Sweeping robot base injection mold
The base product of the sweeping robot is shown in Figure 1. The maximum size of the product is 403.13 mm x 292.00mm x 170.30 mm, the average thickness of the plastic part is 2.30 mm, the material of the plastic part is ABS, the shrinkage rate is 1.0045, and the weight of the plastic part is 777.51 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 lines, cold materials, jet lines, etc.
It can be seen from Figure 1 that the structure of the plastic part is complex. There is a hollow column in the circular pit on the top surface of the plastic part for the passage of compressed air. The structure and shape of the rollers on the two sides of the plastic part are complex, and the slider core needs to be designed. The tail structure of the plastic part is also very complicated, requiring the design of a large slider and long-distance core pulling. The inner top surface of the plastic part is designed with multiple deep bones, the deepest part reaches 98.59mm, and there are also several raised posts with deep height. The difficulty of mold design lies in the design of three sliders, the design of movable mold inserts, and the smooth ejection of plastic parts.
The mold design cavity rank is 1 out of 1, the mold base is a non-standard mold base 7085, and the mold is a large mold. In order to increase the mold clamping accuracy and resist the inward force of the cavity caused by the injection pressure, five inclined positioning blocks are designed on the four sides of the mold blank. The four corners of the mold core are designed for the positioning of the tiger's mouth. The direction of the tiger's mouth is for the rear mold core to be raised and the front mold core to be recessed. Tiger mouth angle 5 ゜
The gate of the mold is selected in the circular pit on the top surface of the plastic part, and the needle valve type hot nozzle is used to feed the glue at a single point. Needle valve gates differ according to the valve needle driving power source. There are four valve needle driving methods: spring type, cylinder type, hydraulic type and electronic type. Although the spring-driven valve needle has a lower cost, the system is difficult to control, the gate trace is unstable, and the application is less. Early Japanese companies developed some spring-driven needle valve nozzles, the biggest advantage of which is that it occupies a smaller template area and lower system manufacturing costs.
The development of the needle valve hot nozzle is mainly reflected in the driving mode of the valve needle. After decades of development, the current drive method of the needle valve hot nozzle has been greatly developed compared with the past. At present, there are mainly hydraulic drive, pneumatic drive, electromagnetic drive and integral floating of the valve needle fixing plate. . Electromagnetic drive overcomes the shortcomings of possible leakage of hydraulic drive, and has been used in places where the environment is required such as dust-free workshops. Pneumatic drive has developed into a way that one cylinder drives 4 valve needles. The design of the standard parts of the cylinder makes the mold processing simple. The previous high-precision cylinder hole processing is eliminated from the template, and the processing of the cylinder is completed by the hot runner supplier. The overall floating of the valve needle fixing plate can drive all the valve needles, which is beneficial to reduce the number of cylinders and save mold space. This set of molds uses an oil cylinder to drive the needle valve hot runner system as shown in Figure 5. It can be seen from Figure 5 that the key assembly dimensions and tolerance design of the hydraulically driven valve needle are designed.
Usually the cylinder body is designed on the fixed mold base plate, and the cylinder body position needs to take up a lot of space. Sweeping robot base injection mold
The processing accuracy of the cylinder is required to be high, which causes the cost of the mold to rise. In the mold assembly process, in order to ensure the high-precision (coaxiality) coordination with the cavity plate, runner plate, and fixed mold seat plate, the processing accuracy of the corresponding matching parts of the mold must be improved. After the cylinder body is processed on the fixed mold seat plate, a cooling circuit needs to be processed. When processing the gas path, be careful not to interfere with the cooling circuit. The biggest advantage of pneumatic drive is that there is no need to worry about air leakage and will not cause environmental pollution.
Two rear mold sliders are respectively designed at the roller installation positions on the two sides of the plastic part. Both sliders are driven by inclined guide posts. The shovel is a built-in shovel, which extends to the rear mold to make a 10 ゜ inclination backhoe. The backhoe mechanism in the rear mold slider can increase the mold rigidity and increase the mold clamping ability under the injection pressure. The sliding block at the end of the plastic part has a complicated glue position and a long sliding block stroke, so the sliding block adopts an oil cylinder to pull the core. The inclined surface and bottom surface of all sliders are designed with wear-resistant blocks, which is convenient for flying molds and adjustments.
The structure and shape of the plastic parts are complex, and the tightening force on the movable mold is large. Therefore, the straight ejector, the thimble and the ejector are designed. See mold design drawing 2.
The size of the plastic part is large and the glue position is complicated. Cutting the insert at the deep glue position is good for deep bone processing and polishing, and it is also good for exhaust during injection molding.
All sliders, cavities and cores are designed with cooling circuits to facilitate the normal production of injection molding.
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
WhatsApp: +86 136 8261 9739
Skype: daisymold@outlook.com