Spring-Assisted Link Mechanism for Vehicle Seat Pitching

Solution Overview

Problem

Vehicle seats with pitching functions require significant force to transition between tilted and seated positions due to their center of gravity and weight, leading to increased width and weight, which complicates boarding and seating, especially when a child safety seat is attached.

Innovation Solution

A vehicle seat design incorporating a link mechanism with rotating shafts equipped with springs that assist in swinging the main frame between seated and tilted positions, reducing the need for a bulky assist mechanism and maintaining a compact width and lightweight structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a massive assisting means including coil spring and hook is used to apply assisting force for displacing the main frame, then the assist function is achieved, but the width of the vehicle seat increases and the weight increases

Engineering Contradiction:

Improveassisting force for displacing main frameVSAvoidwidth of vehicle seat

Core Design Contradiction:

Ease of operationVSArea of moving object

Solution Approach 1:

The assisting means is merged with the link mechanism by integrating the coil spring into the rotating shaft assembly. The spring is positioned within the link mechanism structure rather than as a separate external component, combining the assisting function with the existing mechanical linkage that connects the seat cushion to the vehicle floor.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The coil spring is nested within the link mechanism structure. The spring is positioned inside the rotating shaft assembly and the link mechanism housing, utilizing the internal space of the existing structure rather than adding external bulk. This nesting approach allows the spring to be contained within the footprint of the link mechanism.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Ease of operation

If a massive assisting means including coil spring and hook is used to apply assisting force for displacing the main frame, then the assist function is achieved, but the weight of the seat increases

Engineering Contradiction:

Improveassisting force for displacing main frameVSAvoidweight of seat

Core Design Contradiction:

Ease of operationVSWeight of stationary object

Solution Approach 1:

The assisting means is merged with the link mechanism by integrating the coil spring into the rotating shaft assembly. The spring is positioned within the link mechanism structure rather than as a separate external component, combining the assisting function with the existing mechanical linkage that connects the seat cushion to the vehicle floor.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The coil spring is nested within the link mechanism structure. The spring is positioned inside the rotating shaft assembly and the link mechanism housing, utilizing the internal space of the existing structure rather than adding external bulk. This nesting approach allows the spring to be contained within the footprint of the link mechanism.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Ease of operation

If a massive assisting means is located outside the fixing position of seat sliding device, then the assist function is provided, but the space for boarding and seating in rear seat is narrowed

Engineering Contradiction:

Improveassisting functionVSAvoidspace for boarding and seating

Core Design Contradiction:

Ease of operationVSArea of stationary object

Solution Approach 1:

The assisting means is repositioned from a lateral arrangement (outside the slide rail) to a longitudinal arrangement (within the link mechanism). By changing the spatial dimension from width to length, the spring and hook assembly is located within the front-rear direction where it does not encroach on the lateral space needed for boarding and seating operations.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 spring-assisted link mechanism facilitates easier transition between positions while maintaining a compact width and reducing the overall weight of the seat, enhancing user accessibility and space utilization.

Implementation Method 1

a spring that urges the main frame to swing from the forward tilted position to the seated position or from the seated position to the forward tilted position

Methodology Applied

Scientific EffectElastic potential energy: Elasticity

Data Source

PatentUS11376994B2Vehicle seat

Publication Date: 2022.07.05 TACHI S CO LTD

AI summary

Provided is a vehicle seat having a pitching function, which not only has an assist function for bringing a main frame to a seated position or a forward tilted position, but also prevents the increase in the width and the increase in the weight of the seat. The vehicle seat includes: a base frame; a main frame disposed on the base frame and having a back frame and a cushion frame; and a link mechanism that allows the main frame to swing to the seated position and the forward tilted position with respect to the base frame. A third rotating shaft of the link mechanism is provided with a torsion spring that urges the main frame to swing from the forward tilted position to the seated position.