Electric powered work machinery

Abstract

Provided is an electric work machine comprising: an electric motor serving as a prime mover; an inverter for controlling the electric motor; a power supply system for supplying electric power to the inverter; a drive battery device for storing electric power supplied from the power supply system and supplying the electric power to the inverter; a control battery for supplying control power for the inverter, the power supply system, and the drive battery device; and an opening / closing cover for covering the power supply system, wherein the electric work machine also comprises a control electric power blocking device for blocking the supply of the control electric power to the inverter, the power supply system, and the drive battery device in concert with opening of the opening / closing cover.

Description

[Technical Field]

[0001] The present invention relates to an electric work machine such as a hydraulic excavator. [Background technology]

[0002] Some construction machines, such as hydraulic excavators, are designed so that the cab can be tilted up relative to the rotating frame, facilitating maintenance of hydraulic equipment, wiring, and other components located below the cab. Among these types of construction machines, there is one known that has a function that inhibits operation of the engine and hydraulic actuators when it detects that the cab has been tilted up (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-45955 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, electric powered work machines, which do not emit engine exhaust fumes and are quiet, have been increasingly used, especially in indoor and underground work sites. When tilting up the driver's cab of an electric powered work machine to expose the parts requiring maintenance, for example, if the key switch is on, a certain amount of voltage may remain in the electrical system even when the prime mover (electric motor) is stopped. When performing maintenance in this state, care must be taken to avoid residual voltage, which reduces work efficiency.

[0005] An object of the present invention is to provide an electric working machine that can sufficiently reduce the voltage of the electrical system during maintenance. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides an electric work machine including an electric motor as a prime mover, an inverter that controls the electric motor, a power supply system that supplies power to the inverter, a drive battery device that stores power supplied from the power supply system and supplies it to the inverter, a control battery that supplies control power to the inverter, the power supply system, and the drive battery device, and an open / close cover that covers the power supply system, the electric work machine including a control power cut-off device that cuts off the supply of control power to the inverter, the power supply system, and the drive battery device in conjunction with opening of the open / close cover, a sensor that detects the opening of the open / close cover, a base frame, a driver's cab including a driver's seat and mounted on the base frame, and ... and a rotating shaft arranged at the front of the cab to connect the cab to the base frame so that the rear of the cab can rise and fall, and a machine room interposed between the base frame and the cab and accommodating the power supply system and the inverter, the cab is the opening and closing cover and is configured to tilt up and down around the rotating shaft as a fulcrum to open and close the machine room, the sensor is arranged at a position closer to the rotating shaft than the inverter and is configured to detect a tilt-up state of the cab, and when the sensor detects that the cab has tilted up, the control power cut-off device cuts off the supply of control power to the inverter, the power supply system, and the drive battery device, and the inverter is arranged at the rear of the machine room. [Effects of the Invention]

[0007] According to the present invention, the voltage of the electrical system can be sufficiently reduced when maintenance is performed on an electric working machine. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side view of an electric powered working machine according to an embodiment of the present invention; [Figure 2] A diagram showing the driver's cab of the electric powered work machine in Figure 1 in a tilted state. [Figure 3] FIG. 2 is a diagram showing the main part of a tilt mechanism provided in the electric powered working machine of FIG. 1; [Figure 4] The diagram of the sensor that detects the tilt-up state of the driver's cab on the electric powered work machine in Figure 1. [Figure 5] Circuit diagram of the main parts of the electric power system of the electric powered working machine of Figure 1 DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] 1. Electric powered work machinery Fig. 1 is a side view of an electric work machine according to one embodiment of the present invention, and Fig. 2 is a view showing a state in which the driver's cab of the electric work machine in Fig. 1 is tilted. Hereinafter, the direction in which an operator sitting in the driver's seat faces (leftward in Fig. 1) will be referred to as the front of the rotating bed 12. Furthermore, in this embodiment, a hydraulic excavator will be described as an example of an electric work machine, but the present invention can also be applied to other electric work machines such as wheel loaders and bulldozers.

