Electric tool and method for supplying power to electric tool

Patent metadata

Field	Value
Publication number	US-11450895-B2
Application number	US-201816641519-A
Country	US
Kind code	B2
Filing date	Aug 27, 2018
Priority date	Aug 25, 2017
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

The present disclosure relates to an electric tool and a power supply method for an electric tool. The electric tool includes: a housing; a motor, accommodated in the housing; battery pack mounting portions, at least two battery packs being detachably mounted in the battery pack mounting portions; a main switch, being in an open state or a closed state according to an operation of a user, when the main switch is in a closed state, the battery packs are capable of supplying power to the motor, and when the main switch is in an open state, the battery packs stop supplying power to the motor; and a control assembly, detecting a state of the main switch, when the main switch is in an open state, the control assembly controls transfer of electric energy of a battery pack with a high voltage to a battery pack with a low voltage of the at least two battery packs.

First claim

What is claimed is:

1. An electric tool, comprising:
a housing;
a motor, accommodated in the housing;
battery pack mounting portions, at least two battery packs being detachably mounted in the battery pack mounting portions, wherein each of the battery packs comprises a battery pack housing and a plurality of cells disposed in the battery pack housing;
a main switch, being in an open state or a closed state according to an operation of a user, wherein when the main switch is in a closed state, the battery packs are capable of supplying power to the motor, and when the main switch is in an open state, the battery packs stop supplying power to the motor; and
a control assembly, detecting a state of the main switch, wherein when the main switch is in an open state, the control assembly controls transfer of electric energy of a battery pack with a high voltage to a battery pack with a low voltage of the at least two battery packs;
a parameter measurement module, wherein the parameter measurement module is electrically connected to the control assembly, the control assembly obtains state parameters, detected by the parameter measurement module, of the battery packs, and determines whether the parameters of the battery packs meet a preset condition, and when the state parameters of the battery packs meet the preset condition, the control assembly controls transfer of electric energy of a battery pack with a high voltage to a battery pack with a low voltage of the at least two battery packs;
a self-locking control assembly, wherein one end of the self-locking control assembly is connected to the battery packs, the other end is separately connected to the main switch and the control assembly, the self-locking control assembly comprises a capacitor assembly and a MOS transistor, a first end of the capacitor assembly is separately connected to the battery packs, the main switch, and the MOS transistor, and a second end of the capacitor is connected to the control assembly, when the battery packs are mounted into the battery pack mounting portions, the capacitor assembly is charged, and the MOS transistor is turned on, so that the battery packs provide power to the control assembly, and when the state parameters of the battery packs do not meet the preset condition, the control assembly controls the MOS transistor to open, so that the self-locking control assembly is open, to enable the control assembly to enter a static low power consumption mode.

2. The electric tool according to claim 1 , further comprising a switching switch connected to the battery pack mounting portions, wherein the control assembly controls the switching switch to switch between a first state and a second state, and when the main switch is in an open state, the control assembly controls the switching switch to switch to the first state, so that the at least two battery packs are connected in parallel to enable a battery pack with a high voltage to charge a battery pack with a low voltage;
wherein when the main switch is in a closed state, the control assembly controls the switching switch to switch to the second state, so that the at least two battery packs are connected in series to supply power to the motor.

3. The electric tool according to claim 1 , further comprising a balancing transformer and a balancing switch, wherein the balancing transformer is a multi-winding same-core transformer, the at least two battery packs are separately connected to a winding of the same-core transformer through two balancing switches, and when the main switch is in an open state, the control assembly controls two balancing switch connected to the low-voltage battery pack to close, so that the at least two battery packs are connected in series to enable a battery pack with a high voltage to charge a battery pack with a low voltage through the balancing transformer;
wherein when the main switch is in a closed state, the control assembly controls two balancing switch connected to the low-voltage battery pack to close, so that the at least two battery packs are connected in series to enable a battery pack with a high voltage to charge a battery pack with a low voltage through the balancing transformer.

4. The electric tool according to claim 2 , wherein the main switch comprises the switching switch, the main switch is a single-pole multi-throw switch formed by linkage of a first switch, a second switch, and a third switch, the first switch is electrically connected to the battery packs and the motor, the second switch and the third switch are separately located between the at least two battery packs, and when the first switch is in an open state according to an operation of the user, the linked second switch and third switch are separately in the first state, so that the at least two battery packs are connected in parallel to enable a battery pack with a high voltage to charge a battery pack with a low voltage.

5. The electric tool according to claim 4 , further comprising a fourth switch, wherein one end of the fourth switch is connected to the second switch of the single-pole multi-throw switch, the other end is connected to the first switch of the single-pole multi-throw switch and negative electrodes of one of the battery packs, and when the main switch is in an open state, and the control assembly controls the fourth switch to close when the parameters of at least two battery packs meet a preset condition, and controls the at least two battery packs to be connected in parallel to enable a battery pack with a high voltage to charge a battery pack with a low voltage.

6. The electric tool according to claim 2 , further the switching switch comprising at least two switching switches separately connected between the at least two battery packs, wherein the control assembly controls states of the at least two switching switches, and when the main switch is in an open state, the control assembly controls the switching switch to be in the first state, so that the at least two battery packs are connected in parallel to enable a battery pack with a high voltage to charge a battery pack with a low voltage.

7. The electric tool according to claim 6 , wherein the at least two battery packs comprise a first battery pack and a second battery pack, the at least two switching switch comprises a first switching switch and a second switching switch, the control assembly comprises a bidirectional power supply, and the bidirectional power supply comprises a first input terminal, a second input terminal, a first output terminal, and a second output terminal, the first input terminal is electrically connected to a positive electrode of the first battery pack by the first switching switch, the first output terminal is electrically connected to a negative electrode of the first battery pack, the second input terminal is electrically connected to a positive electrode of the second battery pack, the second output terminal is electrically connected to a negative electrode of the second battery pack by the second switching switch, and when the main switch is open, the control assembly controls the first switching switch and the second switching switch to be separately in the first state, so that the bidirectional power supply controls a battery pack with a high voltage to charge a battery pack with a low voltage by using a preset charging current;
wherein when the main switch is in a closed state, the control assembly controls the first switching switch and the second switching switch to be separately in the second state, and the at least two battery packs are connected in series to supply power to the motor.

8. The electric tool according to claim 1 , wherein the preset condition comprises at least one of the following:
determining, based on t

Assignees

• Positec Power Tools Suzhou Co Ltd

Inventors

• Deng Qiang
• Chen Mingming

Classifications

• H02J7/855 Primary

  with circuits adapted for supplying loads from the battery · CPC title

• H02J7/667

  disconnection of loads if battery is not under charge, e.g. in vehicle if engine is not running · CPC title

• H01M50/00

  Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells · CPC title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H02J7/342

  The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging (with circuits for polarity protection H02J7/68) · CPC title