Core Drill Interchangeable Bit Axial Stop Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing core drilling methods, especially hand-guided drilling, face challenges in ensuring accurate centering and preventing the drilled hole from 'running away' without excessive material removal or requiring manual intervention, leading to potential operating errors and inefficiencies.
Innovation Solution
A core drilling machine with an axially extending hollow drilling shaft, a coaxial tool holder with a locking mechanism, and an axial stop element that allows controlled axial movement of the drill bit and center drill, enabling automatic transition from pilot hole drilling to core hole completion without manual interruption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a center drill is used to drill a pilot hole in hand-guided core drilling, then the hole can be initially positioned, but the drill must drill through the entire workpiece which causes excessive material removal
Solution Approach 1:
The drilling process is segmented into two distinct phases: pilot hole drilling by the center drill and core hole completion by the drill bit. The axial stop element segments the drilling depth, allowing the center drill to drill only to a limited depth rather than through the entire workpiece, thus reducing excessive material removal while maintaining centering precision.
Solution Approach 2:
The system dynamically transitions between center drill operation and drill bit operation. The axial stop element enables the center drill to move axially to a limited position during pilot hole drilling, then automatically disengages to allow the drill bit to complete the hole, creating a dynamic drilling system that adapts to different drilling phases.
2Productivity
If the operator manually increases contact pressure to deactivate the center drill, then the drilling process can transition to core hole completion, but this requires manual intervention which can lead to operating errors
Solution Approach 1:
The drilling system is self-regulating through the axial stop element mechanism. When the drill bit penetrates the workpiece and engages the axial stop element, the system automatically transitions from center drill operation to drill bit operation without requiring manual intervention. The operator simply maintains continuous drilling pressure, and the system self-manages the transition, eliminating operating errors associated with manual deactivation.
Solution Approach 2:
The axial stop element provides mechanical feedback based on drill bit penetration depth. When the drill bit reaches the appropriate depth and engages the axial stop element, this physical contact provides feedback that automatically triggers the transition mechanism, eliminating the need for the operator to judge when to increase contact pressure and reducing operational errors.
3Measurement precision
If the center drill is allowed to drill deeply to ensure proper centering, then centering accuracy is improved, but this increases drilling time and reduces productivity
Solution Approach 1:
The axial stop element is pre-positioned to define the exact depth at which the center drill should stop drilling the pilot hole. This preliminary positioning ensures that the center drill drills just deep enough to achieve proper centering and create an adequate pilot hole, without unnecessary additional drilling time. The stop element is set in advance to optimize both centering accuracy and drilling efficiency.
Data Source
Figure 1~10
Figure 2
Figure 3
AI summary
The invention relates to a core drill (10) having an axially extending hollow drill shaft (22, 64) that is pivotally mounted in a housing (14) of the core drill (10) and that can be rotated by means of a drive unit; a coaxial tool holder for receiving a core bit (40) that can be mounted in an axially displaceable manner, wherein the tool holder comprises a locking mechanism securing the core bit in a radial direction against axially falling out when inserted in the tool holder, wherein the locking mechanism connects the core bit (40) in a rotationally fixed manner to the hollow drill shaft (22, 64) and allows a limited axial displacement of the core bit relative to the hollow drill shaft (22, 64); wherein the hollow drill shaft is suitable for receiving a shaft of an interchangeable center drill (42) in the front interior thereof, and an axial stop element for the center drill (42) preventing complete displacement of the center drill into the interior of the hollow drill shaft in a first position, and allowing complete displacement of the center drill into the interior of the hollow drill shaft in a second position; and an activation device (70, 72, 74, 76) for activating the first or the second position of the stop element as a function of the axial position of the core bit relative to the hollow drill shaft.