Rotatable Core Molding Device for Arc-Shaped Bent Inner Space Extraction

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Solution Overview

Problem

Conventional molding devices face challenges in removing molded products with arc-shaped bent inner spaces, particularly made of metal, due to irreversible deformation and high catching forces, leading to defects.

Innovation Solution

A molding device with a rotatable core and fixing members that apply a first force to peel the core off and then rotate it to smoothly extract the product, reducing pressure and resistance, and using tapered portions to facilitate separation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a simple molding device with linear ejector pin is used, then device complexity is reduced, but molded product with arc-shaped bent inner space cannot be extracted due to interference between core and product

Engineering Contradiction:
Improvemolding device complexityVSAvoidmolded product extraction
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The core is designed to rotate about a rotation axis, transforming from a static component to a dynamic one. This rotation enables the core to follow an arc-shaped path during extraction, matching the arc-shaped bent inner space geometry and allowing successful removal of the molded product without interference

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The extraction motion is changed from linear (one-dimensional) to rotational (adding angular dimension). The core rotates about a rotation axis perpendicular to the mold separation direction, enabling movement along an arc-shaped path that corresponds to the inner space geometry, thus resolving the extraction interference problem

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If conventional linear extraction method is used for metal molded product, then extraction process is simple, but irreversible deformation and defects occur due to high catching force and low elasticity of metal

Engineering Contradiction:
Improveextraction process simplicityVSAvoidmolded product quality
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The rotational motion of the core dynamically adapts to the geometry of the arc-shaped bent inner space, distributing extraction forces along the arc path rather than applying concentrated linear force. This reduces peak stresses that would cause irreversible deformation in brittle metal materials

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The core follows an arc-shaped rotational path about a rotation axis, matching the curved geometry of the inner space. This curved extraction path reduces stress concentrations and allows gradual separation from the metal molded product, preventing defects caused by sudden linear extraction

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Force

If core and molded product are separated linearly, then separation force is concentrated, but high resistance and pressure cause defects on arc-shaped bent inner space product

Engineering Contradiction:
Improveseparation force applicationVSAvoidproduct surface quality
Core Design Contradiction:
ForceVSManufacturing precision

Solution Approach 1:

The rotational mechanism transforms concentrated linear separation force into distributed force applied along an arc-shaped path. As the core rotates, the separation force is continuously redirected, reducing peak pressure on any single point of the molded product surface and preventing defects

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3308876B1Molding device and method for manufacturing molded product
Publication Date: 2023.05.10 TAIHO KOGYO CO LTD
  • EP3308876B1 patent drawingFigure 1(a)~1(f)
  • EP3308876B1 patent drawingFigure 2~3(c)
  • EP3308876B1 patent drawingFigure 4(a)~4(f)

AI summary

Provided is a molding device 1 for manufacturing a molded product having an arc-shaped bent inner space, wherein the molding device 1 includes: a pair of molds 10, 20 which is joinable to each other and separable from each other, and is capable of forming a cavity C which has a shape corresponding to an outer shape of the molded product in a joined state during molding; a core 30 which has a shape corresponding to an inner shape of the molded product, and is disposed in the inside of the cavity C which the pair of molds 10, 20 forms during molding; and a rotation member 40 which is joined to a terminal end of the core 30, and is rotatable together with the core 30 after molding. Compared to a conventional molding device, the molding device 1 of the present invention becomes a molding device capable of suppressing the occurrence of a defect on a molded product having an arc-shaped bent inner space at the time of taking out the molded product.