than the first rotational speed third rotational speed.

[0015] The electric working machine includes a cooling device that cools the hydraulic oil, and when the temperature of the hydraulic oil detected by the oil temperature detection device is higher than the allowable temperature range upper limit of the control device cools the hydraulic oil by driving the cooling device, and when the temperature of the hydraulic oil is lower limit of below the allowable temperature range, the cooling device may be stopped.

[0016] The electric working machine includes an inverter that adjusts the power supplied from the battery unit to the electric motor, a rotation speed detection device that detects the rotation speed of the electric motor, and a working operation member that operates the operation of the working device. The switching member includes an unloading operation member that can be switched between a load position that permits the operation of the working device and an unloading position that does not permit the operation of the working device. The control device may control the rotation speed of the electric motor by adjusting the power supplied from the inverter to the electric motor based on the rotation speed of the electric motor detected by the rotation speed detection device.

Advantages of the Invention

[0017] According to the above configuration, it is possible to reduce wasted power consumption in the electric working machine and improve work efficiency.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 4C

Figure 5

Embodiments for Carrying Out the Invention

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] First, the overall configuration of the electric working machine 1 according to this embodiment will be described. FIG. 5 is an overall side view of the electric working machine 1. The electric working machine 1 is an excavator called a backhoe. The electric working machine 1 includes a machine body (swivel base) 2, a traveling device 10, a working device 20, and the like. Further, the electric working machine 1 includes an electric motor 9 (FIG. 1) as a prime mover, and operates by the power of the electric motor 9.

[0021] On the machine body 2 of the electric working machine 1, there are provided a driver's seat 4 on which an operator sits, and a protection mechanism 6 that protects the driver's seat 4 from the front, rear, left, right, and above. The protection mechanism 6 is called a cabin. On each side surface of the protection mechanism 6, there is provided a transparent portion (so-called window) through which the surroundings can be visually observed from the driver's seat 4. The protection mechanism 6 partitions the internal space where the driver's seat 4 is provided from the outside.

[0022] Around the driver's seat 4 inside the protection mechanism 6, an operating device 5 for operating the electric working machine 1 is provided. The operator can operate the operating device 5 while sitting on the driver's seat 4. In this embodiment, the side of the working device 20 (in the direction of arrow A1 in FIG. 5) with respect to the protection mechanism 6 is defined as the front, and the opposite side (in the direction of arrow A2 in FIG. 5) is defined as the rear for description. Also, the horizontal direction orthogonal to the front-rear direction is defined as the width direction for description. Further, in the state facing forward A1, the left side is defined as the leftward direction and the right side is defined as the rightward direction for description.

[0023] The traveling device 10 supports the machine body 2 so as to be able to travel. The traveling device 10 has a traveling frame (track frame) 11 and a traveling mechanism 12. The traveling frame 11 is a structure that attaches the traveling mechanism 12 around it and supports the machine body 2 on the upper part. The traveling mechanism 12 is, for example, a crawler-type traveling mechanism. The traveling mechanisms 12 are respectively provided on the left side and the right side of the traveling frame 11. The traveling mechanism 12 has idlers 13, drive wheels 14, a plurality of roller wheels 15, an endless crawler belt 16, and traveling motors ML, MR.

[0024] The idler 13 is disposed at the front portion of the traveling frame 11. The drive wheel 14 is disposed at the rear portion of the traveling frame 11. A plurality of idler wheels 15 are provided between the idler 13 and the drive wheel 14. The crawler belt 16 is wound around the idler 13, the drive wheel 14, and the idler wheels 15.

[0025] The left traveling motor ML is included in the traveling mechanism 12 on the left side of the traveling frame 11. The right traveling motor MR is included in the traveling mechanism 12 on the right side of the traveling frame 11. These traveling motors ML and MR are composed of hydraulic motors. In each traveling mechanism 12, the drive wheel 14 is rotationally driven by the power of the traveling motors ML and MR to circulate the crawler belt 16 in the circumferential direction.

[0026] A dozer device 18 is mounted on the front portion of the traveling device 10. The dozer device 18 swings up and down by the extension and contraction of the dozer cylinder C5. The dozer cylinder C5 is attached to the traveling frame 11. The dozer cylinder C5 is composed of a hydraulic cylinder.

[0027] The machine body 2 is rotatably supported about the swivel axis X via a swivel bearing 3 on the traveling frame 11. A swivel motor MT is provided inside the machine body 2. The swivel motor MT is composed of a hydraulic motor (a hydraulic actuator included in hydraulic equipment). The machine body 2 swivels about the swivel axis X by the power of the swivel motor MT.

[0028] The working device 20 is supported at the front portion of the machine body 2. The working device 20 includes a boom 21, an arm 22, a bucket (working tool) 23, and hydraulic cylinders C1 to C5. The proximal end side of the boom 21 is pivotally attached to a swing bracket 24 so as to be rotatable about a horizontal axis (an axis extending in the width direction of the machine body 2). Therefore, the boom 21 can swing in the vertical direction (the perpendicular direction). The arm 22 is pivotally attached to the distal end side of the boom 21 so as to be rotatable about a horizontal axis. Therefore, the arm 22 can swing in the front-rear direction or the vertical direction. The bucket 23 is provided at the distal end side of the arm 22 so as to be capable of performing a curl operation and a dump operation.

[0029] Instead of or in addition to the bucket 23, it is possible to attach other work tools (hydraulic attachments) drivable by a hydraulic actuator to the tip of the arm 22. Examples of other work tools include a hydraulic breaker, a hydraulic crusher, an angle bloom, an earth auger, a pallet fork, a sweeper, a mower, a snow blower, etc.

[0030] The swing bracket 24 swings left and right by the expansion and contraction of a swing cylinder C1 provided in the machine body 2. The boom 21 swings up and down (front and back) by the expansion and contraction of a boom cylinder C2. The arm 22 swings up and down (front and back) by the expansion and contraction of an arm cylinder C3. The bucket 23 performs a curl operation and a dump operation by the expansion and contraction of a bucket cylinder (work tool cylinder) C4. The swing cylinder C1, the boom cylinder C2, the arm cylinder C3, and the bucket cylinder C4 are composed of hydraulic cylinders.

[0031] The electric working machine 1 drives the traveling device 10 by traveling motors ML and MR, drives the working device 20 by hydraulic cylinders C1 to C5, and turns the machine body 2 by a turning motor MT to perform operations such as excavation. Hydraulic actuators such as the traveling motors ML and MR, the turning motor MT, and the hydraulic cylinders C1 to C5 are included in the hydraulic equipment. Not only the working device 20 but also the traveling device 10 is a working device provided in the electric working machine 1. Hereinafter, for convenience, the working device 20 and the traveling device 10 are collectively referred to as "working devices 20, 10".

[0032] Next, the electrical configuration of the electric working machine 1 will be described. FIG. 1 is an electrical block diagram of the electric working machine 1. In FIG. 1, the control device 7 has a CPU 7a and a storage unit 7b. The CPU 7a controls the operations of each part provided in the electric working machine 1 shown in FIG. 1. The storage unit 7b is composed of a volatile memory, a non-volatile memory, etc. Information, data, programs, etc. for the CPU 7a to control the operations of each part are stored in the storage unit 7b in a readable and writable manner.

[0033] The operating device 5 has operating members such as a working operation lever 5a, a traveling operation lever 5b, an unloading lever 5c, an accelerator dial 5d, and a mode selection SW (switch) 5e. Further, the operating device 5 also has a potentiometer, a switch, a sensor, etc. (not shown) for detecting the presence or absence of operation, the operation position, or the operation amount of each operating member 5a to 5e.

[0034] The working operation lever 5a is a member for operating the operation of the working device 20. The traveling operation lever 5b is a member for operating the operation of the traveling device 10. In FIG. 1, for the sake of convenience, the working operation lever 5a and the traveling operation lever 5b are each shown as one block, but actually, a plurality of working operation levers 5a and traveling operation levers 5b are provided respectively. The working operation lever 5a and the traveling operation lever 5b are examples of the "working operation members" of the present invention.

[0035] The unloading lever 5c is a member that can be switched between a load position (first position) that permits the operation of the working device 20 and an unloading position (second position) that does not permit (prohibits) the operation of the working device 20. The unloading lever 5c is installed, for example, on the side of the driver's seat 4 (FIG. 5) so as to be swingable up and down.

[0036] By swinging the unloading lever 5c downward to position it at the load position (first position, lowered position), the passage for the operator to get on and off the cab 4R is closed. By swinging the unloading lever 5c upward to position it at the unloading position (second position, raised position), the above passage is opened. The unloading lever 5c is an example of the "unloading operation member" of the present invention. Further, the unloading lever 5c is an example of a configuration included in the "switching member" of the present invention.

