Flexible Dowel Pin Assembly for Accurate Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in mechanical engineering is achieving precise positioning of components while balancing precision and ease of assembly, as conventional dowel pins with fixed distances can lead to overconstraint and manufacturing difficulties due to noncircular holes and varying tolerances.
Innovation Solution
A flexible dowel pin design allowing transverse movement between its parts, which includes a cylindrical body divided into two parts with a connecting member for relative transverse movement, and elevated contact surfaces on a reduced diameter circumferential surface to accommodate noncircular holes, ensuring alignment and reducing manufacturing demands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional dowel pins with fixed distances are used, then manufacturing precision can be achieved, but ease of assembly deteriorates due to overconstraint and mounting difficulties
Solution Approach 1:
The dowel pin is designed with a movable connection between its parts, allowing it to transition from a fixed rigid structure to a dynamic flexible structure. This enables the dowel pin to adapt to manufacturing tolerances and noncircular holes during assembly, eliminating overconstraint while maintaining positioning accuracy when installed.
Solution Approach 2:
The invention changes the physical state of the dowel pin from rigid to flexible by introducing a movable connection. This parameter change allows the dowel pin to accommodate variations in hole geometry and positioning, resolving the conflict between precision and ease of assembly.
2Manufacturing precision
If tight tolerance machining is applied to both dowel pins and holes, then positioning accuracy is improved, but manufacturing complexity increases
Solution Approach 1:
The flexible dowel pin changes the physical parameter of rigidity, allowing the system to achieve positioning accuracy without requiring both the pin and hole to be machined to tight tolerances. The flexibility compensates for manufacturing variations.
Solution Approach 2:
The elevated contact surfaces are positioned specifically at critical locations on the dowel pin, providing localized precision contact points while the rest of the structure remains simpler. This local quality approach maintains accuracy without requiring complex machining throughout the entire component.
3Ease of operation
If clearance fit is used for easy assembly, then ease of operation is improved, but manufacturing precision deteriorates due to positioning variations
Solution Approach 1:
The elevated contact surfaces create localized high-contact-area zones on the dowel pin. These localized quality enhancements ensure precise positioning at the critical contact points while allowing clearance fit for easy assembly, resolving the contradiction between ease of operation and positioning precision.
Data Source
AI summary
A dowel pin (1) according to a first aspect with a cylindrical body (4). The cylindrical body (4) is divided into first and second parts (2,3). The first part (2) is movably connected to the second part (3) allowing only relative transverse movement between the first and second parts (2,3). According to a second aspect, the dowel pin (1) comprises a cylindrical circumferential surface (5) and first and second longitudinal ends. The circumferential surface (5) comprises a first plurality of primary radially lifted contact areas (33) at a first distance D1 from the first longitudinal end and a second distance D2 from the second longitudinal end, with D1 being less than D2, and a second plurality of secondary lifted contact areas (35,36) at a third distance D3 from the first longitudinal end and a fourth distance D4 from the second longitudinal end, D3 being larger than D4.