Management of Injection Mold Design Drawings
The management of injection mold design drawings is a core component of the entire mold production lifecycle, encompassing processes such as drawing, review, archiving, version control, and distribution. The degree of standardization directly impacts mold design quality, manufacturing efficiency, and ease of subsequent maintenance. A complete set of mold design drawings includes assembly drawings, parts drawings, 2D engineering drawings, 3D models, and bills of materials (BOMs). These drawings serve as the sole technical basis for mold manufacturing, inspection, and maintenance, and therefore their accuracy, completeness, and traceability must be guaranteed. Effective drawing management reduces design errors and communication costs, while also providing data support for mold modification and reuse. It is a crucial foundation for efficient production in modern mold companies.
The creation and standardization of design drawings is a prerequisite for management. They must adhere to unified drawing specifications and technical standards to ensure readability and consistency. Drawing software typically uses AutoCAD (2D) and UG and Pro/E (3D). Drawing layer settings, line types, fonts, and dimensioning styles must conform to company standards. For example, outline lines should use 0.3mm solid lines, dimension lines should use 0.15mm solid lines, and the font should use Fangsong GB2312 with a font size of 3.5mm. Part drawings must include complete views (front, top, and cross-sectional views), dimensioning, tolerance requirements, surface finish, material grade, and heat treatment requirements. For example, cavity parts must include dimensional tolerances (e.g., Φ50±0.005), surface finish (Ra0.1), and hardness requirements (HRC48-52). Assembly drawings must clearly show the assembly relationships of each part, clearances (e.g., H7/g6 for guide pins and guide bushings), installation dimensions, and important technical specifications (e.g., mold closing sequence and ejector stroke). The 3D model must be completely consistent with the 2D drawing, and interference checks must be performed to ensure assembly feasibility.
The review and approval process of design drawings is the key to ensuring the quality of drawings. A multi-level review system needs to be established to ensure strict checks at every level. First, the designer conducts a self-review to check the completeness of the drawings, the correctness of the dimensions, and the consistency with the plastic part drawings; then the design team leader conducts a second review, focusing on the rationality of the mold structure, the feasibility of the process, and whether the selection of standard parts is appropriate; finally, the chief engineer or technical director conducts a final review, evaluating the economy, reliability, and safety of the mold as a whole, and signing the approval opinion. Problems found during the review process need to be promptly fed back to the designer for modification, and the modified drawings need to be resubmitted for review until all problems are resolved. Audit records need to be archived in detail, including audit opinions, modification content, and responsible persons, to ensure that every drawing is strictly checked and design errors are eliminated in the bud.
Drawing version control is a core management component, used to track drawing revisions and avoid manufacturing errors caused by version confusion. Each drawing must be labeled with a version number (such as A, B, C, or V1.0, V2.0). The initial version is A or V1.0, and the version number increases with each revision. When a mold requires modification or optimization, designers must make revisions based on the original drawing, noting the reason, details, date, and person who made the revision in the revision history column. Before a new drawing version is released, the old version must be recycled and marked as “obsolete” in the management system to prevent misuse. Significant revisions (such as changes to cavity dimensions or major structural adjustments) require a review by relevant departments (design, manufacturing, and quality inspection) to assess the impact of the changes on mold manufacturing and part quality. Only after passing this review can a new version be released. Strict version control ensures that manufacturing always uses the latest and most accurate drawings, minimizing losses caused by version errors.
Drawing archiving and distribution require a digital management system to improve management efficiency and data security. Traditional paper drawing archiving takes up a lot of space, is difficult to find, and is easily damaged. Modern mold companies generally use PDM (Product Data Management) or PLM (Product Lifecycle Management) systems for drawing management. All drawings (including 2D and 3D drawings, bill of materials, and review records) must be uploaded to the system and stored by mold number, project name, and design date. Access permissions must be set (e.g., designers can edit, manufacturing personnel can read only) to prevent unauthorized modification or deletion. Drawings are distributed electronically through the system. Receiving departments (e.g., manufacturing workshops and procurement departments) must confirm receipt upon receipt. The system automatically records the distribution history for easy traceability. Drawings that need to be distributed externally (e.g., part drawings sent to suppliers for processing) must be encrypted or have sensitive information (such as overall structure) removed. A confidentiality agreement must be signed to prevent technical leaks. Furthermore, the system must regularly back up data to prevent drawing loss due to hardware failure and ensure data security and integrity.
Drawing reuse and knowledge management are important means of improving design efficiency. By accumulating and leveraging previous design experience, the design cycle for new molds can be shortened. A drawing database is established within the management system, categorizing and organizing drawings of commonly used mold structures (such as ejector mechanisms and core pulls), standard components, and typical parts to form a design template or standard library. When designing a new mold, designers can call up similar drawings from the database and modify them, rather than starting from scratch, significantly improving design efficiency. The system also records the design parameters, performance, and failure scenarios of each mold set, forming a knowledge base that provides a reference for new mold designs. For example, when designing a similar bottle cap mold, the cavity dimensions, cooling system layout, and demolding mechanism design of previously successful molds can be referenced to avoid duplication of effort and design errors. Drawing reuse and knowledge management can shorten the design cycle for new molds by 30%-50%, enhancing a company’s core competitiveness.
