1. Product introduction of automobile headlights

It can be said that the part with the highest requirements for automobile appearance is the lamp, so the requirements for mold design and manufacturing are extremely high. The main parts that make up the front and rear lights of the car are: left and right lenses, left and right decorative frames, left and right lamp shells, left and right reflectors, etc.

2. Appearance requirements of automobile headlights

(1) Lens

The product is transparent, with patterns on the inner side and high appearance requirements.

(2) Decorative frame

The appearance of the product is aluminized, and some areas need sanding.

(3) Lamp shell

The product is an internal functional part, and the assembly requirements of lamp cap hole and back cover hole are high.

(4) Reflector

The products are electroplated parts with strict light distribution requirements, and the appearance surface is aluminized.

Summary of die technology for automobile headlamp lens

The lateral core pulling mechanism is the most important core structure of the mold. The mold cleverly adopts the inner core pulling mechanism of "T-groove guide block + oblique inward slider", which successfully solves the problem of the lateral parting of transparent parts leaving traces on the surface of plastic parts.

The mold adopts an ordinary gating system and is fed by a fan-shaped gate tower. Compared with the previous hot runner gating system, it not only greatly reduces the cost, but also has better light transmittance of the lamp lens.

The mold adopts the combined cooling system of "vertical cooling water pipe + inclined cooling water pipe + spacer well", and the water channel is arranged along the mold cavity. The molding cycle is successfully controlled within 35 seconds, effectively ensuring the accuracy of plastic parts and the labor productivity of the mold.

The plastic parts are pushed out by pushing blocks, which is not only stable, but also the traces left have no effect on the appearance.

Since the mold was put into production, its action has been stable and smooth, and all quality indexes of plastic parts have met the design requirements. It is a successful example of large, complex and long-life injection mold design.

Summary of die technology for decorative frame of automobile headlights

The decorative frame of automobile headlights is one of the most important parts on the headlights. The appearance requirements are strict, and the mold needs electroplating treatment. For the mold of automobile headlamp decorative frame, the following points should be paid attention to in the design:

(1) The galvanized parts should first avoid the fusion line, because any fusion line of the galvanized parts will appear, which will affect the appearance of the plastic parts. When designing the gating system, avoid the fusion line. If the fusion line is inevitable, try to drive it to the non appearance area. Before designing the gating system, it should be verified by mold flow analysis.

(2) The surface of the decorative frame is generally designed with patterns. When designing the mold, pay attention to the depth of the pattern of the plastic part, which is generally easy to produce flow lines.

(3) The molding process range of plastic parts is small, and the surface of plastic parts is easy to produce bright spots and difficult to control. When designing the mold gating system, the runner should be thick and large. The gate adopts a fan-shaped gate. The maximum size of the gate width is about 35~40mm, which is conducive to melt filling.

(4) Decorative frame plastic parts are easy to stick to the fixed mold. The preliminary design prevention to solve the problem of plastic parts sticking to the fixed mold is generally:

a. On the inner side where the plastic part is easy to stick to the mold and has a large wrapping force, the reverse buckle pattern is designed with a depth of 0.5~1mm, and the reverse buckle pattern is designed near the fillet of the plastic part.

b. Where the clamping force of the plastic part is large, the corresponding inner side of the plastic part is designed with reinforcing ribs, and the reverse buckle hook is designed on the push rod. According to the characteristics of this plastic part, stiffeners and boss columns (commonly known as cylinder columns) should be designed on the side plastic parts in the six LED lamp areas to avoid deformation of the plastic parts.

In this mold design, the area with large holding force of plastic parts has a mold ejection slope of more than 5 degrees, and a 0.5mm deep buckle pattern is designed on the side of the moving mold, so the mold ejection and demoulding are smooth, the mechanisms move smoothly, the mold is safe, stable and reliable, and the mold has no phenomenon of sticking to the mold, which successfully solves the problem of sticking to the mold of this kind of plastic parts. After the trial production of the mold of this model, the loading effect is good and the size is stable. The modified headlights have been recognized and praised by customers in the auto show, creating certain economic benefits for customers.

Summary of die technology for automotive headlamp reflector

For the mold of automobile lamp reflector, the main design points are:

(1) Special injection molding process equipment is needed, and the injection molding machine specially producing BMC plastic is used, and the requirements for injection molding process equipment are very strict.

(2) BMC material is a kind of super hard plastic. In the mold design, it is necessary to design heating system and parting surface design discharge system. Formed parts must be quenched to improve wear resistance and mold life.

(3) The reflector plastic part is a device for preventing direct light, reflecting and avoiding direct light on the car lamp, and the light distribution requirements are strict. Plastic parts are the most important appearance parts of cars. There are many patterns on the surface of plastic parts for decorative beauty.

(4) The ejection system of BMC material mold design should be balanced, and the pusher specification should be designed as large as possible, and the number should be as large as possible, otherwise it will cause difficulty in demoulding plastic parts.

(5) Because the demoulding slope of high photoelectric plated parts is too small, it will cause difficulties in demoulding, so the demoulding slope of the side wall of the mirror plastic parts should be designed as large as possible, and it is generally recommended to be 5 ° ~ 10 °. Of course, the premise is not to affect the function and shape of plastic parts.

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

(7) Note that the lamp cap holes of the left and right reflectors and the surface patterns of the plastic parts are translated left and right, and cannot be designed as mirror symmetry, because the bulb and the lamp cap will not be separated left and right, and the other features are mirror symmetry.

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