US 12,460,380 B2
Electric work machine
Akira Watanabe, Ushiku (JP); Ken Takeuchi, Kasumigaura (JP); Yuki Makimura, Tsuchiura (JP); Kenta Tanigaki, Abiko (JP); and Seiji Ishida, Hitachinaka (JP)
Assigned to HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo (JP)
Appl. No. 18/843,864
Filed by HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo (JP)
PCT Filed Mar. 16, 2023, PCT No. PCT/JP2023/010447
§ 371(c)(1), (2) Date Sep. 4, 2024,
PCT Pub. No. WO2023/182182, PCT Pub. Date Sep. 28, 2023.
Claims priority of application No. 2022-044918 (JP), filed on Mar. 22, 2022.
Prior Publication US 2025/0179772 A1, Jun. 5, 2025
Int. Cl. E02F 9/20 (2006.01); B60L 9/00 (2019.01); B60L 15/00 (2006.01); B60L 15/20 (2006.01); B60L 50/60 (2019.01); B60L 50/70 (2019.01); E02F 9/22 (2006.01)
CPC E02F 9/207 (2013.01) [B60L 9/00 (2013.01); B60L 15/007 (2013.01); B60L 15/20 (2013.01); B60L 50/60 (2019.02); B60L 50/70 (2019.02); E02F 9/2296 (2013.01); B60L 2200/40 (2013.01); E02F 9/2203 (2013.01); E02F 9/2285 (2013.01); E02F 9/2292 (2013.01)] 3 Claims
OG exemplary drawing
 
1. An electric construction machine, comprising:
an inverter connected to a plurality of power sources, each having a suppliable electric power that changes; an electric motor driven by an electric power supplied from the plurality of power sources via the inverter; a hydraulic pump driven by the electric motor; an actuator that operates by hydraulic pressure generated by the hydraulic pump; a control device that that is configured to control the electric power supplied to the electric motor via the inverter, and a power storage device connected to the inverter,
wherein the plurality of power sources includes the power storage device, and a commercial power source or a fuel cell system,
wherein the control device is configured to set or compute a rotation speed command and an allowable torque of the electric motor on the basis of a required rotation speed of the electric motor or a drive torque of the hydraulic pump and a maximum supply power to which each suppliable electric power of the plurality of power sources has been added, and
wherein the inverter is configured to set the allowable torque to a torque command if a calculated torque of the electric motor computed on the basis of the rotation speed command and a rotation speed of the electric motor exceeds the allowable torque, and to set the calculated torque to the torque command if the calculated torque does not exceed the allowable torque, and the inverter is configured to supply an electric power that generates a torque corresponding to the torque command to the electric motor.