Vehicle Seat Frame Mechanical Interlock Eliminates Welding

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Solution Overview

Problem

The existing methods for assembling vehicle seat frames through welding are inefficient and costly, requiring a separate welding facility and process, which increases manufacturing costs and complexity.

Innovation Solution

A vehicle seat frame configuration that uses a first member with a first engaging pawl and pressing surface, a second member with a second engaging pawl and pressing surface, and a third member with concave portions, allowing the members to be joined without welding by engaging the paws with the concave portions and using screws to enhance the pressing force, thereby eliminating the need for a welding process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If welding is used to join members of the seat frame, then the strength and reliability of the joint is improved, but the manufacturing cost and process complexity increase due to requiring separate welding facilities and processes

Engineering Contradiction:

Improvejoint strengthVSAvoidassembly process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the welding process (thermal/chemical joining) with a mechanical joining system consisting of engaging paws and recesses. The first and second members are equipped with engaging paws that fit into corresponding recesses of the third member, creating a mechanical interlock that eliminates the need for welding facilities and processes while maintaining joint strength and reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The engaging paws and recesses act as intermediary mechanical features that facilitate the connection between seat frame members. These intermediary structures enable direct mechanical engagement between components, replacing the need for external welding processes and reducing overall system complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Strength

If welding is used to join members of the seat frame, then the joint strength is improved, but the manufacturing cost increases due to requiring welding facilities and processes

Engineering Contradiction:

Improvejoint strengthVSAvoidmanufacturing cost

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The patent substitutes the expensive welding process with a simpler mechanical engagement system. The engaging paws and recesses create strong joints through direct mechanical interlocking, eliminating the need for costly welding equipment, specialized facilities, and complex welding procedures while maintaining adequate joint strength for the application.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The mechanical engagement components (engaging paws and recesses) can be integrated into the seat frame members during molding or forming processes, making them cost-effective to manufacture. This approach replaces expensive post-assembly welding operations with low-cost integrated mechanical features.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If welding is used to join members of the seat frame, then the joint reliability is improved, but the productivity decreases due to the time-consuming welding process and need for separate facilities

Engineering Contradiction:

Improvejoint reliabilityVSAvoidassembly productivity

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent replaces the time-consuming welding process with a rapid mechanical engagement system. The engaging paws and recesses allow for quick assembly of seat frame members without requiring heating, cooling, or post-weld processing steps, thereby significantly improving assembly productivity while maintaining joint reliability through mechanical interlocking.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The engaging paws and recesses are pre-formed as integral features of the seat frame members during manufacturing. This preliminary preparation eliminates the need for complex assembly operations during final assembly, allowing workers to simply engage the pre-configured mechanical features to complete the joining process rapidly.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS10793036B2Vehicle seat

Publication Date: 2020.10.06 TOYOTA BOSHOKU KK

AI summary

A vehicle seat includes a seat cushion, a seat back and a seat frame. The seat frame has a first member provided with a first engaging pawl and a first pressing surface, a second member provided with a second engaging pawl and a second pressing surface, and a third member provided with a first concave portion and a second concave portion. The first engaging pawl is disposed on an inner side of the first concave portion, the second engaging pawl is disposed on an inner side of the second concave portion, and at least a portion of the first pressing surface and at least a portion of the second pressing surface press each other, causing the first engaging pawl to engage with the first concave portion, and the second engaging pawl to engage with the second concave portion.