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Research on the Design of Stretch Forming Dies for Aluminum Profiles

The design of stretch forming dies for aluminum profiles has consistently been a research focus in the stretch forming process field. In order to achieve rapid mold design, scholars both domestically and internationally have conducted extensive research.

Stretch Forming Machine and Process

The forming die for profile stretching is a key factor in determining the quality of the stretch formed components. The use of digital methods allows for the rapid and intelligent design of stretch forming dies for aluminum profiles.

However, current research primarily focuses on knowledge-based die design, with limited exploration into how mold design knowledge is applied in the design of stretch forming dies for aluminum profiles.

To address this gap, the author, based on the analysis of the design process of stretch forming dies for aluminum profiles, has constructed a knowledge model for die design. They have established a knowledge-based digital design method for stretch forming dies for aluminum profiles, solving key issues in digital mold design, and demonstrated the effectiveness of this method through practical examples.

Analysis of the Aluminum Profile Stretch Forming Die Design Process

Research on the Design of Stretch Forming Dies for Aluminum Profiles
Research on the Design of Stretch Forming Dies for Aluminum Profiles

The design process of stretch forming dies for aluminum profiles can be divided into three stages: overall scheme design, outline design, and detailed design, each with different design contents.

  • Overall Scheme Design: This phase involves the preliminary planning of the die structure based on the structural characteristics of the formed part. It serves as a crucial foundation for subsequent die design.
  • Outline Design: Building upon the overall scheme design, this stage includes the design of structural parameters and surface shapes.
  • Detailed Design: This phase focuses on the design of structural elements, standard components, and fillets.

The top 5 stretch forming die design process exhibits several characteristics

  • Application of Knowledge: It requires the application of a substantial amount of theoretical knowledge, specialized expertise, and experience in die design.
  • Sequential Impact: Results from each stage of the design process influence the subsequent stage, providing a certain degree of flexibility in the design workflow.
  • Utilization of Mature Designs: Similar parts aim to leverage existing mature design solutions to enhance the reliability of die design.
  • Refinement and Reuse: Refining and reusing the design process for stretch forming dies in the enterprise can improve design efficiency.
  • Need for Advanced CAD Systems: The modeling approach for dies is often non-standard, and the use of generic CAD software results in low design efficiency. There is an urgent need for advanced and rapid die CAD systems.

Knowledge-Based Mold Design Approach

Knowledge Composition

The design knowledge for stretch forming dies for aluminum profiles is primarily categorized into scheme design knowledge and parameter design knowledge. Different models for mold overall scheme design and parameter design are established for different designs.

Design knowledge from various domains and forms varies in expression and reasoning methods. Understanding the characteristics of different domain knowledge is essential to find the most suitable methods for representation and reasoning for effective knowledge utilization.

Mold Design

Knowledge-based mold design involves transforming implicit knowledge, such as standardized design information, optimal design methods, and processes, into explicit knowledge. This knowledge is represented in various forms like parameters, formulas, rules, checks, reports, and design tables. Through operations like definition, modification, insertion, the design process automatically captures and reuses design knowledge. It guides users through the entire process of overall scheme design, outline design, and detailed design of the mold. Eventually, it generates a numerical model for the stretch forming die and stores mold information in a knowledge base.

The application of mold design knowledge standardizes the mold design process, reduces repetitive work for designers, and continuously enhances and improves the knowledge base through dynamic accumulation, better serving the design of forming dies.

Mold Structure Schemes and Parameters

The design of mold structure schemes is primarily determined by part characteristics. While the structure of stretch forming dies for aluminum profiles is relatively simple, it varies for different types of parts. Using a grouping approach based on specific mold structure design scenarios, typical knowledge is summarized and presented in graphical forms.

The structural parameter design for stretch forming dies mainly involves designing parameters such as plate thickness, base plate, mold body thickness, and working clearance. This knowledge is primarily empirical, belonging to procedural knowledge with high execution efficiency. Structural parameters are crucial for building three-dimensional models, and the knowledge of structural parameters serves as the main basis for structural parameter design. To express this knowledge quickly, directly, and accurately, a method based on production rule representation is adopted, which has the advantages of flexibility, ease of understanding, and similarity to human thinking.

Advancing Mold Design with XML Integration

In the entire process of digital design for stretch forming processes, systems such as process parameter design, mold design, and formability evaluation require interaction, necessitating information exchange and sharing.

Due to differences in systems and varied data structures, using geometric information from CAD models for extensive engineering calculations and design decisions is challenging.

Addressing the Integration Challenge

To address the need for information integration, a method based on XML (a standard published by W3C, a markup language for describing various data) for representing mold design information is proposed.

Semantic Representation and Extension

This method establishes the semantic representation of mold design content, extending the integrated application of mold design information based on the XML format.

Creating a Standard Model

By creating a standard model for the design information of stretch forming dies, the method enables a complete and clear expression of mold design information.

Facilitating Transfer and Sharing

This facilitates the transfer and sharing of mold information over the network. In the design process of stretch forming dies, information in each design stage is continuously enriched, forming a complete mold design information model

Components of Mold Design Information

The information includes scheme information, geometric information, and numerical model information. Scheme and geometric information can be directly parsed and read from XML files.

Numerical Model Information

Numerical model information in XML files is represented as mold numbers, which users can use to retrieve information from the mold library.

XML File as the Main Carrier

The XML file for mold information is the main carrier of mold information, providing geometric references for trajectory calculations in numerical control instructions through the transfer of mold geometric information to the process parameter design system.

Design Application Example

PBA aluminum bending machine

Taking a specific component as an example, this section illustrates the supportive role of knowledge in the overall scheme design and structural parameter design of stretch forming dies. The stretch forming die design subsystem consists of a die structure parameter design module and a die geometry modeling module. The knowledge guides the die design process through the browser-accessible die structure parameter design module.

  • External System Interaction:
    External interfaces utilize XML files for obtaining and transmitting different data information with other systems. XML description files are defined based on various information content specifications, including die design features, forming a representation and interface standard within the stretch forming die design system. This enables information exchange and integration between application systems and between application systems and databases.
  • Internal System Interaction:
    The die geometry modeling module accesses the die structure parameter design module through an internal browser to view design knowledge. After completing the die design, the generated numerical model files are transmitted to the die knowledge base subsystem through an upload process.
  • Designing a Specific Part:
    Based on the description of the part information, it is identified as a corner profile part undergoing edge deformation. According to typical knowledge, the forming die adopts a structure comprising a bottom plate and a die body.
  • Structure Parameter Design:
    The structure parameter design involves using a method based on production rule rules to design the parameters of the die structure based on the selected forming die’s structural scheme.
  • Integration of Parameters and Surface Design:
    Finally, these parameters are combined with surface design. Using the knowledge-based stretch forming die design system, a three-dimensional numerical model of the die is generated in the geometric modeling system, resulting in the final design outcome.

In summary, the use of knowledge-based stretch forming die design methods enables faster and more accurate completion of stretch forming die design, significantly reducing the design cycle and production costs.