[0011] 1 is a hydraulic excavator, and includes a vehicle body 10 and a front work implement 20 connected to the vehicle body 10. The vehicle body 10 includes a running body 11 and a revolving body 12.

[0012] -Traveling body- The running body 11 forms the base structure of the electric work machine and is a crawler-type running body equipped with left and right tracks 13. The left and right tracks 13 are driven by left and right travel drive devices 14, respectively. The travel drive devices 14 are composed of a travel motor (hydraulic motor) and a reducer. A blade (earth removal device) 11a is attached to the front of the frame (track frame) of the running body 11. The blade 11a moves up and down by a blade cylinder (not shown). A rotating body 12 is provided above the running body 11 via a slewing ring 15. By driving the slewing ring 15 with a slewing motor (not shown), the rotating body 12 swivels around a vertical axis relative to the running body 11. The slewing motor is a hydraulic motor, but when an electric motor is used, a hydraulic motor and an electric motor may be used together. Note that although a crawler-type running body 11 is exemplified in this embodiment, the running body 11 may also be a wheel-type running body.

[0013] -Rotating body- The revolving body 12 includes a revolving frame 16, a driver's cab (operator's cabin) 17, an exterior cover 18, a counterweight 19, and the like.

[0014] The revolving frame 16 is a base frame of the revolving body 12. This revolving frame 16 is connected to the running body 11 via a revolving ring 15. A swing post 16a is connected to the front of the revolving frame 16 via a vertically extending shaft (not shown). The swing post 16a swings left and right by a swing cylinder (not shown).

[0015] The cab 17 is mounted on the revolving frame 16. The cab 17 includes a driver's seat 17a where the operator sits, an operating lever device 17b operated by the operator, and the like. The operating lever devices 17b are, for example, electric lever devices, and are provided on the left and right sides of the driver's seat 17a. For example, tilting the lever of the right operating lever device 17b forward commands the boom lowering operation, tilting it backward commands the boom raising operation, tilting it to the left commands the bucket crowding operation, and tilting it to the right commands the bucket dumping operation. Tilt the lever of the left operating lever device 17b forward commands the right turn operation, tilting it backward commands the left turn operation, tilting it to the left commands the arm dump operation, and tilting it to the right commands the arm crowding operation. In addition, the cab 17 is also provided with a controller 38, a key switch 39, and the like.

[0016] The exterior cover 18 is interposed between the revolving frame 16 and the cab 17, and surrounds devices such as a power supply system 50 (FIG. 5), power source 31, electric motor 41 (prime mover), hydraulic pump 42, and control valve 43, thereby forming a machinery room that houses the power supply system 50. In addition, the machinery room enclosed by the exterior cover 18 houses a drive battery device 32, an inverter 33, a DC / DC converter 34, a control battery 35, a control power cutoff device (controller relay) 36, and a key switch relay 37. The power supply system 50 includes an AC box 51, a power conversion device 52, a junction box 53, power transmission lines 54 and 55 (FIG. 5), etc.

[0017] The counterweight 19 is a weight that balances the weight with the front working implement 20 and is supported at the rear end of the revolving frame 16.

[0018] -Front work equipment- The front working implement 20 is an articulated working device and is made up of a working arm 21 and a bucket 22. The working arm 21 is made up of a boom 23, an arm 24, a boom cylinder 25, an arm cylinder 26, and a bucket cylinder 27. The boom cylinder 25, the arm cylinder 26, and the bucket cylinder 27 are all double-acting hydraulic cylinders that drive the front working implement 20. The boom cylinder 25 is located on the ventral side of the boom 23, the arm cylinder 26 is located on the dorsal side of the boom 23, and the bucket cylinder 27 is located on the dorsal side of the arm 24. The ventral side refers to the underside of the working arm 21 when the tip of the arm 24 is facing forward, and the dorsal side refers to the upper side of the working arm 21 when in the same position.

[0019] The boom 23 is connected to the vehicle body 10 (swing post 16a) via a pin so as to be rotatable up and down. The arm 24 is connected to the tip of the boom 23 via a pin so as to be rotatable back and forth. The bucket 22 is rotatably connected to the tip of the arm 24 via a pin. The bucket 22 is an attachment and can be replaced with another attachment such as a grapple.

