Wire Harness Protector Clamp Geometry to Prevent Rotation

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Solution Overview

Problem

Existing wire harness protectors face issues with clamps disengaging from the clamp attachment part due to dimensional tolerances, leading to rotation and potential disengagement.

Innovation Solution

A protector design featuring a protector body with a routing part and a clamp attachment part, where the clamp includes pair of clamp-side flat parts and the clamp attachment part has pair of rotation prevention portions with body-side flat parts, preventing the clamp from rotating and disengaging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a clamp is locked in a locking hole to hold a wire harness, then the wire harness is secured, but the clamp may rotate around the locking hole and disengage due to dimensional tolerances

Engineering Contradiction:
Improveclamp retentionVSAvoidclamp position stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent introduces asymmetric flat parts on both the clamp and clamp attachment part that prevent rotational movement. The body-side flat part on the clamp attachment part and the corresponding clamp-side flat part create a non-circular engagement geometry, eliminating the rotational degree of freedom while maintaining the locking function. This asymmetric design directly addresses the rotation and disengagement problem caused by dimensional tolerances.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The flat parts act as intermediary elements between the locking hole and the clamp body. Rather than relying solely on the circular locking hole engagement, the flat parts serve as intermediate geometric features that constrain rotation and provide a stable mating surface, preventing direct rotational movement around the locking hole.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If dimensional tolerances are present in the locking hole and locking protrusion, then manufacturing is easier, but the clamp rotates and may disengage

Engineering Contradiction:
Improvelocking mechanism fabricationVSAvoidclamp engagement reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The asymmetric flat part design is easy to manufacture using standard machining or molding processes. The flat parts can be created as simple geometric features on the clamp and clamp attachment part without requiring complex tolerancing, while effectively preventing rotation and disengagement that would otherwise result from dimensional variations in the circular locking hole.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The flat parts are designed into the clamp and clamp attachment part during manufacturing, preliminarily establishing the anti-rotation geometry before assembly. This preliminary design ensures that when components are assembled with normal dimensional tolerances, the rotation prevention function is already built-in, eliminating the need for post-assembly adjustments or special tolerance control.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS12288972B2Protector having clamp engaging mechanism
Publication Date: 2025.04.29 YAZAKI CORP
  • US12288972B2 patent drawing
  • US12288972B2 patent drawing
  • US12288972B2 patent drawing

AI summary

A protector includes: a protector body having a routing part in which a wire harness is routed, and a clamp attachment part in which a locking hole is formed; and a clamp which is locked in the locking hole to hold the wire harness. The clamp includes a pair of clamp-side flat parts which are formed to face in directions opposite to each other. The clamp attachment part has a pair of rotation prevention portions which are provided with the locking hole therebetween and which include body-side flat parts facing the clamp-side flat parts.