[0037] The accelerator dial 5d is rotationally operated to indicate the rotational speed of the electric motor 9. The angle range within which the accelerator dial 5d can be rotationally operated corresponds to the indication range within which the rotational speed of the electric motor 9 can be indicated. Therefore, by changing the operation position of the accelerator dial 5d, the indicated value of the rotational speed of the electric motor 9 can also be changed. Specifically, the control device 7 calculates the indicated value of the rotational speed of the electric motor 9 according to the operation state (presence or absence of operation and operation position) of the accelerator dial 5d. The accelerator dial 5d is an example of the "indicating member" of the present invention.

[0038] The mode selection SW5e is a switch that is operated to select either a normal mode (first mode) for controlling the drive of the electric motor 9 or an ECO mode (ecology mode, second mode) that reduces power consumption compared to the normal mode. The mode selection SW5e is an example of the "selection member" of the present invention.

[0039] The starter SW (switch) 8 is provided inside the protection mechanism 6 and is operable by an operator seated in the driver's seat 4. The starter SW8 is operated to start or stop the electric working machine 1. Specifically, by turning on the starter SW8, the control device 7 starts each part provided in the electric working machine 1. Also, by turning off the starter SW8, the control device 7 stops each part provided in the electric working machine 1.

[0040] The electric motor 9 is a drive source (an example of a prime mover) of the electric working machine 1 and is composed of, for example, a permanent magnet embedded type three-phase AC synchronous motor. The inverter 38 is a motor drive device that drives the electric motor 9. The inverter 38 is connected to the electric motor 9 and the junction box 39.

[0041] The junction box 39 is connected to the battery unit 30, the DC-DC converter 40, and the charging port 41 in addition to the inverter 38. The junction box 39 outputs the power output from the battery unit 30 to the inverter 38 and the DC-DC converter 40.

[0042] The inverter 38 converts the DC power input from the battery unit 30 via the junction box 39 into three-phase AC power, and supplies the three-phase AC power to the electric motor 9. Thereby, the electric motor 9 is driven. Further, the inverter 38 can arbitrarily adjust the current and voltage of the power supplied to the electric motor 9. The control device 7 controls the operation of the inverter 38 to drive or stop the electric motor 9.

[0043] The rotation speed detection device 42 is composed of a sensor, an encoder, a pulse generator, etc. that detect the rotation speed (actual rotation speed) of the electric motor 9. The control device 7 controls the driving of the electric motor 9 by the inverter 38 based on, for example, the rotation speed (actual rotation speed) of the electric motor 9 detected by the rotation speed detection device 42. More specifically, the control device 7 controls the driving of the electric motor 9 by the inverter 38 so that the actual rotation speed of the electric motor 9 detected by the rotation speed detection device 42 matches the target rotation speed (the indicated value by the accelerator dial 5d or the predetermined rotation speeds R1 to R3 described later).

[0044] The DC-DC converter 40 is a voltage conversion device that converts the DC voltage input from the battery unit 30 via the junction box 39 into a different voltage. In the present embodiment, the DC-DC converter 40 is a step-down converter that converts the high voltage of the battery unit 30 into a predetermined low voltage according to the electrical components provided in the electric working machine 1. The DC-DC converter 40 supplies power to the low-voltage battery 33 after voltage conversion. The electrical components provided in the electric working machine 1 include lighting, heaters, etc. in addition to the respective parts shown in FIG. 1. Electric power The charging port 41 has a connector (not shown) into which a charging cable (not shown) is fitted and a connection detection device 41a. The charging port 41 is connected to an external power source (commercial power source, etc.) via a charging cable. The connection detection device 41a is composed of a sensor or the like that detects that a charging cable is fitted to the charging port 41 and an external power source is connected.

[0045]

[0046] ​ The junction box 39 outputs the power input from an external power source through a charging cable to the charging port 41 to the battery unit 30. The battery unit 30 is charged with the power input from the charging port 41 via the junction box 39.

[0047] The battery unit 30 has a plurality of battery packs 31 and 32. Each of the battery packs 31 and 32 is a secondary battery (storage battery) such as a lithium-ion battery composed of at least one battery. When each of the battery packs 31 and 32 is composed of a plurality of batteries, the plurality of batteries are electrically connected in series and / or in parallel. Further, the battery constituting each of the battery packs 31 and 32 has a plurality of cells inside, and the plurality of cells are electrically connected in series and / or in parallel to form the battery pack. Each of the battery packs 31 and 32 has an electric capacity capable of operating each part of the electric working machine 1 for a predetermined time. The battery packs 31 and 32 are connected in parallel to each other.

[0048] In the present embodiment, two battery packs 31 and 32 are provided in the battery unit 30, but the number of battery packs included in the battery unit 30 is not limited to two, and may be one or three or more.

[0049] Each of the battery packs 31 and 32 is provided with a connection switching part 31a and 32a. Each of the connection switching parts 31a and 32a is composed of, for example, a relay or a switch, and is switchable between a connected state and a disconnected state.

[0050] The control device 7 switches one of the connection switching parts 31a and 32a to the connected state and the other connection switching part to the disconnected state, so that power is output from one of the plurality of battery packs 31 and 32 to the junction box 39, and the output of power from the other battery pack is stopped. That is, the control device 7 controls the output and output stop of the power of each of the battery packs 31 and 32.

[0051] In addition, the control device 7 switches the internal connection state of the junction box 39 to connect or disconnect the inverter 38, the DC-DC converter 40, or the charging port 41 to / from each battery pack 31, 32. The junction box 39 and the connection switching parts 31a, 32a are connection switching devices that switch the connection and disconnection of the inverter 38, the DC-DC converter 40, and the charging port 41 with respect to each battery pack 31, 32.

[0052] In addition, each of the battery packs 31, 32 is provided with a BMU (battery management unit; battery monitoring device) 31b, 32b. In FIG. 1, the BMUs 31b, 32b are provided inside the corresponding battery packs 31, 32, but the BMUs 31b, 32b may be built in the corresponding battery packs 31, 32, or may be installed outside the battery packs 31, 32.

[0053] The BMU 31b monitors and controls the corresponding battery pack 31. The BMU 32b monitors and controls the corresponding battery pack 32. Specifically, the BMUs 31b, 32b control the opening and closing of relays provided inside the battery packs 31, 32 to control the start and stop of power supply from the battery packs 31, 32. In addition, the BMUs 31b, 32b detect the temperature, voltage, current, or terminal voltage of the internal cells of the battery packs 31, 32.

[0054] Furthermore, the BMUs 31b, 32b detect the remaining capacity (remaining power amount) of the battery packs 31, 32 by a voltage measurement method based on, for example, the terminal voltage of the cells inside the battery packs 31, 32. Note that the method for detecting the remaining capacity of the battery packs 31, 32 is not limited to the voltage measurement method, and other methods such as a Coulomb counter method, a battery cell modeling method, and an impedance track method may be used. Also, a capacity detection unit for detecting the remaining capacity of the battery packs 31, 32 may be provided separately from the BMUs 31b, 32b.

[0055] The low-voltage battery 33 is a battery with a voltage lower than that of the battery unit 30. The low-voltage battery 33 is charged by the power supplied from the DC-DC converter 40. The low-voltage battery 33 supplies power to the electrical components provided in the power-operated work machine 1.

[0056] The radiator 35 cools the cooling water for cooling high-heat-generating electrical devices such as the electric motor 9, the inverter 38, the DC-DC converter 40, and the battery unit 30. The high-heat-generating electrical devices are electrical devices that generate more heat than other electrical devices provided in the power-operated work machine 1 by operating with power. The cooling water is not just simple water but is composed of a liquid that does not freeze even in cold regions, for example.

[0057] The radiator 35 has a fan motor 35a, a radiator fan that is rotationally driven by the power of the fan motor 35a, and a heat exchange section (not shown). The fan motor 35a is driven by the power of the low-voltage battery 33.

[0058] The cooling pump 36 is provided in a cooling water passage (not shown) disposed in the machine body 2 together with the radiator 35 and the above-mentioned high-heat-generating electrical devices. The cooling pump 36 discharges and circulates the cooling water through the cooling water passage.

[0059] The oil cooler 37 cools the hydraulic oil that has passed through hydraulic devices such as the aforementioned hydraulic actuators ML, MR, MT, C1 to C5 and the hydraulic pumps P1, P2 and the control valve CV (shown in FIG. 2 etc.) to be described later. The oil cooler 37 has a fan motor 37a, an oil cooler fan that is rotationally driven by the power of the fan motor 37a, and a heat exchange section (not shown). The fan motor 37a is driven by the power of the low-voltage battery 33. The oil cooler 37 is an example of the "cooling device" of the present invention.

[0060] The display device 43 is composed of a liquid crystal display or a touch panel, etc., and displays various kinds of information. The oil temperature detection device 44 is composed of a sensor that detects the temperature of the hydraulic oil. Hereinafter, the temperature of the hydraulic oil is referred to as the "operating oil temperature".

