Power tool and control method of the same

Patent metadata

Field	Value
Publication number	US-11070164-B2
Application number	US-202017080978-A
Country	US
Kind code	B2
Filing date	Oct 27, 2020
Priority date	May 3, 2018
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

A power tool has a functional component, a motor, a power supply module, a controller and a drive circuit including a first drive terminal and a second drive terminal respectively electrically connected to a first power terminal and a second power terminal of the power supply module, multiple high-side switches wherein high-side terminals of the high-side switches are respectively electrically connected to the first drive terminal, and multiple low-side switches wherein low-side terminals of the low-side switches are respectively electrically connected to the second drive terminal. The controller is configured to output a first control signal to one high-side switch to place it in an on or off state and output a second control signal to one low-side switch to place it in the other state. The low-side terminal of one high-side switch is connected to the high-side terminal of one low-side switch.

First claim

What is claimed is:

1. A power tool, comprising:
a functional component for realizing a function of the power tool;
a motor for driving the functional component, the motor having a plurality of windings;
a power supply module configured to provide a power supply current, the power supply module comprising a first power terminal and a second power terminal;
a drive circuit electrically connected to the motor, the drive circuit comprising:
a first drive terminal electrically connected with the first power terminal;
a second drive terminal electrically connected with the second power terminal;
a plurality of high-side switches wherein high-side terminals of the plurality of high-side switches are respectively electrically connected to the first drive terminal;
a plurality of low-side switches wherein low-side terminals of the plurality of low-side switches are respectively electrically connected to the second drive terminal; and

a controller configured to:
output a first control signal to a one of the plurality of high-side switches to place the one of the plurality of high-side switches in an on state or an off state; and
output a second control signal to a one of the plurality of low-side switches to place the one of the plurality of low-side switches in the other of the on state and the off state;

wherein the low-side terminal of the one of the plurality of high-side switches is connected to the high-side terminal of the one of the plurality of low-side switches, and
wherein an interval between a falling edge of the first control signal and a rising edge of the second control signal is a first preset duration.

2. The power tool of claim 1 , wherein the first control signal output by the controller is a first PWM signal and the second control signal output by the controller is a second PWM signal.

3. The power tool of claim 2 , wherein a duty cycle of the first PWM signal ranges from 10% to 95%.

4. The power tool of claim 2 , wherein a sum of a duty cycle of the first PWM signal and a duty cycle of the second PWM signal is less than 100%.

5. The power tool of claim 2 , wherein a duty cycle of the second PWM signal ranges from 10% to 95%.

6. The power tool of claim 1 , wherein the first preset duration ranges from 5 microseconds to 10 microseconds.

7. The power tool of claim 1 , wherein an interval between a rising edge of the first control signal and a falling edge of the second control signal is a second preset duration.

8. The power tool of claim 7 , wherein the second preset duration ranges from 5 microseconds to 30 microseconds.

9. The power tool of claim 1 , wherein an interval between a falling edge of the first control signal and a rising edge of the second control signal is a first preset duration and an interval between a rising edge of the first control signal and a falling edge of the second control signal is a second preset duration.

10. The power tool of claim 9 , wherein a ratio of the first preset duration to the second preset duration is less than or equal to 1.

11. The power tool of claim 1 , wherein the controller outputs the first control signal and the second control signal synchronously.

12. The power tool of claim 1 , wherein the power tool further comprises a current measuring module configured to detect or estimate phase current and the controller is configured to output the second control signal to turn off one of the plurality of low-side switches or output the first control signal to control to turn off one of the plurality of high-side switches when the phase current is less than or equal to zero.

13. The power tool of claim 1 , wherein the controller comprises a temperature sensor arranged inside the controller, the controller estimates a temperature of the drive circuit according to a detection value of the temperature sensor, and, when the detection value of the temperature of the drive circuit exceeds a predetermined threshold, the controller controls the drive circuit to stop working.

14. A power tool, comprising:
a functional component for realizing a function of the power tool;
a motor for driving the functional component, the motor having a plurality of windings;
a power supply module configured to provide a power supply current, the power supply module comprising a first power terminal and a second power terminal;
a drive circuit electrically connected to the motor, the drive circuit comprising:
a first drive terminal electrically connected with the first power terminal;
a second drive terminal electrically connected with the second power terminal;
a first high-side switch wherein a high-side terminal of the first high-side switch is electrically connected to the first drive terminal;
a first low-side switch wherein a low-side terminal of the first low-side switch is electrically connected to the second drive terminal; and

a controller configured to:
output a first control signal to the first high-side switch to place the first high-side switch in an on state or an off state; and
output a second control signal to the first low-side switch to place the first low-side switch in the other of the on state and the off state;

wherein the low-side terminal of the first high-side switch is connected to the high-side terminal of the first low-side switch, and
wherein an interval between a falling edge of the first control signal and a rising edge of the second control signal is a first preset duration.

15. The power tool of claim 14 , wherein the drive circuit further comprises a second low-side switch, a low-side terminal of the second low-side switch is electrically connected to the second drive terminal, the controller is configured to output the first control signal to the first high-side switch and the second low-side switch to form a first current circuitry, and, in the first current circuitry, the power supply current provided by the power supply module passes through the first drive terminal, the first high-side switch, the plurality of windings, the second low-side switch and the second drive terminal.

16. The power tool of claim 14 , wherein the first control signal output by the controller is a first PWM signal and the second control signal output by the controller is a second PWM signal.

17. The power tool of claim 16 , wherein a duty cycle of the first PWM signal ranges from 10% to 95%.

18. The power tool of claim 14 , wherein an interval between a rising edge of the first control signal and a falling edge of the second control signal is a second preset duration.

Assignees

• Nanjing Chervon Ind Co Ltd

Inventors

• Wang Hongwei
• Yang Dezhong
• Sun Yongan

Classifications

• H02P6/085 Primary

  in a bridge configuration · CPC title

• H02P29/68 Primary

  based on the temperature of a drive component or a semiconductor component · CPC title

• B23D45/16

  Hand-held sawing devices with circular saw blades · CPC title

• B23D49/10

  Hand-held or hand-operated sawing devices with straight saw blades · CPC title

• B25F5/00

  Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for · CPC title