Pneumatic Control Device for Stretch Blow Molding

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Solution Overview

Problem

The existing compressed air control devices in stretch blow molding systems face issues with the multitude of control lines causing movement impediment and reduced service life due to centrifugal forces and oscillation during rotation.

Innovation Solution

The device features a blow block with control lines exclusively arranged inside the housing, allowing for reduced external control lines and enabling the blow block to move freely, with detachable valve modules and a control unit that can be connected via a single control line or field bus, minimizing external cable connections and protecting the control unit from vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If multiple separate control lines are connected to each valve module externally, then individual control of valve modules is enabled, but the control lines impede movement and cause abrasion during rotation

Engineering Contradiction:
Improveindividual control capabilityVSAvoidservice life
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

Multiple separate control lines are merged into a single multi-conductor cable that connects to the blow molding block at one point. This allows individual control of each valve module while eliminating the abrasion problem caused by multiple separate external lines, as the single cable rotates together with the block without chafing against the housing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

A single multi-conductor cable performs multiple functions by containing all control lines for individual valve modules within one cable. This universal cable serves as both the structural connection and the control interface, eliminating the need for multiple separate external connections.

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

2Ease of manufacture

If control lines are arranged outside the housing, then connection to valve modules is simplified, but the blow block movement is impeded and abrasion occurs

Engineering Contradiction:
Improveconnection simplicityVSAvoidmovement freedom
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

All control lines are merged into a single cable that is arranged inside the housing of the blow molding block. This internal arrangement allows the cable to move freely with the block during rotation without being impeded by the housing structure, while still maintaining simple connection at the single external interface.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If a single control line is used to connect control unit to blow block, then movement freedom is improved, but individual control of multiple valve modules becomes complex

Engineering Contradiction:
Improvemovement freedomVSAvoidcontrol signal distribution
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

A single multi-conductor cable serves as a universal control interface that maintains movement freedom while enabling individual control of multiple valve modules. The cable's multiple conductors allow complex control signal distribution internally without requiring multiple external connection points.

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

Data Source

PatentEP3395538B1Device for pneumatic control
Publication Date: 2020.09.09 NORGREN GMBH
  • EP3395538B1 patent drawingFigure 1
  • EP3395538B1 patent drawingFigure 2
  • EP3395538B1 patent drawingFigure 3a~3b

AI summary

The present invention relates to a device (10; 100; 300) for the compressed air control of stretch blow molding machines, wherein the device (10; 100; 300) comprises a blow block (20; 120; 320) with a housing (21; 121, 321) and at least two valve modules (23a to 23f; 123a to 123f; 323a to 323f). The device further comprises a control unit (30; 130; 330) which can be electrically connected to each of the at least two valve modules (23a to 23f; 123a to 123f; 323a to 323f) via a separate control line. The separate control lines (28a to 28f; 128a to 128f; 328a to 328f) are arranged exclusively inside the housing (21; 121, 321).