[0061] The AI (Auto Idling)-SW (Switch) 45 is composed of a pressure sensor that operates by the hydraulic pressure of the hydraulic oil. The AI-SW 45 turns on when at least one of the working devices 20 and 10 is operating, and turns off when neither of the working devices 20 and 10 is operating. That is, the AI-SW 45 detects the presence or absence of the operation of the working devices 20 and 10. The AI-SW 45 is an example of the "operation detection device" of the present invention.

[0062] Next, the hydraulic circuit provided in the electric working machine 1 will be described. FIG. 2 is a diagram showing the hydraulic circuit K provided in the electric working machine 1. The hydraulic circuit K is provided with hydraulic devices such as hydraulic actuators C1 to C5, ML, MR, MT, control valve CV, hydraulic pumps P1, P2, hydraulic oil tank 48, oil cooler 37, operation valves PV1 to PV6, unloading valve 58, and oil passage 50.

[0063] Among the plurality of provided hydraulic pumps P1 and P2, one is the working hydraulic pump P1, and the other is the control hydraulic pump P2. These hydraulic pumps P1 and P2 are driven by the power of the electric motor 9.

[0064] The working hydraulic pump P1 sucks the hydraulic oil stored in the hydraulic oil tank 48 and then discharges the hydraulic oil toward the control valve CV. In FIG. 2, for the sake of convenience, one working hydraulic pump P1 is shown, but it is not limited thereto, and the number of working hydraulic pumps P1 may be appropriately provided so as to supply hydraulic oil to each of the hydraulic actuators C1 to C5, ML, MR, MT.

[0065] The control hydraulic pump P2 sucks the hydraulic oil stored in the hydraulic oil tank 48 and then discharges it to output hydraulic pressure for signals or control. That is, the control hydraulic pump P2 supplies (discharges) pilot oil. The number of control hydraulic pumps P2 may also be appropriately provided.

[0066] The control valve CV has a plurality of control valves V1 to V8. Each control valve V1 to V8 controls the flow rate of the hydraulic oil output from the hydraulic pumps P1 and P2 to each hydraulic actuator C1 to C5, ML, MR, and MT. and Control (regulation ) do it does.

[0067] Specifically, the swing control valve V1 controls the flow rate of the hydraulic oil supplied to the swing cylinder C1. The boom control valve V2 controls the flow rate of the hydraulic oil supplied to the boom cylinder C2. The arm control valve V3 controls the flow rate of the hydraulic oil supplied to the arm cylinder C3. The bucket control valve V4 controls the flow rate of the hydraulic oil supplied to the bucket cylinder C4. The dozer control valve V5 controls the flow rate of the hydraulic oil supplied to the dozer cylinder C5. The left travel control valve V6 controls the flow rate of the hydraulic oil supplied to the left travel motor ML. The right travel control valve V7 controls the flow rate of the hydraulic oil supplied to the right travel motor MR. The swing control valve V8 controls the flow rate of the hydraulic oil supplied to the swing motor MT.

[0068] The operation valves (remote control valves) PV1 to PV6 operate in response to the operations of the operation levers 5a and 5b (Fig. 1) provided in the operation device 5. In proportion to the operation amount (operation quantity) of each operation valve PV1 to PV6, pilot oil acts on each control valve V1 to V8, causing the spools of each control valve V1 to V8 to move straight. Then, hydraulic oil with a flow rate proportional to the movement amount of the spools of each control valve V1 to V8 is supplied to the hydraulic actuators C1 to C5, ML, MR, and MT to be controlled. Further, each hydraulic actuator C1 to C5, ML, MR, and MT is driven according to the supply amount of the hydraulic oil from each control valve V1 to V8.

[0069] In other words, when the operation levers 5a and 5b are operated, the hydraulic oil (pilot oil) acting on the control valves V1 to V8 is adjusted, and the control valves V1 to V8 are controlled. Then, the flow rate of the hydraulic oil supplied from the control valves V1 to V8 to the hydraulic actuators C1 to C5, ML, MR, and MT is adjusted, and the driving and stopping of the hydraulic actuators C1 to C5, ML, MR, and MT are controlled.

[0070] The oil passage 50 is composed of, for example, a pipe formed of a material such as a hose or metal. The oil passage 50 is a flow path that connects each part provided in the hydraulic circuit K and allows hydraulic oil or pilot oil to flow to each part. The oil passage 50 includes a first oil passage 51, a second oil passage 52, a first suction oil passage 54, a second suction oil passage 55, and a restriction oil passage 57.

[0071] The first suction oil passage 54 is a flow path through which the hydraulic oil pumped by the hydraulic pump P1 for operation is suctioned from the hydraulic oil tank 48. The second suction oil passage 55 is a flow path through which the hydraulic oil pumped by the hydraulic pump P2 for control is suctioned from the hydraulic oil tank 48. The first oil passage 51 is a flow path through which the hydraulic oil discharged by the hydraulic pump P1 for operation flows toward the control valves V1 - V8 of the control valve CV. The first oil passage 51 branches into a plurality within the control valve CV and is connected to each of the control valves V1 - V8. The second oil passage 52 is a flow path through which the hydraulic oil that has passed through the control valves V1 - V8 flows toward the hydraulic oil tank 48. The hydraulic oil tank 48 stores the hydraulic oil. The second oil passage 52 includes a reciprocating oil passage 52a and a discharge oil passage 52b.

[0072] A plurality of reciprocating oil passages 52a are provided in pairs of two to connect each of the control valves V1 - V8 and the hydraulic actuators C1 - C5, ML, MR, MT to be controlled. The reciprocating oil passage 52a is a flow path that supplies hydraulic oil from the connected control valves V1 - V8 to the hydraulic actuators C1 - C5, ML, MR, MT or returns the hydraulic oil from the hydraulic actuators C1 - C5, ML, MR, MT to the control valves V1 - V8. One end side of the discharge oil passage 52b branches into a plurality and is connected to each of the control valves V1 - V8. The other end of the discharge oil passage 52b is connected to the hydraulic oil tank 48.

[0073] A part of the hydraulic oil flowing through the first oil passage 51 to any of the control valves V1 to V8 passes through the control valves V1 to V8, flows through one of the reciprocating oil passages 52a, and is supplied to the hydraulic actuators C1 to C5, ML, MR, MT to be controlled. Then, the hydraulic oil discharged from the hydraulic actuators C1 to C5, ML, MR, MT returns to the control valves V1 to V8 connected through the other of the reciprocating oil passages 52a, passes through the control valves V1 to V8, and flows through the discharge oil passage 52b.

[0074] The other part of the hydraulic oil flowing through the first oil passage 51 to any of the control valves V1 to V8 flows through the control valves V1 to V8 and into the discharge oil passage 52b without being supplied to the hydraulic actuators C1 to C5, ML, MR, MT. An oil cooler 37 is provided in the discharge oil passage 52b. The oil cooler 37 cools the hydraulic oil flowing through the discharge oil passage 52b from any of the control valves V1 to V8.

[0075] The hydraulic oil cooled by the oil cooler 37 returns to the hydraulic oil tank 48 through the discharge oil passage 52b. As described above, the oil passages 54, 51, 52 are arranged to circulate the hydraulic oil with respect to the hydraulic oil tank 48, the hydraulic pump P1, and the control valves V1 to V8 of the control valve CV (and some of the hydraulic oil also with respect to the hydraulic actuators C1 to C5, ML, MR, MT).

[0076] The restriction oil passage 57 is a flow passage for flowing the hydraulic oil discharged from the control hydraulic pump P2 to the operation valves PV1 to PV6. One end of the restriction oil passage 57 is connected to the control hydraulic pump P2, and the other end side branches into a plurality and is connected to the primary ports (primary ports) of the primary sides of the respective operation valves PV1 to PV6.

[0077] The limiting oil passage 57 is provided with an unloading valve 58 composed of a two-position switching valve. The unloading valve 58 switches to either the first position 58a or the second position 58b in conjunction with the operation of the unloading lever 5c (Fig. 1). When the unloading valve 58 switches to the first position 58a, hydraulic oil is supplied from the hydraulic pump P1 for operation to the hydraulic actuators C1 to C5, ML, MR, and MT, and the operation of the hydraulic actuators C1 to C5, ML, MR, MT, the working device 20, and the traveling device 10 is permitted. Also, when the unloading valve 58 switches to the second position 58b, the supply of hydraulic oil from the hydraulic pump P1 for operation to the hydraulic actuators C1 to C5, ML, MR, and MT is cut off, and the operation of the hydraulic actuators C1 to C5, ML, MR, MT, the working device 20, and the traveling device 10 is not permitted (operation prohibited state).

[0078] Specifically, when the unloading lever 5c is operated to the load position (first position), the unloading valve 58 is switched by the control device 7 to the first position (oil supply position, load position) 58a, and the hydraulic oil discharged from the control hydraulic pump P2 to the limiting oil passage 57 is supplied to the operation valves PV1 to PV6, enabling the control valves V1 to V8 to be operable. As a result, the hydraulic actuators C1 to C5, ML, MR, MT, the working device 20, and the traveling device 10 also become operable, and the operation of these respective parts C1 to C5, ML, MR, MT, 20, 10 is permitted. The hydraulic oil discharged from the operation valves PV1 to PV6 returns to the hydraulic oil tank 48 through another discharge oil passage (not shown).

