Mould for the front and rear shells of the walking robot's right leg
The product diagram of the front and rear shells of the right leg of the walking robot is shown in Figure 1. The maximum size of the product is 468.58 mm x 116.13 mm x 62.72 mm, the average thickness of the plastic part is 3.13 mm, the plastic part material is PC, and the shrinkage rate is 1.006. The mass of the plastic parts is 291.5 grams and 256 grams respectively. The technical requirements for plastic parts are that there must be no defects such as peaks, dissatisfaction with injection molding, flow lines, pores, warpage deformation, silver streaks, cold materials, and jet lines.
It can be seen from Figure 1 that the plastic part is shaped as a shell composed of irregular curved surfaces. The front and rear shells are positioned at the peripheral stop and fixed with self-tapping screws. The front and rear shells each have a side through hole, which requires the design of the movable mold slider core. Due to the long size of the plastic parts, the front and rear shells are both irregularly curved, so it is required that the front and rear shells must not be deformed, the curved surfaces of the joints are in good agreement and the gap is uniform.
The mold design cavity ranking is 1+1. For the front and rear shells that need to be assembled together, they are arranged in the same set of molds. Due to the same molding conditions and shrinkage, it is easy to control the consistency of their dimensions; on the other hand, , Since the parting surface is a high and low undulating surface, the front and rear shells are arranged in the same set of molds. It should be noted that the mold cores of the movable mold and the fixed mold need to be designed and processed separately. When designing the pouring system, the two mold cores are at the joint Make the parting surface as smooth as possible, so that the glue inlet position of the runner is smooth, and the molten plastic is easy to fill.
Due to the large size of the plastic parts, the mold base is a large straight non-standard mold base 6580, the gate is a latent gate, and the mold is glued at two points before the submersible. The size of the mold is large, so it is fixed by pressing the mold core with a compression block. The material of the plastic part is PC, which has poor fluidity, which makes it difficult to fill the mold. When the parting surface is processed, 0.02 margin flows out as a whole, which is used as a vent slot, which is conducive to rapid filling.
PC material injection molding large-scale plastic parts, due to the long plastic process, hot runner molding is often used, when non-hot runner injection molding is used, the mold often needs to be heated to maintain the mold temperature to avoid heat loss. Therefore, heat insulation boards are designed on the mold panel and the bottom plate respectively to prevent mold heat from being transmitted to the injection molding machine.
The two lateral parting and core pulling mechanisms are driven by inclined guide posts and slide obliquely.
The ejection of the plastic parts adopts the ejector tube.
