Stepper Motor Drilling Machine Feed Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing drilling machines are costly and complex, as they struggle to prevent overload states during fast feed operations and generate precise core drillings.
Innovation Solution
A drilling machine equipped with a stepper motor that limits feed motion upon resistance, coupled with a worm gear pair and a plunger system for manual and automatic feed control, and a three-speed gear for adaptable drilling tool operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a series motor is used for feed operation, then fast feed motion is achieved, but overload state occurs during drilling operation
Solution Approach 1:
The patent replaces the series motor (electromechanical system prone to overload) with a stepper motor (precision motion control system). The stepper motor inherently limits feed motion when resistance is encountered, preventing overload of the drilling motor while maintaining controlled feed speed during normal operation.
Solution Approach 2:
The control unit monitors the feed motion and automatically interrupts it when the stepper motor encounters resistance, indicating that the drilling tool has engaged with the workpiece. This feedback mechanism prevents overload by stopping feed motion at the appropriate moment.
2Reliability
If control means with sensing means are added to prevent overload, then reliability is improved, but device complexity increases
Solution Approach 1:
The stepper motor inherently provides overload protection through its control characteristics. When resistance is encountered, the motor simply stops stepping, automatically preventing overload without requiring additional sensing means or complex control circuitry. The system serves itself by utilizing the inherent properties of the stepper motor.
3Productivity
If continuous feed motion is maintained, then productivity is improved, but chip accumulation and overheating occur
Solution Approach 1:
The control unit is designed to periodically interrupt the feed motion during drilling operation. These periodic interruptions allow chips to be broken and released from the core drilling bore, preventing chip accumulation and associated harmful effects while maintaining overall productivity through continued drilling cycles.
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 solution effectively prevents overloading, allows for precise core drilling, and simplifies the design by enabling controlled feed motion and chip removal, enhancing drilling efficiency and safety.
Implementation Method 1
the feed motion of a stepper motor is limited when reaching a certain resistance so that, as a consequence of which, also the motor of the drilling unit cannot be overloaded by a too fast feed motion
Implementation Method 2
a worm gear pair is provided by means of which the stepper motor can be coupled with the intermediate shaft
Implementation Method 3
By these features a suitable reduction of the feed operation is guaranteed
Implementation Method 4
on the intermediate shaft a plunger is provided which is axially displaceable between a first position, in which a driving movement of the drive is transmitted onto the intermediate shaft by means of the plunger
Implementation Method 5
a lever is coupled with the intermediate shaft allowing a manual rotation of the intermediate shaft
Implementation Method 6
the drilling unit comprises a three-speed gear for driving the drilling tool
Data Source
AI summary
A drilling machine comprises a stand on which a carriage is guided and can be moved by a drive supported on the stand and engagable with the carriage for generating feed motion of the carriage along the guide. A drilling unit on the carriage includes a motor-driven spindle. An axially-fixed intermediate shaft on the stand engages the carriage and translates rotary motion of the intermediate shaft into linear motion of the carriage along the guide. The drive is engagable with the intermediate shaft for moving the carriage along the guide with a stepper motor. A lever is engagable with an axially-displaceable plunger for shifting the plunger between first and second positions corresponding to an engaged position and a disengaged position, in which the plunger allows for manual rotation of the intermediate shaft when rotating the lever.