[0020] The boom cylinder 25 has a base end connected to the vehicle body 10 (swing post 16a) and a tip end connected to the boom 23. The arm cylinder 26 has a base end connected to the boom 23 and a tip end connected to the arm 24. The bucket cylinder 27 has a base end connected to the arm 24 and a tip end connected to the bucket 22 via the bucket link 22a.

[0021] 2.Tilt mechanism Fig. 3 is a diagram showing the main parts of the tilt mechanism provided in the electric work machine of Fig. 1, and Fig. 4 is a configuration diagram of a sensor that detects the tilted-up state of the cab. As shown in Fig. 3, the cab 17 is connected to the revolving frame 16 via a rotation shaft 17c that extends horizontally (in the left-right direction in this embodiment), and is configured so that it can be tilted up and down around the rotation shaft 17c as a fulcrum. In this embodiment, the rotation shafts 17c are provided coaxially at two locations on the left and right of the front of the cab 17, and connect brackets 16B, 17B provided on the revolving frame 16 and the cab 17, respectively. The rear of the cab 17 moves up and down around these rotation shafts 17c as fulcrums. Fig. 2 shown above shows the cab 17 in a tilted-up state.

[0022] As described above, the cab 17 tilts about the rotation shaft 17c as a fulcrum, thereby opening and closing the upper opening of the machinery room defined by the exterior cover 18. As described above, the machinery room houses various devices such as the power supply system 50, and the cab 17 sits on the exterior cover 18 to close the upper opening of the machinery room, and by covering the upper opening of the machinery room, also serves as an opening and closing cover that covers the devices such as the power supply system 50 housed in the machinery room.

[0023] Among the devices housed in the machinery room, the junction box 53, inverter 33, and other devices that are generally expected to require frequent maintenance are located in the rear area of ​​the machinery room (i.e., the area opposite the rotating shaft 17c that is open widely above and below) (Fig. 2). In this way, the positional relationship between the rotating shaft 17c and the devices to be maintained, such as the junction box 53 and inverter 33, is set so that workers can easily access the devices that require frequent maintenance when the cab 17 is tilted up.

[0024] The electric work machine of this embodiment is also equipped with a sensor 60 that detects when an openable cover that covers the power supply system 50 and the like is open, i.e., when the cab 17 is tilted up. The sensor 60 is attached to the revolving frame 16 or the cab 17 (the cab 17 in this embodiment) so as to be located near the rotation shaft 17c of the cab 17 when viewed in the axial direction of the rotation shaft 17c (at a position closer to the rotation shaft 17c than the cab 17a). The sensor 60 may be of either a contact type or a non-contact type as long as it can detect a change in the distance between two members. In this embodiment, a configuration in which a type of limit switch is used as the sensor 60 is exemplified.

[0025] Specifically, the sensor 60 includes a body 61 and a lever 62. The body 61 houses a contact (e.g., a microswitch) and is fixed to the frame of the cab 17 via a bracket 63. The lever 62 is rotatably attached to the body 61 and configured to rotate relative to the body 61 to open and close a contact inside the body 61. The rotation center of the lever 62 coincides (or nearly coincides) with the center line of the rotation shaft 17c of the cab 17. In this embodiment, a bracket 64 is attached to the swivel frame 16 so as to face the rear side of the lever 62 of the sensor 60. The lever 62 of the sensor 60 is pressed against the bracket 64 by a spring (not shown) housed inside the body 61. As the cab 17 tilts up or down, the lever 62 engages with the bracket 64 and rotates relative to the body 61 of the sensor 60. The contacts of sensor 60 are closed when cab 17 is in the state shown in Fig. 4 (when cab 17 is horizontal), but when cab 17 tilts up (stands up from a horizontal position), lever 62 rotates and opens. When cab 17 tilts down (falls down from an upright position to a horizontal position), the contacts of sensor 60 close.

[0026] 3. Electric system 5 is a circuit diagram of the main parts of the electric system of the electric working machine of this embodiment. The electric system includes an inverter 33, a drive battery device 32, a power supply system 50, a controller 38, a control battery 35, a control power cutoff device 36, etc.

