Vehicular Seat Slide Spring Locking Mechanism

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Solution Overview

Problem

Conventional vehicular seat slide devices face challenges in assembling performance when attaching springs to upper rails, with issues such as improper positioning leading to unintended movement and stress concentration at limited portions, affecting the engagement of lock levers and lower rails.

Innovation Solution

A vehicular seat slide device design featuring a spring with a continuously bent locking portion that is inserted into a locking hole while elastically deformed, ensuring even stress distribution and reliable positioning, and including contact portions that maintain contact with the upper rail's inner surface to prevent variation in spring positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the spring is attached to the upper rail using conventional methods, then the spring can be positioned and fastened to the upper rail, but the assembly process becomes complex and time-consuming due to separate positioning and fastening configurations

Engineering Contradiction:
Improveassembling performanceVSAvoidassembly process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The locking portion is designed to combine both positioning and fastening functions into a single integrated structure. When the locking portion is inserted into the locking hole, it automatically positions the spring relative to the upper rail and secures it in place, eliminating the need for separate positioning and fastening configurations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The locking portion is designed to automatically position itself when inserted into the locking hole. The elastic deformation of the spring body during insertion causes the locking portion to engage with the peripheral edge of the locking hole, achieving both positioning and fastening without requiring additional positioning configurations or complex assembly steps.

Inventive Principle:
Principle #25Self-service

2Reliability

If the rear end portion of the spring is not properly positioned, then the spring can be attached to the upper rail, but the biasing force on the lock plate is insufficient, allowing unintended movement of the upper rail

Engineering Contradiction:
Improvepositioning accuracyVSAvoidassembling difficulty
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The invention replaces complex mechanical positioning mechanisms with elastic deformation-based positioning. The spring body is elastically deformed during insertion, allowing the locking portion to engage with the peripheral edge of the locking hole, which automatically ensures proper positioning of the rear end portion of the spring relative to the lock plate.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The spring body undergoes elastic deformation as a parameter change during the insertion process. This deformation allows the locking portion to be inserted into the locking hole and then locks at the peripheral edge, ensuring accurate positioning without requiring complex positioning configurations or increasing assembly difficulty.

Inventive Principle:
Principle #35Parameter changes

3Strength

If the locking portion is made with a limited joining portion, then the spring structure is simplified, but stress concentrates at the joining portion, potentially compromising the engagement between lock lever and lower rail

Engineering Contradiction:
Improvestress distributionVSAvoidspring structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The locking portion is designed with a continuously bent configuration instead of sharp angles or limited joining portions. This curved structure distributes stress more evenly throughout the locking portion, preventing stress concentration while maintaining a relatively simple spring overall structure.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The spring is divided into distinct functional portions: the locking portion with continuously bent configuration for stress distribution, the biasing portion for maintaining engagement, and the attachment portion for securing to the upper rail. This segmentation allows each portion to be optimized for its specific function while keeping the overall structure manageable.

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

Enhances the assembling performance by simplifying the attachment process, ensuring accurate positioning, and maintaining engagement between the lock lever and lower rail, while preventing unintended movement and stress concentration.

Implementation Method 1

the locking portion is inserted into the locking hole in a state where the spring body is elastically deformed

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

a spring attached to the upper rail and biasing in a lock direction in which the lock lever engages with the lower rail

Methodology Applied
Scientific EffectSpring biasing force: Spring

Data Source

PatentEP3061645B1Vehicular seat slide device
Publication Date: 2019.09.11 AISIN SEIKI KK
  • EP3061645B1 patent drawingFigure 1
  • EP3061645B1 patent drawingFigure 2~3
  • EP3061645B1 patent drawingFigure 4~5(b)

AI summary

A vehicular seat slide device includes a lower rail, an upper rail provided to be movable relative to the lower rail along a long-side direction of the lower rail and supporting a seat above, a lock lever supported by the upper rail and configured to restrict the relative movement of the upper rail by engaging with the lower rail. The vehicular seat slide device includes a spring attached to the upper rail and biasing in such a manner that the lock lever engages with the lower rail. The spring includes a locking portion inserted in a locking hole provided at an upper edge of the upper rail and opening to a side surface of the upper rail, the locking portion is insertable into the locking hole by elastically deforming the spring body towards an inner side relative to the locking hole, the locking portion is restricted from being detached from the locking hole in an insertion direction by being locked at a peripheral edge of the locking hole due to recovery of the elastic deformation.