Cleaning head cable shield is an important part of cleaning robot main engine cleaning head. The maximum dimensions of the cleaning head cable cover products are 135.54mm x 122.41mm x 36.00mm, the average thickness of plastic parts is 4.50mm, the material of plastic parts is ABS, the shrinkage rate is 1.0045, and the mass of plastic parts is 23.17g. The technical requirements of plastic parts are that there should be no defects such as peaking, injection molding dissatisfaction, flow pattern, porosity, warping deformation, silver pattern, cold material, jet pattern and so on.
The plastic parts are irregular shaped plastic parts. For this plastic part, the structure is not complicated at first sight, but due to the irregular shape, it is difficult to select the opening direction of the mold, design the parting surface and determine the mold structure. Due to the extremely irregular shape of the plastic parts, the mold design cavity placement choice 1 out of 2, if the injection molding machine is large, plastic parts production batch is large, you can also choose 1 out of 4 cavity placement. If the size of the plastic part is particularly large, the cavity can also be selected as 1 out of 1.
The bottom of the plastic part has a horizontal cylinder with a through hole, and a raised side wall also has a horizontal side slot. These two places need to design the slider core withdrawal. The difficulty of this set of mold design is the analysis of mold opening direction. The analysis of mold opening direction is closely related to the design of ejection, gate and parting surface. Before mold design, we must first analyze the product and determine a reasonable mold opening direction. This set of mold is a step parting surface. The parting surface is not complicated. The difficulty lies in the choice of the opening direction, that is, which side of the plastic part is placed in the moving mold and which side is placed in the fixed mold. The correct judgment will leave the side of the strong adhesive force in the moving mold to facilitate the ejection and demoulding of the plastic parts, and the other side will design the pouring system. In most cases, the opening direction of the mold can be determined by using factors such as the wrapping force, leaving the plastic part in the moving mold. This set of die will have a horizontal cylindrical hole on one side of the design of the moving die, which is conducive to shortening the distance of the core pulling of the slide block.
The actual mold design adopts 1 out 1 arrangement, and the mold embryo is non-standard mold embryo CT4555. When designing the mold alignment, it is necessary to pay attention to the multi-cavity mold with multi-step parting surface or large drop, the front and back dies of each hole should be separated and should not be connected together. If it is connected together, it will produce larger and more steps, and it is not possible to CNC directly clear the Angle, what is more, the mold joint is uneven, which affects the layout of the distributary channel of the pouring system, so that the elevation and fluctuation of the distributary channel are too large, which is not conducive to the rapid and effective filling of molten plastic.
When the parting surface has multiple steps and the front and rear die are inserted, the force on the parting surface is not uniform during the mold closing. Therefore, a zero degree positioning block is designed on the four sides of the mold, which is conducive to ensuring the mold closing accuracy. In addition, on the parting surface, the four sides of the mold are designed to balance the block, a total of 6 places. The balance block needs to be designed to correspond to each other before and after the mold edge, and the material is the same as that of the wear-resistant block.
The plastic parts adopt a single hot nozzle, feed the glue to the parting surface, and then shoot into the mold cavity through the side gate. In order to prevent the heat exchange between the mold and the injection molding machine, a heat insulation plate is installed on the panel. The front and rear die cooling system adopts straight through cooling system. The ejection of plastic parts adopts thimble ejection.