[0027] -Inverter- The inverter 33 controls the rotation speed of the electric motor 41. The electric motor 41 is a prime mover of a hydraulic system that drives hydraulic actuators such as the boom cylinder 25, and drives a hydraulic pump 42. The pressurized oil discharged from the hydraulic pump 42 is supplied to the hydraulic actuators via a control valve 43, and drives the hydraulic actuators. The hydraulic actuators driven by the pressurized oil discharged from the hydraulic pump 42 include the boom cylinder 25, the arm cylinder 26, and the bucket cylinder 27, as well as a swing motor, a swing cylinder, a travel motor, and a blade cylinder, all of which are not shown.

[0028] -Drive battery device- The drive battery device 32 is connected to the power supply system 50, the inverter 33, and the control battery 35 via power transmission lines 54, 55, and stores power supplied from the power supply system 50 and supplies the stored power to the inverter 33 and the control battery 35. The drive battery device 32 is equipped with a plurality of battery modules 32a, battery relays 32b, 32c, a pre-charge relay 32d, a pre-charge resistor 32e, a BMU 32f, etc.

[0029] The positive and negative terminals of the battery module 32a are connected to the power transmission lines 54 and 55 via battery relays 32b and 32c, respectively. The connection between the positive terminal of the battery module 32a and the power transmission line 54 is disconnected or connected by opening and closing the contacts of the battery relay 32b. Similarly, the connection between the negative terminal of the battery module 32a and the power transmission line 55 is disconnected or connected by opening and closing the contacts of the battery relay 32c. The pre-charge relay 32d and pre-charge resistor 32e serve to prevent excessive current from flowing through the power transmission lines 54 and 55 when the contacts of the battery relays 32b and 32c are closed. The pre-charge relay 32d and the battery relays 32b and 32c are opened and closed by control signals from the BMU 32f. The BMU 32f transmits monitoring data such as the voltage and temperature of each battery module 32a to the controller 38 and outputs control signals to the pre-charge relay 32d and the battery relays 32b and 32c according to commands based on the monitoring data received from the controller 38.

[0030] -Power supply system- The power supply system 50 supplies power from the power source 31 to the inverter 33, the drive battery 32, and the control battery 35 via power transmission lines 54 and 55. In this embodiment, a configuration is illustrated in which an on-board three-phase AC power source is used as the power source 31. The power supplied to the drive battery 32 and the control battery 35 is stored in the drive battery 32 and the control battery 35, respectively. The power supplied to the inverter 33 drives the inverter. As described above, the power supply system 50 includes the AC box 51, the power conversion device 52, the junction box 53, the power transmission lines 54 and 55, etc.

[0031] The AC box 51 is provided on a path that leads the three phases (L1, L2, L3 phases) and neutral wire N of the power source 31 to the power conversion device 52. In the power supply system 50, the power of the power source 31 that is supplied via the AC box 51 is converted from AC (alternating current) to DC (direct current) by the power conversion device 52 and is output via the junction box 53.

[0032] The AC box 51 is equipped with a voltage monitoring device 51a, a voltage monitoring relay 51b, and a power supply relay 51c. The voltage monitoring device 51a monitors the voltages between the L1, L2, and L3 phases and the neutral line N. The power monitoring device 51a operates using power from the control battery 35 supplied via the control power cutoff device 36. The contacts of the voltage monitoring relay 51b close when power is supplied to the voltage monitoring device 51a and the output of the voltage monitoring device 51a is normal. When power is not supplied to the voltage monitoring device 51a or when the output of the voltage monitoring device 51a is abnormal, the contacts of the power monitoring relay 51b open.

