Design Analysis and Manufacture of Precision Injection Mold for Hinge Sheath_Hinge Knowledge_Tallsen

Summary: Through the analysis of double-sided hinge sheaths in precision injection molding, this article discusses the optimal design of frame selection and fine positioning of the parting surface for irregular and complex plastic parts. It emphasizes the importance of ensuring precision in plastic parts and highlights the design skills for functional plastic hooks with smooth ejection and reliable fixation. The article also explains the design points for mold exhaust and balanced ejection systems. After the mold is put into production, the quality of the plastic parts is stable and meets customer requirements.

The quality of plastic parts in precision injection molding is affected by various factors, including the materials of the plastic parts, the injection process, the injection mold, and the injection molding machine. However, the injection mold is crucial in achieving precision injection molding. Precision injection mold design and manufacturing have higher requirements compared to general injection molding. This article focuses on the design accuracy, precise mold positioning, sealing material design, core fixing, plastic part exhaust and ejection system, pouring system, and temperature control.

Process analysis of plastic parts structure:

The article focuses on the analysis of a double-sided hinge sheath used in automotive wiring harnesses. This plastic part is made of high-temperature resistant PA66 and features a complex shape with a minimum wall thickness of 0.45mm. The design of this plastic part requires precision injection molding to ensure quality.

Mold design:

The parting surface design is the first step in mold design for precision injection molds. The selection of the parting surface greatly affects the quality of plastic parts, mold use, and manufacturing. The parting surface should be selected considering the natural transition of the part and its effect on the appearance. The design should also consider the ease of processing and manufacturing. Accurate positioning is crucial in precision injection molding, and fine positioning blocks are commonly used for precise mold positioning. The article provides examples of parting surface and fine positioning block designs for the analyzed plastic part.

Detail design of functional plastic hook:

The design of the plastic hook focuses on ensuring its function, smooth ejection, and reliable fixation. To ensure function, the design considers the generation position, direction, and control of flash at the plastic hook. Smooth ejection is achieved by considering the demoulding slope for the plastic hook holes. The design also addresses the fixing and reliability of the plastic hook by designing the push rod width and properly positioning the cores.

Large insert design:

The design of large inserts, such as upper mold fixed inserts and cavity inserts, is essential in precision injection molding. The article discusses the dimensions and material requirements for the large inserts and emphasizes their positioning and fixation in the mold.

Exhaust and ejection system design:

Exhaust design is necessary to eliminate air and volatile gases during plastic filling in the mold cavity. The article suggests three forms of exhaust design: parting surface, inlay gap, and ejection of the plastic part. The ejection system design should ensure sufficient ejection force and a balanced arrangement of the ejection system. The article provides an example of push rod ejection layout and push rod designs.

Mold working process:

The article describes the working process of the mold, from the injection of molten plastic into the mold cavity to the ejection of plastic parts and gate waste. It explains the roles of various components in the mold during the working process.

In conclusion, the precision of precision molds depends on the design, processing, and assembly of parts. This article highlights the importance of technical requirements in mold design and the consideration of mold structure. It stresses the significance of parting surface design, core design for precision, and the exhaust and ejection system in achieving precision injection molding. The article concludes that precision injection mold design has achieved excellent results.

In summary, this expanded article provides a detailed analysis of the design and manufacturing considerations for precision injection molds, focusing on the specific example of a double-sided hinge sheath. The article discusses the importance of various design aspects, including parting surface design, fine positioning, detail design of functional plastic hooks, large insert design, exhaust and ejection system design, and mold working process. By considering these factors, the quality of plastic parts can be ensured, meeting customer requirements and achieving stable production.