[0079] Further, when the unloading lever 5c is operated to the unloading position (second position), the unloading valve 58 is switched by the control device 7 to the second position (oil cutoff position, unloading position) 58b, and the hydraulic oil discharged from the control hydraulic pump P2 to the restriction oil passage 57 is no longer supplied to the operation valves PV1 to PV6, and the control valves V1 to V8 become inoperable (operation prohibited state). As a result, the hydraulic actuators C1 to C5, ML, MR, MT, the working device 20, and the traveling device 10 also become inoperable, and the operations of these parts C1 to C5, ML, MR, MT, 20, 10 are not permitted. Not only the unloading lever 5c but also the unloading valve 58 is an example of a configuration included in the "switching member" of the present invention.

[0080] In addition to the above, the hydraulic circuit K is provided with an operation detection oil passage (not shown) for detecting the operation states of the control valves V1 to V8. The operation detection oil passage is an oil passage that returns the pilot oil discharged from the control hydraulic pump P2 to the hydraulic oil tank 48 through a plurality of switching valves for switching the positions of the control valves V1 to V8 in sequence. In the operation detection oil passage, an AI-SW45 (FIG. 1) is connected upstream of the control valve V1 disposed closest to the control hydraulic pump P2.

[0081] When any one of the control valves V1 to V8 is operated from the neutral position to the switching position, a part of the operation detection oil passage is blocked, and the pressure of the pilot oil in the operation detection oil passage becomes somewhat high (so-called pressure build-up state), and the AI-SW45 is turned on. That is, it is detected by the AI-SW45 that at least one of the working devices 20, 10 is operating. Further, when all of the control valves V1 to V8 are in the neutral position, since the operation detection oil passage is open, the pressure of the pilot oil in the operation detection oil passage does not become high to a certain extent (so-called no pressure build-up state), and the AI-SW45 is turned off. That is, it is detected by the AI-SW45 that the working devices 20, 10 are not operating.

[0082] Next, the operation of the electric working machine 1 will be described. FIG. 3 is a diagram showing an example of a control map of the rotational speed of the electric motor 9. Specifically, the control map in FIG. 3 graphically shows the correlation between the control value of the rotational speed of the electric motor 9 and the operating oil temperature. The horizontal axis of the control map in FIG. 3 indicates the operating oil temperature [°C], and the vertical axis indicates the rotational speed [rpm] of the electric motor 9. The data representing the control map in FIG. 3 is stored in advance in the storage unit 7b (FIG. 1) of the control device 7.

[0083] The control device 7 determines whether the operating oil temperature T detected by the oil temperature detection device 44 is within any of the five predetermined temperature ranges I to V shown in FIG. 3. The third temperature range III is an allowable temperature range, which is equal to or higher than a predetermined temperature T2 (for example, 30°C) and equal to or lower than a predetermined temperature T3 (for example, 87°C). The temperature T2, T3, and the allowable temperature range T2 to T3 are set, for example, to the operating oil temperature and temperature range that enable each part of the electric working machine 1 to operate stably.

[0084] Among the temperature ranges I and II lower than the allowable temperature range III, the first temperature range I is set to be lower than a predetermined temperature T1 (for example, 2°C). The second temperature range II is set to be equal to or higher than the temperature T1 and lower than the temperature T2. Among the temperature ranges IV and V higher than the allowable temperature range III, the fourth temperature range IV is set to be higher than the temperature T3 and equal to or lower than a predetermined temperature T4 (for example, 103°C). The temperature T1 is an example of the "first temperature" of the present invention, and the temperature T4 is an example of the "second temperature" of the present invention. Fifth temperature range V is set to be higher than the temperature T4 (for example, 103°C).

[0085] During the driving of the electric motor 9, the control device 7 controls the rotational speed R of the electric motor 9 within a predetermined range R1 to R5 according to the operating oil temperature T, the unloading lever 5c, and the state of the AI-SW 45. The first rotational speed R1 is the rotational speed corresponding to the stop state of the electric motor 9 (for example, 0 rpm).

[0086] The second rotational speed R2 is the rotational speed (e.g., 250 rpm) of the electric motor 9 that can generate the hydraulic pressure of the hydraulic oil that AI-SW45 can detect the presence or absence of the operation of the working devices 20 and 10. More specifically, when at least one of the working devices 20 and 10 operates, AI-SW45 switches to the on state, and when the working devices 20 and 10 are not operating, the second rotational speed R2 is set to the rotational speed of the electric motor 9 for generating a hydraulic pressure equal to or higher than the minimum hydraulic pressure of the hydraulic oil that can switch AI-SW45 to the off state.

[0087] The third rotational speed R3 is the lower limit value (e.g., 1,000 rpm) of the rotational speed of the electric motor 9 for performing work by the working devices 20 and 10. More specifically, the third rotational speed R3 is set to the rotational speed of the electric motor 9 in the no-load state that can immediately operate the working devices 20 and 10 in response to the operation of the operation levers 5a and 5b. The third rotational speed R3 is a rotational speed higher than the first rotational speed R1 and the second rotational speed R2 and is also the idling rotational speed. The second rotational speed R2 is a rotational speed greater than the first rotational speed R1 and less than the third rotational speed R3. Also, the second rotational speed R2 is an idling rotational speed lower than the rotational speed of the electric motor 9 when performing work by the working devices 20 and 10.

[0088] The fifth rotational speed R5 is a predetermined maximum rotational speed (e.g., 2,200 rpm) that can be set for the electric motor 9. The fourth rotational speed R4 is a rotational speed limited to be less than the fifth rotational speed R5 and greater than the third rotational speed R3.

[0089] Note that the numerical values of the above-described temperatures T1 to T4 and rotational speeds R1 to R5 are merely examples and are not limited thereto. Also, the first rotational speed R1 corresponding to the stopped state of the electric motor 9 is not limited to 0 rpm, and may be an extremely small rotational speed such as less than 1 rpm, for example. Further, in this example, when the control device 7 sets the rotational speed of the electric motor 9 to 0 rpm (first rotational speed), the power supply from the inverter 38 to the electric motor 9 is continued. However, for example, the control device 7 may set the rotational speed of the electric motor 9 to 0 rpm by cutting off the power supply from the inverter 38 to the electric motor 9 and completely stopping the electric motor 9.

[0090] Figs. 4A to 4C are flowcharts showing the control operation of the rotational speed of the electric motor 9 in the electric working machine 1. The series of control operations shown in Figs. 4A to 4C are executed by the CPU 7a (Fig. 1) of the control device 7 based on a software program stored in advance in the storage unit 7b and the control map of Fig. 3. Hereinafter, for convenience, the rotational speed of the electric motor 9 will be referred to as the "motor rotational speed".

[0091] When the starter SW8 is turned on by the operator, the control device 7 starts the electric motor 9 by the inverter 38. During the driving of the electric motor 9, the control device 7 detects the operating oil temperature T by the oil temperature detection device 44 (S1 in Fig. 4A).

[0092] When the operating oil temperature T is within the predetermined allowable temperature range III (equal to or higher than the temperature T2 and equal to or lower than the temperature T3) (S2 in Fig. 4A: YES), the control device 7 confirms the selected state of the mode by the mode selection SW5e (Fig. 1). At this time, when the normal mode is selected by the mode selection SW5e (S3 in Fig. 4A: NO), the control device 7 sets the indicated range Rrange of the motor rotational speed R by the accelerator dial 5d (Fig. 1) to be equal to or higher than the third rotational speed R3 and equal to or lower than the fifth rotational speed R5 (S5 in Fig. 4A, the solid circle in the allowable temperature range III of Fig. 3). That is, the control device 7 sets the third rotational speed R3 as the lower limit value of the indicated range Rrange of the motor rotational speed R by the accelerator dial 5d, and sets the fifth rotational speed R5 as the upper limit value.

[0093] On the other hand, when the ECO mode is selected by the mode selection SW5e (S3: YES in Fig. 4A), the control device 7 sets the instruction range Rrange of the motor speed R by the accelerator dial 5d to be equal to or higher than the third speed R3 and equal to or lower than the fourth speed R4 (S4 in Fig. 4A, the E mark in the allowable temperature range III in Fig. 3). That is, the control device 7 sets the third speed R3 as the lower limit value of the instruction range Rrange of the motor speed R by the accelerator dial 5d and sets the fourth speed R4 as the upper limit value.

[0094] Also, when the work devices 20 and 10 have not operated for a predetermined time (for example, 4 seconds) or more and thus the AI-SW45 has been in the off state for a predetermined time (for example, 4 seconds) or more (S6: YES in Fig. 4A), the control device 7 controls the motor speed R to match the second speed R2 (S7 in Fig. 4A, the black dot in the allowable temperature range III in Fig. 3). The processes S6 and S7 in Fig. 4A are so-called AI (auto-idling) control.

