Inner-Hole Cutting Head Positioning for Diameter Variations
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Solution Overview
Problem
Existing hole inner-surface cutting apparatuses face difficulties in cutting the inner surface of penetrating holes with varying diameters, as friction increases when rollers encounter circumferential protrusions or grooves, preventing precise cutting.
Innovation Solution
The apparatus employs a working head with a rotatable cutting tool and positioning mechanisms featuring fluid pressure chambers and guide rollers, allowing for precise alignment and adjustment to maintain cutting precision even over diameter variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rollers are pressed onto the inner surface of the penetrating hole to maintain working head position, then the working head position is kept stable, but friction increases when rollers pass over circumferential protrusions or grooves, preventing axial movement
Solution Approach 1:
The positioning mechanism uses sliders that can dynamically adjust their radial position. When encountering circumferential protrusions or grooves, the sliders can move radially inward or outward to maintain contact with the inner surface, allowing the working head to pass through smoothly while still maintaining positional stability during normal cutting operations.
Solution Approach 2:
The positioning mechanism incorporates a fluid pressure chamber that uses pneumatic or hydraulic pressure to control the radial movement of sliders. By adjusting the fluid pressure, the sliders can be pushed against the inner surface for stable positioning or retracted to reduce friction when passing over irregularities, thus resolving the contradiction between stability and smooth movement.
2Manufacturing precision
If multiple positioning mechanisms are provided at different axial positions, then positioning accuracy is improved, but device complexity increases
Solution Approach 1:
The positioning system is segmented into multiple independent positioning mechanisms distributed at different axial positions along the working head. Each positioning mechanism consists of sliders, guide rollers, and fluid pressure chambers that can operate independently. This segmentation allows the system to maintain high positioning accuracy through multiple contact points while keeping each individual mechanism relatively simple and modular.
Solution Approach 2:
Each positioning mechanism serves multiple functions: it provides radial positioning, allows axial movement, and can adapt to inner diameter variations. By designing universal positioning units that can be replicated at different axial positions, the system achieves high precision without proportionally increasing overall complexity, as each unit is a standardized multi-functional component.
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
This solution enables high-precision cutting of inner surfaces by maintaining the center axis alignment of the working head with the hole axis, even when encountering local diameter changes, ensuring uninterrupted cutting.
Implementation Method 1
a fluid pressure chamber for actuating the piston
Implementation Method 2
guide rollers respectively disposed on distal ends of the sliders and contacting with the inner surface of the penetrating hole
Data Source
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AI summary
A hole inner-surface cutting apparatus (1) includes a working head (20) composed of a rotatable body (20b) having a cutting tool (20c) and a main body (20a), a rotation rod (41) for rotating the rotatable body (20b), and a stroke rod (31) for stroking the working head (20). At least three positioning mechanisms (22A-22C) for positioning the working head (20) along a radial direction in the penetrating hole is provided on the main body (20a). Each of the positioning mechanisms (22A-22C) has three sliders (25) arranged radially, guide rollers (26) respectively disposed on distal ends of the sliders (25), a piston (23) for pressing the sliders (25) radially outward, and a fluid pressure chamber (24) for actuating the piston (23). Further provided is a controller for controlling fluid pressures in the fluid pressure chambers (24) of the positioning mechanisms (22A-22C) independently from each other.