Retractable Pin Molding Tool for Back-Injected Sheets
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Solution Overview
Problem
Existing methods for manufacturing back-injected decorative components for vehicle interiors are complex and costly, requiring pre-forming of sheets in additional tools, which can lead to loss of shape when transferring to back-injection tools, especially for elastically deformable materials.
Innovation Solution
A molding tool with retractable pins and a dual mold system that allows for simultaneous forming and back-injecting of bendable sheets, where pins hold and shape the sheet during molding and retract as the melt is injected, eliminating the need for pre-forming and supporting the sheet with a back-injected layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pre-forming is performed in additional tools before back-injection, then the sheet can be shaped, but the process complexity and costs increase
Solution Approach 1:
The patent combines the pre-forming operation and back-injection operation into a single molding tool. The forming pins are integrated directly into the back-injection mold, eliminating the need for separate pre-forming tools and reducing process complexity while maintaining shape accuracy.
Solution Approach 2:
The forming pins perform the pre-forming action in advance during mold closing, before the back-injection occurs. This preliminary shaping of the sheet ensures proper geometry is achieved before material injection, resolving the contradiction between achieving precise shapes and maintaining process simplicity.
2Manufacturing precision
If pre-forming is performed in additional tools, then the sheet can be shaped, but the transfer to back-injection tools causes loss of shape
Solution Approach 1:
By integrating the forming pins directly into the back-injection mold, the patent eliminates the transfer step between tools. The sheet is formed and then immediately back-injected in the same tool, preventing shape loss that would occur during tool transfer.
Solution Approach 2:
The forming action and back-injection action occur continuously in sequence within the same tool without interruption or transfer. This continuous process ensures the shaped sheet retains its geometry throughout the manufacturing process.
3Adaptability or versatility
If elastically deformable materials are used, then material flexibility is improved, but shape maintenance during transfer becomes difficult
Solution Approach 1:
The forming pins perform preliminary shaping of the elastically deformable sheet before back-injection. This preliminary action ensures the sheet achieves the desired shape while still in a controllable state, allowing elastic materials to be used without losing shape retention.
Solution Approach 2:
The forming pins act as intermediaries that temporarily hold and maintain the sheet's shape during the transition from unformed to formed state. These pins provide mechanical support to elastic materials during the critical shaping phase, enabling shape retention despite material elasticity.
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 simplifies the process, reduces complexity and costs, and enables the use of elastically deformable materials by maintaining the sheet's shape through the molding and back-injection process with a single tool, ensuring accurate and reliable fabrication of bent sheets for vehicle interior components.
Implementation Method 1
The pin is elastically mounted to or in the first mold half and points towards the second half of the mold. Further, the pin is retractable in response to a force exerted on the pin by a pressure of the injected melt during back injection.
Data Source
Figure 1~2
Figure 3~4b
Figure 5a~5b
AI summary
This document relates, inter alia, to a molding tool for forming and back-injecting a bendable sheet (13) comprising a mold, comprising a first mold half (1) and a second mold half (11). The first half (1) is arranged opposite the second half (11) forming a cavity (15) for maintaining the bendable sheet (13) and receiving a melt (12). Further, the mold comprises at least one pin (3) for holding the bendable sheet (13) and the pin (3) is retractable in response to a force exerted on the pin (3) by a pressure of the injected melt (12) during back injection.