[0095] Also, when the unloading lever 5c (Fig. 1) and the unloading valve 58 (Fig. 2) are switched to the unloading position (S8: YES in Fig. 4A), the control device 7 controls the motor speed R to match the first speed R1 (S9 in Fig. 4A, the black square in the allowable temperature range III in Fig. 3). Thereby, the electric motor 9 comes to a rotational stop state. The processes S8 and S9 in Fig. 4A are so-called AS (auto-stop) control.

[0096] Also, when the accelerator dial 5d is operated while the unloading lever 5c and the unloading valve 58 are in the load position (S10: YES in Fig. 4A), the control device 7 calculates an instruction value of the motor speed R according to the operation position of the accelerator dial 5d and changes the motor speed R to match the instruction value (S11 in Fig. 4A).

[0097] At this time, since the operating oil temperature T is within the allowable temperature range III, when the normal mode is selected by the mode selection SW5e, within the instruction range Rrange (R3 to R5) set in the process S5 of FIG. 4A, the control device 7 calculates an instruction value of the motor speed R according to the operation position of the accelerator dial 5d. Also, when the ECO mode is selected by the mode selection SW5e, within the instruction range Rrange (R3 to R4) set in the process S4 of FIG. 4A, the control device 7 calculates an instruction value of the motor speed R according to the operation position of the accelerator dial 5d.

[0098] Thereafter, when the starter SW8 is turned off by the operator, the control device 7 determines that there is an instruction to stop the electric motor 9 (S12: YES in FIG. 4A), and stops driving the electric motor 9 by stopping the power supply to the electric motor 9 by the inverter 38 (S13 in FIG. 4A). Thereby, the electric working machine 1 becomes a stopped state.

[0099] On the other hand, if the starter SW8 is not turned off by the operator, the control device 7 determines that there is no instruction to stop the electric motor 9 (S12: NO in FIG. 4A), and executes the processes after S1 again. In this case, the electric motor 9 is in operation.

[0100] Also, when the operating oil temperature T is outside the allowable temperature range III (T2 to T3) (S2: NO in FIG. 4A) and the operating oil temperature T is lower than the allowable temperature range III (S14: YES in FIG. 4A), the control device 7 further determines whether the operating oil temperature T is within either of the temperature ranges I and II.

[0101] For example, when the operating oil temperature T is within the low temperature range II that is equal to or higher than the temperature T1 and lower than the temperature T2 (S15: YES in FIG. 4B), the control device 7 checks the mode selection state by the mode selection SW5e. At this time, when the normal mode is selected by the mode selection SW5e (S16: NO in FIG. 4B), the control device 7 sets the instruction range Rrange of the motor speed R by the accelerator dial 5d to be equal to or higher than the third speed R3 and equal to or lower than the fifth speed R5 (S18 in FIG. 4B, FIG. 3 low S mark in temperature range II).

[0102] On the other hand, when the ECO mode is selected by the mode selection SW5e (S16: YES in Fig. 4B), the control device 7 sets the instruction range Rrange of the motor speed R by the accelerator dial 5d to be equal to or higher than the third speed R3 and equal to or lower than the fourth speed R4 (S17 in Fig. 4B, Fig. 3's low E mark in temperature range II).

[0103] Also, when the AI-SW45 has been in the off state for a predetermined time or more (S19: YES in Fig. 4B), the control device 7 controls the motor speed R to match the third speed R3 (S20 in Fig. 4B, Fig. 3's low black mark in temperature range II). The processes S19 and S20 in Fig. 4B are also AI control.

[0104] Also, even when the unload lever 5c and the unload valve 58 are switched to the unload position (S21: YES in Fig. 4B), the control device 7 controls the motor speed R to match the third speed R3 (S22 in Fig. 4B). That is, when the operating oil temperature T is in the temperature range II lower than the allowable temperature range III, even if the operator switches the unload lever 5c to the unload position, indicating an intention not to operate the working devices 20 and 10, the control device 7 does not execute the AS (auto-stop) control and continues to rotationally drive the electric motor 9 at a speed equal to or higher than the third speed R3 to perform warm-up by circulating the operating oil. The processes S19 to S22 in Fig. 4B are so-called warm-up control.

[0105] Also, when the accelerator dial 5d is operated while the unload lever 5c and the like are in the load position (S10: YES in Fig. 4A), the control device 7 calculates an instruction value of the motor speed R according to the operation position of the accelerator dial 5d and changes the motor speed R to match the instruction value (S11 in Fig. 4A).

[0106] At this time, since the operating oil temperature T is in the low temperature range II, when the normal mode is selected by the mode selection SW5e, within the instruction range Rrange (R3 to R5) set in the process S18 of FIG. 4B, the control device 7 calculates an instruction value of the motor speed R according to the operation position of the accelerator dial 5d. Also, when the ECO mode is selected by the mode selection SW5e, within the instruction range Rrange (R3 to R4) set in the process S17 of FIG. 4B, the control device 7 calculates an instruction value of the motor speed R according to the operation position of the accelerator dial 5d.

[0107] Further, when the operating oil temperature T is within the extremely low temperature range I less than the temperature T1 (S15: NO, T < T1 in FIG. 4B), the control device 7 sets the instruction range Rrange of the motor speed R by the accelerator dial 5d to be equal to or higher than the third speed R3 and equal to or lower than the fourth speed R4, regardless of whether the normal mode or the ECO mode is selected by the mode selection SW5e (S17 in FIG. 4B, the solid circles and open circles in the extremely low temperature range I in FIG. 3).

[0108] Also, even if the AI - SW45 is off for a predetermined time or more (S19: YES in FIG. 4B), or the unloading lever 5c or the like is switched to the unloading position (S21: YES in FIG. 4B), the control device 7 controls the motor speed R to match the third speed R3 (S20, S22 in FIG. 4B, the black circles in the extremely low temperature range I in FIG. 3). That is, when the operating oil temperature T is in the extremely low temperature range I lower than the allowable temperature range III and the low temperature range II, even if it is indicated that the unloading lever 5c is switched to the unloading position and the working devices 20, 10 are not to be operated, the control device 7 does not execute AS (auto stop) control and continues to rotationally drive the electric motor 9 at a speed equal to or higher than the third speed R3 to circulate the operating oil, thereby performing warm-up.

[0109] Also, when the accelerator dial 5d is operated with the unloading lever 5c or the like in the load position (S10: YES in FIG. 4A), the control device 7 calculates an instruction value for the motor speed R according to the operation position of the accelerator dial 5d, and changes the motor speed R so as to match the instruction value (S11 in FIG. 4A). At this time, since the operating oil temperature T is in the extremely low temperature range I, regardless of whether the normal mode or the ECO mode is selected by the mode selection SW5e, within the instruction range Rrange (R3 to R4) set in the process S17 of FIG. 4B, the control device 7 calculates an instruction value for the motor speed R according to the operation position of the accelerator dial 5d.

[0110] Also, when the operating oil temperature T is outside the allowable temperature range III (T2 to T3) (S2: NO in FIG. 4A) and the operating oil temperature T is higher than the allowable temperature range III (S14: NO in FIG. 4A), the control device 7 further determines whether the operating oil temperature T is in either of the temperature ranges IV and V.

[0111] For example, when the operating oil temperature T is within the high temperature range IV that is higher than the temperature T3 and equal to or lower than the temperature T4 (S23: YES in FIG. 4C), the control device 7 checks the mode selection state by the mode selection SW5e. At this time, when the normal mode is selected by the mode selection SW5e (S24: NO in FIG. 4C), the control device 7 sets the instruction range Rrange of the motor speed R by the accelerator dial 5d to be equal to or higher than the third speed R3 and equal to or lower than the fifth speed R5 (S26 in FIG. 4C, the solid circle in the high temperature range IV in FIG. 3).

[0112] On the other hand, when the ECO mode is selected by the mode selection SW5e (S24: YES in FIG. 4C), the control device 7 sets the instruction range Rrange of the motor speed R by the accelerator dial 5d to be equal to or higher than the third speed R3 and equal to or lower than the fourth speed R4 (S25 in FIG. 4C, the open circle in the high temperature range IV in FIG. 3).

[0113] Also, when AI-SW45 is in the OFF state for a predetermined time or longer (S27: YES in FIG. 4C), the control device 7 controls the motor rotation speed R to match the second rotation speed R2 (S28 in FIG. 4C, black dots in the high temperature range IV in FIG. 3). The processes S27 and S28 in FIG. 4C are also AI control.

[0114] Further, even when the unloading lever 5c and the unloading valve 58 are switched to the unloading position (S29: YES in FIG. 4C), the control device 7 controls the motor rotation speed R to match the second rotation speed R2 (S30 in FIG. 4C, black dots in the high temperature range IV in FIG. 3). That is, when the operating oil temperature T is in the high temperature range IV higher than the allowable temperature range III, even if the unloading lever 5c is switched to the unloading position and the intention is not to operate the work devices 20 and 10, the control device 7 does not execute AS (auto stop) control and continues to rotationally drive the electric motor 9 at the second rotation speed R2 smaller than the third rotation speed R3 to circulate the operating oil, thereby cooling the operating oil. The processes S27 to S30 in FIG. 4C are so-called cooling control.

