Cooling device of plastic mold

Abstract

The utility model discloses a cooling device of a plastic mould, which belongs to the field of moulds and comprises a first mould and a second mould, mould cavities are respectively arranged in the first mould and the second mould, and an upper cooling cavity, a middle cooling cavity and a bottom cooling cavity are respectively arranged on the outer wall of each mould cavity. The upper ends and the lower ends of the upper cooling cavity, the middle cooling cavity and the bottom cooling cavity are connected with a liquid inlet pipe and a liquid outlet pipe respectively, the other end of the liquid outlet pipe is connected with a water tank, a circulating water pump is arranged on the water tank, one end of the circulating water pump is connected with a water pipe, and the other end of the water pipe is connected with a heat exchanger. The temperature uniformity of cooling water in the whole heat dissipation process can be achieved.

Description

Technical Field

[0001] This utility model relates to the field of blow molding equipment, specifically to a cooling device for plastic molds. Background Technology

[0002] Plastic molds are widely used in many fields such as automobiles, electronics, home appliances, packaging, and medical. They can provide these industries with high-quality, standard-compliant plastic bottle packaging, ensuring product quality and safety, while meeting the needs of large-scale production and promoting industry development.

[0003] The plastic preform is heated to a suitable blow molding temperature. Under high pressure, the preform rapidly expands and adheres to the inner wall of the mold. After cooling and solidification, a complete plastic bottle is produced. This process can precisely shape bottles of various shapes and sizes to meet the packaging needs of different industries.

[0004] In existing plastic mold cooling devices, the cooling water is relatively cold when it first enters the inlet, allowing for effective heat exchange. However, as the cooling water flows through the outlet area at the bottom of the preform, its temperature rises significantly due to the absorption of a large amount of heat, leading to quality defects such as deformation, cracking, and uneven thickness during the molding process. Therefore, a new type of cooling device for plastic molds is urgently needed. Utility Model Content

[0005] In view of the problems existing in the prior art, the purpose of this utility model is to provide a cooling device for plastic molds to solve the problems mentioned in the background art.

[0006] To solve the above problems, the present invention adopts the following technical solution.

[0007] A cooling device for a plastic mold includes: a first mold and a second mold. The first mold and the second mold are respectively provided with mold cavities. The outer walls of the mold cavities are respectively provided with an upper cooling cavity, a middle cooling cavity, and a bottom cooling cavity. The upper and lower ends of the upper cooling cavity, the middle cooling cavity, and the bottom cooling cavity are respectively connected to an inlet pipe and an outlet pipe. The other end of each outlet pipe is connected to a water tank. The water tank is provided with a circulating water pump. One end of the circulating water pump is connected to a water pipe, and the other end of the water pipe is connected to a heat exchanger.

[0008] Furthermore, the cross-sectional area of ​​the bottom cooling cavity flow channel is larger than that of the middle cooling cavity, and the cross-sectional area of ​​the middle cooling cavity flow channel is larger than that of the upper cooling cavity.

[0009] Furthermore, a temperature sensor is provided on the inner wall of the bottom cooling chamber.

[0010] Furthermore, control valves are respectively provided on the liquid inlet pipes of the upper cooling chamber and the middle cooling chamber near the heat exchanger.

[0011] Furthermore, a first groove is provided on one side of the inner wall of the second mold, and a locking block is fixedly connected in the first groove. The inner wall of the first mold is provided with a second groove corresponding to the second mold.

[0012] Compared with existing technologies, the advantages of this utility model are:

[0013] (1) This solution sets up an upper cooling chamber, a middle cooling chamber, and a bottom cooling chamber, and provides multiple liquid inlet pipes and liquid outlet pipes respectively. This increases the number of independent liquid inlet pipes and liquid outlet pipes, so that the cooling water can be distributed more evenly in all parts of the mold. Valves are installed for individual control. During the cooling process, the cooling water flow rate of each liquid inlet pipe can be adjusted according to actual needs, so that all parts of the preform can be cooled more evenly, avoiding problems such as deformation, cracking and uneven thickness caused by local overheating.

[0014] (2) By setting cooling chambers with different flow channel cross-sectional areas (bottom cooling chamber > middle cooling chamber > top cooling chamber), since the bottom of the preform usually accumulates more heat during the molding process and needs to dissipate heat more quickly, the flow channel cross-sectional area of ​​the bottom cooling chamber is designed to be larger than that of the middle and top cooling chambers. This allows more cooling water to pass through the bottom cooling chamber, thereby improving the cooling effect at the bottom and reducing quality problems caused by overheating at the bottom of the preform. Similarly, the flow channel cross-sectional area of ​​the middle cooling chamber is larger than that of the top cooling chamber to better accommodate the relatively large heat distribution in the middle of the preform and achieve more uniform cooling.

