Work machine

Patent metadata

Field	Value
Publication number	US-12166441-B2
Application number	US-202117921633-A
Country	US
Kind code	B2
Filing date	Mar 31, 2021
Priority date	Apr 28, 2020
Publication date	Dec 10, 2024
Grant date	Dec 10, 2024

Abstract

Provided is a work machine capable of improving workability. The work machine is provided with: a motor 14; a first power supply unit 180 connected to a battery pack 5 and supplying a boosted power to the motor 14; and a second power supply unit 130 connected to an external AC power supply and supplying a boosted power to the motor 14. The voltage and current of the first power supply unit 180 and the voltage and current of the second power supply unit 130 can be variably controlled by a control circuit 182 and a control circuit 136, respectively. The control circuits 136, 182 perform control so that the power output from the respective first power supply unit 180 and the second power supply unit 130 is combined and supplied to the motor 14.

First claim

The invention claimed is:

1. A work machine comprising:
a motor;
a first power supply unit connected to a DC power supply, boosting an output voltage of the DC power supply, and outputting the boosted output voltage to the motor;
a second power supply unit electrically connected to the motor in parallel together with the first power supply unit, connected to an external AC power supply, boosting an output voltage of the AC power supply, and outputting the boosted output voltage to the motor; and
a controller controlling boosting amounts of the first power supply unit and the second power supply unit,
wherein the controller controls the boosting amounts of the first power supply unit and the second power supply unit so that power output from the first power supply unit and power output from the second power supply unit are combined and supplied to the motor, and an output voltage value of the first power supply unit becomes larger than an output voltage value of the second power supply unit.

2. The work machine according to claim 1 , further comprising:
a first output current detection unit detecting an output current value of the first power supply unit,
wherein the controller controls a boosting amount of the first power supply unit based on a detected value of the first output current detection unit.

3. The work machine according to claim 2 , wherein the controller controls the boosting amount of the first power supply unit so that the detected value of the first output current detection unit falls below a predetermined first current threshold value.

4. The work machine according to claim 3 , further comprising:
a first output voltage detection unit detecting an output voltage value of the first power supply unit; and
a second output voltage detection unit detecting an output voltage value of the second power supply unit,
wherein the controller controls the boosting amount of the second power supply unit so that a detected value of the second output voltage detection unit matches a predetermined second voltage target value, and controls the boosting amount of the first power supply unit so that a detected value of the first output voltage detection unit matches a predetermined first voltage target value which is larger than the second voltage target value.

5. The work machine according to claim 4 , wherein the controller controls the boosting amount of the first power supply unit so that the detected value of the first output current detection unit falls below the first current threshold value while the first voltage target value is fixed.

6. The work machine according to claim 1 , further comprising:
a rotation speed detection unit detecting a rotation speed of the motor; and
a motor driving circuit connected between the first power supply unit and the second power supply unit and the motor and controlling driving of the motor by changing an amount of power to be supplied to the motor,
wherein the controller is able to set a target rotation speed of the motor and controls the motor driving circuit so that a detected value of the rotation speed detection unit matches the target rotation speed.

7. The work machine according to claim 6 , wherein the controller is able to switch between an assist mode and a single mode, the assist mode being a mode in which power output from the first power supply unit and power output from the second power supply unit are combined and supplied to the motor, the single mode being a mode in which power output from the second power supply unit is supplied to the motor, and power is not supplied from the first power supply unit.

8. The work machine according to claim 7 , wherein the controller sets the target rotation speed in the assist mode to be higher than the target rotation speed in the single mode.

9. The work machine according to claim 1 , wherein the first power supply unit is able to change an output voltage value by PAM control.

10. The work machine according to claim 9 , further comprising:
a first output voltage detection unit detecting an output voltage value of the first power supply unit,
wherein the controller controls a boosting amount of the first power supply unit so that a detected value of the first output voltage detection unit matches a first voltage target value, sets the first voltage target value to be less than a predetermined assist threshold value in a case where an output current value of the AC power supply is less than a first current value, and sets the first voltage target value to be equal to or greater than the assist threshold value in a case where the current value of the AC power supply is equal to or greater than the first current value.

11. The work machine according to claim 10 , wherein the controller is able to change the first voltage target value in a range of the assist threshold value or more so that power output from the first power supply unit and power output from the second power supply unit are combined and supplied to the motor.

12. The work machine according to claim 1 , wherein a work machine main body portion and an adapter are electrically connected to each other, the work machine main body portion including the second power supply unit, the adapter being provided outside the work machine main body portion, having the battery pack mountable thereon, and including the first power supply unit.

13. The work machine according to claim 1 , further comprising:
a power detection circuit detecting a state of power flowing through the first power supply unit and the second power supply unit,
wherein the controller sets a first target value, which is a target value of the output voltage of the first power supply unit, and a second target value, which is a target value of the output voltage of the second power supply unit, so that power output from the first power supply unit and power output from the second power supply unit are combined and supplied to the motor, and the controller changes the first target value and the second target value in accordance with a detected value of the power detection circuit.

14. The work machine according to claim 13 , wherein the power detection circuit detects an output voltage of the DC power supply, and the controller decreases the first target value and the second target value more when the output voltage of the DC power supply is less than a first threshold value than when the output voltage of the DC power supply is equal to or greater than the first threshold value.

15. The work machine according to claim 14 , wherein the controller stops output of the first power supply unit when the output voltage of the DC power supply is less than a second threshold value which is smaller than the first threshold value.

16. A work machine comprising:
a motor;
a first power supply unit connected to a DC power supply, boosting an output voltage of the DC power supply, and outputting the boosted output voltage to the motor;
a second power supply unit electrically connected to the motor in parallel together with the first power supply unit, connected to an external AC power supply, boosting an output voltage of the AC power supply, and outputting the boosted output voltage to the motor; and
a controller controlling boosting amounts of the first power supply unit and the second power supply unit,
wherein the controller controls an output voltage value of the first power supply unit becomes larger than an output voltage value of the second power supply unit, so that power output from the first power supply unit and power output from the second power supply unit are combined and s

Assignees

• Koki Holdings Co Ltd

Inventors

• Hoshino Kenichi
• Nakano Yasushi
• Sudo Tomoaki
• Nakayama Eiji

Classifications

• H02J7/977

  of the battery · CPC title

• H02J7/933

  the cycle being controlled or terminated in response to electric parameters · CPC title

• H02P27/08

  with pulse width modulation · CPC title

• H02J7/1438

  in combination with power supplies for loads other than batteries · CPC title

• H02J7/1423

  with multiple batteries · CPC title