Fastening Tool Earth Claw Breaks Insulating Coating
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Solution Overview
Problem
Conventional fastening tools for vehicles lack an earth function, necessitating additional earth terminals to be welded or screwed, increasing manufacturing costs and not allowing for simultaneous electrical conduction during attachment.
Innovation Solution
A fastening tool with a collar bolt and earth claw that maintains mutual clearance between members, featuring a torque transmitter and an earth claw with elasticity to break the insulating coating layer for electrical conduction, allowing for simultaneous fastening and electrical connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional fastening tool is used to fasten members, then the mutual clearance between members can be maintained, but additional earth terminals are required which increases manufacturing cost
Solution Approach 1:
The invention merges the fastening function and earth function into a single integrated fastening tool. The collar bolt serves dual purposes: fastening the members together while simultaneously breaking the insulating coating layer through its earth claw to establish electrical conduction. This eliminates the need for separate earth terminals and reduces manufacturing cost.
Solution Approach 2:
The collar bolt is designed with multi-functionality, performing both mechanical fastening and electrical earth functions. The earth claw with elasticity allows it to break the insulating coating layer and create metal-to-metal contact for electrical conduction, while the same component maintains the mutual clearance between members during fastening.
2Reliability
If an earth terminal is welded or screwed to ensure electrical conduction, then electrical conduction is achieved, but manufacturing cost increases
Solution Approach 1:
The earth function is merged into the fastening operation itself. The earth claw on the collar bolt breaks the insulating coating layer and establishes electrical contact during the same fastening process, eliminating the need for separate welding or screwing operations for earth terminals.
Solution Approach 2:
The fastening tool performs the earth function automatically during the fastening process. The elastic earth claw self-adjusts to break the insulating coating layer and create reliable electrical contact without requiring additional manual intervention or separate earth terminal installation steps.
3Reliability
If the earth claw has elasticity to break the insulating coating layer, then electrical conduction is achieved, but the structure becomes more complex
Solution Approach 1:
The elasticity is applied locally only to the earth claw portion of the collar bolt, not to the entire structure. This localized elastic feature allows the earth claw to flex and break the insulating coating layer while the rest of the collar bolt maintains its structural integrity for fastening functions.
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 stable electrical conduction between members by bending the earth claw into the insulating coating layer during fastening, reducing manufacturing costs and improving workability while maintaining mutual clearance.
Implementation Method 1
an earth claw having elasticity is formed at an outer periphery of an end surface of the collar bolt facing the second member by protruding toward the second member
Data Source
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AI summary
A fastening tool according to the invention includes: a female screw member (10) having an inverse screw that is fixed to the first member (1); a collar bolt (11) that is screwed with the female screw member (10); a fastening bolt (27) that is inserted into a center hole (19) of the collar bolt (11) from the second member side (2) and rotates the collar bolt (11) through a torque transmitter (25), thereby moving the collar bolt to a position colliding with the second member (2); and a fastening nut (33) that is fixed to the first member (1). An earth claw (21) protruding toward the second member (2) is formed at an outer periphery of an end surface of the collar bolt (11) facing the second member. The earth claw (21) is configured to bite into the second member (2) in an axial direction due to axial force generated by screwing the fastening bolt (27) with the fastening nut (33), thereby breaking an insulating coating layer (3) and thus ensuring electrical conduction.