The decorative frame of car headlights is one of the important parts on the car lights, with strict appearance requirements and electroplating treatment required for the mold. For the decorative frame mold of car headlights, the following points should be noted during design:

(1) Electroplated parts should first avoid welding lines, as any welding lines in the electroplated parts will appear and affect the appearance of the plastic parts. When designing the pouring system, welding lines should be avoided. If welding lines are unavoidable, it should be managed to drive them to non appearance areas. Before designing the pouring system, it should be verified through mold flow analysis.

(2) Decorative frames are generally designed with patterns on their surfaces. When designing molds, it is important to pay attention to the depth of the patterns on the plastic parts, as they are generally prone to flow patterns.

(3) The range of plastic material forming process is small, and the surface of plastic parts is prone to bright spots and difficult to control. When designing the mold pouring system, the runner should be thick and large, and the gate should be a fan-shaped gate with a gate width of about 35-40mm, which is conducive to melt filling.

(4) Decorative frame plastic parts are prone to the phenomenon of adhesive molds. The early design precautions to solve the problem of adhesive molds for plastic parts are generally:

a. Design a reverse buckle pattern on the inner side of the plastic part that is easy to adhere to the mold and has a high clamping force, with a depth of 0.5-1mm. The reverse buckle pattern is designed near the rounded corner of the plastic part.

b. Design reinforcing ribs on the inner side of the plastic part corresponding to the high clamping force of the fixed mold, and design inverted hooks on the push rod. According to the characteristics of this plastic part, reinforcing ribs and BOSS columns (commonly known as driver columns) should be designed on the side plastic parts in the six LED light areas to avoid deformation of the plastic part.

In this mold design, the area with high clamping force of the plastic parts is designed with a mold inclination of over 5 degrees and a 0.5mm deep reverse buckle pattern on the moving mold side. Therefore, the mold ejection and demolding are smooth, and all mechanisms move smoothly. The mold is safe, stable, and reliable. There is no phenomenon of the mold sticking to the mold, successfully solving the problem of such plastic parts sticking to the mold. After the trial production of the model mold, the loading effect was good and the size was stable. The modified headlights received recognition and praise from customers at the car exhibition, creating certain economic benefits for them.

Summary of Automotive Headlamp Reflector Mold Technology

The main design points for the car lamp reflector mold are:

(1) We need specialized injection molding equipment and use injection molding machines that specialize in producing BMC plastic. The requirements for injection molding equipment are very strict.

(2) BMC material belongs to special hard plastic, and in mold design, heating system and parting surface layout system need to be designed. The formed parts must be quenched to improve wear resistance and mold life.

(3) Reflector plastic parts are used on car headlights to prevent direct light, reflect light, and avoid direct light, with strict lighting requirements. Plastic parts are important exterior components of automobiles, with many patterns on the surface for decorative and aesthetic purposes.

(4) The ejection system of the BMC material mold design should be balanced, and the specifications of the push rods should be designed as large as possible, with as many as possible, otherwise it will cause difficulty in demolding the plastic parts.

(5) Because the demolding angle of high photoelectric plated parts is too small, it can cause difficulty in demolding. Therefore, the demolding angle of the side wall of the reflector plastic parts should be designed as large as possible, and it is generally recommended to be between 5 ° and 10 °. Of course, the premise is that it cannot affect the function and appearance of the plastic parts.

(6) Plastic parts cannot have sharp corners or edges, and all corners need to be designed as rounded corners, as the formed parts of the mold are prone to stress cracking after quenching.

(7) Note that the left and right reflector lamp cap holes and the surface pattern of the plastic parts are left and right translational, and cannot be designed as mirror symmetrical, because the bulb and lamp cap are not separated from each other, and other features are mirror symmetrical.