[0033] The power supply relay 51c has three contacts provided in the power supply paths of the L1, L2, and L3 phases that supply power from the power supply 31 to the power conversion device 52, and opens and closes the three contacts to interrupt and connect the power supply path connecting the power supply 31 and the power conversion device 52. The coil of the power supply relay 51c is connected in series to one of the L1, L2, and L3 phases (the L1 phase in this embodiment) of the power supply 31 via the contacts of the voltage monitoring relay 51b. When the contacts of the power supply monitoring relay 51b are closed (when the voltage monitoring device 51a is energized and the output of the voltage monitoring device 51a is normal), the contacts of the power supply relay 51c are closed, and power is supplied from the AC box 51 to the power conversion device 52. When the contacts of the power supply monitoring relay 51b are open (when the voltage monitoring device 51a is not energized or when the output of the voltage monitoring device 51a is abnormal), the contacts of the power supply relay 51c are open, and the power supply from the AC box 51 to the power conversion device 52 is interrupted.

[0034] The power conversion device 52 converts the power supplied from the power source 31 via the AC box 51 from AC (alternating current) to DC (direct current) and outputs it to the power transmission lines 54, 55. The power output from the power conversion device 52 to the power transmission lines 54, 55 is distributed via the junction box 53 and supplied to the inverter 33, the drive battery device 32, and the control battery 35. The power supplied to the drive battery device 32 and the control battery 35 is stored in the drive battery device 32 and the control battery 35, respectively. The power supplied to the inverter 33 drives the inverter.

[0035] -Control battery- The control battery 35 is connected to the power transmission lines 54, 55 via the DC / DC converter 34, and is also connected to the controller 38, inverter 33, drive battery 32, and power supply system 50 via a control power supply circuit 35A. The control power supply circuit 35A is wired so that a main line 35a connected to the control battery 35 and DC / DC converter 34 branches into multiple branch lines. Each branch line of the control power supply circuit 35A is connected to the controller 38, inverter 33, drive battery 32 (BMU 32f), and power supply system 50 (voltage monitoring device 51a and power conversion device 52).

[0036] Therefore, the power supplied via the power supply system 50 or the drive battery 32 is stepped down by the DC / DC converter 34, and the stepped down power is supplied to and stored in the control battery 35. The power stored in the control battery 35 is output to the control power supply circuit 35A and used as control power for the controller 38, the inverter 33, the drive battery 32, and the power supply system 50.

[0037] -controller- The controller 38 is connected to the inverter 33, the drive battery 32 (BMU 32f), and the power supply system 50 (power conversion device 52) via control lines. The controller 38 operates on control power from the control battery 35, and controls the inverter 33 and the power supply system 50 (power conversion device 52) based on data input from the drive battery 32 (BMU 32f).

[0038] -Controlled power cutoff device- The control power cutoff device 36 cuts off the supply of control power to the inverter 33, the drive battery device 32, and the power supply system 50 in conjunction with the opening of the driver's cab 17, which serves as an open / close cover that covers the power supply system 50, etc.

[0039] In this embodiment, the control power cutoff device 36 is a relay provided in the main line 35a of the control power supply circuit 35A (a portion closer to the control battery 35 than the branch lines connected to the inverter 33, the power supply system 50, the drive battery 32, and the controller 38). The control power cutoff device 36 has contacts provided in the main line 35a of the control power supply circuit 35A, and one end of the coil is connected to an electric wire leading from the main line 35a via a sensor 60. The other end of the coil of the control power cutoff device 36 is grounded via a key switch relay 37. The contacts of the key switch relay 37 close when the key switch 39 is on and open when the key switch 39 is off.

[0040] 4.Operation (a) When driving, etc. During operation, the key switch 39 is turned on with the cab 17 lying horizontally (not tilted up). When the cab 17 is horizontal and the key switch 39 is on, the contacts of the sensor 60 and the key switch relay 37 are both closed, power is received by the coil from the control power supply circuit 35A, and the contacts of the control power cutoff device 36 are closed. This causes electricity to flow to electrical components such as the controller 38, inverter 33, drive battery unit 32 (BMU 32f), and power supply system 50 (voltage monitoring device 51a and power conversion device 52), and these electrical components start up.

[0041] In the drive battery 32, the BMU 32f switches the contacts of the pre-charge relay 32d and the battery relays 32b and 32c from the open position to the closed position in sequence, and the power stored in the drive battery 32 is supplied to the power transmission lines 54 and 55. Thereafter, when a predetermined set time has elapsed since the battery relays 32b and 32c were switched to the closed position, the pre-charge relay 32d is switched to the open position by the BMU 32f.