[0015] (3) This solution sets the temperature sensor on the inner wall of the bottom cooling chamber. During the entire cooling process, the water temperature at the bottom of the circulating cooling chamber is the area where heat accumulates, thus enabling real-time monitoring of the bottom water temperature. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the circulating cooling chamber, liquid inlet, and liquid outlet of this utility model;

[0017] Figure 2 This is a schematic diagram of the structure of the card block and groove of this utility model.

[0018] Explanation of the labels in the diagram:

[0019] 1. First mold; 2. Second mold; 3. Mold cavity; 4. Upper cooling cavity; 5. Middle cooling cavity; 6. Bottom cooling cavity; 7. Inlet pipe; 8. Outlet pipe; 9. Water tank; 10. Circulating water pump; 11. Water pipe; 12. Heat exchanger; 13. Temperature sensor; 14. Control valve; 15. First groove; 16. Locking block; 17. Second groove. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0021] Please see Figures 1-2 This utility model provides a cooling device for a plastic mold, comprising: a first mold 1 and a second mold 2. The first mold 1 and the second mold 2 are respectively provided with mold cavities 3. The outer wall of each mold cavity 3 is respectively provided with an upper cooling cavity 4, a middle cooling cavity 5, and a bottom cooling cavity 6, dividing the outer wall of the mold cavity into three cooling cavities (upper, middle, and lower) to provide targeted cooling for different parts of the preform. The upper and lower ends of the three cooling cavities are respectively connected to inlet pipes 7 and outlet pipes 8, allowing the cooling cavities to be connected to a water tank 9 and a heat exchanger 12 to form a complete cooling circulation system. The other end of each outlet pipe 8 is connected to a water tank 9 to ensure sufficient cooling water in the cooling system. A circulating water pump 10 is provided on the water tank 9, with one end of the circulating water pump 10 connected to a water pipe 11. The circulating water pump 10 ensures that cooling water continuously flows between the cooling cavities, the water tank 9, and the heat exchanger 12. The other end of the water pipe 11 is connected to a heat exchanger... The device 12 transfers heat from the hot water returning from the cooling chamber to the external medium, thereby lowering the hot water temperature. The cross-sectional area of ​​the flow channel in the bottom cooling chamber 6 is larger than that in the middle cooling chamber 5, and the cross-sectional area of ​​the flow channel in the middle cooling chamber 5 is larger than that in the upper cooling chamber 4. The difference in the cross-sectional area of ​​the flow channels for heat distribution in different parts can reasonably distribute the flow rate of cooling water while ensuring the cooling effect. This avoids the problem of over-cooling or under-cooling caused by different cooling needs in different parts. The control valve 14 installed on the liquid inlet pipe 7 is individually controlled. During the cooling process, the flow rate of cooling water in each liquid inlet pipe 7 can be adjusted according to actual needs, so that all parts of the bottle preform can be cooled more evenly. This solves the problem that when the cooling water flows through the outlet area at the bottom of the bottle preform, its temperature rises significantly because a large amount of heat has been absorbed from the top of the bottle preform, resulting in quality defects such as deformation, cracking, and uneven thickness of the bottle body during the molding process.

[0022] Please see Figures 1-2Temperature sensor 21 is located at the bottom of the circulating cooling chamber 4. During the entire cooling process, the water temperature at the bottom of the circulating cooling chamber 4 is the area where heat accumulates, enabling real-time monitoring of the bottom water temperature.

[0023] See Figures 1-2 The inner wall of the second mold 2 is provided with a first groove 15, and a locking block 16 is fixedly connected in the first groove 15. The inner wall of the first mold 1 is provided with a second groove 17 corresponding to the second mold 2. When the first mold 1 and the second mold 2 are closed, the locking block 16 will be embedded in the second groove 17 corresponding to the first mold 1 to prevent the mold from opening or misaligning due to force during the injection molding process, thus ensuring the smooth molding of the preform.