[0115] Also, when the accelerator dial 5d is operated while the unloading lever 5c and the like are in the load position (S10: YES in FIG. 4A), the control device 7 calculates an instruction value of the motor rotation speed R according to the operation position of the accelerator dial 5d and changes the motor rotation speed R to match the instruction value (S11 in FIG. 4A).

[0116] At this time, since the operating oil temperature T is in the high temperature range IV, when the normal mode is selected by the mode selection SW5e, within the instruction range Rrange (R3 to R5) set in the process S26 in FIG. 4C, the control device 7 calculates an instruction value of the motor rotation speed R according to the operation position of the accelerator dial 5d. Also, when the ECO mode is selected by the mode selection SW5e, within the instruction range Rrange (R3 to R4) set in the process S25 in FIG. 4C, the control device 7 calculates an instruction value of the motor rotation speed R according to the operation position of the accelerator dial 5d.

[0117] Also, when the operating oil temperature T is within the extremely high temperature range V where T > T4 (S23: NO, T > T4 in FIG. 4C), regardless of whether the normal mode or the ECO mode is selected by the mode selection SW5e, the control device 7 sets the upper and lower limit values of the instruction range Rrange of the motor speed R by the accelerator dial 5d to the third speed R3 (S31 in FIG. 4C, the solid circles and open circles in the extremely high temperature range V in FIG. 3). That is, when the operating oil temperature T is within the extremely high temperature range V, the instruction range Rrange of the motor speed R by the accelerator dial 5d is set to a constant third speed R3. For this reason, no matter how the accelerator dial 5d is operated from the neutral position to any position, the instructed value of the motor speed R becomes the third speed R3, and the speed R of the electric motor 9 is limited to the third speed R3.

[0118] Also, even if the AI-SW45 is turned off for a predetermined time or more (S27: YES in FIG. 4C), or the unloading lever 5c or the like is switched to the unloading position (S29: YES in FIG. 4C), the control device 7 controls the motor speed R to match the second speed R2 (S30 in FIG. 4C, the black circles in the extremely high temperature range V in FIG. 3). That is, when the operating oil temperature T is within the extremely high temperature range V, even if the unloading lever 5c is switched to the unloading position, indicating an intention not to operate the working devices 20 and 10, the control device 7 does not execute the AS control and continues to rotationally drive the electric motor 9 at the second speed R2 to circulate the operating oil, thereby cooling the operating oil.

[0119] Also, when the accelerator dial 5d is operated while the unloading lever 5c or the like is in the load position (S10: YES in FIG. 4A), the control device 7 calculates the instructed value of the motor speed R and changes the motor speed R to match the instructed value (S11 in FIG. 4A). At this time, since the operating oil temperature T is within the extremely high temperature range V, regardless of the mode selection state by the mode selection SW5e and the operation position of the accelerator dial 5d, the control device 7 determines the constant value R3 set in the process S31 in FIG. 4C as the instructed value of the motor speed R.

[0120] When the operating oil temperature T is in temperature ranges IV and V higher than the allowable temperature range III, the control device 7 may control the motor speed R to match the second speed R2 and rotate the fan motor 37a of the oil cooler 37 at a predetermined speed to cool the operating oil. That is, when the working devices 20 and 10 are not operating, the oil cooler 37 is driven while rotating the electric motor 9 at the second speed R2 to cool the operating oil.

[0121] Also, when the operating oil temperature T is lower than the allowable temperature range III, the control device 7 may stop the oil cooler 37 to reduce power consumption and promote warm-up of the operating oil when controlling the motor speed R to match the third speed R3. Further, even when the operating oil temperature T is within the allowable temperature range III, the control device 7 may stop the oil cooler 37 to reduce power consumption when controlling the motor speed R to match the first speed R1 or the second speed R2.

[0122] In the above embodiment, an example in which the temperature range of the operating oil temperature T is divided into five, i.e., the first to fifth temperature ranges I to V, is shown, but it is not limited thereto. For example, the temperature range of the operating oil temperature T may be divided into two, i.e., within the allowable temperature range and outside the allowable temperature range. Also, the temperature range of the operating oil temperature T may be divided into three, i.e., within the allowable temperature range, a temperature range lower than the allowable temperature range, and a temperature range higher than the allowable temperature range. Further, the temperature range of the operating oil temperature T may be divided into four or six or more. Also, as the motor speeds R for performing AI control in each temperature range, not only two, i.e., the second speed R2 and the third speed R3, but also three or more predetermined speeds may be set.

[0123] In the above embodiment, an example in which the second to fourth speeds R2 to R4 of the electric motor 9 are set to constant values is shown, but it is not limited thereto. For example, the control device 7 may change the second to fourth speeds R2 to R4 according to the remaining capacities of the battery packs 31 and 32 provided in the battery unit 30. Specifically, at least one of the second to fourth speeds R2 to R4 may be changed to a smaller value as the remaining capacities of the battery packs 31 and 32 become smaller.

[0124] In the above embodiments, the working operation lever 5a and the traveling operation lever 5b are used as the working operation members, the unloading lever 5c is used as the switching member and the unloading operation member, the mode selection SW5e is used as the selection member, and the accelerator dial 5d is used as the instruction member. However, the present invention is not limited thereto. For example, various operation members such as levers, joysticks, slide switches, toggle switches, push buttons, dials, or keys may be used as the working operation member, the switching member, the unloading operation member, the selection member, and the instruction member. Further, for example, as the unloading valve 58, a mechanical operation valve or an electromagnetic valve that operates electrically may be used.

[0125] In the above embodiments, the example in which the AI-SW45 composed of a pressure switch is used as the work detection device is shown. However, the present invention is not limited thereto. For example, a potentiometer, a sensor, or a switch that detects the presence or absence of the operation of the working operation lever 5a and the traveling operation lever 5b may be used as the work detection device.

[0126] The electric working machine 1 of the present embodiment has the following configuration and exhibits effects.

[0127] The electric working machine 1 of this embodiment includes a machine body 2, a battery unit 30 mounted on the machine body 2, an electric motor 9 driven by the power from the battery unit 30, a hydraulic device (hydraulic motors ML, MR, MT, hydraulic cylinders C1 to C5, hydraulic pumps P1, P2, control valve CV) operated by the power from the electric motor 9, working devices 20, 10 (working device 20, traveling device 10) operated by the hydraulic pressure of the hydraulic oil supplied from the hydraulic device, a control device 7 for controlling the drive of the electric motor 9, switching members 5c, 58 (unloading lever 5c, unloading valve 58) that can be switched to either a first position that permits the operation of the working devices 20, 10 or a second position that does not permit the operation of the working devices 20, 10, and an oil temperature detection device 44 for detecting the temperature T of the hydraulic oil. The control device 7 controls the rotational speed R of the electric motor 9 to a predetermined first rotational speed R1 corresponding to the stopped state of the electric motor 9 when, during the drive of the electric motor 9, the switching members 5c, 58 are switched to the second position and the temperature T of the hydraulic oil is within a predetermined allowable temperature range III (predetermined temperature T2 to T3) that is neither a low temperature state nor a high temperature state.

[0128] According to the above configuration, since the operator does not operate the electric working machine 1, when the switching members 5c, 58 are switched to the second position that does not permit the operation of the working devices 20, 10, if the temperature T of the hydraulic oil is within the allowable temperature range III, the rotational speed R of the electric motor 9 decreases to the first rotational speed R1 corresponding to the stopped state. Therefore, it is possible to suppress the power of the battery unit 30 from being wasted by the electric motor 9, reduce the wasted power consumption in the electric working machine 1, and improve the working efficiency. Further, when the temperature T of the hydraulic oil is outside the allowable temperature range III, that is, when the temperature T of the hydraulic oil is either in a low temperature state or a high temperature state, by not controlling the rotational speed R of the electric motor 9 to the first rotational speed R1, the electric motor 9 continues to rotate without completely stopping, so that the hydraulic oil can be circulated by hydraulic devices such as the hydraulic pumps P1, P2 to warm up or cool the hydraulic oil, and it is possible to improve the working efficiency.

[0129] In this embodiment, The control device 7 During the driving of the electric motor 9, when the switching members 5c and 58 are switched to the second position and the temperature T of the hydraulic oil is not within the allowable temperature range III, the rotational speed R of the electric motor 9 is controlled to a predetermined idling rotational speed R2, R3 that is greater than the first rotational speed R1 and lower than the lower limit value of the rotational speed when the working devices 20 and 10 perform work.

[0130] As described above, when the switching members 5c and 58 are switched to the second position, the rotational speed R of the electric motor 9 decreases to the first rotational speed R1 or the idling rotational speeds R2 and R3 according to whether the temperature T of the hydraulic oil is within the allowable temperature range III. Therefore, wasteful power consumption can be reduced. In addition, the operating time of the working devices 20 and 10 can be extended by the amount of reduced wasteful power consumption, and the working efficiency can be improved.

