Bicycle Frame Unit Segmentation and Pressing

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Solution Overview

Problem

The existing frame units for bicycles face issues with residual stress and welding defects due to manual welding processes, leading to safety concerns such as cracks and reduced productivity, especially when joining components like the head tube, seat tube, and stays, which affects rigidity and durability.

Innovation Solution

The integration of left and right frame bodies, each comprising parts of the head tube, seat tube, and stays, with a support ring installed on the head tube, allowing for press-forming and automated welding, minimizing residual stress and improving welding quality and productivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If manual welding process is used to join head tube, seat tube, frame, and stays, then flexibility for various designs is achieved, but residual stress and welding defects occur leading to cracks and reduced safety

Engineering Contradiction:

Improvedesign flexibilityVSAvoidsafety

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The frame unit is divided into separate components (head tube, seat tube, frame, stays) that are joined through pressing and coupling rather than welding. This segmentation allows design flexibility while eliminating welding-induced residual stress and defects, thereby maintaining both adaptability and reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The welding process (thermal-chemical joining) is replaced with a mechanical pressing and coupling system. This substitution eliminates the harmful thermal effects and residual stresses associated with welding, improving safety and reliability while still achieving the necessary structural integrity and design flexibility.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If manual welding is performed by workers with varying skills, then joining of components is achieved, but welding quality varies and productivity deteriorates

Engineering Contradiction:

Improvejoining capabilityVSAvoidmanufacturing efficiency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The pressing and coupling mechanism is designed to automatically align and join frame components without requiring skilled manual welding operations. The self-aligning features and standardized interfaces enable consistent joining quality and facilitate automated manufacturing, thereby improving both ease of manufacture and productivity.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The joining process parameters are changed from thermal-welding parameters (temperature, heat input, welding speed) to mechanical pressing parameters (pressure, alignment, coupling force). This parameter change enables automated control and consistent quality, eliminating the variability associated with manual welding skills and significantly improving manufacturing efficiency.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If preheating process is performed before welding the head tube to upper and lower frames, then welding quality is improved, but excessive working time is required and productivity deteriorates

Engineering Contradiction:

Improvewelding qualityVSAvoidworking time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The preheating process is completely removed from the manufacturing sequence by eliminating welding altogether. The pressing and coupling method does not require thermal preheating, thereby achieving high joining quality without the time-consuming preheating step, thus improving productivity while maintaining manufacturing precision.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The thermal preheating process is replaced with a mechanical pressing process that does not require thermal preparation. This substitution eliminates the time-consuming preheating step while still achieving reliable component joining, thereby reducing working time and improving productivity without sacrificing joining quality.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This approach enhances the rigidity and durability of the frame unit by reducing the risk of cracks and damage from impact loads, while automating the welding process to improve efficiency and aesthetics.

Implementation Method 1

press-forming a left frame body so that a part of a head tube, a part of a seat tube, a part of a frame, and a left stay are integrally formed

Methodology Applied

Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

automated welding, minimizing residual stress and improving welding quality

Methodology Applied

Scientific EffectWelding: Welding

Data Source

PatentUS9254885B2Frame unit for bicycle and method of manufacturing the same

Publication Date: 2016.02.09 HYUNDAI MOTOR CO LTD

AI summary

A frame unit for a bicycle includes: a left frame body in which a part of a head tube, a part of a seat tube, a part of a frame, and a left stay are integrally formed; and a right frame body in which a part of the head tube, a part of the seat tube, a part of the frame, and a right stay are integrally formed, in which the left frame body and the right frame body are coupled so as to integrally form the head tube, the seat tube, and the frame, and a support ring is installed to the head tube.