[0024] The working principle is as follows:

[0025] First, the first mold 1 and the second mold 2 are closed, so that the mold cavities 3 inside the two form a complete preform forming space. At this time, the locking block 16 in the first groove 15 on one side of the inner wall of the second mold 2 will be embedded in the second groove 17 on the inner wall of the first mold 1 to ensure the accuracy and tightness of the mold closing and prevent problems such as material leakage during injection molding. Then, the plastic melt is injected into the closed mold cavity 3. During this process, the plastic melt releases a lot of heat, causing the temperature of the mold cavity 3 and its surroundings to rise.

[0026] Meanwhile, the circulating water pump 10 on the water tank 9 starts, drawing out the cooling water from the water tank 9 and transporting it through the water pipe 11 to the heat exchanger 12 for pre-cooling treatment, reducing the temperature of the cooling water and increasing its heat absorption capacity. After being pre-cooled by the heat exchanger 12, the cooling water enters the upper cooling chamber 4, the middle cooling chamber 5, and the bottom cooling chamber 6 through the liquid inlet pipe 7. Since the cross-sectional area of ​​the flow channel in the bottom cooling chamber 6 is larger than that in the middle cooling chamber 5, and the cross-sectional area of ​​the flow channel in the middle cooling chamber 5 is larger than that in the upper cooling chamber 4, under the same pressure provided by the circulating water pump 10, more cooling water will flow into the bottom chamber. The cooling chamber 6 is followed by the middle cooling chamber 5. The upper cooling chamber 4 receives relatively less cooling water, which allows the bottom of the preform to be cooled more thoroughly. This is because the bottom of the preform usually accumulates more heat during the molding process and requires a faster cooling rate to ensure molding quality. The temperature sensor 13 on the inner wall of the bottom cooling chamber 6 monitors temperature changes in real time and feeds the temperature signal back to the control system. Based on the temperature information fed back by the temperature sensor 13 and the actual molding situation of the preform, the operator can adjust the control valve 14 to control the flow rate of cooling water entering the two cooling chambers.

[0027] After absorbing heat, the cooling water's temperature rises, turning into hot water. It then flows back to the water tank 9 through the outlet pipe 8. The returning hot water mixes with the cold water that did not participate in the circulation in the water tank 9, causing the water temperature in the water tank 9 to rise. Then, the circulating water pump 10 draws water out of the water tank 9 again and sends it to the heat exchanger 12 for cooling. This cycle repeats continuously, carrying away the heat emitted by the preform until the preform is completely cooled and solidified. This solves the problem that when the cooling water flows to the outlet area at the bottom of the preform, its temperature rises significantly because a large amount of heat has already been absorbed from the top of the preform, causing quality defects such as deformation, cracking, and uneven thickness of the bottle during the molding process.

[0028] The above description is merely a preferred embodiment of this utility model; however, the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and its improved concept, should be included within the protection scope of this utility model.

Claims

1. A cooling device for a plastic mold, characterized by comprising: The utility model relates to a cooling cavity of injection mould, including: First mould (1), second mould (2), first mould (1) and second mould (2) are equipped with mould cavity (3) respectively, the outer wall of mould cavity (3) is equipped with upper cooling cavity (4) respectively, middle cooling cavity (5), bottom cooling cavity (6), the upper end and the lower end of upper cooling cavity (4), middle cooling cavity (5), bottom cooling cavity (6) are connected with liquid inlet pipe (7) and liquid outlet pipe (8) respectively, the other end of liquid outlet pipe (8) is connected with water tank (9) evenly, be equipped with circulating water pump (10) on water tank (9), the one end of circulating water pump (10) is connected water pipe (11), the other end of water pipe (11) is connected with heat exchanger (12).

2. The temperature decreasing device for plastic mold according to claim 1, wherein The flow passage cross-sectional area of the bottom cooling cavity (6) is greater than the flow passage cross-sectional area of the middle cooling cavity (5), and the flow passage cross-sectional area of the middle cooling cavity (5) is greater than the flow passage cross-sectional area of the upper cooling cavity (4).

3. The temperature decreasing device for plastic mold according to claim 1, wherein The inner wall of the bottom cooling cavity (6) is provided with a temperature sensor (13).

4. The temperature decreasing device for plastic mold according to claim 1, wherein The liquid inlet pipe (7) on the upper cooling cavity (4) and the middle cooling cavity (5) is provided with a control valve (14) near the heat exchanger (12).

5. The temperature decreasing device for plastic mold according to claim 1, wherein A first recess (15) is formed in the inner wall of the second mould (2), and a clamping block (16) is fixedly connected in the first recess (15). Second recesses (17) corresponding to the second mould (2) are formed in the inner wall of the first mould (1).

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