Bolt Coating Peeling Tip for Low Torque Conductivity

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Solution Overview

Problem

Conventional bolts fail to reliably peel coatings from nuts with low torque, leading to incomplete coating removal and conduction failures, and require high fastening torque to secure conductivity.

Innovation Solution

A bolt design featuring a coating peeling part with trapezoidal crushing parts and a protruding part at the tip end, which peels coating near the screw thread and valley bottom of the nut, allowing complete coating removal and discharge, and a helically formed locking part for stable conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional earth bolt with a bent flank or convex part is used to peel coating, then coating peeling function is provided, but high fastening torque is required to secure conductivity

Engineering Contradiction:
ImproveconductivityVSAvoidfastening torque
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The coating peeling part is segmented into multiple functional elements: crushing parts with projected flanks for initial coating removal, and protruding parts that extend beyond the screw thread outer diameter to peel coating from the valley bottom. This segmentation allows each element to perform a specific peeling function, achieving complete coating removal without requiring high fastening torque.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coating peeling part performs preliminary coating removal action before the regular screw thread establishes metal-to-metal contact. The crushing and protruding parts peel coating in advance, ensuring that when conductivity is needed, the contact surface is already prepared, eliminating the need for high torque to achieve conduction.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a tip end part of screw thread is used to peel coating, then some coating removal is achieved, but coating cannot be completely peeled and peeled coating invades into gap between screw threads causing conduction failure

Engineering Contradiction:
ImproveconductivityVSAvoidconduction failure
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The protruding parts extend in the radial direction beyond the outer diameter of the regular screw thread, adding a dimensional element to the coating peeling mechanism. This allows the protruding parts to reach and peel coating from the valley bottom area that the standard screw thread cannot access, preventing coating invasion into screw thread gaps.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The protruding parts are extracted as separate elements from the regular screw thread structure. By positioning these parts to project beyond the screw thread outer diameter, the invention extracts and addresses the specific problem of coating remaining in the valley bottom, ensuring complete coating removal and preventing conduction failure.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If a convex part with flank angle equal to female screw is formed in flank to dig into nut, then coating peeling is achieved, but high fastening torque is required

Engineering Contradiction:
ImproveconductivityVSAvoidfastening torque
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The crushing parts have flanks that are projected at different angles compared to the regular screw thread flanks. This asymmetric design allows the crushing parts to effectively peel coating without requiring the high fastening torque that would be needed if the entire screw thread had to dig into the nut. The asymmetric geometry concentrates the peeling action where needed.

Inventive Principle:
Principle #4Asymmetry

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

Enables reliable coating peeling and secure conductivity with low torque by completely removing coatings and ensuring contact between the bolt and nut, preventing conduction failures and enhancing fastening stability.

Implementation Method 1

the screw thread projected in the coating peeling part causes plastic flow within the nut

Methodology Applied
Scientific EffectPlastic flow: Plasticity

Data Source

PatentEP3054174B1bolt
Publication Date: 2018.12.05 AOYAMA SEISAKUSHO CO LTD
  • EP3054174B1 patent drawingFigure 1
  • EP3054174B1 patent drawingFigure 2
  • EP3054174B1 patent drawingFigure 3~4

AI summary

The bolt of the present invention can reliably peel coating even when fastened with a low torque, and can secure sufficient conductivity. A coating peeling part 4 for peeling coating is formed at a tip end of an axis part 2 in which a regular screw part 1 is formed. The coating peeling part 4 includes crushing parts 5 having a trapezoidal top part and having a flank which is projected at a different angle with respect to the flank of the regular screw part 1; and a protruding part 6 which is arranged adjacent to the crushing parts 5 and whose top part projects beyond the outer diameter of the regular screw part 1.