Electric Connection Box Lid Cutout for Rotational Locking
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Solution Overview
Problem
Existing electric connection boxes often experience half-fitting issues due to deformation caused by the repulsive force of the packing, which prevents complete locking of the lid, especially in rotational fitting configurations.
Innovation Solution
The electric connection box design includes a cutout portion on the hanging wall of the lid, creating a larger clearance between the hanging wall lower end surface and the step portion at the rotation tip end portion, allowing for further rotation and ensuring complete locking of the lock portions, preventing half-fitting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the lid is rotationally fitted to the housing, then the packing gradually contacts the packing abutment end surface from the rotation base portion side, but the repulsive force of the packing causes lid deformation making complete locking difficult
Solution Approach 1:
The patent introduces a preliminary action by providing a rotation guide portion that pre-guides the rotational movement of the lid before the lock portions engage. This preliminary guidance ensures that the lid follows the correct rotational path, compensating for deformation caused by packing repulsive force and enabling complete locking of all lock portions.
Solution Approach 2:
The rotation guide portion acts as an intermediary element between the lid and the housing. It mediates the rotational fitting process by providing a guided path that accommodates lid deformation while ensuring proper engagement of the lock portions with the lock grooves.
2Object-affected harmful factors
If the hanging wall lower end surface abuts the step portion, then water intrusion is prevented, but lid deformation prevents complete abutment at all locations
Solution Approach 1:
The rotation guide portion provides preliminary guidance during rotation, ensuring that the hanging wall lower end surface progressively and completely abuts the step portion throughout the rotational movement. This preliminary guidance ensures complete sealing contact is achieved even when lid deformation occurs due to packing repulsive force.
3Reliability
If the lock portions are provided to fix the lid, then the lid is secured to the housing, but deformation prevents lock portions from reaching locking positions
Solution Approach 1:
The rotation guide portion performs a preliminary action by guiding the rotational movement before the lock portions engage. This ensures that even if lid deformation occurs during rotation, the lock portions will still reach their correct locking positions in the lock grooves, enabling complete and reliable fixation.
Solution Approach 2:
The rotation guide portion serves as an intermediary that facilitates the engagement between the lid and housing by providing a guided rotational path. This intermediary structure ensures that lock portions can overcome deformation effects and achieve proper locking.
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 design ensures reliable locking of the lid by allowing a larger rotational movement, preventing half-fitting and ensuring a watertight seal, even when deformation occurs due to the repulsive force of the packing.
Implementation Method 1
the packing 513 abuts against the packing abutment end surface 515 and elastically deforms
Implementation Method 2
The lid is configured to be rotated to cover the opening about the rotational axis and to be fitted to the housing
Data Source
AI summary
An electric connection box includes a housing having an opening and side walls, a lock protruding plate, a lid having a hanging wall having a hanging wall lower end surface and a hook, lock portions, a rotation tip end portion of the lid being provided between the lock portions, an annular packing, a step portion and a cutout portion provided on the hanging wall on a first portion of the lid, the first portion comprising the rotation tip end portion. The cutout portion is formed by cutting a lower tip end of the hanging wall such that a first clearance between the hanging wall lower end surface and the step portion at the first portion is larger than a second clearance between the hanging wall lower end surface and the step portion at a second portion of the lid, the second portion being different from the first portion.