[0042] In the AC box 51, the voltage monitoring device 51a switches the contact of the voltage monitoring relay 51b from the open position to the closed position, and current flows from one of the three phases of the power supply 31 (phase L1 in the example of FIG. 5) to the coil of the power supply relay 51c. This closes the contact of the power supply relay 51c, and AC power is supplied from the power supply 31 to the power conversion device 52 via the AC box 51.

[0043] Furthermore, in the power conversion device 52, the power supplied from the power source 31 via the AC box 51 is converted from AC (alternating current) to DC (direct current) and output to the power transmission lines 54, 55. The power on the power transmission lines 54, 55 is appropriately guided via the junction box 53 to the inverter 33, the DC / DC converter 34, and the drive battery device 32. The power supplied to the DC / DC converter 34 is stepped down and supplied to the control battery 35.

[0044] Furthermore, inverter 33 receives power from control power supply circuit 35A in its control circuit, and controls the power supplied via junction box 53 to control the rotation speed of electric motor 41. Hydraulic pump 42 is driven by electric motor 41, and pressure oil discharged from hydraulic pump 42 is supplied via control valve 43 to hydraulic actuators such as boom cylinder 25, causing these hydraulic actuators to operate.

[0045] (b) During maintenance, etc. For example, when the cab 17 is tilted up for maintenance of the power supply system 50 (junction box 53), the inverter 33, or the like, the contacts of the sensor 60 open. Therefore, regardless of whether the key switch 39 is on or off, the power supply from the control power supply circuit 35A is cut off, the coil is demagnetized, and the contacts of the control power cutoff device 36 open. This cuts off the power supply to all electrical components, such as the controller 38, the inverter 33, the drive battery unit 32 (BMU 32f), and the power supply system 50 (the voltage monitoring device 51a and the power conversion device 52), and all of these electrical components stop operating.

[0046] In the drive battery 32, when the BMU 32f stops operating, the contacts of the precharge relay 32d and the battery relays 32b and 32c all open, and the connection between the drive battery 32 and the power transmission lines 54 and 55 is cut off.

[0047] In the AC box 51, when the voltage monitoring device 51a stops operating, the contacts of the voltage monitoring relay 51b open, and accordingly the contacts of the power supply relay 51c also open, cutting off the supply of AC power to the power conversion device 52. This also cuts off the connection between the power source 31 and the power transmission lines 54 and 55.

[0048] In this way, the power transmission lines 54, 55 are disconnected from the power supply 31 and the drive battery 32, and the power supply to the inverter 33 is also stopped. The inverter 33 itself is also stopped by disconnecting it from the control power supply circuit 35A. The electric motor 41, hydraulic pump 42, and hydraulic actuator are also stopped. The power supply from the power transmission lines 54, 55 to the DC / DC converter 34 and, ultimately, to the control battery 35 is also stopped.

[0049] As described above, the control power cutoff device 36 is configured to cut off the supply of control power to the inverter 33, the drive battery 32, and the power supply system 50 when the sensor 60 detects that the driver's cab 17 is open. In particular, in this embodiment, the control power cutoff device 36 is configured as a relay, and a contact opens when the sensor 60 detects that the driver's cab 17 is open. This contact is provided in the main line 35a of the control power supply circuit 35A, and cuts off the supply of control power not only to the inverter 33, the drive battery 32, and the power supply system 50, but also to the controller 38.

[0050] When the key switch 39 is OFF, the contacts of the key switch relay 37 are open, and therefore the contacts of the control power cutoff device 36 are open regardless of whether the cab 17 is tilted up or not. The circuit operation caused by the contacts of the control power cutoff device 36 opening is the same as when the cab 17 is tilted up.

[0051] 5.Effects (1) In this embodiment, by providing the control power cutoff device 36, when the cab 17 is tilted up (opened), the supply of control power to the inverter 33, the drive battery device 32, and the power supply system 50 is cut off regardless of whether the key switch 39 is on or off. This stops the electric motor 41 and the hydraulic pump 42, stops all hydraulic actuators, and causes a drop in voltage of electrical equipment including the power supply system 50.

