Rotary tool

Patent metadata

Field	Value
Publication number	US-11745301-B2
Application number	US-201816499319-A
Country	US
Kind code	B2
Filing date	Feb 23, 2018
Priority date	Mar 30, 2017
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

Abstract

Provided is a rotary tool. In the rotary tool, the rotating tip tool is mounted on a spindle by the fixture, and the spindle and the tip tool are rotated by a motor. The rotary tool has a switch which can switch the motor between a rotation state and a stop state, and a control device which controls the rotation of the motor corresponding to the operation of the switch. When the switch is turned off after a required time T elapses after the motor is started, the control device stops the rotary tool ( 104 d, 106 d ) by performing a common braking operation on the spindle, and when the switch is turned off before the required time T elapses after the motor is started, the control device stops the tip tool ( 101 d ) by inertia without applying a braking force.

First claim

What is claimed is:

1. A rotary tool which rotates a spindle and a tip tool forward or backward by a motor, and uses a fixture screwed with the spindle to install the tip tool on the spindle,
the rotary tool comprising:
a switch; and
a control device which controls a rotation and a stop of the motor corresponding to an operation of the switch,
wherein when the switch is turned on, the control device is configured to perform a start control that controls the motor to a second target rotation speed higher than a first target rotation speed before controlling the motor to a constant-speed rotation at the first target rotation speed.

2. The rotary tool according to claim 1 , wherein the motor is a brushless motor and has an inverter circuit which comprises a plurality of switching elements for controlling the motor, and the control device adjusts the braking force by controlling the inverter circuit.

3. The rotary tool according to claim 1 , wherein during the start control, the control device controls the motor to gradually decrease a rotation speed of the motor to reach the first target rotation speed after increasing the rotation speed of the motor to the second target rotation speed.

4. The rotary tool according to claim 1 , comprising a speed adjusting device capable of being operated by an operator,
wherein the control device is capable of selecting a low speed control or a high speed control according to an operation of the speed adjusting device.

5. The rotary tool according to claim 4 , wherein in a case when the low speed control is selected, the control device performs the start control, and
wherein in a case when the high speed is selected, the control device does not perform the start control.

6. The rotary tool according to claim 4 , wherein among the low speed control and the high speed control, the control device performs the start control only when the low speed control is selected.

7. The rotary tool according to claim 4 , wherein during a driving of the motor, the control device is capable of performing a braking control to apply a braking force to the motor when the switch is turned off.

8. The rotary tool according to claim 7 , wherein the control device sets a first braking force, which is applied to the motor if the switch is turned off before a predetermined period elapses after a start of the motor, to be weaker than a second braking force, which is applied to the motor if the switch is turned off after the predetermined period elapses after the start of the motor.

9. The rotary tool according to claim 7 , wherein at least during the high speed control is selected, the control device adjusts the braking force such that a loosening torque applied to the fixture during a braking of the motor is smaller than a fastening torque applied to the fixture during a start of the motor.

10. A rotary tool, comprising:
a spindle, configured to mount a tip tool;
a motor, configured to rotate the spindle;
a fixture, configured to be screwed to the spindle for fixing the tip tool;
a switch;
a speed adjusting device, configured to be operated by an operator, the speed adjusting device is configured to be able to selectively set a target rotation speed to a first rotation speed or a second rotation speed higher than the first rotation speed;
a control device, configured to control a rotation and a stop of the motor corresponding to an operation of the switch, the control device is configured to control a rotation of the motor to the first rotation speed or the second rotation speed that is set,
wherein when the target rotation speed is the first rotation speed, the control device is configured to control an excess amount, which is an amount by which the rotation speed of the motor to temporarily exceed the target rotation speed in a process before the motor is driven at the target rotation speed, so as to be larger compared with when the target rotation speed is the second rotation speed.

11. The rotary tool according to claim 10 , wherein during a driving of the motor, the control device is capable of performing a braking control to apply a braking force to the motor when the switch is turned off.

12. The rotary tool according to claim 11 , wherein the control device sets a first braking force, which is applied to the motor if the switch is turned off before a predetermined period elapses after a start of the motor, to be weaker than a second braking force, which is applied to the motor if the switch is turned off after the predetermined period elapses after the start of the motor.

13. The rotary tool according to claim 10 , wherein the speed adjusting device is configured to set the target rotation speed to the first rotation speed, the second rotation speed and a third rotation speed, the first rotation speed and the third rotation speed are smaller than the second rotation speed,
wherein the first rotation speed is a lowest speed of the target rotation speed, and the second rotation speed is a highest speed of the target rotation speed.

14. A rotary tool, comprising:
a spindle, configured to mount a tip tool;
a motor, configured to rotate the spindle;
a fixture, configured to be screwed to the spindle for fixing the tip tool;
a switch, configured to be operated by an operator;
a speed adjusting device, configured to be operated by the operator, the speed adjusting device is configured to be set to one of a first target rotation speed or a second target rotation speed, the first target rotation speed is smaller than the second target rotation speed;
a control device, configured to control the motor to start the motor and rotate the motor at the first target rotation speed or the second rotation speed when the switch is turned on, and the control device is configured to brake the motor when the switch is turned off,
wherein the control device is configured to change a control of starting the motor, and a control of braking the motor based on a setting on the speed adjusting device.

15. The rotary tool according to claim 14 , wherein the control device is configured to change a first acceleration of the motor in an acceleration direction when starting the motor, and change a second acceleration of the motor in a deceleration direction when braking the motor, based on the setting on the speed adjusting device.

16. The rotary tool according to claim 14 , wherein when one of the first target rotation speed or the second target rotation speed is set, the control device is configured such that the first acceleration of the motor in the acceleration direction when starting the motor is larger than the second acceleration of the motor in the deceleration direction when braking the motor.

17. The rotary tool according to claim 14 , wherein the control device is configured such that:
when the switch is operated such that the motor is braked right after the motor reaches the first target rotation speed after the motor is started, the motor is decelerated by a first braking force, and
when the switch is operated such that the motor is braked right after the motor reaches the second target rotation speed after the motor is started, the motor is decelerated by a second braking force,
wherein the second braking force is larger than the first braking force.

18. The rotary tool according to claim 14 , wherein the control device is configure to control the motor such that:
a first force is applied to the fixture to fasten the fixture in a process from when the motor is started to when the motor is rotated at the first target rotation speed,
a

Assignees

• Koki Holdings Co Ltd

Inventors

• Sakai Hironori
• Yoshinari Takuya
• Mashiko Hironori

Classifications

• B24B23/022 Primary

  Spindle-locking devices, e.g. for mounting or removing the tool · CPC title

• B24B47/12

  by mechanical gearing or electric power (B24B47/16 takes precedence) · CPC title

• B25F5/00 Primary

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

• H02P1/04

  Means for controlling progress of starting sequence in dependence upon time or upon current, speed, or other motor parameter · CPC title

• H02P6/24

  Arrangements for stopping · CPC title