[0131] Further, in the present embodiment, when the switching members 5c and 58 are switched to the second position during the driving of the electric motor 9, if the temperature T of the hydraulic oil is lower than the allowable temperature range III, the control device 7 controls the rotational speed R of the electric motor 9 to match a predetermined third rotational speed R3 for the working devices 20 and 10 to be in an idling state. If the temperature T of the hydraulic oil is higher than the allowable temperature range III, the control device 7 controls the rotational speed R of the electric motor 9 to match a predetermined second rotational speed R2 that is greater than the first rotational speed R1 and smaller than the third rotational speed R3.

[0132] As described above, when the switching members 5c and 58 are switched to the second position and the temperature T of the hydraulic oil is lower than the allowable temperature range III, the rotational speed R of the electric motor 9 decreases to the third rotational speed R3, thus reducing wasted power consumption. Moreover, by operating hydraulic devices such as the hydraulic pumps P1 and P2 to circulate the hydraulic oil, warm-up can be achieved, and the time required for warm-up can also be shortened. Further, when the switching members 5c and 58 are switched to the second position and the temperature T of the hydraulic oil is higher than the allowable temperature range III, the rotational speed R of the electric motor 9 decreases to the second rotational speed R2 which is smaller than the third rotational speed R3, thus reducing wasted power consumption and enabling cooling by circulating the hydraulic oil. Furthermore, as described above, when the switching members 5c and 58 are switched to the second position, by controlling the rotational speed R of the electric motor 9 to the first to third rotational speeds R1 to R3 according to the temperature T of the hydraulic oil, it becomes possible to reduce wasted power consumption while maintaining the balance between warm-up and cooling of the hydraulic oil.

[0133] Also, in the present embodiment, the electric working machine 1 includes a work detection device (AI-SW) 45 that operates by the hydraulic pressure of the hydraulic oil and detects the presence or absence of operation of the working devices 20 and 10. The second rotational speed R2 is set to the rotational speed R of the electric motor 9 that can generate a hydraulic pressure of the hydraulic oil capable of detecting the presence or absence of operation of the working device 20、10 by the work detection device 45. Thereby, even if the rotational speed R of the electric motor 9 is decreased to the second rotational speed R2, the work detection device 45 can detect the presence or absence of operation of the working devices 20 and 10.

[0134] Further, in the present embodiment, when the switching members 5c and 58 are in the first position and the working devices 20 and 10 have not operated for a predetermined time or more during the driving of the electric motor 9, if the temperature T of the hydraulic oil is lower than the allowable temperature range III, the control device 7 controls the rotational speed R of the electric motor 9 to match the third rotational speed R3, and if the temperature T of the hydraulic oil is equal to or higher than the allowable temperature range III, the control device 7 controls the rotational speed R of the electric motor 9 to match the second rotational speed R2. Thereby, when the working devices 20 and 10 have not operated for a predetermined time or more, the rotational speed R of the electric motor 9 is decreased to the third rotational speed R3 or the second rotational speed R2 according to the level of the temperature T of the hydraulic oil with respect to the allowable temperature range III, wasted power consumption is reduced, and warm-up or cooling can be performed by circulating the hydraulic oil.

[0135] Further, in the present embodiment, the electric working machine 1 includes an instruction member (accelerator dial) 5d that is operated to instruct the rotational speed R of the electric motor 9, and the control device 7 sets the rotational speed R of the electric motor 9 that can be instructed by the operation of the instruction member 5d according to the temperature T of the hydraulic oil. Further, during the driving of the electric motor 9, the control device 7 calculates an instruction value of the rotational speed R of the electric motor 9 according to the operation state of the instruction member 5d, and controls the rotational speed R of the electric motor 9 to match the instruction value. Thereby, according to the operation state of the instruction member 5d and the temperature T of the hydraulic oil, the rotational speed R of the electric motor 9 can be controlled to circulate the hydraulic oil at an appropriate flow rate and pressure, and the working devices 20 and 10 can be stably operated.

[0136] Further, in the present embodiment, the control device 7 sets an instruction range Rrange of the rotational speed R of the electric motor 9 that can be instructed by the operation of the instruction member 5d within the range from the third rotational speed R3 of the electric motor 9 for the working devices 20 and 10 to be in the idling state to the maximum rotational speed (fifth rotational speed) R5, which is the upper limit value of the rotational speed of the electric motor 9 that can be set, according to the temperature T of the hydraulic oil. Thereby, according to the operation state of the instruction member 5d and the temperature T of the hydraulic oil, the rotational speed R of the electric motor 9 can be changed within an appropriate range.

[0137] Further, in the present embodiment, the electric working machine 1 includes a selection member (mode selection SW) 5e for selecting either a first mode (normal mode) or a second mode (ECO mode) that reduces power consumption compared to the first mode. When the temperature T of the hydraulic oil is within the allowable temperature range III, the control device 7 sets the upper limit value of the instruction range Rrange of the rotational speed R of the electric motor 9 by the operation of the instruction member 5d when the second mode is selected by the selection member 5e to be smaller than the upper limit value of the instruction range Rrange when the first mode is selected by the selection member 5e. Thereby, when the temperature T of the hydraulic oil is neither in the extremely low temperature range I nor in the extremely high temperature range V, when the second mode is selected, the upper limit value of the rotational speed R of the electric motor 9 is suppressed to be smaller than the upper limit value of the rotational speed R when the first mode is selected, and the power consumption can be reduced.

[0138] Further, in the present embodiment, when the temperature T of the hydraulic oil is lower than a predetermined first temperature T1 that is lower than the allowable temperature range III, regardless of whether the first mode or the second mode is selected by the selection member 5e, the control device 7 sets the upper limit value of the instruction range Rrange of the rotational speed R of the electric motor 9 by the operation of the instruction member 5d to a value smaller than the maximum rotational speed R5. The maximum rotational speed R5 is, for example, the upper limit value of the rotational speed of the electric motor 9 that can be instructed by the instruction member 5d when the temperature T of the hydraulic oil is within the allowable temperature range III and the first mode is selected by the selection member 5e. As described above, when the temperature T of the hydraulic oil is in the extremely high When in the temperature range V and the kinematic viscosity of the hydraulic oil is high, even when the instruction member 5d is operated to the maximum, the rotational speed R of the electric motor 9 is suppressed to be smaller than the maximum rotational speed R5, preventing cavitation from occurring in the hydraulic equipment or oil passage through which the hydraulic oil flows, and reducing the power consumption.

[0139] Further, in the present embodiment, when the temperature T of the hydraulic oil is higher than a predetermined second temperature T4 that is higher than the allowable temperature range III, regardless of whether the first mode or the second mode is selected by the selection member 5e, the control device 7 sets the rotational speed R (the upper limit value and the lower limit value of the instruction range Rrange) of the electric motor 9 that can be instructed by the instruction member 5d to the third rotational speed R3. Thereby, when the temperature T of the hydraulic oil is in the extremely high temperature range V, it is possible to prevent the high-temperature hydraulic oil from flowing and wearing or damaging the hydraulic equipment or the oil passage.

[0140] Further, in the present embodiment, the electric working machine 1 includes a cooling device (oil cooler) 37 that cools the hydraulic oil. When the temperature T of the hydraulic oil detected by the oil temperature detection device 44 is higher than the allowable temperature range III, the control device 7 drives the cooling device 37 to cool the hydraulic oil. When the temperature T of the hydraulic oil is equal to or lower than the allowable temperature range III, the control device 7 stops the cooling device 37. Thereby, when the temperature T of the hydraulic oil is high, when the switching members 5c and 58 are switched to the second position, or when the working devices 20 and 10 do not operate for a predetermined time or more, the electric motor 9 is rotated at the low second rotational speed R2 to reduce wasted power consumption. In addition, by using the cooling device 37 in combination, the time required to cool the hydraulic oil to the allowable temperature range III can be shortened. Further, when the temperature T of the hydraulic oil is low, the cooling device 37 is stopped to reduce wasted power consumption, and the electric motor 9 is rotated to circulate the hydraulic oil, thereby warming up the machine.

[0141] Furthermore, in the present embodiment, the electric working machine 1 includes an inverter 38 that adjusts the power supplied from the battery unit 30 to the electric motor 9, a rotation speed detection device 42 that detects the rotation speed R of the electric motor 9, and working operation members 5a and 5b (working operation lever 5a, traveling operation lever 5b) for operating the working devices 20 and 10. The switching members 5c and 58 include an unloading operation member 5c that can be switched between a load position that permits the operation of the working devices 20 and 10 and an unloading position that does not permit the operation of the working devices 20 and 10. The control device 7 controls the rotation speed R of the electric motor 9 by adjusting the power supplied from the inverter 38 to the electric motor 9 based on the rotation speed R of the electric motor 9 detected by the rotation speed detection device 42.

