Battery-Powered Machine Tool Pulse Control for Locked-Tool Release
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing machine tools with battery-operated electric motors face issues such as increased motor current demand and potential damage due to locked rotors, especially when drilling deep holes or encountering hard surfaces, which mechanical couplings fail to address effectively and incur high costs and wear, while electronic couplings are energy-intensive and inefficient.
Innovation Solution
Implementing a method that controls the electric motor with alternating current pulses of different maximum amperages in two operating modes to provide haptic feedback and release locked tools, optimizing energy efficiency and reducing wear, without mechanical couplings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical coupling is used to decouple the output shaft from the electric motor when high torque is applied, then the electric motor can continue to rotate without damage, but the machine tool experiences increased weight, space requirements, manufacturing costs, and mechanical wear
Solution Approach 1:
The patent replaces the mechanical coupling system with an electronic control system that monitors motor parameters (current, temperature, rotational speed) and interrupts power supply when threshold values are exceeded. This substitution eliminates the need for mechanical wear components while providing reliable motor protection through electronic sensing and control.
Solution Approach 2:
The patent extracts the protection function from the mechanical coupling system and implements it as a separate electronic control system. The control device independently monitors motor parameters and executes protection logic without requiring physical decoupling mechanisms, thereby removing the need for heavy mechanical components.
2Reliability
If a mechanical coupling is used to protect against locked rotor conditions, then motor protection is achieved, but the coupling components are subject to wear and require servicing or replacement
Solution Approach 1:
The patent replaces wear-prone mechanical coupling components with an electronic control system that uses sensors to detect locked rotor conditions (through monitoring of current, temperature, and rotational speed) and executes protection logic. This electronic system has no moving parts that wear, eliminating maintenance requirements while providing reliable protection.
Solution Approach 2:
The control device continuously monitors motor parameters and automatically executes protection logic without requiring external intervention or maintenance. The system self-diagnoses abnormal conditions and takes protective action, eliminating the need for manual inspection and servicing of protection mechanisms.
3Ease of operation
If electronic coupling with high current pulses is used to release a locked tool, then the tool can be freed, but energy consumption increases rapidly and battery charge level decreases
Solution Approach 1:
The patent implements periodic current pulse sequences with varying amperages instead of continuous high-current operation. The control device applies a series of current pulses with different amperage levels in a structured sequence, providing cumulative torque to release locked tools while allowing energy dissipation between pulses, thereby reducing overall energy consumption compared to sustained high-current operation.
Solution Approach 2:
The patent changes current pulse parameters (amperage, duration, interval) dynamically based on the locking condition and energy state. The control device adjusts pulse amperage and timing to provide sufficient torque for tool release while optimizing energy efficiency, using lower amperage pulses when possible and higher amperage pulses only when necessary to overcome the locking condition.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method provides haptic feedback comparable to mechanical couplings while significantly reducing energy consumption and preventing damage, allowing prolonged operation and efficient torque transmission.
Implementation Method 1
an electric motor (3) which is designed to rotationally drive an output shaft (4)
Implementation Method 2
a battery (2), an electric motor (3) which is designed to rotationally drive an output shaft (4)
Data Source
AI summary
A method for operating a machine tool having a battery and an electric motor which is designed to rotationally drive an output shaft that can be coupled to a tool, is described, a control device for actuating the electric motor and a device for determining a parameter being provided. The machine tool can be operated in a first operating mode and a second operating mode, the machine tool being transferred from the first operating mode into the second operating mode if the parameter determined by the device exceeds or falls below a defined threshold value. In the second operating mode, the electric motor is controlled by an amperage profile, the amperage profile comprising first current pulses (10) and second current pulses (11). The level of a maximum amperage (A1) of the first current pulses (10) is greater than the level of a maximum amperage (A2) of the second current pulses (11). A machine tool that can be operated using a method of this kind is also described.