Double-helix cooling water path structure for reducing buckling deformation of polyethylene three-way pipe

Abstract

The invention discloses a double-helix cooling waterway structure for reducing buckling deformation of a polyethylene three-way pipe, which is provided with a polyethylene three-way pipe mould and comprises two helix cooling waterways, and the helix cooling waterways are respectively arranged in a pipeline in the horizontal direction of the polyethylene three-way pipe mould. The invention has the beneficial effects that the double-helix cooling water path is adopted to cool the pipeline, the number of corresponding air pockets is smaller, and the generated buckling deformation is far smaller than that of a bent water path system.

Description

Technical Field

[0001] The present invention relates to the technical field of cooling of injection molds, and specifically relates to a double - helix cooling waterway structure for reducing the warping deformation of polyethylene three - way pipes. Background Art

[0002] The production level of molds is closely related to the lifespan and quality of products as well as the R & D capabilities of new products. It is also the primary criterion for measuring manufacturing levels. As the most fundamental process equipment, in many industrial chains, mold parts meet more than 80% of the product usage requirements. The wide range of industries it involves further demonstrates its importance, thus attracting the attention of enterprises and researchers. What differentiates it from other processing methods is that the products obtained through its processing have extremely high precision, a relatively short processing cycle, low material waste rate, high utilization rate, and more considerable product profits. There are many methods for processing products using molds, and injection molding is just one of the more mature and common ones. So far, the annual output of injection molds basically accounts for more than 60% of the total number of molds, and it can be widely used in high - end aerospace equipment, automotive instrument equipment, etc. Currently, this data is still showing an upward trend, indicating that the market demand for plastic molds has a good prospect.

[0003] In the actual production situation of three - way pipes and their injection molding process, when injecting the three - way pipe, direct - gate two - point gating is used, the gate diameter is 30 mm, and the cooling waterway uses side cooling and internal cooling. Due to the relatively high difficulty in manufacturing the conformal cooling channels and the relatively high processing difficulty of the mold, in the existing technology, linear channels are used to arrange the cooling water pipes. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the present invention aims to provide a double - helix cooling waterway structure for reducing the warping deformation of polyethylene three - way pipes. The spiral cooling waterway designed by the present invention can effectively reduce the warping deformation rate.

[0005] In order to achieve the above - mentioned purpose, the present invention adopts the following technical solutions:

[0006] A double - helix cooling waterway structure for reducing the warping deformation of polyethylene three - way pipes, having a polyethylene three - way pipe mold. The structure includes two spiral cooling waterways, and the spiral cooling waterways are respectively arranged in the horizontal - direction pipes of the polyethylene three - way pipe mold.

[0007] It should be noted that the spiral cooling waterway has a water inlet and a water outlet, and extends into the pipe in a spiral form.

[0008] It should be noted that the spiral cooling waterway is close to the inner wall of the pipe.

[0009] The beneficial effects of the present invention are as follows: The double - helix cooling waterway is used to cool the pipeline, and the corresponding number of cavitations is less, and the warpage deformation generated is much smaller than that of the bent waterway system. Brief Description of the Drawings

[0010] Figure 1 It is a schematic structural diagram of the double - helix cooling waterway and the pipeline plastic part of the present invention;

[0011] Figure 2 It is a schematic structural diagram of the double - helix cooling waterway in the present invention;

[0012] Figure 3 It is a schematic diagram of the ejection volume shrinkage rate of the double - helix cooling circuit in the present invention;

[0013] Figure 4 It is a schematic diagram of the average temperature of the parts of the double - helix circuit in the present invention. Detailed Implementation Modes

[0014] The present invention will be further described below in conjunction with the drawings. It should be noted that this embodiment is based on the present technical solution, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to this embodiment.

[0015] The present invention is a double - helix cooling waterway structure for reducing the warpage deformation of a polyethylene three - way pipe, and has a polyethylene three - way pipe mold. The structure includes two spiral cooling waterways, and the spiral cooling waterways are respectively arranged in the pipelines in the horizontal direction of the polyethylene three - way pipe mold.

[0016] Furthermore, the spiral cooling waterway of the present invention has a water inlet and a water outlet, and extends into the pipeline in a spiral form.

