Design Analysis and Manufacture of Precision Injection Mold for Hinge Sheath_Hinge Knowledge_Tallsen1

Summary: Through the analysis of double-sided hinge sheaths, the design requirements for precision injection molds are established. This includes the optimal design of the frame selection and fine positioning of the parting surface for irregular and complex plastic parts. The importance of ensuring precision in plastic parts is also explained, along with the design skills for functional plastic hooks with smooth ejection and reliable fixation. Additionally, the article discusses the design points for mold exhaust and a balanced ejection system to ensure stable quality of plastic parts that meet customer requirements.

In precision injection molding, the quality of plastic parts is influenced by various factors such as the materials used, injection process, injection mold, and injection molding machine. The injection mold plays a crucial role in realizing precision injection molding, and its design and manufacturing require higher accuracy and precise mold positioning, sealing material design, core fixing, plastic part exhaust and ejection system, pouring system, and temperature control. This article focuses on the design and manufacturing of precision injection molds.

Process Analysis of Plastic Parts Structure:

The article presents a case study of a double-sided hinge sheath used for an automobile engine wiring harness. The plastic part is made of high-temperature resistant PA66 material and has a complex shape with a minimum wall thickness of 0.45mm. The design of this plastic part poses challenges for general injection molding processes and requires precision injection molding techniques.

Mold Design and Parting Surface Design:

The parting surface design is the first step in mold design, and its selection greatly impacts the quality of plastic parts and the ease of mold use and manufacturing. The parting surface should be chosen to ensure natural transition and avoid stress concentration and brittle fracture. It should also not affect the appearance of the plastic parts. The article provides a detailed explanation of how to select the parting surface based on the structure of the plastic part.

Fine Positioning and Functional Plastic Hook Design:

In precision injection molds, accurate positioning is crucial. The article explains the fine positioning method using guide post positioning and inlaid blocks. The design of functional plastic hooks should ensure function, smooth ejection, and reliable fixation. The article discusses the design considerations for flash generation, smooth ejection using demolding slope, and reliable fixation of cores.

Large Insert Design and Exhaust/Ejection System Design:

The article highlights the design of large inserts, including upper mold fixed fire inserts and cavity large inserts. The material, dimensions, and positioning of the large inserts are explained. The design of the exhaust and ejection system is also discussed, including the need for sufficient ejection force and a balanced arrangement of the ejection system. The article provides detailed information on the number and design of push rods for ejection.

Mold Working Process:

The article describes the working process of the mold, starting from the injection of molten plastic into the mold cavity to the ejection of plastic parts and gate waste. The role and operation of various components, such as sprue sleeve, puller rod, and ejector system, are explained.

The precision of precision molds depends on both the processing and manufacturing of parts and the design of the mold structure. This article emphasizes the importance of design in achieving precision injection molding. By considering the function and performance of plastic parts, the design focuses on the parting surface, core design, exhaust, and ejection system to ensure precision and achieve stable quality of plastic parts. The article concludes by highlighting the positive recognition received from customers for the product.