Method of operating a rotary tool

• US 8,636,079 B2
• Filed: 10/08/2010
• Issued: 01/28/2014
• Est. Priority Date: 07/23/2004
• Status: Active Grant

• Current Assignee: Katsuyuki Totsu
• Original Assignee: Katsuyuki Totsu
• Inventors: Totsu, Katsuyuki
• Primary Examiner(s): Lopez, Michelle
• Application Number:
  US12/924,934
• Publication Number:
  US 20110030981A1
• Time in Patent Office: 1,208 Days
• Field of Search: 173 5- 6, 173/11, 173/178, 173180-181, 173/104, 173/170, 173/217, 173/1, 310/50, 318/281, 318/434
• US Class Current: 173/1
• CPC Class Codes: B25B 21/00 Portable power-driven screw or nut setting or loosening tools; details or components, e.g. casings, bodies, of portable power-driven tools not particularly related to the operation performed B25F5/00; for mounting or dismounting wheels B60B29/006; Attachments for drilling apparatus serving the same purpose machines B23P19/06
• CPC Class Codes: B25B 23/14 Arrangement of torque limiters or torque indicators in wrenches or screwdrivers couplings for transmitting rotation or clutches F16D; devices for measuring torque per se G01L
• CPC Class Codes: B25B 23/147 specially adapted for electrically operated wrenches or screwdrivers
• CPC Class Codes: H02P 6/22 in a selected direction of rotation
• CPC Class Codes: H02P 6/24 Arrangements for stopping

Abstract

A method of operating a rotary tool driven by a brushless motor including a DC brushless motor for rotationally driving a rotary bit, a torque setting clutch mechanism, a drive switch for drive-controlling a drive control circuit of the brushless motor, and a control means to rotationally drive the brushless motor by an operation of the drive switch and wherein the method includes a first step for stop-controlling of the drive control circuit, a second step for rotating forward or in reverse the brushless motor through the control and a third step for control-operating a semiconductor of an inverter circuit provided in the drive control circuit to short-circuit the magnetizing windings of the brushless motor, thus braking the rotor of the brushless motor and stopping the brushless motor.

Claims

1. A method of operating a rotary tool driven by a brushless motor comprising:

a DC brushless motor for rotationally driving a rotary bit,

a torque setting clutch mechanism provided in a shaft-coupling portion for coupling said rotary bit and an output shaft of said brushless motor,

a drive switch for drive-controlling a drive control circuit of said brushless motor, and

a control means configured so as to rotationally drive said brushless motor by an operation of said drive switch and so as to stop a rotational drive of said brushless motor by detecting clutch action of said clutch mechanism, wherein;

first Hall elements for respectively detecting a lever operation and a push operation are respectively provided for a lever operation mechanism and a push operation mechanism both being said drive switch for said brushless motor, a second Hall element for detecting a clutch action is provided for said dutch mechanism, and a third Hall element for detecting forward/reverse switching operation is provided for a forward/reverse switching operation mechanism that performs forward/reverse switching operation of said blushless motor;

said control means is configured so that, based on a drive switch operation signal provided by one of said first Hall elements, said drive control circuit of said brushless motor is drive-controlled so as to rotationally drive said brushless motor and so that, based on a clutch mechanism action signal provided by said second Hall element, said drive control circuit of said brushless motor is stop-controlled so as to stop the rotational drive of said brushless motor; and

said brushless motor drive control circuit is comprised of;

an internal AC/DC conversion means connected to an external commercial power source for obtaining a power supply voltage for driving said brushless motor, an inverter circuit comprising a semiconductor bridge configuration that converts said power supply voltage into a brushless motor drive voltage, a drive circuit for ON/OFF-controlling a semiconductor that comprises said bridge configuration of said inverter circuit, and a position detection circuit for detecting a position of a rotor with respect to magnetizing windings in said brushless motor;

wherein said method comprises;

a first step for, when stop-control of said drive control circuit of said brushless motor is performed by said control means based on said clutch mechanism action signal provided by said second Hall element, interrupting a drive power for said brushless motor and further control-operating said semiconductor, which comprises said bridge configuration of said inverter circuit provided in said drive control circuit of said brushless motor, so as to short-circuit said magnetizing windings of said brushless motor, thus braking said rotor of said brushless motor;

a second step for rotating forward or in reverse said brushless motor through said control means based on a forward/reverse switching operation signal provided by said third Hall element; and

a third step for, based on an operation suspension signal of said drive switch provided by the first Hall elements, control-operating said semiconductor, which comprises said bridge configuration of said inverter circuit provided in said drive control circuit of said brushless motor, so as to short-circuit said magnetizing windings of said brushless motor, thus braking said rotor of said brushless motor and stopping said brushless motor, said third step being executed when, during forward or reverse rotation of said brushless motor, a lever operation or push operation of said lever operation mechanism or push operation mechanism, both being said drive switch, is suspended.

