Variable Blow Molding for Fuel Tank Adaptability

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Solution Overview

Problem

The existing blow molding processes for producing fuel tanks face challenges in placing fuel system components during molding and lack flexibility in producing tanks of variable quantity, size, and configuration due to the fixed nature of extrusion equipment and mold designs.

Innovation Solution

The method involves using a blow molding apparatus with grippers and spreaders to stretch and shape a parison within a mold, allowing for the introduction of components during the molding process and enabling the production of fuel tanks with varying layer configurations and sizes by using extruders and molds that can accommodate different parison shapes and sizes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If extrusion equipment is used to produce parison layers, then fixed quantities of parison layers of fixed size and configuration are produced, but flexibility in producing fuel tanks of variable quantity, size, and configuration is limited

Engineering Contradiction:
Improveflexibility in producing fuel tanks of variable quantity, size, and configurationVSAvoidfixed nature of extrusion equipment and mold designs
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the mold cavity variable and adjustable. The mold cavity can be reconfigured to produce fuel tanks of different sizes, shapes, and layer configurations. This dynamic capability allows the same extrusion equipment to produce varied products by changing the mold cavity configuration rather than requiring dedicated equipment for each product variant.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements universality through a multi-functional mold system that can produce multiple types of fuel tanks with different configurations. The mold assembly includes a cavity that can be adjusted to create tanks of variable quantity, size, and layer structure, allowing one piece of equipment to perform multiple production functions that previously required separate dedicated machines.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If components are placed in the tank during blow molding, then components can be molded in place, but placement of components becomes difficult because components attach to the inside surface only after the mold has been closed

Engineering Contradiction:
Improveintegration of fuel system components during moldingVSAvoiddifficulty of component placement
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The patent applies preliminary action by providing preliminary support structures (such as pins or fixtures) within the mold cavity that hold components in their correct positions before the blow molding process begins. This preliminary positioning ensures components are correctly placed and supported during the molding process, eliminating the difficulty of component placement after mold closure.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses intermediary support structures as mediators between the mold cavity and the components being molded. These intermediaries (pins, fixtures, or support elements) facilitate proper component positioning and attachment during the molding process, enabling easy component integration without the operational difficulties of direct placement.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If a multiple layer parison is extruded, then structural, barrier, and adhesive layers can be formed, but dedicated extrusion equipment is required which produces fixed quantities of parison layers

Engineering Contradiction:
Improvemultiple layer structure with structural, barrier, and adhesive layersVSAvoidfixed quantity and configuration of parison layers
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by enabling the mold cavity to be reconfigured for producing fuel tanks with different layer configurations. The same extrusion equipment that produces multi-layer parison can adapt to create tanks with variable quantities and arrangements of structural, barrier, and adhesive layers by adjusting the mold cavity configuration, providing versatility while maintaining manufacturing precision.

Inventive Principle:
Principle #15Dynamics

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 allows for the efficient integration of fuel system components during the molding process and provides flexibility in producing fuel tanks of various sizes and configurations, improving the manufacturing efficiency and adaptability of the blow molding process.

Implementation Method 1

an extruder to heat and extrude a quantity of plastic material

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

the extruder to heat and extrude a quantity of plastic material to form a parison

Methodology Applied
Scientific EffectExtrusion: Extrusion

Implementation Method 3

a blow pin to introduce a quantity of pressurized gas into the parison to inflate the parison

Methodology Applied
Scientific EffectPressurisation: Pressurisation

Implementation Method 4

a blow pin to introduce a quantity of pressurized gas into the parison

Methodology Applied
Scientific EffectGas compression: Compression

Implementation Method 5

the mold halves closed together to bond the parison to one another

Methodology Applied
Scientific EffectPressure bonding: Compression

Data Source

PatentEP2743055B1Method of manufacturing an article
Publication Date: 2017.10.04 TI AUTOMOTIVE TECHNOLOGY CENTER GMBH
  • EP2743055B1 patent drawingFigure 1
  • EP2743055B1 patent drawingFigure 2
  • EP2743055B1 patent drawingFigure 3

AI summary

A method of manufacturing a product, including extruding a parison (24), and separating the parison into parison halves by cutting a partially expanded parison or by pulling apart a longitudinally weakened parison, and forming the parison halves against corresponding mold halves. The method may also include applying a film against the parison halves and/or the mold halves, and forming the film and parison halves against the mold halves to produce multi-layer product halves. Apparatuses for performing the method are also disclosed.