Plastic injection mould for car variable speed control mechanism shell
See Figure 1 for the housing product of the car's speed control mechanism. The maximum size of the product is 148.19 mm x 102.21mm x 57.94 mm, the average thickness of the plastic part is 2.33 mm, the material of the plastic part is PC+ABS, the shrinkage rate is 1.006, and the quality of the plastic part is 83.64 grams. 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, jet lines, etc.
It can be seen from Figure 1 that the plastic part has a rectangular cross-section closed cylinder with a simple structure at one end. After assembly, this end is located in the middle of the driver's seat. The gear shift lever passes through the center and the outer surface is covered with a leather sleeve. The plastic part cylinder at the other end is tilted by 14 ゜, and multiple buckles are designed along the edge of the cylinder to facilitate clamping during assembly. The inner hole of the plastic part needs to be designed with two sliders to pull the core from the two ends respectively, and the distance between the cut and the core is relatively large. On the two large triangular planes, there are concave areas and pillars. In addition to the sliding core pulling to solve the inner hole cylindrical shape of the plastic part, the other two sides also need to design the sliding core pulling.
The structure of the plastic part is complex, and the mold is a complex mold. For this set of molds, the primary problem of mold design is to determine the direction of mold opening. The mold opening direction analysis is one of the most basic tasks of mold design. After the mold opening direction analysis is completed, the parting surface can be designed and the next step can be carried out. The choice of the mold opening direction is related to the mold manufacturing cost, the appearance of the plastic part, the quality of the injection part and the injection cycle, etc., and may also affect the life of the mold.
For this set of molds, the plastic part can be designed to stand up, that is, the axis of the rectangular tube of the plastic part coincides with the mold opening direction; another design is to design the plastic part upside down. Both of these two design schemes need to design the form of 4 sliding blocks surrounding the plastic part. In the way of designing the plastic part upright, the center of the plastic part needs to be designed with an oblique core-pulling slider, the mold opening stroke will be increased, the ejection force of the plastic part is relatively large, and the ejection of the plastic part is difficult. Therefore, the actual mold design adopts the design method of laying down the plastic part.
Car products generally have larger production batches. The mold design cavity ranking is shown in Figure 2, and the 3D mold diagram is shown in the attached file. Due to the four-sided sliding block of the plastic part, the plane layout of the mold is relatively large. The mold base is a non-standard mold base 6090, which is a large-scale mold. The gating system feeds glue into the two hot nozzles of the hot runner. Each cavity has a gate, which is located on the upper surface of the plastic part. The two sliding blocks are interlocked to increase rigidity and prevent the sliding blocks from dislocation due to impact force during pouring. This is one of the most important details of mold design. The hot runner brand is SINO, and the Chinese name is Xianrui. It is the domestic brand of Yudo company YUDO, and its quality standards are roughly equivalent to YUDO.
The mold has 8 sliders, the structure is complex, and the contact area of the parting surface is small. For this reason, a balance weight is designed on the parting surface to increase the pressure bearing area of the parting surface. Four zero-degree positioning blocks are designed on the edge of the mold base. Increase the accuracy of mold clamping. At the same time, the four corners of the front and rear mold cores are respectively designed with positioning jaws to prevent the parting surface from being dislocated during injection. The angle of the tiger's mouth is 5 ゜, the protrusion of the rear mold, and the recess of the front mold.
The two sliders in the center hole of the plastic part are driven by an oil cylinder due to their long strokes, while the other two sliders are driven by oblique guide posts. Wear-resistant plates are designed on the inclined surface and bottom surface of each slider, which is convenient for adjustment during flying mold and assembly. Due to the limited position, the two sliders in the middle share a shovel base. When designing a common shovel base, the angles and other dimensions on both sides need to be designed completely symmetrically. The shovel base of the two hydraulic cylinder sliders is an inlaid structure, and the end face of the shovel extends into the movable mold to realize the backhoe locking.
ABIS MOLD TECHNOLOGY CO.,LTD
Daisy Wang (Sales Engineering)
M: +86-150 1652 6799
E: daisy@abismold.com
A: Building B#,YingKeli Industrial Part, LongDong Community, LongGang District, Shenzhen, China 518116
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