2. A method of operating a rotary tool driven by a brushless motor comprising:

a DC brushless motor for rotationally driving a rotary bit,

a load current detection means for detecting a load current of said brushless motor,

a drive switch for drive-controlling a drive control circuit of said brushless motor, and

a control means configured so as to rotationally drive said brushless motor by an operation of said drive switch and so as to stop a rotational drive of said brushless motor when a load current detected by said load current detection means exceeds a predetermined set value, wherein;

first Hall elements for respectively detecting a lever operation and a push operation are respectively provided for a lever operation mechanism and a push operation mechanism both being said drive switch for said brushless motor, and a third Hall element for detecting forward/reverse switching operation is provided for a forward/reverse switching operation mechanism that performs forward/reverse switching operation of said blushless motor;

said control means is configured so that, based on a drive switch operation signal provided by one of said respective first Hall elements, said drive control circuit of said brushless motor is drive-controlled so as to rotationally drive said brushless motor and so that, when a load current detected by said load current detection means exceeds a set value, said drive control circuit of said brushless motor is stop-controlled so as to stop the rotational drive of said brushless motor; and

said brushless motor drive control circuit is comprised of;

an internal AC/DC conversion means connected to an external commercial power source for obtaining a power supply voltage for driving said brushless motor, an inverter circuit comprising a semiconductor bridge configuration that converts said power supply voltage into a brushless motor drive voltage, a drive circuit for ON/OFF-controlling a semiconductor that comprises said bridge configuration of said inverter circuit, and a position detection circuit for detecting a position of a rotor with respect to magnetizing windings in said brushless motor;

wherein said method comprises;

a first step for interrupting a drive power for said brushless motor, when a load current detection signal that is detected by said load current detection means to exceed a set value which has been set previously, by way of outputting stop control signal to a drive circuit provided in the drive control circuit of the blushless motor, said first step further control-operating said semiconductor, which comprises said bridge configuration of said inverter circuit provided in said drive control circuit of said brushless motor, so as to short-circuit said magnetizing windings of said brushless motor, thus braking said rotor of said brushless motor;

a second step for rotating forward or in reverse said brushless motor through said control means based on a forward/reverse switching operation signal provided by said third Hall element, and

a third step for, based on an operation suspension signal of said drive switch provided by the first Hall elements, control-operating said semiconductor, which comprises said bridge configuration of said inverter circuit provided in said drive control circuit of said brushless motor, so as to short-circuit said magnetizing windings of said brushless motor, thus braking said rotor of said brushless motor and stopping said brushless motor, said third step being executed when, during forward or in reverse rotation of said brushless motor, a lever operation or push operation of said lever operation mechanism or push operation mechanism, both being said drive switch, is suspended.

3. A method for operating a rotary tool driven by a brushless motor, said rotary tool comprising:

a DC brushless motor for rotationally driving a rotary bit;

a torque setting clutch mechanism in a shaft coupling portion for coupling said rotary bit and an output shaft of said brushless motor,

a drive switch for drive-controlling a drive control circuit of said brushless motor;

a control means configured so as to rotationally drive said brushless motor by an operation of said drive switch and so as to stop a rotational drive of said brushless motor by detecting clutch action of said clutch mechanism;

first Hall elements for respectively detecting a lever operation and a push operation of a lever operation mechanism and a push operation mechanism, both being said drive switch of said brushless motor;

a second Hall element for detecting a clutch action of said clutch mechanism;

a forward/reverse switching operation mechanism for performing forward/reversing switching operation of said brushless motor; and

a third Hall element for detecting forward/reverse switching operation of said forward/reverse switching operation mechanism;

said control means being configured so that, based on a drive switch operation signal provided by one of said first Hall elements, said drive control circuit of said brushless motor being is drive controlled so as to rotationally drive said brushless motor and so that, based on a clutch mechanism action signal provided by said second Hall element, said drive control circuit of said brushless motor is stop-controlled so as to stop the rotational drive of said brushless motor; and

said brushless motor drive control circuit being comprised of;

an internal AC/DC conversion means connected to an external commercial power source for obtaining a power supply voltage for driving said brushless motor, an inverter circuit comprising a semiconductor bridge configuration that converts said power supply voltage into a brushless motor drive voltage, a drive circuit for ON/OFF-controlling a semiconductor that comprises said bridge configuration of said inverter circuit; and

a position detection circuit for detecting a position of a rotor with respect to magnetizing windings in said brushless motor;

wherein said method comprises;

interrupting, when stop-contra of said drive control circuit of said brushless motors is performed by said control means, a drive power for said brushless motor based on said clutch mechanism action signal provided by said second Hall element, and control-operating said semiconductor that comprises said bridge configuration of said inverter circuit provided in said drive control circuit of said brushless motor so as to short circuit said magnetizing windings of said brushless motor, thus braking said rotor of said brushless motor;

control-operating, when a lever operation or push operation of said lever operation mechanism or push operation mechanism, both being a brushless motor drive switch, is suspended, said semiconductor that comprises said bridge configuration of said inverter circuit provided in said drive control circuit of said brushless motor so as to short circuit said magnetizing winding of said brushless motor, thus abruptly breaking said rotor of said brushless motor and stopping said brushless motor; and

rotating, based on a forward/reverse switching operation signal provided by said third Hall element, said brushless motor forward or in reverse through said control means.