Method for Operating a Hand-Held Power Tool

Patent metadata

Field	Value
Publication number	US-2024149411-A1
Application number	US-202318496993-A
Country	US
Kind code	A1
Filing date	Oct 30, 2023
Priority date	Nov 8, 2022
Publication date	May 9, 2024
Grant date	—

Abstract

A method for operating a hand-held power tool, in particular a rotary impact wrench, the hand-held power tool comprising an electric motor, the method including selecting an application class depending on at least one hardness and/or strength property of a substrate in which a screwdriving operation is to be carried out, and selecting an operation mode from an operation mode group comprising a first operation mode and a second operation mode, based at least in part on the application class. The first operation mode has a first maximum torque level of the electric motor per application class and the second operation mode has a second maximum torque level per application class. Furthermore, a hand-held power tool, in particular an impact wrench, having an electric motor and a control unit is disclosed, the control unit being designed for carrying out a method according to the disclosure.

First claim

What is claimed is:

1 . A method of operating a hand-held power tool which includes an electric motor, comprising:
selecting an application class depending on at least one hardness and/or strength property of a substrate in which a screwdriving operation is to be carried out; and selecting an operation mode from an operation mode group comprising a first operation mode and a second operation mode, based at least in part on the application class, wherein the first mode of operation has a first torque level delivered by the hand-held power tool per application class and the second mode of operation has a second maximum torque level per application class, the second maximum torque level per application class different from the first torque level delivered by the hand-held power tool per application class.

2 . The method according to claim 1 , wherein the application class is selected from a group of application classes comprising a “hard screwdriving” and a “soft screwdriving”.

3 . The method according to claim 2 , wherein, per application class, a maximum torque level of the respective first maximum torque level is higher than a corresponding maximum torque level of the second maximum torque level.

4 . The method according to claim 3 , wherein for each application class the respective second maximum torque level compared to the corresponding first maximum torque level is characterized by a lower rotational speed of the electric motor and/or a lower impact duration.

5 . The method according to claim 3 , wherein selecting the operation mode comprises:
selecting the first operation mode when the application class soft screwdriving is present, and selecting the second operation mode when the application class hard screwdriving is present.

6 . The method according to claim 1 , wherein:
selecting the application class is performed by a user, via an application software and/or a user interface on the hand-held power tool.

7 . The method according to claim 1 , wherein:
selecting the operation mode is performed by a user, optionally via an application software and/or a user interface on the hand-held power tool.

8 . The method according to claim 1 , wherein:
selecting the operation mode is at least partially automatic.

9 . The method according to claim 1 , wherein:
selecting the application class is at least partially automatic.

10 . The method according to claim 9 , wherein selecting the application comprises:
ascertaining a signal of an operating variable of the electric motor; and selecting the application class based at least in part on the signal of the operating variable.

11 . The method according to claim 10 , further comprising:
providing at least one model signal waveform, wherein the model signal waveform is assignable to one of the application classes; comparing the signal of the operating variable to the model at least one signal waveform and ascertaining a match score from the comparison; and detecting the application class at least in part based on the ascertained match score.

12 . The method according to claim 11 , wherein:
the signal of the operating variable is compared with the at least one model signal waveform using a comparison method to determine whether at least a predetermined threshold value of the match is satisfied.

13 . The method according to claim 10 , further comprising:
performing a machine learning phase using at least two example applications, wherein the example applications cover different application classes, and the selection of the application class is based at least in part on application classes learned in the machine learning phase.

14 . The method according to claim 13 , wherein performing the machine learning phase further comprises:
storing and classifying signals of the operating variable associated with the example applications into at least one or more application classes; and generating model signal waveforms associated with the application classes from the signals of the operating variable.

15 . The method according to claim 13 , wherein the at least two example applications are executed by a user of the hand-held power tool and/or read from a database.

16 . The method according to claim 13 , wherein the operating variable is a speed of the electric motor or an operating variable correlated to the speed.

17 . The method according to claim 13 , wherein:
ascertaining the signal of the operating variable comprises receiving the signal of the operating variable as a time course of measured values of the operating variable, or as measured values of the operating variable as a variable of the electric motor correlated with the time course.

18 . The method according to claim 13 , wherein ascertaining the signal of the operating variable comprises:
receiving the signal of the operating variable as a time course of measured values of the operating variable; and transforming the time course of the measured values of the operating variable into a course of the measured values of the operating variable as a variable of the electric motor correlated with the time course.

19 . A hand-held power tool comprising:
an electric motor; a measured value transducer of an operating variable of the electric motor; and a control unit configured to carry out the method according to claim 1 .

20 . The method of claim 1 wherein the hand-held power tool is a rotary impact wrench.

Assignees

• Bosch Gmbh Robert

Inventors

• Schuller Marcus
• Herr Tobias
• Erbele Simon
• Herberger Wolfgang

Classifications

• B25B23/1405

  for impact wrenches or screwdrivers · CPC title

• B25B23/1475 Primary

  for impact wrenches or screwdrivers · CPC title

• B25B21/02 Primary

  with means for imparting impact to screwdriver blade or nut socket · CPC title