Portable Drilling Machine Motor Overload Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing portable drilling devices face issues with motor overload management, where sudden power interruption can lead to unsafe torque restoration and difficulty in restarting the motor, potentially causing damage to the cutting tool and motor burnout.
Innovation Solution
A portable drilling device with a main control unit that includes first and second control units to reduce and restore power supply to the motor based on overload conditions, along with a third unit for stopping power if the overload persists, and a display system for indicating different control states, ensuring safe and efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If power supply is suddenly interrupted when overload is detected, then motor burnout is prevented, but torque restoration after power resumption creates safety hazards and cutting tool damage
Solution Approach 1:
The control unit detects overload conditions before they cause motor burnout and proactively reduces power supply. By anticipating the overload situation and taking preliminary action to reduce power, the system prevents both motor burnout and subsequent torque shock when power is restored, eliminating the need for sudden power interruption.
2Reliability
If power supply is continuously reduced to prevent overload, then motor safety is improved, but operational continuity and productivity decrease
Solution Approach 1:
The control unit dynamically adjusts power supply to the motor based on real-time load conditions. When overload is detected, power is gradually reduced to prevent motor burnout. When the load returns to normal levels, power is automatically restored, allowing the drilling operation to continue without interruption. This dynamic adjustment maintains motor safety while preserving operational continuity.
Solution Approach 2:
The control unit continuously monitors motor load current and uses this feedback to adjust power supply accordingly. When overload is detected, the feedback mechanism triggers power reduction; when load normalizes, feedback signals power restoration. This closed-loop feedback system ensures motor protection while maintaining productivity through automatic recovery.
3Ease of operation
If manual power switch operation is required to reset motor after overload, then precise control is achieved, but ease of operation deteriorates
Solution Approach 1:
The control unit automatically detects when motor load returns to normal levels after an overload event and autonomously restores power supply without requiring manual intervention. The system serves itself by monitoring its own operational state and making appropriate power adjustments, greatly improving ease of operation.
Solution Approach 2:
The control unit performs multiple functions: it monitors motor load, detects overload conditions, reduces power to prevent burnout, monitors load recovery, and automatically restores power. This multi-functional control system consolidates what would otherwise require separate manual operations into a single automated unit, improving convenience without proportionally increasing complexity.
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
Prevents recurrence of overload conditions, improves operability and safety by automatically restoring power when the overload is cleared, and prevents motor burnout by gradually adjusting voltage, thus enhancing the reliability of the drilling process.
Implementation Method 1
a body (2) including a motor (12) can be secured to a workpiece by means of an electromagnet (16) or the like
Data Source
Figure 1
Figure 2
Figure 3
AI summary
It is an object of the present invention to prevent recurrence of an overload condition after occurrence of the overload condition, thereby improving operability and safety in a drilling device. A motor 12 for rotating a drill is connected to an AC power source 10 through a motor control unit 28, a current detector 30, and a power switch 36. A magnet 16 is also connected to the AC power source 10 through the power switch 36 and a full-wave rectifier 18. The motor control unit 28 rotationally drives the motor on the basis of a signal sent from a main control unit according to a state in which a motor start switch 38 is on. The main control unit 14 controls the motor control unit 28 to gradually reduce a supply voltage to the motor 12 when the motor 12 becomes overloaded, to gradually increase the voltage to the normal power supply condition when the overload condition is vanished, and to stop power supply to the motor 12 if the overload condition continues for a predetermined period.