Guide-Groove Bolt Structure for Oblique Thread Engagement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bolts designed to prevent seizure due to oblique installation either increase the under-head length or are insufficient in preventing damage to soft internal threads, such as those made of aluminum alloy.
Innovation Solution
A bolt with a tapered surface, a guide portion, and a threaded portion, where the guide portion is formed between the tapered surface and the threaded portion, extending around the axis with a deeper radial groove depth, and is continuously formed with the threaded portion to prevent forced catching of the internal thread, allowing for idling and reducing seizure without increasing the under-head length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a guide boss portion is formed to protrude from the distal end of the shank to correct tilt and prevent seizure, then seizure prevention is improved, but the under-head length of the bolt increases
Solution Approach 1:
The invention transitions from a three-dimensional protruding guide boss to a two-dimensional guide portion formed by groove depth variation. The guide portion is created by making the groove depth deeper at the distal end portion compared to the base end portion, eliminating the need for axial protrusion while maintaining tilt correction functionality.
Solution Approach 2:
The invention changes the geometric parameters of the groove rather than adding a separate guide structure. By varying the groove depth parameter along the axial direction (deeper at distal end, shallower at base end), the guide function is achieved without increasing the overall bolt length.
2Reliability
If the guide portion is formed with deeper groove depth at distal end to enable idling and prevent forced catching, then seizure prevention is improved, but the manufacturing complexity increases
Solution Approach 1:
The guide function is merged with the existing groove structure of the threaded portion. Rather than creating a separate guide component, the groove itself is modified to serve dual purposes: thread engagement and tilt correction through its depth variation.
Solution Approach 2:
The groove is designed to perform multiple functions: it provides the standard thread engagement function while simultaneously serving as a guide mechanism through its depth variation. This multi-functionality eliminates the need for separate guide structures.
Data Source
AI summary
A bolt which can prevent seizure is provided due to the bolt being installed obliquely. A guide portion is formed between a groove portion formed at a distal end portion of the threaded portion and a surface end position on a base end side of the tapered surface, a starting end portion of the guide portion being an intersection between the surface end position on the base end side of the tapered surface and a helix according to the groove portion, a terminal end portion of the guide portion overlaps with the distal end portion of the threaded portion, an angle in the direction around the axis of the bolt from the starting end portion to the terminal end portion is set in the range of 90° to 360°.