[0052] Therefore, even if an operator opens the cab 17 without turning off the key switch 39, the electric system is reliably stopped and power is not supplied to the power transmission lines 54, 55. Therefore, when inspecting or repairing equipment related to the electric system during maintenance of the electric work machine, the voltage of the electrical system can be sufficiently reduced.

[0053] (2) When the sensor 60 detects that the cab 17 is open, the control power cutoff device 36 cuts off the supply of control power to the inverter 33, the drive battery 32, and the power supply system 50. For example, it is possible to configure the contacts of the control power cutoff device 36 to be mechanically linked to the cab 17 so that the contacts open in direct linkage with the tilt-up of the cab 17; however, in this case, the layout of the contacts of the control power cutoff device 36 is restricted. In contrast, in this embodiment, a sensor 60 is provided that detects the tilt-up of the cab 17, and a configuration is adopted in which the control power is cut off in response to the output of this sensor 60, thereby ensuring design freedom and enabling flexible changes to the equipment layout.

[0054] However, in order to obtain the essential effect (1) described above, the sensor 60 can be omitted as appropriate. For example, if a configuration in which the contacts of the control power cutoff device 36 are mechanically linked directly to the cab 17 to open and close does not impede the layout design, a contact that is mechanically linked to the cab 17 without using the sensor 60 can be used as the control power cutoff device 36.

[0055] (3) Furthermore, the contacts of the control power cutoff device 36 are provided on the control power supply circuit 35A, and when the cab 17 tilts up, the control power supply to the drive battery 32, the inverter 33, and the power supply system 50 is cut off by cutting off the control power supply circuit 35A. In this way, the control power to each electrical device can be cut off without relying on control by the controller 38, so that even if an abnormality occurs in the controller 38, the control power to each electrical device, such as the power supply system 50, can be reliably cut off. By cutting off the control power to each electrical device, such as the power supply system 50, without relying on the controller 38, the controller 38 itself can also be stopped when the cab 17 tilts up. Therefore, the contacts of the control power cutoff device 36 can be provided on the main line 35a of the control power supply circuit 35A, and the control power can be rationally controlled using a single contact.

[0056] However, the configuration related to effect (3) is not essential to achieving effect (1). For example, to ensure the operation of some electrical equipment such as warning lights while the cab 17 is tilted up, a configuration may be adopted in which control power is supplied to electrical equipment such as the power supply system 50 via the controller 38, and the controller 38 controls the control voltage according to the output of the sensor 60. Alternatively, a configuration may be adopted in which contacts of the control power cutoff device 36 are individually provided on each branch line connected to electrical equipment to which the supply of control power should be cut off, rather than on the main line 35a of the control power supply circuit 35A, thereby ensuring the supply of control power to the controller 38 and necessary equipment.

[0057] (4) In this embodiment, tilting up the cab 17 allows the machinery room to be opened widely, and the cab 17 also serves as an inspection cover, making it possible to achieve both compactness of the machine body and ease of maintenance. In this configuration, when opening the machinery room to perform maintenance on electrical equipment such as the power supply system 50 or the inverter 33, the worker necessarily lifts up the cab 17. In this embodiment, the power supply to electrical equipment such as the power supply system 50 can be rationally shut off in light of this necessary procedure of the worker.

[0058] In this embodiment, the control power is cut off upon detecting the tilt-up of the cab 17, but the openable cover that detects its opening can be changed as appropriate depending on the configuration of the electric work machine. In this embodiment, for example, it is also possible to adopt a configuration in which the control power is cut off upon detecting the opening of the cover of the junction box 53 (including the partition that separates the junction box 53). In this case, a limit switch or proximity sensor can be used to detect the opening of the openable cover by detecting the separation of the cover of the junction box 53 from the main body. Additionally, even in hydraulic excavators and other electric work machines that do not employ a cab lift-up mechanism, a configuration in which the control power is cut off upon detecting the opening of the openable cover of a maintenance access port used for inspecting electrical equipment, etc., with a sensor can be adopted.

