Automobile parts Automotive front bumper rear bumper mould

1. Mould structure analysis

The injection mold for the main body of the front bumper adopts an internal parting surface, which passes through the hot runner and is controlled by the sequence valve. The structure of large lifter inner with horizontal lifter and straight ejector block is adopted for both sides of the undercut. The maximum overall dimension is 2500 × 1560 × 1790mm.

The advanced inner parting line surface technology is used in the design of the mould. The so-called inner parting line technology is relative to the external parting line. Generally, the parting line of the fixed& moving mould is based on the maximum projection contour line of the product, which is called external parting line, and the general mold is in accordance with this parting line mode. Internal parting line is to hide the parting clip line on the non appearance surface of the product (i.e. surface B or C, and the appearance surface is A surface). After assembly on the vehicle, the parting line can not be seen, so the appearance will not be affected.

In order to realize this function, the track technology is used to control the horizontal lifter (or straight ejector block) to run on the secondary track change, so as to ensure the deformation and demoulding of plastic parts. The mechanism controlled by the track technology of secondary track change is called inner parting line technology. In the design of automobile injection mold, inner parting line technology is specially designed for automobile bumper. However, this technology is more complex than the outer parting bumper in terms of difficulty and structure, and the technical risk is also higher. The mold cost and mold price will be much higher than the external parting bumper. However, due to its beautiful appearance, it is widely used in medium and high-grade automobiles.

2.Gating system design

The mould gating system adopts integral hot runner system, which has the advantages of convenient assembly and disassembly, low requirement of machining accuracy, no risk of glue leakage, reliable assembly accuracy, no need of repeated disassembly and assembly, and low maintenance and repair costs.

The front bumper is an appearance part, and there is no weld mark on the surface. During injection molding, the weld line must be moved to the non appearance surface or eliminated, which is one of the key and difficult points in the mold design. This mold adopts the 8-point sequence valve hot runner gate control technology, namely SVG Technology, which is another advanced technology adopted in this mold. It controls the opening and closing of eight heat injection nozzles through the cylinder drive, so as to achieve the ideal effect of no weld mark on the surface of plastic parts.

3. Ejection system

three times ejection

4.Core technology of inner parting line bumper mould

Track diagram of secondary track change of automobile inner parting line bumper mould: