Wire Harness Connection Structure for Controlled Collision Severance
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Solution Overview
Problem
Conventional wire harness connection structures face issues with high contact resistance due to small contact areas between electric wires, leading to increased weight and complexity, especially in high-voltage and large-current applications, and difficulty in predicting and controlling wire severance during vehicle collisions.
Innovation Solution
A connection structure where the end portions of electric wires are subjected to fusing processing to form extension and protruding portions with complementary shapes, allowing for increased contact area and easier separation under tension, using a connecting member to crimp these portions and reduce engagement force, thereby facilitating efficient current flow and controlled severance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the diameters of the two electric wires are increased to increase the connection area of the end faces, then the contact area is increased, but the overall weight of the wire harness increases
Solution Approach 1:
The invention transitions from face-to-face contact (2D surface contact) to line contact through the tapered portion inserted in the concave portion (1D linear contact along the axial direction). This dimensional change allows for sufficient contact area without requiring increased wire diameters, thereby avoiding weight increase while achieving reliable electrical connection.
Solution Approach 2:
The invention changes the contact geometry parameters by forming a concave portion with specific depth and width, and a tapered portion with specific taper angle. These parameter optimizations enable effective contact area without increasing wire diameter, resolving the contradiction between connection area and weight.
2Reliability
If the contact area between the two electric wires is increased by using socket contact, then the contact resistance is reduced, but the structure becomes more complicated and the connection structure becomes larger in size
Solution Approach 1:
The invention divides the contact interface into distinct functional elements: the concave portion in one wire and the tapered protruding portion in the other wire. This segmentation creates a specialized connection interface that achieves low contact resistance through precise geometric matching without requiring complex socket contact structures.
Solution Approach 2:
The invention employs asymmetric geometry with a concave portion on one side and a tapered protruding portion on the other side. This asymmetric design creates optimal contact conditions through the tapered interface, achieving low contact resistance while maintaining structural simplicity compared to symmetric socket contact designs.
3Device complexity
If the end faces of the two electric wires are merely butted against each other, then the connection structure is simple, but the contact area is small and the contact resistance is high
Solution Approach 1:
The concave and tapered portions are pre-formed during wire manufacturing before assembly. This preliminary action ensures that when the wires are connected, the tapered portion naturally inserts into the concave portion, automatically creating optimal contact conditions without requiring complex assembly procedures, thus maintaining simplicity while reducing contact resistance.
Solution Approach 2:
The tapered portion acts as an intermediary element that mediates the connection between the two wires. By inserting this tapered intermediary into the concave portion, the invention achieves improved contact conditions and reduced contact resistance while keeping the overall connection structure simple and easy to assemble.
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
The solution reduces contact resistance, allows for the use of smaller diameter wires to minimize weight, and enables controlled severance of the wire harness during collisions, ensuring reliable electrical connection and protection.
Implementation Method 1
the first connection end portion and the second connection end portion are integrally connected to each other by crimping the first extension portion and the second extension portion from a radial-direction outer side by the connecting member
Implementation Method 2
end portions of the first electric wire and the second electric wire are respectively provided with a first connection end portion and a second connection end portion in which conductors of the end portions have been subjected to fusing processing
Data Source
Figure 1
Figure 2
Figure 3~4(B)
AI summary
To provide a connection structure of a wire harness that enables the wire harness to be severed in the event of a vehicle collision and can restrain an increase in the weight of the wire harness. End portions of electric wires are respectively provided with connection end portions in which conductors of the end portions have been subjected to fusing processing, the connection end portion has an extension portion and a concave portion, the connection end portion has an extension portion and a protruding portion, the protruding portion is at least partially provided with a tapered portion, the connection end portions and are integrally connected to each other by crimping the extension portions and from the radial-direction outer side by the connecting member, and at the connection end portion, the crimping of the extension portion to press the tapered portion inserted in the concave portion causes the engagement force between the extension portion and the connecting member to become weaker than the engagement force between the extension portion and the connecting member when tension is applied to the electric wires.