[0142] As described above, by switching the unloading operation member 5c between the load position and the unloading position, the operation of the working devices 20 and 10 can be permitted or not permitted. Also, the rotation speed R of the electric motor 9 can be surely set to the indicated value by the indicating member 5d or the predetermined rotation speeds R1 to R3. Further, the presence or absence of the operation of the working operation members 5a and 5b corresponding to the presence or absence of the operation of the working devices 20 and 10 can be detected by the AI-SW45. Furthermore, by controlling the rotation speed R of the electric motor 9 to the first rotation speed R1 while continuously supplying power from the battery unit 30 to the electric motor 9 by the inverter 38, the power consumption can be reduced when increasing the rotation speed R of the electric motor 9 thereafter, compared to the case of cutting off the power supply from the battery unit 30 to the electric motor 9, and the responsiveness of the electric motor 9 can be improved.

[0143] In the above embodiment, an example of applying the present invention to an electric working machine 1 such as a backhoe has been described. However, the application target of the present invention is not limited to this. For example, it may be applied to other construction machines such as a wheel loader, a compact track loader, and a skid steer loader, or may be applied to agricultural machines such as a tractor, a combine, a rice transplanter, and a lawn mower.

Explanation of Reference Numerals

[0144] 1 Electric working machine 2 Machine body 5a Working operation lever (working operation member) 5b Traveling operation lever (working operation member) 5c Unloading lever (switching member, unloading operation member) 5d Accelerator dial (indicating member) 5e Mode selection SW (mode selection switch, selection member) 7 Control device 9 Electric motor 10 Traveling device (working device) 20 Working device 30 Battery unit 37 Oil cooler (cooling device) 38 Inverter 42 Rotation speed detection device 44 Oil temperature detection device 45 AI-SW (idling switch, working detection device) 58 Unloading valve (switching member) C1~C5 Hydraulic cylinders CV Control valve ML, MR, MT Hydraulic motors P1, P2 Hydraulic pumps R Rotation speed R1 First rotation speed R2 Second rotation speed R3 Third rotation speed R5 Maximum rotation speed, fifth rotation speed Rrange Indicating range T Temperature of hydraulic oil T1 First temperature T4 Second temperature III(T2~T3) Allowable temperature range

Claims

1. A machine body, a battery unit mounted on the machine body, an electric motor driven by electric power from the battery unit, a hydraulic device operated by power from the electric motor, a working device operated by the hydraulic pressure of hydraulic oil supplied from the hydraulic device, a control device for controlling the drive of the electric motor, a switching member that can be switched to either a first position that permits the operation of the working device or a second position that does not permit the operation of the working device, and an oil temperature detection device for detecting the temperature of the hydraulic oil, wherein the control device during driving of the electric motor, when the switching member is switched to the second position and the temperature of the hydraulic oil is within a predetermined allowable temperature range that is neither a low temperature state nor a high temperature state, controls the rotational speed of the electric motor to a predetermined first rotational speed corresponding to the stopped state of the electric motor, during driving of the electric motor, when the switching member is switched to the second position and the temperature of the hydraulic oil is not within the allowable temperature range, controls the rotational speed of the electric motor to a predetermined idling rotational speed that is greater than the first rotational speed and less than or equal to the lower limit value of the rotational speed when the working device performs work. An electric working machine.

2. The control device during driving of the electric motor, when the switching member is switched to the second position, if the temperature of the hydraulic oil is lower than the lower limit value of the allowable temperature range, controls the rotational speed of the electric motor to match a predetermined third rotational speed, if the temperature of the hydraulic oil is higher than the upper limit value of the allowable temperature range, controls the rotational speed of the electric motor to a predetermined second rotational speed that is greater than the first rotational speed and less than the third rotational speed. The electric working machine according to Claim 1.

3. Comprising a work detection device for detecting the presence or absence of operation of the working device by the hydraulic pressure of the hydraulic oil, wherein the second rotational speed is set to a rotational speed capable of generating the hydraulic pressure of the hydraulic oil at which the work detection device can detect the presence or absence of operation of the working device. The electric working machine according to Claim 2.

4. The control device during driving of the electric motor, when the switching member is in the first position and the working device has not operated for a predetermined time or more, if the temperature of the hydraulic oil is lower than the lower limit value of the allowable temperature range, controls the rotational speed of the electric motor to match the third rotational speed, The power-operated work machine according to claim 3, wherein if the temperature of the hydraulic oil is equal to or higher than the lower limit value of the allowable temperature range, the rotational speed of the electric motor is controlled to the second rotational speed.

5. A machine body, a battery unit mounted on the machine body, an electric motor driven by electric power from the battery unit, a hydraulic device operated by power from the electric motor, a working device operated by the hydraulic pressure of the hydraulic oil supplied from the hydraulic device, a control device for controlling the drive of the electric motor, a switching member that can be switched to either a first position that permits the operation of the working device or a second position that does not permit the operation of the working device, an oil temperature detection device that detects the temperature of the hydraulic oil, and is provided with The control device is during the drive of the electric motor, when the switching member is in the first position and the working device has not operated for a predetermined time or more, if the temperature of the hydraulic oil is lower than the lower limit value of a predetermined allowable temperature range, the rotational speed of the electric motor is controlled to match a predetermined third rotational speed that is greater than a predetermined first rotational speed corresponding to the stopped state of the electric motor and less than or equal to the lower limit value of the rotational speed when the working device performs work, The power-operated work machine, wherein if the temperature of the hydraulic oil is equal to or higher than the lower limit value of the allowable temperature range, the rotational speed of the electric motor is controlled to a predetermined second rotational speed that is greater than the first rotational speed and less than the third rotational speed.

6. equipped with an indicating member that is operated to indicate the rotational speed of the electric motor, The control device is The power-operated work machine according to any one of claims 1 to 5, wherein the rotational speed of the electric motor that can be indicated by the operation of the indicating member is set according to the temperature of the hydraulic oil.

7. equipped with a selection member that selects either a first mode or a second mode that reduces power consumption compared to the first mode, The control device, when the temperature of the hydraulic oil is within the allowable temperature range, sets the upper limit value of the indication range of the rotational speed of the electric motor by the operation of the indicating member when the second mode is selected by the selection member to be smaller than the upper limit value of the indication range when the first mode is selected by the selection member. The power-operated work machine according to claim 6.

8. When the temperature of the hydraulic oil is lower than a predetermined first temperature that is lower than the allowable temperature range, regardless of whether the first mode or the second mode is selected by the selection member, the upper limit value of the instruction range of the rotational speed of the electric motor by the operation of the instruction member is set to a value smaller than a predetermined maximum rotational speed. The electric working machine according to claim 7, wherein the maximum rotational speed is the upper limit value of the rotational speed that can be instructed by the instruction member when the temperature of the hydraulic oil is within the allowable temperature range and the first mode is selected.

9. The electric working machine according to claim 7, wherein when the temperature of the hydraulic oil is higher than a predetermined second temperature that is higher than the allowable temperature range, regardless of whether the first mode or the second mode is selected by the selection member, the rotational speed that can be instructed by the instruction member is set to a predetermined third rotational speed that is higher than the first rotational speed.

10. Comprising a cooling device for cooling the hydraulic oil. The control device. When the temperature of the hydraulic oil detected by the oil temperature detection device is higher than the upper limit value of the allowable temperature range, the hydraulic oil is cooled by driving the cooling device. The electric working machine according to claim 1, wherein when the temperature of the hydraulic oil is equal to or lower than the lower limit value of the allowable temperature range, the cooling device is stopped.

11. An inverter for adjusting the power supplied from the battery unit to the electric motor. A rotational speed detection device for detecting the rotational speed of the electric motor. And a working operation member for operating the operation of the working device. The switching member includes an unloading operation member that can be switched between a load position that permits the operation of the working device and an unloading position that does not permit the operation of the working device. The control device. The electric working machine according to claim 1, wherein the rotational speed of the electric motor is controlled by adjusting the power supplied from the inverter to the electric motor based on the rotational speed of the electric motor detected by the rotational speed detection device.

12. Comprising a cooling device for cooling the hydraulic oil. The control device. When the temperature of the hydraulic oil detected by the oil temperature detection device is higher than the upper limit value of the allowable temperature range, the hydraulic oil is cooled by driving the cooling device. The electric working machine according to claim 5, wherein when the temperature of the hydraulic oil is equal to or lower than the lower limit value of the allowable temperature range, the cooling device is stopped. An inverter that adjusts the power supplied from the battery unit to the electric motor, a rotation speed detection device that detects the rotation speed of the electric motor, and a work operation member that operates the operation of the work device, and the switching member includes an unloading operation member that can be switched to either a load position that permits the operation of the work device or an unloading position that does not permit the operation of the work device, the control device controls the rotation speed of the electric motor by adjusting the power supplied from the inverter to the electric motor based on the rotation speed of the electric motor detected by the rotation speed detection device. The electric working machine according to claim 5.

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