Drilling tool

Patent metadata

Field	Value
Publication number	US-12023744-B2
Application number	US-201917298370-A
Country	US
Kind code	B2
Filing date	Dec 13, 2019
Priority date	Dec 20, 2018
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

A drilling tool includes a tool body, a brushless motor, a first detector, a second detector and a control device. The brushless motor is housed in the tool body and configured to drive the tool accessory. The first detector is configured to detect first information corresponding to a load applied to the tool accessory. The second detector is configured to detect second information corresponding to a rotation state of the tool body around the driving axis. The control device is configured to control operation of the drilling tool. The control device is configured to set a conduction angle for the brushless motor based on the first information, and to determine, based on the first information and the second information, whether or not excessive rotation of the tool body due to jamming of the tool accessory occurs.

First claim

The invention claimed is:

1. A drilling tool configured to perform a drilling operation by rotationally driving a tool accessory around a driving axis, the drilling tool comprising:
a tool body;
a brushless motor housed in the tool body and configured to drive the tool accessory;
a first detector configured to detect first information corresponding to a load applied to the tool accessory;
a second detector configured to detect second information corresponding to a rotation state of the tool body around the driving axis; and
a control device configured to control operation of the drilling tool,
wherein the control device is configured:
to set a conduction angle for the brushless motor based on the first information, and
to determine, based on the first information and the second information, whether or not excessive rotation of the tool body due to jamming of the tool accessory occurs.

2. The drilling tool as defined in claim 1 , wherein:
the control device is configured:
to set the conduction angle to be smaller as the load is larger,
to set the conduction angle to a first conduction angle or to a second conduction angle that is larger than the first conduction angle, and
to change a determination criterion for determining whether or not the excessive rotation occurs, based on a setting frequency that the first conduction angle has been set.

3. The drilling tool as defined in claim 2 , wherein the control device is configured, when the setting frequency is higher than a threshold, to set the determination criterion to be higher than when the setting frequency is equal to or lower than the threshold.

4. The drilling tool as defined in claim 2 , wherein:
the control device is configured:
to store a setting history of the conduction angle in a storage device, and
to calculate the setting frequency based on the setting history.

5. The drilling tool as defined in claim 1 , wherein:
the control device is configured:
to set the conduction angle to be smaller as the load is larger,
to set the conduction angle to a first conduction angle or to a second conduction angle that is larger than the first conduction angle, and
to change an output to be produced by the brushless motor when the conduction angle is the first conduction angle, based on a determination history relating to the excessive rotation.

6. The drilling tool as defined in claim 5 , wherein:
the control device is configured, when a frequency that the excessive rotation has been determined to occur is higher than a threshold, to set the output to be produced when the conduction angle is the first conduction angle to be lower than when the frequency is equal to or lower than the threshold.

7. The drilling tool as defined in claim 6 , wherein:
the control device is configured:
to store the determination history relating to the excessive rotation, and
to calculate the frequency that the excessive rotation has been determined to occur, based on the determination history.

8. The drilling tool as defined in claim 1 , wherein:
the control device is configured:
to set the conduction angle to be smaller as the load is larger,
to set the conduction angle to a first conduction angle or to a second conduction angle that is larger than the first conduction angle, and
to determine whether or not the excessive rotation of the tool body occurs only when the conduction angle is the first conduction angle.

9. The drilling tool as defined in claim 1 , wherein:
the control device is configured:
to calculate an index value corresponding to the excessive rotation based on the first information and the second information and determine whether or not the excessive rotation occurs, based on a result of comparison between the index value and a reference value, and
to change a determination criterion for determining whether or not the excessive rotation occurs, by changing the reference value, or a factor to be used in calculation of the index value.

10. The drilling tool as defined in claim 1 , wherein:
the control device is configured to stop the brushless motor driving the tool accessory in response to determining that there is a possibility of the excessive rotation.

Assignees

• Makita Corp

Inventors

• Sunabe Hikaru
• Ito Akihiro

Classifications

• B25D16/006

  Mode changers; Mechanisms connected thereto · CPC title

• B25B23/147

  specially adapted for electrically operated wrenches or screwdrivers · CPC title

• B25F5/02

  Construction of casings, bodies or handles {(B25F5/006, B25F5/008 take precedence)} · CPC title

• B25D16/00

  Portable percussive machines with superimposed rotation {, the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit (combined percussion and rotary drilling adapted for earth drilling E21B6/00)} · CPC title

• B23B45/00

  Hand-held or like portable drilling machines, e.g. drill guns; Equipment therefor (details or components, e.g. casings, bodies, of portable power-driven tools not particularly related to the operation performed B25F5/00) · CPC title