[0017] Furthermore, the spiral cooling waterway of the present invention is close to the inner wall of the pipeline.

[0018] Embodiment

[0019] Simulation Experiment

[0020] The process parameters are set as follows: injection time 2 s, melt temperature 245 °C, and the rest are all according to the default parameters for warpage deformation analysis.

[0021] Result analysis of the volume shrinkage rate: The more uniform the volume shrinkage, the better. It can be seen from the figure that the volume shrinkage rate of the three - way pipe is concentrated in the range of 21.05% - 22.23%.

[0022] Result analysis of the cold slug factor: If the plastic part has not been cooled completely before the pressure is released, the holding pressure time must be extended. Therefore, the change situation should be observed from the animation form of the cold slug layer to find out the condensation time of the gate, which can be used as a reference for setting the holding pressure time during mold trial.

[0023] 1. Result analysis of the average temperature of the part: For the average temperature of the part, it is required that the maximum and minimum temperature differences of the part be minimized as much as possible, that is, the temperature distribution should be uniform. At this time, the temperature difference is 44.17 °C, the temperature in the middle part is higher, and the temperature at the end face is lower.

[0024] 2. Result analysis of the coolant temperature: The temperature difference between the inlet and outlet of the cooling water of the tee is 1.83 °C.

[0025] 3. Result analysis of the temperature of the cooling circuit pipe wall: The temperature difference between the pipe wall temperature of the cooling water circuit and the inlet water temperature is 8.04 °C.

[0026] Result analysis

[0027] From the warpage deformation analysis of continuously designing the cooling circuit, data comparison can be carried out to obtain that the conformal cooling circuit has a better effect on reducing the total warpage deformation of the tee. However, since the conformal cooling circuit is designed according to the specific structure of the plastic part, when designing the conformal cooling circuit for the tee, the conformal cooling circuit needs to be in an arc shape for conformal cooling. Therefore, the conformal cooling circuit has a high processing difficulty during mold processing, is not easy to process, and has a high cost.

[0028] Therefore, when an enterprise or factory designs the cooling circuit for the injection molding process, generally a straight-line cooling circuit is considered to reduce the processing cost. It can be seen from the analysis results that when the tee is cooled by the cooling circuit in actual production, the warpage deformation amount is 6.957 mm, and the total warpage is relatively large. However, the volume shrinkage rate of the tee is relatively uniform, and the temperature difference between the inlet and outlet of the cooling water of the cooling circuit is relatively low, which is 1.22 °C.

[0029] And the internal cooling circuit of the tee with a double helix structure proposed by the present invention can make the cooling circuit close to the structure of the plastic part to achieve a better cooling effect. At the same time, using this method for mold processing also reduces the processing difficulty. It can be obtained from the warpage deformation analysis by Mold flow software that the total warpage deformation amount is 7.038 mm, and the total warpage is relatively large. However, the volume shrinkage rate of the tee is relatively uniform, and the temperature difference between the inlet and outlet of the coolant of the cooling circuit is relatively low, which is 1.83 °C.

[0030] Generally speaking, through comprehensive analysis, the warpage deformation of the tee is mainly affected by the uneven shrinkage of the plastic part and the angular effect deformation. The optimized cooling circuit design of the present invention can reduce the warpage deformation to a certain extent.

[0031] For those skilled in the art, various corresponding changes and modifications can be made according to the above technical solutions and concepts, and all such changes and modifications should be included within the protection scope of the claims of the present invention.

Claims

1. A double - helix cooling water channel structure for reducing the warping deformation of a polyethylene three - way pipe, having a polyethylene three - way pipe mold, characterized in that, The structure includes two spiral cooling water channels, and the spiral cooling water channels are respectively arranged in the pipelines in the horizontal direction of the polyethylene tee mold.

2. The double - helix cooling water channel structure for reducing the warping deformation of the polyethylene three - way pipe according to claim 1, wherein, The spiral cooling water channels have water inlets and water outlets and extend into the pipelines in a spiral form.

3. The double - helix cooling water channel structure for reducing the warping deformation of a polyethylene three - way pipe according to claim 1 or 2, characterized in that, The spiral cooling water channels are close to the inner wall of the pipelines.

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