Vehicle Lid Lock Shaft Member Segmentation and Stopper Retention

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Solution Overview

Problem

The existing lid lock apparatus for vehicles faces issues with the shaft member inclining due to mismatched load application and axial center, leading to failure in locking the lid, and the stopper falling off due to repeated deflection, which complicates assembly and increases component count.

Innovation Solution

The design includes a shaft member with a relief portion and a recess portion, along with a contact portion that engages at the axial center, preventing inclination and using a stopper holder to prevent the stopper from falling off, while maintaining a compact design and efficient assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If a relief portion is formed at the shaft member to allow overlapping arrangement of the drive unit, then the thickness dimension of the lid lock apparatus is reduced, but the shaft member inclines in the thickness direction causing failure in locking the lid member

Engineering Contradiction:
Improvethickness dimension of lid lock apparatusVSAvoidlocking function of lid member
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

The shaft member is divided into functionally distinct segments: a guide portion that maintains axial alignment and a relief portion that accommodates the drive unit. This segmentation allows the shaft member to both reduce thickness dimension and prevent inclination by separating the load-bearing function from the space-saving relief structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The guide portion acts as an intermediary element between the housing and the relief portion. It provides a stable reference axis that prevents the relief portion from inclining, thereby mediating between the conflicting requirements of compactness and reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If the stopper is simply mounted on the holding portion by insertion, then the assembly process is simple, but the stopper may be lifted up and fall off due to repeated deflection

Engineering Contradiction:
Improveassembly process of stopperVSAvoidretention of stopper on holding portion
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The snap-fit mounting mechanism utilizes elastic deformation dynamics. The stopper is designed to deflect elastically during insertion and then lock into position, creating a dynamic retention system that maintains reliability while preserving simple assembly. The elastic member's ability to deform and recover provides both the mounting simplicity and the retention force needed.

Inventive Principle:
Principle #15Dynamics

3Object-affected harmful factors

If a sliding resistance is present at the seal member for waterproofing, then waterproofing is achieved, but the sliding resistance accelerates the inclination of the shaft member

Engineering Contradiction:
Improvewaterproofing performanceVSAvoidaxial alignment of shaft member
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The shaft member is segmented into a guide portion and a relief portion, with the seal member positioned at the guide portion. This segmentation isolates the sliding resistance effect to the guide portion, where it does not cause inclination, while the relief portion maintains smooth movement without the destabilizing friction effect.

Inventive Principle:
Principle #1Segmentation

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 ensures smooth operation of the lid lock by preventing shaft member inclination and stopper detachment, enhancing sealing performance and reducing assembly complexity while maintaining a reduced thickness profile.

Implementation Method 1

a shaft member configured to project from a housing by means of a spring force

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

an electric motor provided within the housing is operated to rotate a worm wheel so that the shaft member moves against the spring force

Methodology Applied
Scientific EffectMechanical transmission: Worm Drive

Implementation Method 3

a sliding resistance caused by a seal member for waterproofing provided at a front portion of the shaft member

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2182148B1Lid lock apparatus for vehicle
Publication Date: 2018.02.14 AISIN SEIKI KK
  • EP2182148B1 patent drawingFigure 1
  • EP2182148B1 patent drawingFigure 2
  • EP2182148B1 patent drawingFigure 3

AI summary

A lid lock apparatus for a vehicle includes a housing (2), a drive motor (3), an output gear (5) having an engagement piece (53), and a shaft member (6) of which one end is engageable with a lid member (91). The shaft member (6) includes a support portion (62), a relief portion (64), and a recess portion (65). The shaft member (6) further includes a contact portion (65a) obtained by a portion of the engagement piece (53) closest to an axial center (P) of the shaft member (6) to extend radially outwardly in a case where the contact portion (65a) is formed at the engagement piece (53), the contact portion being obtained by a portion of the recess portion (65) closest to the axial center (P) to extend radially inwardly in a case where the contact portion (65a) is formed at the recess portion (65).