COMBINATION ELECTRIC TOOL AND CONTROL METHOD THEREFOR

• US 20170043470A1
• Filed: 03/11/2015
• Published: 02/16/2017
• Est. Priority Date: 04/24/2014
• Status: Active Grant

• Current Assignee: Suzhou Cleva Electric Applicance Company Limited
• Original Assignee: Suzhou Cleva Electric Applicance Company Limited
• Inventors: Kong, Zhao
• Granted Patent: US 11,059,158 B2
• Time in Patent Office: Days
• CPC Class Codes: B25F 3/00 Associations of tools for different working operations with one portable power-drive means; Adapters therefor
• CPC Class Codes: H02H 7/0844 Fail safe control, e.g. by comparing control signal and controlled current, isolating motor on commutation error
• CPC Class Codes: H02H 7/0854 responsive to rate of change of current, couple or speed, e.g. anti-kickback protection H02H7/0851 takes precedence
• CPC Class Codes: H02H 7/0856 characterised by the protection measure taken
• CPC Class Codes: H02K 11/33 Drive circuits, e.g. power electronics H02K11/38 takes precedence
• CPC Class Codes: H02K 7/14 Structural association with mechanical loads, e.g. with hand-held machine tools or fans with fan or impeller for cooling the machine H02K9/06

Abstract

A combination electric tool includes a main body and at least one working part drivable via and separably attachable to the main body. The main body includes an electric motor and a control circuit with a signal recognition module having a microcontroller. The working part includes an identification module, the signal recognition module and the identification module being communicable such that the microcontroller can recognize the working part. A control method includes attaching the main body to the working part; judging which kind of working part is attached and selecting corresponding preset programs; sampling a working parameter value of the electric motor; comparing the sampled working parameter value of the electric motor with a corresponding preset value, and judging whether the electric motor is at an abnormal working state; and if yes, powering off the electric motor, and if no, returning to the previous step.

Claims

1. A combination electric tool comprising:

at least one main body;

at least one working part drivable by the main body and which may be separated from or attached to the main body;

the main body including an electric motor and a control circuit, the control circuit including a signal recognition module having a microcontroller; and

the working part including an identification module, the signal recognition module and the identification module being one of electrically connected and in wireless communication such that the microcontroller can recognize the working part.

2. The combination electric tool according to claim 1, wherein the identification module in each of the working parts includes an identification resistor, and a resistance value of each of the identification resistors is unique.

3. The combination electric tool according to claim 1, wherein the identification module in each of the working parts includes a plurality of interfaces at least one of which is a common interface, and when the main body and the working part are attached, the common interface is electrically connected to the control circuit.

4. The combination electric tool according to claim 3, wherein the control circuit includes a sampling resistor which may be electrically connected to the microcontroller and the common interface.

5. The combination electric tool according to claim 1, wherein the identification module in each of the working parts includes a sensor which is configured to acquire working state parameters of the working part.

6. The combination electric tool according to claim 1, wherein the signal recognition module further includes a wireless signal receiver, and the identification module includes a wireless signal transmitter.

7. The combination electric tool according to claim 1, wherein the control circuit includes a monitoring control module which is electrically connected to the electric motor and the microcontroller.

8. The combination electric tool according to claim 7, wherein the control circuit further includes a voltage monitoring module, the voltage monitoring module being electrically connected to a battery pack provided on the main body and to the microcontroller and configured to monitor a voltage of the battery pack.

9. The combination electric tool according to claim 7, wherein a first connecting part is provided on the main body, a second connecting part is provided on the working part, and the identification module is electrically connected to the control circuit when the first connecting part and the second connecting part are attached.

10. A control method for the combination electric tool having a main body and at least one working part, the main body having an electric motor and a control circuit having a microcontroller, the control method comprising the following steps:

(1) attaching the main body to the working part;

(2) judging which kind of working part is attached and selecting corresponding preset programs using the microcontroller;

(3) sampling a working parameter value of the electric motor using the microcontroller;

(4) comparing the sampled working parameter value of the electric motor with a corresponding preset value, and judging whether the electric motor is at an abnormal working state; and

(5) if yes as judged in step (4), powering off the electric motor, and if no as judged in step (4), returning to the step (4).

11. The control method according to claim 10, wherein the working parameter value of the electric motor compared in step (4) is a current value, and the step of judging whether the electric motor is at an abnormal working state comprises:

if the sampled current value of the electric motor is greater than the preset value, adding 1 to an overcurrent counter;

if the current value of the electric motor is not greater than the preset value, adding 1 to a non-overcurrent counter;

if the count of the non-overcurrent counter reaches a preset non-overcurrent number, resetting the non-overcurrent counter and the overcurrent counter at the same time; and

if the count of the overcurrent counter exceeds a preset overcurrent number, powering off the electric motor.

12. The control method according to claim 10, wherein, in step (2), the preset programs are a driving program and a protecting program for the electric motor.