[0059] (5) Because the sensor 60 is located near the rotation axis 17c of the cab 17, even when the cab 17 is tilted up, the width of the space around the sensor 60 can be kept narrow, thereby protecting the sensor 60. Therefore, it is possible to prevent a worker from touching the sensor 60 with a tool or the like while performing maintenance on the junction box 53, the inverter 33, or the like, and damaging or causing a malfunction of the sensor 60.

[0060] Note that the position of the sensor 60 is not necessarily limited in order to obtain the essential effect (1) described above. For example, a sensor (limit switch, proximity sensor, etc.) that detects the separation or distance between two members may be used as the sensor 60, and even if this is configured to be installed on the opposite side of the rotation shaft 17c with respect to the driver's seat 17a, it is still possible to detect the lifting up of the driver's cab 17. Even with such a configuration, the control power can be cut off when the driver's cab 17 is lifted up, and the effect (1) described above can be obtained.

[0061] In addition, in the present embodiment, the rotating shaft 17c is arranged at the front of the cab 17, and the rear side of the cab 17 moves up and down around the rotating shaft 17c as a fulcrum, but the opening and closing direction of the cab 17 is not limited to this. For example, the rotating shaft 17c may be arranged at the left side, right side, or rear of the cab 17, and the right side, left side, or front of the cab 17 may move up and down. [Explanation of symbols]

[0062] 16... Swing frame (base frame), 17... Driver's cab (opening / closing cover), 17c... Rotating shaft, 18... Exterior cover (machine room), 32... Drive battery device, 33... Inverter, 35... Control battery, 36... Control power cut-off device, 38... Controller, 41... Electric motor, 50... Power supply system, 60... Sensor

Claims

1. an electric motor as a prime mover; an inverter for controlling the electric motor; a power supply system that supplies power to the inverter; a drive battery device that stores power supplied from the power supply system and supplies the power to the inverter; a control battery that supplies power for controlling the inverter, the power supply system, and the drive battery device; an opening / closing cover for covering the power supply system; In an electric powered working machine equipped with a control power cutoff device that cuts off the supply of control power to the inverter, the power supply system, and the drive battery device in conjunction with opening of the open / close cover; a sensor that detects the opening of the opening / closing cover; A base frame; a driver's cab including a driver's seat and mounted on the base frame; a rotating shaft that connects the cab to the base frame and is disposed at the front of the cab so that the rear of the cab can be raised and lowered; a machine room interposed between the base frame and the cab and accommodating the power supply system and the inverter, The cab is the opening / closing cover and is configured to tilt up and down around the rotation shaft as a fulcrum to open and close the machine room, The sensor is disposed at a position closer to the rotation shaft than the inverter and is configured to detect a tilt-up state of the cab, When the sensor detects that the driver's cab is tilted up, the control power cut-off device cuts off the supply of the control power to the inverter, the power supply system, and the drive battery device; The inverter is disposed at the rear of the machine room. An electric work machine characterized by:

2. (delete)

3. The electric power operating machine according to claim 1, the control power cutoff device is a relay provided in a control power supply circuit that connects the inverter, the power supply system, and the drive battery device with a control battery, The relay is configured to open a contact point when the sensor detects that the cover is open. An electric work machine characterized by:

4. The electric power operating machine according to claim 3, a controller that operates using the control power from the control battery and controls the inverter and the power supply system; The relay cuts off the supply of the control power to the controller when the sensor detects that the openable cover is opened. An electric work machine characterized by:

5. (delete)

6. The electric power operating machine according to claim 1, The electric working machine is characterized in that the sensor is disposed at a position closer to the rotary shaft than the driver's seat.

7. The electric power operating machine according to claim 1, The sensor a body fixed to the cab and having contacts therein; a lever that rotates relative to the body to open and close the contacts, Detecting a tilt-up state of the cab based on the state of the contacts; A bracket is attached to the base frame so as to face the rear side of the lever and be able to abut against it. An electric work machine characterized by:

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